AIM:To test and compare the perceptual eye position and fixation stability of adolescents with emmetropia and adolescents with low myopia, investigating the characteristics of the perceptual eye position and fixation stability of adolescents with low myopia.METHODS: Cross-sectional study. A total of 132 adolescents(264 eyes)who visited in the ophthalmology clinic of our hospital from April to December 2023 were randomly selected as the research subjects. Participants were categorized into normal control group(n=45, 90 eyes), simple low myopia group(n=45, 90 eyes)and low myopia with anisometropia group(n=42, 84 eyes)according to their refractive status and were underwent assessments for perceptual eye position and fixation stability.RESULTS: Compared with the normal control group, the static and dynamic horizontal perceptual eye position deviation of the simple low myopia group and the low myopia with anisometropia group were significantly increased(P<0.05). Compared with the simple low myopia group, the static and dynamic horizontal perceptual eye position deviation of the low myopia with anisometropia group were significantly increased(P<0.05). There was no significant difference in static and dynamic vertical perceptual eye position deviation among the three groups(P>0.05); compared with the normal control group, the horizontal and vertical fixation stability of the simple low myopia group and the low myopia with anisometropia group were significantly worse(all P<0.01), but there was no differences in the simple low myopia group and the low myopia with anisometropia group(P >0.05).CONCLUSION: Abnormalities are observed in perceptual eye position and fixation stability function in adolescents with low myopia compared with those adolescents with emmetropia, even at best corrected visual acuity. The occurrence of anisometropia could lead to an increased degree of horizontal perceptual eye position displacement.

Objective To explore the effectiveness of a PBL-CBL teaching model oriented towards competency evaluation after the introduction of standardized patients in orthopedic clinical internship teaching.Methods Eighty-nine medical students undergoing orthopedic internships at our hospital from 2022 to 2023 were divided into an S-PC teaching group and a PC teaching group.Based on Milestones 2.0,a competency evaluation model for orthopedic interns was established,including six primary in-dicators:patient care,clinical knowledge and skills,interpersonal communication,and more.After the course,students were as-sessed according to the established model.Results The S-PC group showed statistically significant differences in scores for pa-tient care,clinical knowledge and skills,interpersonal communication,system-based practice,and practice-based learning com-pared to the PC group(P＜0.05),with all scores in the S-PC group being higher than those in the PC group.Conclusion In-troducing standardized patients into the PBL-CBL teaching model in clinical education significantly enhances the competency of orthopedic interns.

Objective:To study the distribution of drug resistance genes and virulence genes in multidrug-resistant Salmonella typhimurium strains.Methods:A total of 96 strains of Salmonella typhimurium were collected，and drug sensitivity tests were performed to evaluate the drug resistance and multidrug-resistance of Salmonella typhimurium.Multidrug-resistant Salmonella typhimurium strains were selected to conducted whole genome sequencing，and the distribution of drug resistance genes and virulence genes in the strain were analyzed.Results:Salmonella typhimurium strains had the highest resistance rates to ampicillin and ampicillin/sulbactam，with 89.58% and 76.04%，respectively.Followed by trimethoprim/sulfamethoxazole，ceftriaxone，and aztreonam，with 47.92%，38.54% and 33.33%，respectively，and low resistance rates to ciprofloxacin and levofloxacin，with 8.33% and 4.17%，respectively.Ninety-six strains were all sensitive to carbapenem antibiotics and piperacillin/tazobactam.Fifty-seven strains（59.38%）of Salmonella typhimurium showed multidrug-resistance.Resistance genes were detected in all 57 multidrug-resistant Salmonella typhimurium strains,with higher carrier rates of 98.25%,77.19%,and 59.65% for aac(6')-Iaa,aadA22,and blaTEM-1B,respectively.The multidrug-resistant Salmonella typhimurium strains had the highest carrier rates for invA，sipA，sseL，and sopB.Conclusion:Multidrug-resistant Salmonella typhimurium strains have a high incidence and a high carrier rate for multiple drug resistance genes and virulence genes.The monitoring and prevention of Salmonella typhimurium should be strengthened in the clinic in order to reduce the spreading epidemic of multidrug-resistant strains.

Objective To explore the predictive value of serum cathepsin S(CTSS),progranulin(PGRN)and chemo-kine ligand 12(CXCL12)for acute exacerbation of chronic obstructive pulmonary disease(COPD).Methods A total of 202 patients with COPD who were admitted to the Tongling Municipal Hospital from January 2020 to February 2023 were selected as the research subjects.The patients were divided into an acute exacerbation group(n=64)and a non-acute exacerbation group(n=138)according to whether acute exacerbation occurred.Clinical data such as serum CTSS,PGRN and CXCL12 levels,age,gender,body mass index(BMI),disease course,smoking history,forced expiratory volume in one second/forced vital capacity ratio(FEV1％),and COPD assessment test(CAT)score in the stable period were collected.Univariate analysis was made to compare the differences in relevant indicators between the two groups,and multivariate logistic regression analysis was made to identify the independent risk factors for acute exacerbation in COPD patients.The Pearson correlation method was used to analyze the correlation between serum CTSS,PGRN,CXCL12 levels and FEV1％,CAT score.Relative risk analysis was used to evaluate the influence of different CTSS,PGRN and CXCL12 levels on acute exacerbation in COPD patients.The predictive efficacy of serum CTSS,PGRN and CXCL12 levels on acute exacerbation in COPD patients was evaluated by receiver operating characteristic(ROC)curve.Results Univariate analysis showed that there was no significant difference in age,sex,BMI and disease course of patients between the two groups(P＞0.05),while there were significant differences in the propor-tion of patients with smoking history,FEV1％,CAT score,and serum CTSS,PGRN and CXCL12 levels between the two groups(P＜0.05).Multivariate logistic regression analysis showed that elevated serum CTSS,PGRN and CXCL12 levels were risk factors for acute exacerbation in COPD patients(P＜0.05).There were significant differences in serum CTSS,PGRN and CXCL12 levels among patients with different FEV1％and CAT scores(P＜0.05).Pearson correlation analysis showed that serum CTSS,PGRN and CXCL12 levels were negatively correlated with FEV1％and positively correlated with CAT score(P＜0.05).Risk analysis showed that the risk of acute exacerbation in COPD patients with high serum CTSS,PGRN and CXCL12 levels was 2.089 times[95％confidence interval(CI):1.341-3.253],2.294 times(95％CI:1.363-3.862)and 2.359 times(95％CI:1.459-3.815)of the COPD patients with low serum CTSS,PGRN and CXCL12 levels.ROC analysis indica-ted that the area under the curve for predicting the risk of acute exacerbation in COPD patients based on serum CTSS,PGRN and CXCL12 levels alone was 0.780,0.811 and 0.755,respectively;the area under the curve for predicting the risk of acute exacerbation in COPD patients based on the combination of serum CTSS,PGRN and CXCL12 levels was 0.923.Conclusion Serum CTSS,PGRN and CXCL12 levels are risk factors for acute exacerbation of COPD.Abnormal elevation of serum CTSS,PGRN and CXCL12 levels can significantly increase the risk of acute exacerbation of COPD.The combination of serum CTSS,PGRN and CXCL12 levels is more effective in predicting the risk of acute exacerbation of COPD.

AIM:To investigate the anti-fibrotic effect of Panax notoginseng saponins(PNS)in arecoline(ANE)-induced oral submucous fibrosis,and to analyze the effect of PNS on nuclear factor E2-related factor 2(Nrf2)/glu-tamate-cysteine ligase catalytic subunit(GCLC)signaling pathway.METHODS:CCK-8 assay was used to evaluate the effects of different concentrations of PNS and arecoline on the survival rate of human immortalized keratinocyte cell line Ha-CaT.The results of CCK-8 were used to select 75 mg/L arecoline,and 25,50 and 100 mg/L PNS as subsequent experi-mental concentrations.The cells were set as blank control group,model group,and low,medium and high doses(25,50 and 100 mg/L)of PNS groups.The protein and mRNA expressions of collagen type I(COL-I),E-cadherin,Nrf2,GCLC and glutathione reductase(GR)in each group were detected by Western blot and RT-qPCR.Immunofluorescence method was used to detect the entry of Nrf2 into the nucleus.Biochemical kits were used to detect the content of glutathione(GSH),nicotinamide adenine dinucleotide phosphate(NADPH)and malondialdehyde(MDA),and superoxide dis-mutase(SOD)activity in each group of cells.DCFH-DA fluorescent probe was used to detect the content of intracellular reactive oxygen species(ROS).RESULTS:Compared with the blank control group,the protein and mRNA expression of COL-I in the model group was up-regulated,and the protein and mRNA levels of E-cadherin,Nrf2,GCLC,nuclear Nrf2 and GR were down-regulated.The content of NADPH,MDA and ROS in the cells increased,and the content of GSH and the activity of SOD was significantly reduced.Compared with the model group,the protein and mRNA expression of COL-I was down-regulated,and the protein and mRNA expression of E-cadherin,Nrf2,GCLC,nuclear Nrf2 and GR were up-regulated in PNS 50 and 100 mg/L groups.Compared with the model group,the content of NADPH,MDA and ROS in cells decreased,and the content of GSH and the activity of SOD was significantly enhanced(P<0.05 or P<0.01).CON-CLUSION:Panax notoginseng saponins have anti-fibrosis effects in HaCaT cells,and their mechanism may be related to the activation of Nrf2/GCLC signaling pathway,thereby resisting oxidative stress and improving oral submucosal fibrosis.

Both morbidity and mortality of gastric cancer are in the front rank among malignant tumors.At present,enhanced CT is served as an important imaging method for preoperative diagnosis and assessment of gastric cancer,but it is mostly based on morphological evaluation and unable to perform quantitative analysis.The functional imaging technology represented by energy spectral CT and CT perfusion imaging has a variety of quantitative parameters,which is expected to make up for the shortcomings of conventional CT.The review introduces the basic principles of energy spectral CT and CT perfusion imaging,and summarizes their applications in the diagnosis,pathological classification,grading,staging and efficacy prediction of gastric cancer,aiming to improve the understanding of functional CT imaging for the pretreatment assessment in gastric cancer.

Objective:To detect the expression levels of laboratory of genetics and physiology 2 (LGP2), retinoic acid inducible gene I (RIG-I) and melanoma differentiation associated gene 5 (MDA5) in children with hand, foot and mouth disease (HFMD), and to explore their possible clinical significance in HFMD.Methods:Fifty children with HFMD, who visited Second Affiliated Hospital of Xi′an Jiao Tong University, Xi ′an Children′s Hospital and Xi ′an Central Hospital from May 2020 to May 2021, were selected as the research subjects, and 20 children with physical examination at the same age during the same period were selected as the control group.Children with HFMD were divided into enterovirus 71 (EV-A71) type and coxsackievirus A6 (CV-A6) type according to the results of pathogen detection, and then divided into mild group and severe group according to the severity of the disease.The relative mRNA expression levels of LGP2, RIG-I and MDA5 in each group, and the correlation among the three proteins were compared and analyzed.Results:Among 50 cases of HFMD, 26 cases were EV-A71 type (16 cases were mild and 10 cases were severe) and 24 cases were CV-A6 type (17 cases were mild and 7 cases were severe). There was no significant difference in age and sex between HFMD group and control group ( P>0.05). The relative expression levels of LGP2 mRNA in EV-A71 and CV-A6 HFMD cases were 2.37(1.78, 3.25)% and 1.88 (1.35, 3.13)%, lower than that in control group [2.97(2.61, 3.55)%]. Only the difference between CV-A6 HFMD children and control group was statistically significant ( Z=-2.310, P=0.021). The relative expression levels of RIG-I mRNA in EV-A71 and CV-A6 HFMD cases were 9.95 (7.79, 14.62)% and 9.78(7.04, 15.83)%, lower than that in control group [18.47(13.00, 21.07)%]. The differences were all statistically significant ( P<0.05). The relative expression levels of MDA5 mRNA in EV-A71 and CV-A6 HFMD cases were 4.41(2.82, 5.99)% and 3.98 (2.18, 7.41)%, lower than that in control group [5.10(3.52, 7.71)%], but the differences were not statistically significant.There were no significant differences in the relative expression levels of the three indicators between the mild and severe groups of children with EV-A71 or CV-A6 HFMD.The expression levels of LGP2, RIG-I and MDA5 mRNA were highly correlated( P<0.001). Conclusion:The relative expression levels of LGP2, RIG-I and MDA5 mRNA in children with HFMD are decreased in different degrees than those in normal children.And there is a correlation among them.

Objective:To explore the incidence of secondary hemophagocytic lymphohistiocytosis (sHLH) in elderly patients with severe SARS-CoV-2 infection, and to analyze and summarize its clinical features and risk factors for early identification of high-risk groups.Methods:A retrospective cohort study was conducted. From January to May 2020, No. 960 Hospital of People's Liberation Army, the Second Hospital Affiliated to Cheeloo College of Medicine of Shandong Province, the First Rehabilitation Hospital of Shandong Province, the Public Health Clinical Center Affiliated to Shandong University, and Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine received 248 patients over 60 years old who were diagnosed with severe SARS-CoV-2 infection during their assistance to Hubei or support for diagnosis and treatment of SARS-CoV-2 infection in Shandong Province. The clinical data of patients were collected. According to the hemophagocytic lymphohistiocytosis diagnosis scoring (HScore) criteria, the patients were divided into sHLH group (HScore > 169) and non-sHLH group (HScore < 98). The demographic data, clinical features, laboratory results, the proportion of organ failure and 60-day mortality of patients were collected and compared between the two groups. The risk factors of sHLH and 60-day death were evaluated through binary multivariate Logistic regression analysis in elderly patients with severe SARS-CoV-2 infection. The receiver operator characteristic curve (ROC curve) was plotted to analyze the diagnostic value of indicators only or combined for sHLH.Results:Among 248 elderly patients with severe SARS-CoV-2 infection, 82 patients with incomplete data and untraceable clinical outcomes, and 35 patients with HScore of 98-169 were excluded. Finally, 131 patients were enrolled in the final follow-up and statistics, including 25 patients in the sHLH group and 106 patients in the non-sHLH group. Compared with the non-sHLH group, plasma albumin (ALB), hemoglobin (Hb), lymphocyte count (LYM), platelet count (PLT), fibrinogen (Fib) and prealbumin (PAB) in the sHLH group were significantly reduced, while alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), MB isoenzyme of creatine kinase (CK-MB), serum creatinine (SCr), C-reactive protein (CRP), D-dimer, ferritin (Fer), lactate dehydrogenase (LDH), procalcitonin (PCT), cardiac troponin I (cTnI), triglycerides (TG), interleukin-6 (IL-6), total bilirubin (TBil) were significantly higher. The fever and fatigue in the sHLH group were more severe than those in the non-sHLH group, and the patients in the sHLH group had higher rates of shock, acute kidney injury, liver dysfunction, and cardiac injury than the non-sHLH group. The 60-day mortality of patient in the sHLH group was significantly higher than that in the non-sHLH group [84.0% (21/25) vs. 40.6% (43/106), P < 0.01]. Binary multivariate Logistic regression analysis showed that high Fer [odds ratio ( OR) = 0.997, 95% confidence interval (95% CI) was 0.996-0.998], D-dimer ( OR = 0.960, 95% CI was 0.944-0.977), LDH ( OR = 0.998, 95% CI was 0.997-0.999) and TG ( OR = 0.706, 95% CI was 0.579-0.860) were independent risk factors for sHLH in elderly patients with severe SARS-CoV-2 infection (all P < 0.01), while elevated Fer ( OR = 1.001, 95% CI was 1.001-1.002), LDH ( OR = 1.004, 95% CI was 1.002-1.005) and D-dimer ( OR = 1.036, 95% CI was 1.018-1.055) were independent risk factors for 60-day death of patients (all P < 0.01). The death risk of the sHLH patients was 7.692 times higher than that of the non-sHLH patients ( OR = 7.692, 95% CI was 2.466-23.987, P = 0.000). ROC curve analysis showed that a three-composite-index composed of LDH, D-dimer and TG had good diagnostic value for sHLH in elderly patients with severe SARS-CoV-2 infection [area under the ROC curve (AUC) = 0.920, 95% CI was 0.866-0.973, P = 0.000]. Conclusions:Elderly patients with severe SARS-CoV-2 infection complicated by sHLH tend to be critically ill and have refractory status and worse prognosis. High Fer, LDH, D-dimer and TG are independent risk factors for sHLH, and are highly suggestive of poor outcome. The comprehensive index composed of LDH, D-dimer and TG has good diagnostic value, and can be used as an early screening tool for sHLH in elderly patients with severe SARS-CoV-2 infection.

Objective:To detect the expression level of vitamin D receptor(VDR) in children with hand, foot, and mouth disease(HFMD), and explore its potential value in the diagnosis and treatment of children with HFMD.Methods:A total of 82 children with HFMD hospitalized in the Second Affiliated Hospital of Xi′an Jiaotong University and Xi′an Children′s Hospital from May 2017 to May 2019 were selected as the case group.At the same time, 42 healthy children who underwent physical examination in the Child Health Department during the same period were randomly selected as the control group.Peripheral blood of two groups of children was extracted to detect and compare the expression levels of VDR mRNA in mononuclear cells, and the correlation between the expression level of VDR and HFMD and the correlation with various clinical characteristics were analyzed.Results:The relative expression of VDR in children with EV71 HFMD was 2.03%±0.38%, which was lower than that in children of control group(3.11%±1.29%), and the difference was statistically significant( t=-3.586, P=0.001). However, the relative expression of VDR in children with CA16 HFMD was 3.69%±1.79%, which was higher than that in children of control group, and the difference was not statistically significant( t=1.043, P=0.305). Among children with EV71 HFMD, the relative expression level of VDR was significantly different between the mild group and the severe group(2.18%±0.44% vs. 1.84%±0.17%, t=2.199, P= 0.041). There was no statistical difference regarding the relative expression level of VDR between mild and severe CA16 HFMD(4.16%±1.73% vs. 2.93%±1.73%, t=1.587, P=0.129). Conclusion:Compared with healthy children, the expression level of VDR is significantly lower in children with EV71 HFMD, and may be related to the severity of EV71 HFMD.

Objective:To investigate the association of single nucleotide polymorphisms(SNPs)in the vitamin D receptor(VDR)gene with influenza susceptibility and severity of disease in children.Methods:Peripheral venous blood was collected from 172 children with influenza A (study group) and 88 healthy children (healthy control group) admitted to Xi ′an Children′s Hospital and Xi ′an Central Hospital from February 2019 to February 2021.Serum 25-hydroxyvitamin D(25-OH-D) level was detected by using 25-OH-D kit.The study group was divided into three groups according to clinical syndrome: mild group, severe group, and critical group.Four candidate loci in the VDR gene(ApaI, TaqI, FokI, and BSMI)were selected, and polymorphisms in the VDR gene of each group were determined by polymerase chain reaction restriction fragment length polymorphism and analyzed in relation to children with influenza.Results:Compared with the healthy control group[(109.65±4.35) nmol/L], the serum 25-OH-D levels in the study groups were lower[(73.55±2.46)nmol/L in the mild group, (45.59±4.62) nmol/L in the severe group, and (33.65±3.87) nmol/L in the critical group]( P<0.05); Genotypes AA, Aa and allele A of the ApaI locus(51.74%, 22.67%, and 63.08%, respectively)and genotypes FF, Ff and allele F of the FokI locus(41.86%, 34.88%, and 59.30%, respectively)accounted for a significantly higher proportion of cases in the study group than those in healthy control group(11.36%, 14.77%, 18.75%, 10.23%, 13.64%, and 17.05%, respectively)( P<0.05). The proportion of allele A at the ApaI locus and genotypes AA and Aa in severe group(63.70%, 43.84%, and 28.76%) were significantly higher than those in mild group(47.37%, 35.09%, and 24.56%)( P<0.05); The proportion of allele A and genotype AA and at the ApaI locus in critical group(92.86%, 88.10%, and 49.52%) were significantly higher than those in severe group( P<0.05). Serum 25-OH-D<50 nmol/L( OR=5.087, 95% CI 3.114-5.648), ApaI site genotypes AA ( OR=4.011, 95% CI 1.217-18.624)and Aa( OR=3.839, 95% CI 2.483-1.456), FokI site genotypes FF( OR=4.112, 95% CI 3.215-20.775)and Ff( OR=4.591, 95% CI 0.032-10.936)were risk factors for the onset of influenza in children. Conclusion:Serum 25-OH-D deficiency is associated with childhood influenza, and VDR gene genotype AA and Aa of ApaI locus, and FokI site genotype FF, Ff may increase the risk of childhood influenza susceptibility, and allele A of ApaI locus and genotypes AA and Aa are associated with the severity of influenza.