BACKGROUND:Lumbar fixed-point rotation operation needs collaborative operation of the doctor's hands,and outputs rotation and thumb thrust.Lumbar disc herniation can be treated through disc displacement and adjusting stress distribution.However,the mechanical effects of thumb thrust and the biomechanical effects of loading direction on manipulative effects remain unclear. OBJECTIVE:To compare the biomechanical difference of lumbar fixed-point rotation manipulation for treating lumbar disc herniation under different thrust directions. METHODS:The L3-5 normal three-dimensional finite element model was constructed and validity was verified.According to the intervertebral disc degeneration Pfirrmann grade,intervertebral disc degeneration was simulated by modifying the L4/5 intervertebral space height,the volume of the nucleus pulposus,as well as the material parameters of the annulus fibrosus,nucleus pulposus,and ligament.Finally,the pathological model of L4/5 moderate disc degeneration with left para-central herniation was constructed,and then the pathological models were used as research objects.Simulation technique:spinning to the right;taking the condition on changing the direction of the thumb thrust to establish three modes of operation(M1:thumb push to the left;M2:thumb push to the right;M3:no thrust push).The protrusion displacement and the disc stress,and the stress and strain of the facet joint cartilage were compared in the three operating modes. RESULTS AND CONCLUSION:(1)Maximum displacement value of L4/5 disc herniation:displacement was 2.672 3 mm for M1,1.156 1 mm for M2,1.826 4 mm for M3,M1＞M3＞M2.(2)The maximum Von Mises stress of L4/5 discs was 1.846 7 MPa for M1,0.419 0 MPa for M2,and 1.257 9 MPa for M3,M1＞M3＞M2.(3)L4/5 bilateral small cartilage produced different degrees of contact stress changes:It was 0.485 5 MPa for M1,0.026 7 MPa for M2,and 0.441 4 MPa for M3,M1＞M3＞M2.Right cartilage contact force was 0.000 5 MPa for M1,0.025 9 MPa for M2,and 0.001 3 MPa for M3,M2＞M3＞M1;the left greater than the right,M1 had the highest value;cartilage strain was consistent with contact stress changes.(4)Different operation modes will have some biomechanical influences on the diseased intervertebral disc and accessory structure.The M1 operation mode can maximize the displacement of protrusion,disc stress and left joint cartilage contact,which can better promote disc displacement,balance stress distribution and reduce facet joint disorder,so the operation is better.

BACKGROUND:Pulsed electromagnetic fields,as an important physical therapy,are exactly effective in the treatment of osteoarthritis,but the mechanism has not been fully clarified. OBJECTIVE:To observe the effect of pulsed electromagnetic field on the degeneration of knee joint cartilage in aged rats. METHODS:Eight 6-month-old Sprague-Dawley rats were selected as the young group and were subjected to normal diet with no treatment.Sixteen 22-month-old Sprague-Dawley rats were randomly divided into old group(n=8)and pulsed electromagnetic field group(n=8).The rats in the pulsed electromagnetic field group were subjected to a pulsed electromagnetic field intervention,once a day,5 days per week for continuous 8 weeks.The rats in the old group were given no treatment.All rats were anesthetized and executed after 8 weeks for the detection of relevant indexes. RESULTS AND CONCLUSION:Compared with the young group,serum type Ⅱ collagen C-terminal peptide level was increased in the old group(P<0.05);compared with the old group,serum type Ⅱ collagen C-terminal peptide level was decreased in the pulsed electromagnetic field group(P<0.05).Micro-CT showed that the bone volume fraction,bone mineral density,and number of bone trabeculae decreased(P<0.05)and the trabecular separation increased(P<0.05)in the tibia of rats in the aged group compared with the young group;and the bone volume fraction,bone density,and number of trabeculae increased(P<0.05)and the trabecular separation decreased(P<0.05)in the tibia of rats in the pulsed electromagnetic field group compared with the aged group.The tibial plateau Safranin O-fast green staining showed that the articular cartilage structure of rats in the aged group was disorganized,and the number of chondrocytes was obviously reduced,and the tidal line could not be distinguished.The above results were improved in the pulsed electromagnetic field group.RT-qPCR and western blot assay showed that the mRNA and protein expression levels of matrix metalloproteinase 1,matrix metalloproteinase 13,P53 and P21 in the articular cartilage and subchondral bone of rats were elevated in the aged group compared with the young group(P<0.05)and decreased in the pulsed electromagnetic field group compared with the old group(P<0.05).To conclude,pulsed electromagnetic fields may improve osteoarthritis in aged rats by inhibiting chondrocyte senescence,alleviating articular cartilage degradation and inhibiting subchondral bone osteoporosis through suppressing the expression of P53/P21.

Objective To explore the effect of intermittent fasting combined with diversified management mode on weight loss of overweight and obese people. Methods A total of 120 overweight and obese patients were selected as research objects, and randomly divided into control group (n=60) and experimental group (n=60). The control group was given intermittent fasting, and the experimental group was given diversified management mode on the basis of the control group. Waist circumference, body mass, body mass index (BMI), waist-to-hip ratio and blood lipid level were compared between the two groups; the scores of hunger, satiety, satisfaction and the incidence of adverse reactions were compared between the two groups. Results After intervention, waist circumference, body mass, BMI, waist-to-hip ratio, total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) in the experimental group were significantly lower, and high-density lipoprotein cholesterol (HDL-C) was significantly higher than that in the control group (P < 0.05). After intervention, the hunger score of the experimental group was significantly lower, and the satiety score and satisfaction score were significantly higher than those of the control group (P < 0.05). The total incidence of adverse reactions in the experimental group was 6.67%, which was significantly lower than 20.00% in the control group (P < 0.05). Conclusion The application of intermittent fasting combined with diversified management mode in overweight and obese people is better, which can improve the relevant clinical indicators and blood lipid levels, and has high safety.

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.

Chronic disease management is a challenging issue in China. To address the needs of talents and mature innovation ecosystem related to chronic disease management, The First Affiliated Hospital of Sun Yat-sen University(FAH-SYSU) actively responds to the national strategy to promote the high-quality development of the hospital through strengthening strategic planning, top-level design, and systematic consideration. Precise management of chronic diseases was taken as key measure for the construction of a national medical center. With continuous exploration in establishing talent pool, innovation center and application platform, and chronic disease management system that focuses on core elements of talent and innovation, the FAH-SYSU Model for the precise management of chronic diseases has been initially formed.

Low ionizability and poor chemical instability make some target analytes not suitable for direct LC-MS/MS analysis. To improve the detection performance, chemical derivation is frequently imported. However, such technology involves multiple disciplines such as laboratory medicine, organic chemistry and separation science. At present, it′s still a challenge for general application of chemical derivatization in routine clinical laboratories in our country. This article summarizes the key scientific connotation of chemical derivatization in the detection of vitamins, steroids, neurotransmitters and therapeutic drugs, and describes the derivatization approaches for development of chemical mass spectrometry in the future.

Objective:To establish an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for plasma caffeine concentration detection, and to explore the clinical value of caffeine therapeutic drug monitoring (TDM) in the treatment of premature infants with respiratory distress syndrome (RDS).Method:Take the plasma sample in a centrifuge tube, add the caffeine deuterated isotope internal standard, then add the protein precipitant, vortex the mixture thoroughly, and centrifuge the supernatant to enter the mass spectrometry analysis. The mobile phase were methanol and water, gradient elution; the column temperature was 45 ℃, the method was established using Shimadzu LC-30AD-CL liquid system and AB SCIEX 4500 QTRAP mass spectrometer, and the sensitivity, specificity, linearity, accuracy imprecision, matrix effect, and carry-over of the method were evaluated. Sample from 30 patients diagnosed with neonatal RSD were collected in the Department of Neonatology of Renmin Hospital of Wuhan University from February to April 2021, then detected the trough concentration of caffeine in premature infants with RDS after taking the same dose of caffeine to assess the impact of individual variation on caffeine drug concentration.Results:The detection limit of caffeine was 0.02 μg/ml, and the lowest limit of quantification was 0.05 μg/ml. It showed good linearity ( R2=0.9986, R>0.99) in the concentration range from 1.0 to 100.0 μg/ml, specificity (recovery rate of 85.52%-114.12%), accuracy (recovery rate 85.97%-114.53%), intra-day and inter-day imprecision ( CV 6.01%-11.28%), matrix effects and carryover pollution were negligible. The trough concentration of 30 preterm infants with RSD after taking the same dose of caffeine (10 mg/kg) was (25.45±11.61) μg/ml, and the coefficient of variation was 44.88%. Conclusion:This study established an accurate and reliable UPLC-MS/MS method with low sample consumption to monitor the blood concentration of caffeine; caffeine TDM has certain clinical application value, which can be used to assist RDS diagnosis and treatment and improve the efficacy of caffeine.

Objective:To explore the reasons for delayed medical seeking in patients with heart failure, and to provide new ideas for guiding patients with heart failure to seek medical treatment in time, increasing the scope of in-hospital and out-of-hospital nursing and optimizing the nursing mode.Methods:Using the purposive sampling method, patients with heart failure who had delayed medical seeking in Department of Cardiovascular Medicine in the Affiliated Hospital of Qingdao University were selected as the research objects from June to July 2020. Based on the theory of "health ecology model", 15 patients with heart failure were given semi-structured in-depth interviews. The descriptive phenomenological analysis method in qualitative research and Chinese version of Nvivo11.0 software were used to analyze and refine the interview data.Results:The delayed medical treatment time of 15 patients with heart failure was 7 to 44 days. The reasons for delayed medical seeking were summarized into 5 thematic groups, including insufficient symptom cognition, lack of disease management ability, cognition and experience of special population, insufficient family social support and medical delay.Conclusions:Medical staff should optimize the content and mode of health education for patients with heart failure, improve the self-management ability of patients with heart failure, timely identify special patients and give targeted intervention, and explore the way for patients with heart failure to obtain the support of high-quality medical resources outside the hospital so as to improve the occurrence of delayed medical treatment.

Objective To investigate the effect of dexmedetomidine pretreatment on Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway during myocardial injury induced by liver ischemia-reperfusion (I/R) in rats.Methods Twenty-four healthy adult male SpragueDawley rats,aged 8-10 weeks,weighing 220-250 g,were divided into 3 groups (n=8 each) using a random number table method:sham operation group (group S),liver I/R group (group I/R),and dexmedetomidine pretreatment group (group D).The portal vein,superior and inferior vena cava,subhepatic inferior vena cava and hepatic artery were clamped,and the liver was perfused with 4 ℃ lactated Ringer's solution for 60 min through the portal vein to establish the model of liver cold I/R in anesthetized rats.Dexmedetomidine 100 μg/kg was intraperitoneally injected at 30 min before ischemia in group D.Blood samples were collected at 8 h of reperfusion from the inferior vena cava for determination of serum cardiac troponin Ⅰ (cTnⅠ) and heart-type fatty acid binding protein (H-FABP) concentrations (using the automatic biochemistry analyzer),tumor necrosis factor-alpha (TNF-α) and high-mobility group box 1 protein (HMGB1) concentrations (by enzyme-linked immunosorbent assay).The rats were then sacrificed,andhearts were harvested for examination of histopathological changes (with a light microscope) and for determination of the malondialdehyde (MDA) content (using thiobarbituric acid method) and superoxide dismutase (SOD) activity (by xanthine oxidase method),and expression of phosphorylated STAT1 and STAT3 (p-STAT1,p-STAT3) and phosphorylated JAK2 (p-JAK2) in myocardial tissues (by Western blot).Results Compared with group S,the serum concentrations of cTnI,H-FABP,TNF-α and HMGB1 were significantly increased,the MDA content was increased,the SOD activity was decreased,and the expression of p-JAK2,p-STAT1 and p-STAT3 was up-regulated in I/R and D groups (P＜0.05).Compared with group I/R,the serum concentrations of cTnI,H-FABP,TNF-α and HMGB1 were significantly decreased,the MDA content was decreased,the SOD activity was increased,the expression of pJAK2,p-STAT1 and p-STAT3 was down-regulated (P＜0.05),and pathological changes of myocardium were significantly attenuated in group D.Conclusion The mechanism by which dexmedetomidine pretreatment mitigates myocardial injury induced by liver cold I/R may be related to inhibiting activation of JAK/STAT signaling pathway in rats.

Objective A highly feasible and reliable ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)method was presented for therapeutic drug monitoring of five anti-schizophrenic drugs (aripiprazole, amisulpride, olanzapine, paliperidone and ziprasidone) simultaneously and the reference range of plasma concentration was investigated.Methods establishment and evaluation.The selectivity,accuracy,precision,stability and linear range of established UPLC-MS/MS method were evaluated according to FDA and CLSI.After a ten-month clinical application, a retrospective analysis of 253 positive samples was carried out to investigate conformance of the AGNP therapeutic reference range for Chinese patients.Results The five anti-schizophrenic drugs could be simultaneously measured by the established UPLC-MS/MS within 6 minutes.The LOQs were 0.1 to 9.0 ng/ml.The correlation coefficients were all higher than 0.997 7.The intra-day and inter-day precisions were less than 11.1%,and the recoveries ranged from 86.2% to 104.8%.The clinical results suggested the good consistency in reference range with AGNP for olanzapine, aripiprazole, paliperidone and ziprasidone.While for amisulpride, the plasma concentration level(445.2 ±231.5)ng/ml was significantly higher than the AGNP-recommended range(100 -320)ng/ml.Conclusion The established UPLC-MS/MS method was very suitable for monitoring anti-schizophrenic drugs.