Objective: To analyze the current status of latent tuberculosis infection (LTBI) among freshmen in boarding middle schools in Longgang District, Shenzhen, so as to provide reference for formulating tuberculosis prevention and control strategies in the next stage. Methods: Data for tuberculosis health examination conducted among primary and secondary school students in Longgang District of Shenzhen in September 2022 to May 2023 were utilized to analyze the latent tuberculosis infection rate, and to explore the differences in latent tuberculosis infection rate among different grades, school nature, school categories and school levels. Results: The latent tuberculosis infection rate among freshmen in boarding secondary schools in Longgang District, Shenzhen in 2022 was 2.45%. The infection rate among full middle school (6.45%) and high school (3.37%) were higher than that in boarding junior high school (0.28%), nine year education school (0) and twelve year education school (1.00%) ( P <0.01). Moreover, the infection rate of high school freshmen (2.68%) was higher than that of bording junior high school (0.33%), and the rate of public schools (2.87%) and municipal schools (3.24%) were higher than those of private schools (1.78%) and distric-level schools (2.13%) respectively, with statistical significance observed for all differences( χ 2=43.58, 25.15, 22.69, P <0.01). Conclusions The latent tuberculosis infection rate among new boarding secondary students is relatively low in Longgang District of Shenzhen. However, the infection rate is higher in high school, public and municipal school. School should fully guarantee sports participation of students, enhance students awareness of tuberculosis through health knowledge lectures, and reduce the incidence of tuberculosis among students.

BACKGROUND:Bone marrow mesenchymal stem cells have been widely used to treat neurological diseases.However,due to limitations of the blood-brain barrier,low survival rate and differentiation rate of stem cells at damaged sites,the therapeutic effect is limited. OBJECTIVE:To investigate the effects of Shexiang Huangqi compound dripping pills on proliferation,migration and astrocyte differentiation of bone marrow mesenchymal stem cells. METHODS:Male SD rats were treated with Shexiang Huangqi compound dripping pills for 5 days after continuous gavage.Blood was collected from the abdominal aorta and serum was separated for later use.The effect of 5%,10%and 20%drug-containing serum on the proliferation of bone marrow mesenchymal stem cells was detected by CCK-8 assay.The effect of 10%drug-containing serum on lateral migration of bone marrow mesenchymal stem cells was observed by scratch test.Bone marrow mesenchymal stem cells were cultured in Transwell cells.The effects of 10%drug-containing serum on longitudinal migration of bone marrow mesenchymal stem cells were observed by crystal violet staining and DAPI nuclear staining.Differentiation of bone marrow mesenchymal stem cells into astrocytes was observed by inducing solution with 10%drug-containing serum or co-culture with astrocytes. RESULTS AND CONCLUSION:(1)10%and 20%drug-containing serum promoted cell proliferation more significantly on days 2 and 3,and there was no statistical difference between the two concentrations.(2)At 30 and 48 hours,bone marrow mesenchymal stem cell migration in 10%drug-containing serum group was significantly higher than that in the control group.(3)The number of bone marrow mesenchymal stem cells filtered through Transwell cells in 10%drug-containing serum group was higher than that in the control group.(4)10%drug-containing serum might promote the differentiation of bone marrow mesenchymal stem cells to astrocytes,but the differentiation effect was weak,and astrocytes might further promote the differentiation of bone marrow mesenchymal stem cells into astrocytes induced by drug-containing serum.(5)The results exhibited that the 10%drug-containing serum could promote the proliferation and migration of bone marrow mesenchymal stem cells in vitro.Co-culture with astrocytes may promote the differentiation of bone marrow mesenchymal stem cells towards astrocytes.

Objective To compare the association of the incidence and mortality of leukemia and the human development index(HDI)in different countries or regions in 2022,and the trend of leukemia incidence and mortality with age in countries with different HDI levels.Methods GLOBOCAN 2022 data related to leukemia incidence and mortality in different countries or regions worldwide and HDI were evaluated by Pearson correlation analysis and Kruskal-Wallis test.The incidence and mortality rates of each age and the age change trend were analyzed using the Joinpoint Regression model.Results Age-standardized incidence rate(ASIR),age-standardized mortality rate(ASMR),and mortality to incidence ratio(M/I)were statistically significantly different among the four groups of HDI countries(P<0.001).HDI was positively correlated with ASIR and ASMR and negatively correlated with M/I.Among all ages,ASIR and ASMR of leukemia of the four groups had similar trends with age,and the risk of leukemia was high at ages less than 15 and more than 40.The incidence of leukemia in all age groups in China differed from those in other countries with high HDI,while the mortality rate was lower than those in other countries with high HDI.Conclusion Countries or regions with higher HDI have higher ASIR and ASMR and lower M/I because of their better medical condition.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective To investigate the effects of glutathiones-transferase (GST) T1, GSTM1 and epoxide hydrolase (EPHX1) genes on skin injury in workers exposed to coal tar pitch. Methods Workers from a carbon manufacturing company involved in coal tar pitch production and use were selected as the study subjects using a judgment sampling method. Workers with skin injury after exposed to coal tar were selected as the case group (55 cases), and those with the same workshop and type of work but without skin abnormalities were selected as the control group (197 cases). Urine and blood samples were collected from the workers, and levels of polycyclic aromatic hydrocarbon metabolites, including 1-pyrenol (1-OH-P), 1-naphthol (1-OH-N) and 2-naphthol (2-OH-N), in urine were measured using ultra high-performance liquid chromatography tandem mass spectrometry. The GSTT1, GSTM1 and EPHX1 genes in blood were detected by polymerase chain reaction. Results In the case group, all 55 workers reported skin stinging, 25 workers reported itching and flaking, and 15 workers reported blackheads and pigmentation. Urinary levels of 1-OH-N and 2-OH-N were lower in the worker in the case group than that in the control group (all P<0.05). However, there was no significant difference in the level of 1-OH-P between the two groups (P>0.05). There were significant differences in the number of workers with GSTT1, GSTM1 and EPHX1(His139His) genes between the two groups (all P<0.01). The GSTT1 and GSTM1 genes were positively correlated with post-shift urinary levels of 1-OH-N, 1-OH-P, and 2-OH-N (all P<0.01). The EPHX1 (139Arg locus) gene was positively correlated with post-shift 2-OH-N levels (P=0.03). The GSTT1, GSTM1, and EPHX1 (139Arg locus) genes were associated with reduced skin damage among coal tar workers (all P<0.01), after controlling for age, length of service, gender, smoking, and alcohol consumption. Conclusion Exposure to coal tar pitch can cause skin injury in workers, and the GSTT1, GSTM1, and EPHX1 (139Arg locus) genes are protective factors against skin injury in those workers.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective To investigate the effects and underlying mechanisms of NaNO2 on oxidative damage in human bronchial epithelial cells pretreated with house dust mite(HDM).Methods Human bronchial epithelial cell line 16HBE were pretreated with HDM and then exposed to varying concentrations of NaNO2.Cell viability was assessed using CCK-8 assay to determine the optimal concentration and treatment duration of NaNO2.Then 16HBE cells were randomly divided into normal control group,HDM group(pretreated with HDM),and NaNO2 group(pretreated with HDM followed by NaNO2 exposure).The expression of Krüippel-like transcription factors 2(KLF2),hypoxia-inducible factor-1α(HIF-1α),and Notch1 at protein and mRNA levels in each group were measured by Western blotting and RT-PCR,respectively.The contents of the inflammatory cytokines IL-6 and TNF-α were assessed using ELISA.The production of reactive oxygen species(ROS)were measured using a fluorescence probe detection.The contents of malondialdehyde(MDA)and glutathione(GSH)were quantified by micro-methods.Results CCK-8 assay determined that the optimal intervention of NaNO2 was 500 μmol/L for 24 h.Compared with the normal control group,the HDM group showed reduced protein and mRNA expression of KLF2,but increased protein and mRNA(P＜0.01)expression of HIF-1α,and Notch1 at protein(P＜0.05)and mRNA levels,elevated production of ROS(P＜0.01),and increased contents of MDA,TNF-α,and IL-6,with a decrease in GSH content(P＜0.05).Compared with the HDM group,the NaNO2 group exhibited a significant reduction in KLF2 protein and mRNA levels,increases in HIF-1α protein and mRNA levels,Notch1 protein(P＜0.05)and mRNA levels,elevated ROS content(P＜0.01),and significantly increased contents of MDA,TNF-α(P＜0.001),and IL-6,with a notable decrease in GSH content(P＜0.05).Conclusion NaNO2 may exacerbate HDM-induced oxidative stress injury in human bronchial epithelial cells by regulating the expression of KLF2.

Objective To explore the effect of disposable electronic soft mirror and conventional repeatable soft mirror on the renal function and prostaglandin E2(PGE2),5-hydroxytryptamine(5-HT)levels in patients with upper ureteral calculi and analyze the factors influencing recurrence after retrograde intrarenal surgery(RIRS).Methods 114 patients with upper ureteral calculi from March 2022 to March 2023 were selected and randomly divided into two groups,with 57 cases forming the observation group and 57 cases forming the control group.The observation group was administrated with RIRS via disposable electronic soft mirror,while the control group accepted RIRS via conventional repeatable soft mirror.The two groups were compared in the aspect of surgical data.Patients'serum renal function indicators[blood urea nitrogen(BUN),creatinine(Cr),cystatin C(CysC)],PGE2 and 5-HT levels were tested preoperative and postoperative 24 h.Postoperative complications and recurrence were compared between the two groups after 6 months follow-up.The patients were grouped according to whether there was recurrence or not.The medical records of recurrence group and non-recurrence group were collected,and the risk factors of recurrence were analyzed statistically.Results There was no sxtatistically significant difference between the observation group and the control group in terms of surgical time,intraoperative bleeding,one-time stone removal rate,and hospital stay(P>0.05).After operation both groups saw much higher levels of BUN,Cr,CysC,PGE2 and 5-HT than they did before the operation(P<0.05),but no significant difference in the aforementioned indicators was seen between the two groups either before or after the operation(P>0.05).The incidence of complications and recurrence rate of the observation group were 3.51%and 15.79%respectively,seeing no big difference from 12.28%and 21.05%of the control group(P>0.05).The body mass index(BMI),postoperative residual calculi and urinary tract infections in the recurrence team were remarkably higher than those in the non recurrence team(P<0.05).The results of multivariate Logistic regression analysis showed that after adjusting for confounding factors such as gender,age,course of disease,maximum diameter of calculi,number of calculi,location of calculi,and surgical method,postoperative residual calculi and postoperative urinary tract infections were independent risk factors for postoperative recurrence of upper ureteral calculi after RIRS(P<0.05).Conclusion Both disposable electronic soft endoscopy and conventional repeatable soft endoscopy can achieve satisfactory results in the treatment of upper ureteral calculi,both can impact the renal function and serum PGE2,5-HT levels in patients to a certain extent,and both present a risk of recurrence after surgery.Residual postoperative calculi and postoperative urinary tract infections are independent risk factors inducing recurrence of upper ureteral calculi after RIRS.

Objective To construct a predictive model for septic shock based on the propensity score matching (PSM) method and validate its effectiveness. Methods A total of 114 patients with sepsis were enrolled as study objects, and were divided into septic shock group (40 patients) and sepsis group (74 patients) according to whether they developed septic shock. PSM was performed with a ratio of septic shock to sepsis of 1∶2, resulting in the inclusion of 30 patients in the septic shock group and 60 patients in the sepsis group after matching. The levels of C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), serum amyloid A (SAA), soluble endothelial protein C receptor (sEPCR), endothelial cell-specific molecule 1 (ESM-1), clusterin (CLU), and the Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score and Sequential Organ Failure Assessment (SOFA) score at admission were compared between the two groups. Cox proportional hazards regression analysis was used to identify the factors influencing septic shock, and a predictive model for septic shock was constructed and internally validated using the receiver operating characteristic (ROC) curve. Kaplan-Meier survival curves were plotted to analyze the differences in survival prognosis among patients with different expression levels of the indicators. Results After matching, there were no statistically significant differences in general information between the two groups (P>0.05). At admission, the septic shock group had higher levels of serum PCT, CRP, SAA, IL-6, sEPCR, ESM-1, and higher APACHE Ⅱ and SOFA scores, as well as a lower level of serum CLU compared with the sepsis group (P < 0.05). Cox regression analysis showed that PCT, CRP, SAA, IL-6, sEPCR, ESM-1, APACHE Ⅱ score, and SOFA score were independent risk factors for septic shock (P < 0.05), while CLU was an independent protective factor (P < 0.05). The predictive model for septic shock, constructed based on these factors, showed an internal validation accuracy of 94.44%, an area under the curve of 0.950, a sensitivity of 93.33%, and a specificity of 96.67%. Dead patients had higher levels of PCT, CRP, SAA, IL-6, sEPCR, ESM-1, and higher APACHE Ⅱ and SOFA scores, as well as a lower level of CLU at admission compared with survivors (P < 0.05). Compared with patients with low expression levels or low scores, patients with high expression levels of PCT, CRP, SAA, IL-6, sEPCR, ESM-1, and high APACHE Ⅱ and SOFA scores had higher fatality rates, while patients with high CLU expression levels had a lower fatality rate (P < 0.05). Conclusion The serum biomarkers including PCT, CRP, SAA, IL-6, sEPCR, ESM-1, CLU, and the APACHE Ⅱ and SOFA scores in sepsis patients are closely related to the occurrence of septic shock and survival prognosis. The predictive model constructed by combining these indicators can accurately predict the occurrence of septic shock.

Statistics plays an important role in medical research， and the selection of appropriate statistical methods is crucial for drawing reliable and valuable conclusions. This paper provides a brief introduction to commonly used statistical analysis methods for medical data， covering descriptive analysis， parametric test， nonparametric test， correlation analysis， regression analysis， and analysis of survival data. It focuses on discussing the assumptions of multiple linear regression， logistic regression and Cox proportional risk regression， as well as how to choose the appropriate statistical methods for analyzing and interpreting medical data based on different research objectives and data types.