Background Existing studies have confirmed that fine particulate matter (PM_2.5)is one of the important factors inducing pulmonary fibrosis. Pulmonary fibrosis is the terminal stage of a major category of lung diseases characterized by the destruction of tissue structure, and eventually leading lung ventilation and ventilation dysfunction. No effective pulmonary fibrosis treatment is available yet. Objective To investigate the protective effect of salidroside on pulmonary fibrosis induced by the exposure of PM_2.5 and its molecular mechanism. Methods Seventy 7-week-old male C57BL/6 mice were randomly divided into four groups: control group (intratracheal instillation of normal saline + saline by gavage, n=25), Sal group (intratracheal instillation of normal saline + Sal 60 mg·kg⁻¹ by gavage, n=10), PM_2.5 group (intratracheal instillation of PM_2.5 5 mg·kg⁻¹ + saline by gavage, n=10), and Sal + PM_2.5 group (intratracheal instillation of PM_2.5 5 mg·kg⁻¹ +Sal 60 mg·kg⁻¹ by gavage, n=10). The mice were administered by gavage once daily, intratracheal instillation once every 3 d, and every 3 d constituted an experimental cycle. At the end of the 26-30th cycles, 3 mice in the control group and 3 mice in the PM_2.5 group were randomly sacrificed, and the lung tissues were collected for Masson staining to verify whether the pulmonary fibrosis model was successfully established. After 30 cycles, the model was successfully constructed. After 1 week of continuous observation, the mice were sacrificed, and the blood and lung tissues of the mice were collected to make lung tissue sections. Assay kits were correspondingly employed to detect oxidative stress indicators such as serum malondialdehyde (MDA) and superoxide dismutase (SOD). Western blotting was used to detect the expression of fibrosis-related proteins (Collagen-III, α-SMA), mitochondrial dynamics-related proteins (MFN1, Drp1), and mitophagy-related proteins (PINK1, Parkin, and LC3). Results Compared with the control group, the weight gain rate of the PM_2.5 group was slowed down (P<0.05), which was alleviated by the Sal intervention (P<0.05). The lung coefficient increased after the PM_2.5 exposure (P<0.05), which was alleviated by Sal intervention. Compared with the control group, the PM_2.5 group showed severe alveolar structure damage, inflammatory cell infiltration, and blue collagen deposition, and significantly increased the lung injury score, collagen volume fraction (CVF), Szapiel score, and Ashcroft score (P<0.05), as well as serum oxidative stress levels (P<0.05). The protein expression levels of Collagen-III, α-SMA, Drp1, PINK1, Parkin, and LC3 II/I were increased (P<0.05), and the expression of MFN1 was decreased (P<0.05). Compared with the PM_2.5 group, the Sal intervention alleviated lung injury, reduced inflammatory cell infiltration and collagen deposition, showing decreased lung injury score, CVF, Szapiel score, and Ashcroft score (P<0.05), and decreased serum oxidative stress levels (P<0.05); the protein expression levels of Collagen-III, α-SMA, PINK1, Parkin, and LC3 II/I were decreased (P<0.05), the expression level of Drp1 was decreased, and the expression level of MFN1 was increased. Conclusion In the process of pulmonary fibrosis induced by PM_2.5 exposure in mice, Sal may affect mitochondrial autophagy through PINK1/Parkin pathway and play a protective role. The specific mechanism needs to be further verified.

Objective:To explore the cognition and behavior of nurses in blood purification centers on the quality of death of patients undergoing maintenance hemodialysis.Methods:The descriptive phenomenological research method was adopted. From August to October 2022, a total of 14 nurses from blood purification centers in three hospitals, namely Beijing Union Medical College Hospital, Beijing Hospital and Beijing Chaoyang Hospital were selected as interview subjects by the purposive sampling method. Semi-structured in-depth interview method was used to collect data, and Colaizzi 7-step analysis method was used to analyze data.Results:The cognition and behavior of nurses in the blood purification center towards the quality of death of maintenance hemodialysis patients were analyzed into four themes, namely factors affecting the quality of death of patients, convenient conditions for nurses to carry out quality of death improvement work, proactive measures taken by nurses to improve the quality of death and obstacles in the process of improving the quality of death of patients.Conclusions:The nurses in the blood purification centers have special characteristics in their feelings about the death of patients with maintenance hemodialysis, and they have certain cognition and judgment about the quality of death of patients. Managers need to pay attention to the relevant needs and suggestions of the nurses in the blood purification centers and provide help and guidance, so as to continuously improve the quality of patient death and achieve the goal of optimal death of patients.

Objective:To screen differentially expressed circular RNA (circRNA) in rat articular chondrocyte injury induced by T-2 toxin, and explore the mechanism of cartilage injury.Methods:Twenty-four SD rats (males, body weight 60 - 80 g) were randomly divided into T-2 toxin group (administrated T-2 toxin 100 ng·g -1·d -1 by gavage) and control group (administrated equal amounts of deionized water by gavage) using a random number table method, 12 rats in each group. After 4 weeks of intervention, the articular cartilage was collected for transcriptome sequencing. Deseq2 software [ P < 0.05 and |log 2(fold change)| > 1, fold change was the multiple of differential expression] was used to identify differentially expressed circRNA. Based on the competing endogenous RNAs (ceRNA) hypothesis, the miRanda software was used to predict the microRNA (miRNA, miR) binding sites of differentially expressed circRNA, and Cytoscape 3.10.0 software was used to plot the circRNA-miRNA interaction network. MiRWalk 3.0, MiRDB, and miRTarBase softwares were used to predict downstream target genes, and Cytoscape 3.10.0 software was used to map the circRNA-miRNA-mRNA interaction network. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the biological functions and enrichment pathways of target genes. Results:A total of 19 differentially expressed circRNAs were screened (including 10 upregulated and 9 downregulated). A total of 1 320 miRNAs binding sites and 16 target genes were predicted. Target gene enrichment analysis revealed significant enrichment of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathway ( P < 0.05). Tumour necrosis factor receptor-associated factor 6 (Traf6) and interleukin-1 receptor-associated kinase 1 (Irak1) were enriched in the MAPK and NF-κB signaling pathways, with corresponding miRNA and circRNA of miR-146a-5p and chr2: 94716330|94720889. Conclusion:Nineteen differentially expressed circRNAs in rat articular chondrocyte injury are successfully screened, and chr2: 94716330|94720889 may regulate the MAPK and NF-κB signaling pathways through the miR-146a-5p/Traf6/Irak1 axis, inducing articular chondrocyte injury.

Background Salidroside (SAL) has a protective effect on multiple organ systems. Exposure to fine particulate matter (PM_2.5) in the atmosphere may lead to disruptions in gut microbiota and impact intestinal health. The regulatory effect of SAL on the gut microbiota of mice exposed to PM_2.5 requires further investigation. Objective To evaluate gut microbiota disruption in mice after being exposed to PM_2.5 and the potential effect of SAL. Methods Forty male C57BL/6 mice, aged 6 to 8 weeks, were randomly divided into four groups: a control group, an SAL group, a PM_2.5 group, and an SAL+PM_2.5 group, each containing 10 mice. In the SAL group and the SAL+PM_2.5 group, the mice were administered SAL (60 mg·kg⁻¹) by gavage, while in the control group and the PM_2.5 group, sterile saline (10 mL·kg⁻¹) was administered by gavage. In the PM_2.5 group and the SAL+PM_2.5 group, PM_2.5 suspension (8 mg·kg⁻¹) was intratracheally instilled, and in the control group and SAL group, sterile saline (1.5 mL·kg⁻¹) was intratracheally administered. Each experiment cycle spanned 2 d, with a total of 10 cycles conducted over 20 d. Histopathological changes in the ileum tissue of the mice were observed after HE staining. Colon contents were collected for gut microbiota sequencing and short-chain fatty acids (SCFAs) measurements. Results The PM_2.5 group showed infiltration of inflammatory cells in the ileum tissue, while the SAL+PM_2.5 group exhibited only a small amount of inflammatory cell infiltration. Compared to the control group, the PM_2.5 group showed decreased Shannon index (P<0.05) and increased Simpson index (P<0.05), indicating that the diversity of gut microbiota in this group was decreased; the SAL+PM_2.5 group showed increased Shannon index compared to the PM_2.5 group (P<0.05) and decreased Simpson index (P<0.05), indicating that the diversity of gut microbiota in mice intervened with SAL was increased. The principal coordinates analysis (PCoA) revealed a significant separation between the PM_2.5 group and the control group, while the separation trend was less evident among the control group, the SAL group, and the SAL+PM_2.5 group. The unweighted pair-group method with arithmetic means (UPGMA) clustering tree results showed that the control group and the SAL group clustered together first, followed by clustering with the SAL+PM_2.5 group, and finally, the three groups clustered with the PM_2.5 group. The PCoA and UPGMA clustering results indicated that the uniformity and similarity of the microbiota in the PM_2.5 group were significantly decreased. Compared to the control group, the PM_2.5 group showed decreased abundance of phylum Bacteroidetes and Candidatus_Saccharimonas (P<0.05) and increased abundance of phylum Proteobacteria, genus Escherichia, genus Bacteroides, genus Prevotella, genus Enterococcus, and genus Proteus (P<0.05). Compared to the PM_2.5 group, the SAL+PM_2.5 group showed decreased abundance of phylum Proteobacteria, phylum Actinobacteria, genus Prevotella, and genus Proteus (P<0.05), and increased abundance of Candidatus_Saccharimonas (P<0.05). The PM_2.5 group showed reduced levels of propionic acid, valeric acid, and hexanoic acid compared to the control group (P<0.05), while the SAL+PM_2.5 group showed increased levels of propionic acid, isobutyric acid, butyric acid, valeric acid, and hexanoic acid compared to the PM_2.5 group (P<0.05). Conclusion Exposure to PM_2.5 can cause pathological alterations, microbial dysbiosis, and disturbing production of SCFAs in intestinal tissue in mice. However, SAL can provide a certain degree of protective effect against these changes.

Objective:To explore the method of obtaining the key parameters of the average value articulator in healthy people based on mandibular movement trajectory data, with a view to providing a reference for the clinical application of the average value articulator.Methods:One hundred healthy volunteers (42 males and 58 females) with individual normal occlusion, aged 18-55 years old, who met the inclusion criteria were recruited from Beijing, and their mandibular movement trajectory data were collected. The left and right sagittal condylar inclination(SCI) and transversal condylar inclination(TCI) were obtained from the values of the articulator parameters which were generated in the mandibular movement analysis system.The SCI and TCI were grouped by gender and calculated separately for the two groups and the overall sample; the gender differences in the two parameters and the differences between the mean values of the two parameters and the average value articulator empirical values (35° for SCI and 15° for TCI) for the overall sample were compared.Results:The differences between SCI (35.8°±7.4°) and TCI [11.2° (11.3°)] in males and the corresponding parameters [35.6°±8.3° and 10.8° (9.5°), respectively] in females were not statistically significant ( t=0.10, P=0.922; Z=-0.60, P=0.552); the overall sample SCI (35.7°±7.9°) did not differ statistically from the average value articulator empirical value ( t=1.23, P=0.221), and the overall sample TCI [10.9° (10.3°)] was significantly smaller than the average value articulator empirical value ( W=5 825.00, P<0.001). Conclusions:The mandibular movement trajectory data of 100 adults with individual normal occlusion in this study shows that the gender factor does not affect the setting of the key parameters of the average value articulator, the SCI of the average value articulator empirical values is appropriate, and the TCI has the possibility of being on the large side. In the clinical use of the articulator to assist in the design of restorations, the parameter values should be rationally adjusted according to the actual situation of the patient′s dentition and mandibular movement.

Objective:To investigate the correlation of intratumoral fibrosis with the prognosis of clear cell renal cell carcinoma (ccRCC).Methods:The correlation of the transcriptional expression of the primary collagen with the prognosis in ccRCC was evaluated using the Cancer Genome Atlas (TCGA) database, including 530 ccRCC patients with complete information. Of them, 344 cases were male, 186 cases were female. The age of 264 cases was ≤ 60 years, and the age of 266 cases was > 60 years. The pathology grade of 241 patients was G 1-2 grade, and the pathology of 281 cases were G 3-4 grade, 8 cases were undetermined grade. There were 322 cases with AJCC stage Ⅰ-Ⅱ and 205 cases with AJCC stage Ⅲ-Ⅳ, and 3 cases with undetermined stage. There were 420 cases in M 0 and 78 cases in M 1, and 32 cases without distant metastases information. Furthermore, the paraffin sections of 158 non-cystic ccRCC patients confirmed by pathology from November 2005 to November 2017 were further used to evaluate the level of collagen of ccRCC and the status of the pseudocapsule by the Masson staining, Sirius red staining and multicolor immunofluorescence staining of collagen Ⅰ and collagen Ⅲ. Of them, 112 cases were male, 46 cases were female. There were 100 cases with age ≤ 60 years, and 58 cases with age > 60 years. The pathology grade of 111 cases were G 1-2, and the pathology grade of 47 cases were G 3-4. There were 144 cases with AJCC stage Ⅰ-Ⅱ, 14 cases with AJCC stage Ⅲ-Ⅳ. Kaplan-Meier survival curve were used to analyze the relationship between tumor collagen parameters and the overall survival prognosis of patients with ccRCC. Results:The transcriptome results of the TCGA database indicated that the expression level of COL1A1 in ccRCC tissues was significantly higher than that in adjacent normal tissues ( P<0.001). The high expression of collagen suggested a worse overall survival prognosis ( HR=1.165, P=0.002). In addition, the high ratio of COL1A1/COL3A1 indicated a worse overall survival prognosis ( HR=1.901, P<0.001) compared with the low ratio. We further confirmed that the abundance of collagen in tumor was significantly increased compared with the normal adjacent tissues by the Masson staining [41.0 (14.0-75.0) vs.15.0 (3.0-57.0), P<0.001] and the Sirius red staining [42.5 (10.0-90.0) vs.10.0 (2.5-60.0), P<0.001] on 30 ccRCC tissues and adjacent normal tissues. Based on the Masson staining, we found that high collagen abundance in tumor tissue was associated with more G 3-4 grade of tumor compared with low collagen abundance (38.5% vs.21.3%, OR=2.316, 95% CI 1.146-4.681, P=0.023). Kaplan-Meier survival curve showed that higher collagen abundance was associated with a worse overall survival prognosis in ccRCC ( HR=2.630, P=0.007). However, incomplete fibrous pseudocapsule was associated with a worse overall survival prognosis ( HR=11.140, P<0.001). Conclusions:In ccRCC, intratumoral collagen fiber level was overexpressed. High intratumoral collagen level and incomplete fibrous pseudocapsule may indicate a poor overall survival prognosis.

Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.

Kashin-Beck disease (KBD) is a disabling osteoarthropathy of unknown cause, which occurs most frequently in children and adolescents and affects many regions in China. In adults KBD patients, the degeneration of weight-bearing joints is the most serious, especially the knee joint. Up to now, there are still a large number of adult patients with KBD arthritis of the knee, and they have not been systematically and effectively treated. The main manifestations are knee joint pain, thickening, deformation and restricted movement. In severe cases, it can lead to knee joint varus, valgus, flexion contracture, and rotational deformity, which seriously affects the quality of life and work ability of the patients. Early diagnosis of KBD arthritis of the knee is difficult and there is no effective treatment, so it needs to be differentiated from knee osteoarthritis (OA). KBD and OA have common pathological characteristics. According to the "Consensus of Four-stepladder Program of Knee 0steoarthritis" (2018), OA treatment is divided into four levels: basic treatment, drug treatment, restorative treatment and reconstruction treatment. In this paper, the treatment of KBD arthritis of adult knee joint is summarized, which is also divided into four steps. It is necessary to make stepwise treatments according to the severity of KBD arthritis of the knee and the differences of patient's own condition, so that the limited medical resources can be efficiently used. At the same time, this paper also systematically summarizes the epidemiological characteristics, pathological features and diagnostic criteria of KBD arthritis of the knee, aiming to provide effective reference and guidance for the treatment of KBD arthritis of the knee.

Abstract:To compare the morphology of spinal cord between healthy adolescents with adolescent Chiari malformation type I (CMI) patients and investigate the impact of syringomyelia on the morphology of spinal cord in CMI patients.Methods:The clinical and radiological data of 292 CMI patients diagnosed by our center between June 2012 and March 2019 were retrospectively reviewed. Among them 15 CMI patients without syringomyelia were recruited in the CM group. Among the remaining 277 CMI patients, 274 patients had syringomyelia below the C 3-4 intervertebral disc. According to the principle of best matching, CMI patients with syringomyelia were selected with the closest age to the CM group (±18 months), and 30 CMI patients with syringomyelia were included in the CMS group according to a ratio of 1∶2. Thirty healthy adolescents were enrolled as the control group (NC group) in the same way. The anteroposterior diameters of spinal cord at C 2 (DSCO-C 2), spinal canal at C 2 (DSCA-C 2), midbrain-pontine junction (DPJ), the distance between the tip of cerebellar tonsils and the foramen magnum (AB) and the maximal diameter of the syrinx (D-syrinx) were measured on MRI. All radiographic parameters were measured twice independently by two spine surgeons, and intraclass correlation coefficient (ICC) were determined to demonstrate intra- and inter-observer reliability. One-way ANOVA and SNK- q test were used to compare the above radiographic parameters and age between CM, CMS and NC group. The distribution of genders was compared between the three groups using Chi-square tests. Pearson correlation analysis were conducted to demonstrate the relationship between radiographic parameters in CM and CMS group. Results:ICC ranged between 0.91 and 0.95 in the current study, demonstrating "excellent" reliability of radiographic measurements. No significant difference was noted regarding age and the distribution of genders among the three groups. Patients in CM and CMS groups showed similar DSCO-C 2 values ( P=0.254), both of which were significantly lower than that in NC group ( P<0.001). DSCA-C 2 in CMS group was significantly larger than that in CM ( P=0.003) and NC ( P<0.001) groups, while no significant difference was found between the CM and NC groups ( P=0.216). Moreover, DPJ in CMS group was significantly lower than that in CM group ( P<0.001) and NC group ( P<0.001). There was no significant difference in AB between CM and CMS groups ( P=0.948). DSCO-C 2 was significantly positively correlated with DSCA-C 2 in CMS group ( r=0.906, P<0.001), while AB, D-syrinx, DSCO-syrinx, DSCA-syrinx and DPJ were not significantly correlated with DSCA-C 2. There were significant correlations observed between DPJ and other radiographic parameters in the CMS group (all P>0.05). Significant positive correlation between DSCO-C 2 and DPJ was observed in CM group ( r=0.703, P=0.005). There was no significant correlation between DSCO-C 2 and DSCA-C 2 and DPJ in NC group (all P>0.05). Conclusion:CMI adolescents have significant atrophic change of cervical spinal cord and midbrain-pontine junction compared with healthy adolescents, regardless of the existence of syrinx. Moreover, syrinx in CMI patients indicated more obvious atrophic change of midbrain-pontine junction and dilated spinal canal compared with isolated CMI patients.

COVID-19 is an emerging infectious disease caused by SARS-CoV-2. After the infection of the virus, the host immune system is stimulated to produce multifarious specific antibodies to decrease or eliminate effects of the pathogen. Study of the specific antibodies dynamic characteristics in patients with COVID-19 is very important for the understanding and diagnosis of the disease, research and development of vaccine, and planning of prevention and control strategy. This paper reviews and summarizes the domestic and oversea research on dynamic characteristics of specific antibodies of COVID-19 patients, including the antibody producing, duration and level, and its possible influencing factors in order to improve the understanding of the immunological characteristics of COVID-19.