OBJECTIVE: CRISPR-Cas protects bacteria from exogenous DNA invasion and is associated with bacterial biofilm formation and pathogenicity. METHODS: We analyzed the type I-F CRISPR-Cas system of Legionella pneumophila WX48, including Cas1, Cas2-Cas3, Csy1, Csy2, Csy3, and Cas6f, along with downstream CRISPR arrays. We explored the effects of the CRISPR-Cas system on the in vitro growth, biofilm-forming ability, and pathogenicity of L. pneumophila through constructing gene deletion mutants. RESULTS: The type I-F CRISPR-Cas system did not affect the in vitro growth of wild-type or mutant strains. The biofilm formation and intracellular proliferation of the mutant strains were weaker than those of the wild type owing to the regulation of type IV pili and Dot/Icm type IV secretion systems. In particular, Cas6f deletion strongly inhibited these processes. CONCLUSION The type I-F CRISPR-Cas system may reduce biofilm formation and intracellular proliferation in L. pneumophila.
Legionella pneumophila/pathogenicity* ; CRISPR-Cas Systems ; Biofilms/growth & development* ; Phenotype ; Bacterial Proteins/metabolism* ; Gene Deletion

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the differences in visual perception between children with autism spectrum disorder(ASD)and typically developing(TD)children when watching different intention videos,and to explore the feasibility of machine learning algorithms in objectively distinguishing between ASD children and TD children.Methods A total of 58 children with ASD and 50 TD children were enrolled and were asked to watch the videos containing joint intention and non-joint intention,and the gaze duration and frequency in different areas of interest were used as original indicators to construct classifier-based models.The models were evaluated in terms of the indicators such as accuracy,sensitivity,and specificity.Results When using eight common classifiers,including support vector machine,linear discriminant analysis,decision tree,random forest,and K-nearest neighbors(with K values of 1,3,5,and 7),based on the original feature indicators,the highest classification accuracy achieved was 81.90% .A feature reconstruction approach with a decision tree classifier was used to further improve the accuracy of classification,and then the model showed the accuracy of 91.43% ,the specificity of 89.80% ,and the sensitivity of 92.86% ,with an area under the receiver operating characteristic curve of 0.909(P<0.001).Conclusions The machine learning model based on eye-tracking data can accurately distinguish ASD children from TD children,which provides a scientific basis for developing rapid and objective ASD screening tools.[Chinese Journal of Contemporary Pediatrics,2024,26(2):151-157]

ObjectiveTo observe the effects of Sargassum and Glycyrrhizae Radix et Rhizoma incompatible pair with the Haizao Yuhutang （HYT） on oxidative stress in the liver of goiter rats under the condition of 2 times the dose limit of the Pharmacopoeia of the People's Republic of China 2020. MethodA total of 128 male Wistar rats were randomly divided into a blank group， a model group， a euthyrox group （20 μg·kg^-1）， a HYT group （12.06 g·kg^-1）， a HYT without Sargassum （HYT-H） group （9.90 g·kg^-1）， a HYT without Glycyrrhizae Radix et Rhizoma （HYT-G） group （10.26 g·kg^-1）， a HYT without Sargassum and Glycyrrhizae Radix et Rhizoma （HYT-HG） group （8.10 g·kg^-1）， and a Sargassum and Glycyrrhizae Radix et Rhizoma （HG） group （3.96 g·kg^-1）. The blank group was given deionized water by gavage， and the others were given propylthiouracil （PTU） to replicate the goiter pathological model. Euthyrox was taken as a positive control drug， and the rest of the Chinese medicine groups were given the corresponding decoction by gavage， the material was collected 12 hours after the last dose. The serum levels of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， alkaline phosphatase （ALP）， and the contents of superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px）， malondialdehyde （MDA）， reactive oxygen species （ROS） in liver tissue were detected in each group. The pathological changes in the liver were observed via hematoxylin-eosin （HE） staining. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was utilized to detect the mRNA expressions of Kelch-like Ech-associated protein 1 （Keap1）， nuclear factor E₂-related factor 2 （Nrf2）， heme oxygenase-1 （HO-1）， p53 and Caspase-3 in liver tissues. Western blot was adopted to detect the protein expressions of Nrf2 and HO-1 in liver tissues in oxidative stress-related signaling pathways. ResultCompared with control group， the model group showed significantly increased serum ALT level and contents of MDA and ROS in liver tissues （P<0.05， P<0.01）， significantly reduced activities of SOD and GSH-Px in the liver （P<0.01）， significantly increased mRNA expression of Keap1 （P<0.01）， and significantly decreased mRNA and protein expressions of Nrf2 and HO-1 （P<0.05， P<0.01）. Compared with the model group， the HYT group manifested significantly reduced serum levels of AST， ALT， and ALP （P<0.05， P<0.01）， significantly reduced contents of MDA and ROS in liver tissue （P<0.01）， significantly increased the activities of SOD and GSH-Px （P<0.01）， significantly decreased mRNA expressions of Keap1， p53， and Caspase-3 （P<0.01）， and significantly increased mRNA and protein expressions of Nrf2 and HO-1 （P<0.05， P<0.01）. ConclusionUnder the condition of 2 times the dose limit of the Pharmacopoeia of the People's Republic of China 2020， Sargassum and Glycyrrhizae Radix et Rhizoma incompatible pair with the HYT on oxidative stress in the liver of goiter rats had different effects. The HYT that contains Sargassum and Glycyrrhizae Radix et Rhizoma has a protective effect on the liver of goiter rats， and the effect is better than that of the HG group， the euthyrox group， and the incomplete groups. Its mechanism may be related to activating the Nrf2/HO-1 signaling pathway to alleviate liver oxidative stress and inhibiting the p53/Caspase-3 signaling pathway to reduce hepatocyte apoptosis.

Objective To investigate the influences of Lycium barbarum polysaccharide on apoptosis of corneal epithelial cells induced by hypertonicity through regulating adenosine monophosphate activated protein kinase(AMPK)/uncoordinated 51-like kinase 1(ULK1)autophagy pathway.Methods The ophthalmoxerosis cell model was established by osmotic pressure of 500 mOsm·L-1 on corneal epithelial cells.They were divided into model group,positive control group(0.3％sodium hyaluronate eye drops),inhibitor group(1 mg·mL-1 Lycium barbarum polysaccharide+10 μmol·L-1compound C),experimental-L,-H groups(0.5,1.0 mg·mL 1 Lycium barbarum polysaccharide),and normal cultured CRL-11135 cells were taken as blank group(no treatment was performed).Cell apoptosis was detected by flow cytometry.Autophagy was detected by MDC staining.Western blot was used to detect the expressions of p-AMPK/AMPK and p-ULK1/ULK1.Results The apoptosis rates of experimental-L,experimental-H,positive control,inhibitor,model and blank groups were(26.47±2.13)％,(13.68±2.21)％,(12.54±2.16)％,(18.73±2.12)％,(37.56±3.25)％and(6.35±2.14)％;the relative contents of autophagosomes were(59.63±8.14)％,(89.89±9.04)％,(90.31±9.13)％,(62.75±7.26)％,(43.11±6.45)％and(100.00±0.00)％;p-AMPK/AMPK were 0.45±0.07,0.64±0.08,0.66±0.06,0.53±0.04,0.34±0.05 and 0.87±0.06;p-ULKl/ULKl were 0.54±0.06,0.75±0.05,0.77±0.03,0.65±0.04,0.46±0.04 and 0.92±0.08,respectively.The above indexes in experimental-L,-H groups and positive control group were significantly different from those in model group(all P＜0.05);the above indexes in inhibitor group were significantly different from those in experimental-H group(all P＜0.05).Conclusion Lycium barbarum polysaccharide can inhibit the apoptosis of corneal epithelial cells induced by hypertonicity by activating the AMPK/ULK1 autophagy pathway.

Animals ; SARS-CoV-2 ; Antibodies, Neutralizing ; Macaca mulatta ; COVID-19/prevention & control* ; Antibodies, Viral ; Vaccines

Objective To explore the overall level,distribution characteristics,and differences in household fine particulate matter (PM_2.5) pollution caused by fuel burning in urban and rural areas in China. Methods The relevant articles published from 1991 to 2021 were retrieved and included in this study.The data including the average concentration of household PM_2.5 and urban and rural areas were extracted,and the stoves and fuel types were reclassified.The average concentration of PM_2.5 in different areas was calculated and analyzed by nonparametric test. Results The average household PM_2.5 concentration in China was (178.81±249.91) μg/m³.The mean household PM_2.5 concentration was higher in rural areas than in urban areas[(206.08±279.40) μg/m³ vs. (110.63±131.16) μg/m³;Z=-5.45,P<0.001] and higher in northern areas than in southern areas[(224.27±301.66) μg/m³ vs.(130.11±140.61) μg/m³;Z=-2.38,P=0.017].The north-south difference in household PM_2.5 concentration was more significant in rural areas than in urban areas[(324.19±367.94) μg/m³ vs.(141.20±151.05) μg/m³,χ²=-5.06,P<0.001].The PM_2.5 pollution level showed differences between urban and rural households using different fuel types (χ²=92.85,P<0.001),stove types (χ²=74.42,P<0.001),and whether they were heating (Z=-4.43,P<0.001).Specifically,rural households mainly used solid fuels (manure,charcoal,coal) and traditional or improved stoves,while urban households mainly used clean fuels (gas) and clean stoves.The PM_2.5 concentrations in heated households were higher than those in non-heated households in both rural and urban areas (Z=-4.43,P<0.001). Conclusions The household PM_2.5 pollution caused by fuel combustion in China remains a high level.The PM_2.5 concentration shows a significant difference between urban and rural households,and the PM_2.5 pollution is more serious in rural households.The difference in the household PM_2.5 concentration between urban and rural areas is more significant in northern China.PM_2.5 pollution in the households using solid fuel,traditional stoves,and heating is serious,and thus targeted measures should be taken to control PM_2.5 pollution in these households.
Humans ; Particulate Matter/analysis* ; Air Pollution, Indoor/analysis* ; Cooking ; Environmental Exposure/analysis* ; China ; Rural Population

【Objective】 To compare the effectiveness of the old mode of blood isolation and batch release (the old mode) and the new mode in Chengdu, so as to provide basis for optimizing working strategy. 【Methods】 1) The blood testing report was released one by one in the old mode but released uniformly in accordance with the blood batches classified by blood storage and supply department in the new mode. 2) In the old mode, apheresis platelet samples were detected by serological testing first and nucleic acid testing(NAT) later, and whole blood samples were reasonably arranged according to blood inventory and detection workload. In the new mode, platelets samples collected within our center headquarters were detected by serological test and NAT simultaneously, while those collected outside the center complied with the old strategy. As for whole blood, the same batch samples classified by blood storage and supply department should be arranged to the detection line with the fewest samples.3) The turnaround time(TAT) in the laboratory (referred to as sample TAT) and the TAT in the blood to-detect stock (referred to as blood TAT) in two phases(year 2016 vs 2018, pre- and post- the new mode), involving 164 748 and 179 488 blood samples, were compared by SPSS25.0 software. The constituent ratio of the TATs were compared with Chi-square test, and the difference of blood TAT between old and new mode were compared with Mann-Whitney U test. 【Results】 1) Significant difference was noticed in constituent ratio of TATs between old and new mode (P<0.05). 2)The blood TATof apheresis platelets using the new mode was 0.95(QR: 0.22)days, with the median 0.20 days shorter than that the old mode.. The blood TAT of whole blood in the new mode was 3.77 (QR: 1.99) days, with the median 0.90 days shorter than that in the old mode, and the difference was statistically significant (P<0.05). 【Conclusion】 Compared with the old mode, the new mode showed the following advantages: 1) It can realize the unified issuing of testing reports of blood with the same batch, contribute to the early discovery of errors that occurred during blood donation process, and located the errors wihin intra-batches for investigation. 2) It can advance the issuing of blood testing reports of the same batch. 3) It can make the flow of samples and blood with the same batch between different departments more standardized and orderly, and optimize the process of blood sorting thus shortening blood TAT. 4) It can realize the counting and checking of samples, within the same batch, at different states, so as to minimize the error issuing of unqualified blood and to-detect blood, and is more conducive to ensure the quality, safety and timely supply of blood.

Extracellular vesicles (EVs) with a variety of bioactive molecules can be continuously secreted during the storage of blood components, which can promote cell-cell interaction and mediate cell-to-cell signal transmission. EVs are widely involved in inflammation, metabolism and immunization. In recent years, studies have reported that EVs in the blood components can not only cause transfusion-related lung injury through activating neutrophils, but also act on monocytes to stimulate inflammatory response. EVs can play different regulatory effects on the immune system of patients. In this review, the role and mechanism in transfusion-related immunomodulation (TRIM) of EVs in different blood components have been summarized.

Objective: To investigate the clinicopathological characteristics of reactive epithelial hyperplasia and dysplasia in the stomach, as well as the clinical value of mucin special staining and proliferating cell nuclear antigen (Ki-67) in distinguishing the two gastric lesions. Methods: The clinical pathological data of 63 patients with gastric reactive epithelial hyperplasia, 54 patients with low-grade dysplasia, and 63 patients with high-grade dysplasia diagnosed from May 2018 to May 2021 in Beijing Chaoyang Hospital, Capital Medical University, Beijing, China were analyzed. Alcian blue periodic acid Schiff (AB-PAS) and Ki-67 staining were performed to examine the mucin staining pattern, number of Ki-67 positive cells, Ki-67 staining patterns in the three groups of lesions, and histopathologic characteristics. Results: The positive rates of AB-PAS in the reactive epithelial hyperplasia and gastric dysplasia groups were 87.3%(55/63) and 10.3%(12/117), respectively. The expression of AB-PAS in the reactive epithelial hyperplasia was gradually increased from the base to the surface of the epithelium. In low-grade dysplasia and high-grade dysplasia, there was no mucin present in the dysplasia epithelium. The difference between the two groups was statistically significant (P<0.01). The positive rate of Ki-67 in the epithelial reactive hyperplasia (>10%) was 81.0% (51/63), and the positive cells were mainly located in the neck and middle parts of the mucosal glands (58/63, 92.1%). In the low-grade dysplasia group, the positive rate of Ki-67 (>10%) was 90.7%(49/54); the positive cells were mainly located in the upper mucosa (33/54, 61.1%), showing a banded distribution pattern; in the high-grade dysplasia group, the positive rate (>10%) was 95.2%(60/63), and the positive cells were mainly located in the whole mucosa (49/63, 77.8%), showing a diffuse/diffuse scattered distribution pattern. The three groups had statistically different rates and distribution patterns of Ki-67 expression (P<0.01). Conclusion: The gastric epithelial reactive hyperplasia and dysplasia can be differentiated using clinicopathological features, AB-PAS staining and Ki-67 expression pattern.
Alcian Blue ; Humans ; Hyperplasia ; Ki-67 Antigen/metabolism* ; Periodic Acid ; Staining and Labeling ; Stomach Neoplasms/diagnosis*