The liver has diverse functions such as metabolism， detoxification， and immune defense， and the maintenance of hepatic microenvironment homeostasis is crucial for overall bodily health. The hepatic microenvironment consists of the components such as parenchymal cells， non-parenchymal cells， and non-cellular components. Chronic inflammatory responses induced by various etiological factors may promote the formation and progression of liver fibrosis. During the dynamic progression of liver fibrosis， from the early to advanced stages， various components within the hepatic microenvironment undergo a series of changes， which can promote the malignant progression of liver fibrosis. An in-depth exploration of the mechanisms underlying such changes in each component of the liver fibrosis microenvironment is of great significance for understanding the pathogenesis of liver fibrosis and discovering potential treatment strategies.

BACKGROUND:Intervertebral disc degeneration is clinically considered to be the main cause of low back pain,but due to the unclear pathogenesis of intervertebral disc degeneration,there is still a lack of effective means to delay the progression of the disease.Single-cell RNA sequencing technology can amplify and sequence mRNA at the single-cell level,reveal the gene expression intensity of a single cell,discover different cell subsets in tissues according to the heterogeneity of cells,study the pathogenesis of intervertebral disc degeneration at the molecular level,and provide a new theoretical basis for its early diagnosis and treatment. OBJECTIVE:To introduce the basic principles of single-cell RNA sequencing technology and review the research progress of single-cell RNA sequencing technology in intervertebral disc degeneration in recent years. METHODS:A computer was used to search PubMed,Web of Science,CNKI and WanFang databases for the literature published from 2012 to 2022.Key words were"single-cell RNA sequencing,intervertebral disc degeneration,sequencing Technology"in Chinese and English.Duplicate,poor-quality and irrelevant articles were excluded;a total of 70 articles were eventually included. RESULTS AND CONCLUSION:(1)We identified new cell subsets such as homeostatic chondrocytes,hypertrophy chondrocyte-like nucleus pulposus cells and fibrous nucleus pulposus cells,identified the marker genes and transcription factors of these cell subsets,and described the functions,differentiation paths and cell fate of these cell subsets during the development and progression of intervertebral disc degeneration,and proposed the concept of progenitor nucleus pulposus cells.A cell subpopulation with progenitor nucleus pulposus cells properties was identified and its effectiveness in treating intervertebral disc degeneration was verified in mice.(2)Fibro chondrocyte-like annulus fibrosus cells and annulus fibrosus stem cells with both cartilage and fiber properties were identified,and a new type of composite hydrogel was prepared by combining fibrous cartilage inducers silk fibroin and hyaluronic acid in vitro.Experiments in mice demonstrated that this hydrogel could repair both annulus fibrosus tissue and cartilage matrix,and was remarkably effective in the treatment of intervertebral disc degeneration.(3)Regulatory chondrocytes were found in endplate cartilage.Two distinct fates in the progression of intervertebral disc degeneration were analyzed and the differential genes in the two fates were identified.Intercellular communication analysis indicated that regulatory chondrocytes interact with endothelial cells to promote angiogenesis.(4)Immune cells such as macrophages,T cells,myeloid progenitor cells and neutrophils were identified in the degenerated intervertebral disc tissues,demonstrating the existence of immune response during intervertebral disc degeneration.It was found that apolipoprotein induced the polarization of macrophages M1 and M2 subtypes,and this polarization process affected the activity of progenitor nucleus pulposus cells by amplifying the inflammatory response through the MIF signaling pathway.

BACKGROUND:Avascular necrosis of the femoral head is a refractory orthopedic disease that seriously affects the normal life of patients.Hip preservation is recommended for young patients due to the limited prosthesis longevity and revision.Accurate prediction of the mechanical properties of the necrotic area in the early stage and then intervention is the key to hip preservation. OBJECTIVE:To establish a dynamic contact mechanics finite element model of necrotic femoral head based on human hip CT data and predict effects of both necrotic volume magnitude and its position on biomechanics of the necrotic region under walking movement. METHODS:CT data of a volunteer were collected and then geometry model of the hip was rebuilt.Finite element model of the necrotic femoral head was established using the Abaqus software.Nine different necrotic femoral models were constructed by combined both three different necrotic volume magnitudes(small,medium and big volume)and three different necrotic positions(coincided with,medium deviated with and kept away from the line of the force).The Von Mises of the necrotic region for all models were predicted under both 3 000 N static load and dynamical loads of one whole ISO walking gait cycle.The collapse risk for all models was evaluated based on collapse criterion. RESULTS AND CONCLUSION:(1)More approaching of the necrotic region to the line of force and bigger collapse volume made the maximum Von Mises increasing.This also enlarged the collapse risk of the necrotic region.(2)For different load types,walking movement increased the maximum Von Mises of the necrotic region than that of the value under static load under the same necrotic volume and location.(3)In conclusion,dynamic load would result in increasing of the maximum Von Mises of the necrotic region comparing to static load during exercise.Therefore,the risk of local collapse will increase due to greater Von Mises.However,the overall collapse risk is lower than that of static load due to the dynamic change of bearing area.This factor should be carefully considered by surgeons when they evaluate the mechanical performance of the necrotic femoral head.

ObjectiveTo establish a qualitative and quantitative analysis method for chemical constituents in Liu Junzitang（LJZT）， and to clarify its material basis. MethodThe chemical constituents in LJZT were analyzed by ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS）， and the resulting compounds were identified by using databases， such as MassBank， PubChem， ChemSpider， Traditional Chinese Medicine Systems Pharmacology Database and Analytical Platform（TCMSP）， and by combining with relevant literature. UPLC was used to establish a quantitative method for analysis of 9 compounds in LJZT， including liquiritin， hesperidin， lobetyolin， liquiritigenin， glycyrrhizic acid， nobiletin， tangeretin， atractylenolide Ⅱ and Ⅰ. ResultBy combining the relevant literature， database and MS information， a total of 79 compounds were identified from LJZT， including 31 flavonoids， 15 terpenoids， 14 nitrogen-containing compounds， 6 phenylpropanoids， 6 organic acids and 7 other compounds. The established quantitative analytical method for the nine representative components showed good linearity within their respective linear ranges， and the precision， stability， reproducibility and recovery were in accordance with the requirements. The quantitative results showed that the contents of liquiritin， hesperidin， lobetyolin， liquiritigenin， glycyrrhizic acid， nobiletin， tangeretin， atractylenolide Ⅱ and Ⅰ in LJZT were 0.376 5， 2.602 1， 0.082 6， 0.128 1， 1.778 6， 0.015 7， 0.006 7， 0.030 4， 0.003 2 mg·g^-1， respectively. ConclusionThe established method can quickly， sensitively and accurately analyze the chemical constituents in LJZT， clarify that the material basis of LJZT is mainly flavonoids， terpenoids and nitrogen-containing compounds， and simultaneously determine the contents of the 9 components， which can lay a foundation for the research on quality control， mechanism and clinical application of LJZT.

Objective To evaluate the diagnostic value of myocardial work related parameters in coronary ischemia patients with coronary artery disease(CAD)coronary ischemia using non-invasive left ventricular pressure strain loop(PSL),taking fraction flow reservation(FFR)as the gold standard.Methods From December 2020 to December 2021,53 clinically suspected CAD patients were prospectively enrolled.All patients underwent echocardiography,invasive coronary angiography and FFR measurement.According to the results of coronary angiography,patients were divided into myocardial ischemia group(n=24,FFR≤0.80)and non-myocardial ischemia group(n=29,FFR＞0.80).PSL was used for off-line analysis to obtain the global work index(GWI),global constructive work(GCW),global wasted work(GWW),global work efficiency(GWE),global positive work(GPW),and global systolic constructive work(GSCW)and other myocardial work parameters.The differences of parameter values between the two groups were compared.The diagnostic efficacy of work parameters in myocardial ischemia was analyzed by ROC curve.Results Compared with the non-myocardial ischemia group,GWI,GCW,GPW and GSCW were significantly decreased in the myocardial ischemia group at the 18-,16-,and 12-segment levels(P＜0.001).The ROC curve showed that the AUC results of GWI,GCW,GPW,GSCW at the 18-segment level were 0.803(95％CI 0.679-0.927),0.807(95％CI 0.687-0.928),0.822(95％CI 0.708-0.936),0.819(95％CI 0.703-0.935).The optimal cut-off value of GWI was 1 676.3 mmHg％,and the sensitivity,specificity and accuracy of predicting myocardial ischemia were 70.8％,86.2％and 79.2％,respectively.The optimal cut-off value of GCW was 1 999.4 mmHg％,and the sensitivity,specificity and accuracy of predicting myocardial ischemia were 75.0％,82.8％and 79.2％,respectively.Conclusions Analyzing myocardial work using PSL has good significance for screening suspected myocardial ischemia in CAD patients.

Objective:To explore the pathogenesis of flunarizine-induced parkinsonism from gut-brain axis perspective.Methods:Thirty male C57BL/6 mice were randomly divided into control group and flunarizine group ( n=15). Mice in the control group were given 0.1 mL 50% polyethylene glycol 400+50% saline by gavage once/d for 2 weeks, while mice in the flunarizine group were given 6 mg/mL flunarizine+50% polyethylene glycol 400+50% saline by gavage at a daily dose of 30 mg/kg for 2 weeks. Body mass was recorded 1, 3, 5, 7, 10 and 14 d after drug administration, and motor function was assessed by rotarod test 14 d after drug administration; 16s RNA sequencing was performed in the feces to observe the intestinal flora; intestinal transit function was detected by Evans blue by gavage; and then, the mice were sacrificed and homogenate or frozen sections (brain and intestinal tissues) were prepared; dopamine-ergic neuron expression was detected by Western blotting; RT-qPCR was applied to detect the expressions of inflammatory factors in the substantia nigra, and immunofluorescent staining was used to detect the expressions of ZO-1 and Claudin-5 in the intestinal epithelial tissues. Results:Compared with the control group, the flunarizine group had lower body mass ratio 1, 3, 5, 7, 10 and 14 d after drug administration (ratio to body mass before drug administration). Compared with the control group, the flunarizine group had significantly shortened residence time in rod rotating and lower rotational speed when falling ( P<0.05). Compared with the control group, the flunarizine group had decreased tyrosine hydroxylase protein in the substantia nigra without significant difference ( P>0.05). Compared with the control group, the flunarizine group had significantly increased interleukin-6 and tumor necrosis factor-α in the substantia nigra (1.00±0.00 vs. 2.79±0.83; 1.00±0.00 vs. 3.39±1.37), significantly lower intestinal Evans blue propulsion rate (80.67%±4.51% vs. 50.67%±6.03%), and statistically decreased ZO-1 and Claudin-5 expressions in the colonic epithelial tissues (27.01±1.41 vs. 16.32±2.83; 37.00±2.80 vs. 24.52±2.12, P<0.05). Totally, 576 microorganisms were noted in both control group and flunarizine group, 744 in the control group alone, and 634 in the flunarizine group alone. The intestinal flora β diversity indices in the 2 groups were significantly different based on weighted Unifrac-principle coordinates analysis (PCoA, PCoA1: 39.88%; PCoA2: 30.69%). Compared with the control group, the microbial colony structure of mice in flunarizine group was dominated by phylum thick-walled bacteria and phylum warty microbacteria, and by families Muribaculaceae, Lachnospiraceae and Akkermansiaceae. Compared with the control group, the flunarizine group had significantly decreased relative abundance of Ackermannia spp. and Lactobacillus spp. in the intestinal flora ( P<0.05). Conclusion:Flunarizine may contribute to the pathogenesis of DIP by causing structural disturbances in the intestinal flora and inducing neuroinflammation based on the gut-brain axis.

This article introduces a recent paper published in JAMA titled " Tirzepatide for weight reduction in Chinese adults with obesity: The SURMOUNT-CN randomised clinical trial". The paper details the design, results, and implications of a randomized controlled clinical study of the efficacy and safety of tirzepatide in overweight/obese adults in China(SURMOUNT-CN). This study represents the first Chinese evidence supporting tirzepatide for the treatment of obesity, offering a potent therapeutic option for the prevention and treatment of obesity and weight-related comorbidity.

Objective　To perform the pathogenic and genomics analyses on isolates of Streptococcus suis (Ss) from three human infections in Shenzhen, aiming to provide a basis for the prevention and control of Ss outbreaks. Methods　The suspected bacterial strains from three blood plate cultures of three critically ill patients in three hospitals were subjected to biochemical identification, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), and real-time fluorescent PCR identification, resulting in the identification of three strains positive for Streptococcus suis serotype 2(SS2). Pure positive cultures were taken for an antimicrobial susceptibility test and extracted nucleic acids for whole-genome sequencing and analysis. The whole-genome sequencing and analysis included species identification, antibiotic resistance genes alignment, multilocus sequence typing (MLST), virulence genes alignment, and coregene-based phylogenetic tree analysis. Results　The blood agar isolates from three patients were all identified as Ss, the VITEK 2 identified them as SS2, and MALDI-TOF-MS identified them as Ss. Real-time PCR results for the universal gene gdh and serotype 2 cps2 gene of Ss were both positive. The antimicrobial susceptibility test results showed that all three strains were resistant to erythromycin and clindamycin, with variable sensitivity to tetracycline. Whole-genome sequencing results showed that all three strains were identified as Ss, including one ST7 strain and two ST1 strains. The virulence gene prediction results based on the VFDB database showed that all three strains were positive for mrp, sly, and cps, indicating high virulence gene characteristics. The analysis of the phylogenetic tree based on coregene showed that the three strains were in different evolutionary branches, with two ST1 strains having a closer evolutionary distance. Conclusions　The pathogens responsible for these three critically ill patients were SS2, and all three strains were resistant to erythromycin and clindamycin. Genetically, they all carried virulence genes that are found in highly virulent strains, while showed differences in MLST typing and phylogenetic tree analysis, indicating the presence of different genotypes of high pathogenicity SS2 in Shenzhen area and had caused sporadic cases, which requires high attention.

Objective:To study the early use of inhaled nitric oxide (iNO) as a rescue therapy in extremely premature infants (EPIs) with refractory hypoxic respiratory failure (HRF).Methods:Between January 2021 and December 2021, EPIs with refractory HRF receiving iNO within the first week of life in our NICU were enrolled. Their clinical characteristics and outcomes were retrospectively analyzed.Results:A total of 11 EPIs were included with 5 males and 6 females. The median gestational age (GA) was 24(22.6, 25.2) weeks. The median birth weight (BW) was 580(490, 770) g. The most common primary diagnoses were moderate/severe respiratory distress syndrome (RDS) (5/11) and early-onset sepsis (3/11). The median age starting iNO therapy was 6.5(4.5, 34.0)h and the median duration of iNO was 24(12, 36)h. The median iNO starting dose was 5(5, 8) ppm and the therapeutic range was 5-20 ppm. Therapeutic efficacy was defined as ≥30% FiO 2 reduction after 6 h of iNO treatment. The treatment was effective in 8 cases. The oxygenation index (OI) decreased more than 10% from baseline 1 h after initiation in 9 patients and in all 11 patients after 12 h of iNO. The reduction of OI was more prominent in EPIs with a higher OI at baseline. Of the 11 patients, 8 survived, 1 died and 2 abandoned further treatments. Conclusions:As an early rescue therapy for EPIs with refractory HRF, iNO can improve oxygenation without obvious short-term adverse effects.

Objective:To investigate serum C-reactive protein (CRP) , procalcitonin (PCT) and neutrophil CD64 in predicting early infection after internal fixation of limb fractures.Methods:A total of 2 572 patients with limb fractures undergoing internal fixation in Taishun County People’s Hospital from January 2016 to December 2022 were enrolled. Postoperative infection occurred in 121 cases (infected group) and did not occur in 2 451 cases (uninfected group). Serum levels of PCT, CRP and CD64 were tested at admission and d1, d3, d5 and d7 after operation. Repeated measurement analysis of variance was used to compare the serum levels of PCT, CRP and CD64 at different time points between two groups, the receiver operating characteristic curve (ROC) was used to evaluate the predictive value of each index or in combination for early infection after internal fixation of limbs fractures.Results:The early infection rate after internal fixation was 4.70% (121/2 572). The levels of PCT, CRP and CD64 in the infection group began to rise after operation and decreased on d7; there were significant differences in PCT, CRP and CD64 levels between the two groups on d3, d5 and d7 after operation (PCT: Ftime=678.607, Fintergroup=2 218.323, Finteraction=653.150; CRP: Ftime=392.724, Fintergroup=1 812.502, FInteraction =379.577; CD64: Ftime=373.686, Fintergroup=4 817.438, Finteraction=528.353, all P< 0.001) . The area under the ROC curve of combined detection of PCT, CPR, and CD64 for predicting early infection was 0.856; the sensitivity and specificity of combined detection were 69.2% and 94.7%, respectively. The combined detection of three indicators showed better prediction values than PCT, CRP and CD64 alone ( Z=6.176, 3.838 and 2.431, P<0.01 or <0.05), and also better than combined detection of PCT and CRP ( Z=2.875, P=0.019). Conclusions:The combined detection of CD64, PCT and CRP is of value in prediction of postoperative infection after internal fixation of limb fractures, which is worthy of clinical application.