Objective To introduce a practical method that can be used to efficiently express,purify and identify Alzheimer's disease (AD) related beta-site app-cleaving enzyme 1 (BACE1) in common eukaryotic cells.Methods BACE1 cDNA was fished out from human brain cDNA library and ligated into the pEGFP-c3 expression vector,and then,the recombinant plasmid was transfected into the HEK293 cells.The BACE1 protein was purified with TALON Mental Affinity Resins column.The target protein was identified by Western blotting and fluorescence resonance energy transfer (FRET).BACE1 Activity Assay Kit was employed to test the activity of purified BACE1 in vitro.The recombinant BACE1/pEGFP-c3 plasmid and amyloid precusor protein (APP)/pDsRed-Monomer-N1 plasmid were co-transfected to the HEK293 cells and the cleavage activity of BACE1 in the cells was identified by Western blotting.Results The sequencing data of the obtained BACE1 gene were identical with those in GenBank.Activity test showed that the fluorescent values of blank controls,expressed BACE1 and standard BACE1 were 55.013±3.597,1836.629±154.195 (n=3) and 2639.548±207.1901 (n=3),respectively;as compared with the control group,significant differences were noted in both of the two groups (F=78.681,P=0.000);however,there is no significant difference between expressed BACE1 and standard BACE1 groups (P＞0.05).Westem blotting showed the co-transfected BACE1 could cleave APP in HEK293 cells and the CTF-APP band was detectable.Conclusion A practical protocol is established for high expression,purification and identification of BACE1 in HEK293 cells,which is helpful to obtain BACE1,an important molecular target in AD research and treatment.

Objective To investigate the relationship between single nucleotide polymorphisms of interleukin 23 receptor (IL-23R) gene and Keshan disease (KD) in Northwest Chinese Han population.Methods A total of 285 Chinese Han subjects from Huangling,Shaanxi,including 79 KD patients (case group) and 206 control subjects (control group) were involved in this study.Genomic DNA was extracted from peripheral venous blood.The polymorphism of genetic variation was genotyped by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF).All sample groups were tested for Hardy-Weinberg equilibrium using goodness-of-fit x2 test.Differences in genotype distribution between two groups were compared by x2 test.Logistic regression analysis was applied to detect association using age as a confounding factor.Results The gene frequency distribution of IL-23R gene rs10889677 in case group and control group conformed to the Hardy-Weinberg equilibrium (x2 =0.254,P ＞ 0.05).Correlation analysis results:the difference of genotype frequency of IL-23R gene rs10889677 in case group (CC,CA,AA were 6.3％,36.7％,57.0％,respectively) and control group (CC,CA,AA were 5.3％,43.2％,51.5％,respectively) was not statistically significant (x2 =1.008,P ＞ 0.05).After age adjustment,there was no significant difference in genotype frequency of IL-23R gene rs10889677 (x2sdj =0.669,P ＞ 0.05) between two groups.Conclusion There is no correlation between IL-23R gene rs10889677 and KD in Northwest Chinese Han population.

Objective:To investigate Helicobactor pylori (H. pylori) infection status and interfamilial transmission pattern in Zhengzhou area. Methods:A cross-sectional study was conducted from September 2020 to march 2021, among 731 individual from 266 families randomly selected from 9 communities of Zhengzhou area. H. pylori infection status was determined by serum antibody tests, and 13C-urea breath test was performed in the previously eradicated population to clarify the current infection status. The individual and familial infection rate, infection status for couples and children and adolescent were analyzed. Results:Among 731 individuals from 266 families, 397 of them were H. pylori positive. The individual infection rate was 54.31% (397/731); among infected individuals 77.83% (307/397) were infected with type Ⅰ strain, 22.67% (90/397) were infected by type Ⅱ strain. Annual household income ( χ2=0.419, 0.410, 0.213, all P>0.05), smoking history (χ 2=0.071, P>0.05), drinking history ( χ2=0.071, P>0.05), dining place ( χ2=0.009, P>0.05), gastrointestinal symptoms ( χ2=0.047, P>0.05), family history of gastric disease ( χ2=0.069, P>0.05), and history of gastric cancer ( χ2=0.004, P>0.05) had no significant differences between H. pylori-positive and -negative groups, but the infection rate in individuals with higher education level was lower ( χ2=4.449, P<0.05). The infection rate was significantly higher in≥18 age groups compared with<18 age groups ( χ2=6.531, 23.362, 20.671, 24.244, 37.948, 14.597 and 5.170, all P<0.05). The familial H. pylori infection rate was 87.59% (233/266), and in 61 families all member were infected (26.18%, 61/233). The positive rate was 23.08% (6/26) in 50 families with children under 18 years when both parents were infected. Among 231 coupled families, both couples were infected in 78 families (33.76%), one couple was infected in 113 families (48.92%), and both couples were not infected in 40 (17.32%). With the increase of marriage time, the infection rate of both spouses increased significantly ( χ2=7.775, 12.662, 15.487, all P<0.05). Conclusions:The distribution of H. pylori infection presents a family cluster pattern, and intrafamilial infection is an important transmission rout of H. pylori. The type I strain of H. pylori is the dominate strain in this area.

Objective:To screen differential metabolites and metabolic pathways in urine of adult patients with Kashin-Beck disease (KBD), so as to provide scientific basis for finding specific biomarkers and pathogenesis of KBD.Methods:In Yongshou County, the KBD area in Shaanxi Province, adult KBD patients were selected as the case group, and healthy people without clinical symptoms of KBD were selected as the control group in the same disease area. The subjects' fasting mid-morning urine was collected, and liquid chromatography-mass spectrometry (LC-MS) technology was used to detect small-molecule metabolites in the urine. Multivariate statistical analysis [partial least square discriminant analysis (PLS-DA)] and comparison with KEGG and human metabonomics database (HMDB) were used to identify and screen differential metabolites and metabolic pathways in KBD patients.Results:A total of 58 subjects were included, 39 cases in the case group, including 23 males and 16 females; the age was (61.2 ± 7.8) years old; the body mass index was (22.7 ± 6.5) kg/m 2. There were 19 cases in the control group, including 10 males and 9 females; the age was (50.0 ± 9.0) years old; the body mass index was (24.3 ± 5.5) kg/m 2. Three first-order differential metabolites (HT-2 toxin, T-2 tetraol and seleno-adenosine selenomethionine) were identified and screened, which were highly related to the pathogenesis of KBD, and all were down-regulated. There were 38 second-order differential metabolites, among them, 10 were up-regulated and 28 were down-regulated. Nine differential metabolic pathways were screened, mainly involving amino acid metabolism, lipid metabolism and energy metabolism. Conclusions:The urine metabolism profiles of adult KBD patients and healthy people are significantly different, mainly involving amino acid metabolism, lipid metabolism and energy metabolism. The first-order differential metabolites HT-2 toxin, T-2 tetraol and seleno-adenosine selenomethionine are highly correlated with the pathogenesis of KBD.

Objective:To investigate the knowledge, attitudes, and practices (KAP) of pulse oximetry among pediatric healthcare providers in China and analyze the factor influencing the KAP.Methods:A self-developed questionnaire was used for an online research on the KAP of 11 849 pediatric healthcare providers from 31 provinces, autonomous regions, and municipalities of China from March 11 to 14, 2022.The factors influencing the KAP of pulse oximetry among pediatric healthcare providers were examined by Logistic regression. Results:The scores of KAP, of pulse oximetry were 5.57±0.96, 11.24±1.25 and 11.19±4.54, respectively.The corresponding scoring rates were 69.61%, 74.95%, and 55.99%, respectively. Logistic regression results showed that the gender and working years of pediatric healthcare providers, the region they were located, and whether their medical institution was equipped with pulse oximeters were the main factors affecting the knowledge score (all P<0.05). Main factors influencing the attitude score of pediatric healthcare providers included their knowledge score, gender, educational background, working years, region, medical institution level, and whether the medical institution was equipped with pulse oximeters (all P<0.05). For the practice score, the main influencing factors were the knowledge score, gender, age, and whether the medi-cal institution was equipped with pulse oximeters (all P<0.05). Conclusions:Chinese pediatric healthcare providers need to further improve their knowledge about and attitudes towards pulse oximetry.Pulse oximeters are evidently under-used.It is urgent to formulate policies or guidelines, strengthen education and training, improve knowledge and attitudes, equip more institutions with pulse oximeters, and popularize their application in medical institutions.