Objective:To understand the clinical characteristics of children with SARS-CoV-2 Omicron infection imported from Hong Kong Special Administrative Region.Methods:This retrospective study was conducted to collect the data including clinical manifestations, outcomes and vaccination of 107 children with SARS-CoV-2 Omicron infection imported from Hong Kong Special Administrative Region to be admitted to the designated referral hospital in Shanghai from February to March 2022. According to the occurrence of clinical symptoms, the cases were divided into asymptomatic group and symptomatic group. According to the age of diagnosis, the cases were divided into <3 years group, 3-<6 years group and 6-<18 years group, and the clinical manifestations in different age group were analyzed with t-test and Mann-Whitney rank-sum test. Besides, to analyze the effectiveness of vaccination against SARS-CoV-2 Omicron infection in different age group, the cases aged 3-<18 years were also subdivided into unvaccinated group, 1-dose group and 2-dose group, and the relative risk ( RR) was used to demonstrate the effectiveness. Results:Among the 107 cases, 66 were male and 41 were female, with infection age of 10 (5, 14) years. There were 29 cases in the asymptomatic group, and 78 cases in the symptomatic group, and no significant difference in the age of infection was observed between the 2 groups (11 (6, 14) vs. 10 (5, 14) years, Z=0.49, P>0.05). And there were no severe cases in symptomatic group. The length of hospitalization was (18±6) days, and was longer in symptomatic group than that in asymptomatic group ((19±6) vs. (16±7) d, t=0.17, P=0.030). Eight-two cases (76.6%) had a history of epidemiological exposure and, among whom, 81 cases (75.7%) were associated with household transmission. Among symptomatic group, 57 cases (73.1%) had fever and 20 cases (25.6%) had cough. Of the 74 cases undergoing chest CT examination, 17 cases (23.0%) showed mild abnormalities. Of the 83 cases who received the lab tests, 23 cases (27.7%) had white blood cell counts<4×10 9/L, 3 cases (3.6%) had C-reaction protein >8.0 mg/L, and 6 cases (7.2%) had slightly elevated aspartate transaminase and alanine aminotransferase. Among the 92 children aged 3-<18 years, 31 cases were unvaccinated, 34 cases received 1 dose, and 27 cases received 2 doses. The interval between the last vaccination and infection was 2.2 (0.6, 6.0) months; the interval between the last vaccination and infection in the 2-dose group was longer than that in 1-dose group (6.0 (4.5, 7.3) vs. 0.7 (0.3,2.0) months, Z=3.59, P<0.001).The risk of symptomatic infection was reduced by 45% (RR=0.55, 95% CI 0.35-0.87) with two-dose vaccination compared to non-vaccination in cases aged 3-<18 years. All these cases recovered completely. Conclusions:Children infected with SARS-CoV-2 Omicron are usually mild or asymptomatic. Household transmission is the main pattern of infection with SARS-CoV-2 Omicron in children. Two-dose SARS-CoV-2 vaccination in children aged 3-<18 years can provide partial protection against disease caused by SARS-CoV-2 Omicron.

Objective: To explore the value of metagenomic next-generation sequencing (mNGS) in the etiology diagnosis of bacterial meningitis in children. Methods: The etiological results of 189 children diagnosed with "bacterial meningitis" or "purulent meningitis" or "central nervous system infection" in the Children's Hospital of Fudan University from 1st January 2019 to 31st December 2020 were analyzed retrospectively. The cerebrospinal fluid (CFS) of the children with bacterial meningitis was detected by culture and mNGS respectively, and the difference of pathogen detection rate between the 2 methods was analyzed. According to the age at the time of visit, the children were divided into neonatal group (≤28 days of age) and non-neonatal group (>28 days of age), and χ2 test was used to compare the positive rate between the 2 groups. Taking CFS culture as the gold standard, the sensitivity and specificity of mNGS in the diagnosing of bacterial meningitis in children were analyzed. Results: Among these 189 children with bacterial meningitis, 116 were males and 73 were females. A total of 76 strains of pathogens were detected in blood and (or) CSF cultures, of which 50 strains (65.8%) were Gram-positive bacteria; among those, 18 strains (23.7%) of Streptococcus agalactiae, 17 strains (19.7%) of Escherichia coli and 15 strains (19.7%) of Streptococcus pneumoniae were detected with higher detection rate. The infection rate of Gram-positive bacteria in the non-neonatal group was higher than that in the neonatal group (76.0% (38/50) vs. 50.0% (13/26), χ2=5.24, P=0.020).The same CSF samples of 48 cases were tested by mNGS and culture at the same time, and the detection rate of mNGS was higher than that of CSF culture (20 cases (41.7%) vs. 12 cases (25.0%), χ2=16.45, P<0.001). The consistency of mNGS and culture results was 79.2% (38/48), and the same pathogen was detected in 11 children with both positive mNGS and CSF culture. Taking the results of CSF culture as the gold standard, the sensitivity of mNGS in the diagnosing of bacterial meningitis was 91.7%, and the specificity was 75.0%. Conclusions: The mNGS technology can improve the pathogen detection rate of bacterial meningitis in children, and has a high consistency with CSF culture. In suspected cases where the pathogen cannot be identified by traditional methods, CSF mNGS should be considered timely.

Objective: To explore the etiologies and clinical characteristics of fever of unknown origin (FUO) and to provide clues for early diagnosis of FUO. Methods: The data about etiology, age, sex, clinical course, length of hospital stays and the expression levels of inflammatory factors in fever phase of 357 pediatric inpatients who were diagnosed with FUO in Children's Hospital of Fudan University from 1 January 2016 to 31 December 2020 were collected and retrospectively analyzed. Participants were grouped into infectious disease, inflammatory disease, malignancy and others and according to the classification of diseases and also grouped into those aged<1 year, 1-<3 years,3-<6 years, 6-<12 years and 12-<18 years. Comparisons between groups were performed using the Mann-Whitney U test, Kruskal-Wallis H test and χ² test. Results: Among the 357 patients (217 males and 140 females). The age of onset was 3.9 (1.3, 9.2) years and visiting age was 5.1 (2.0, 9.3) years. The time-consuming of diagnosis was 94 (66, 213) days. The hospital stay was 8 (6, 14) days. The most frequently identified cause of FUO was infectious diseases (163 cases, 45.7%), followed by non-infectious inflammatory diseases (133 cases, 37.2%), malignancy (21 cases, 5.9%) and others (40 cases, 11.2%). The patients at younger age were more likely to be attacked by malignancy, oncologic diagnoses, and others, nevertheless patients at older age were more likely to be attacked by non-infectious inflammatory diseases oppositely (9.8 (3.6, 11.5) vs. 3.0 (1.2, 7.0), 2.3 (1.0, 5.2), 0.9 (0.5, 1.8) years, U=41.30, 15.94, 37.08, all P<0.01);106 (65%) patients were male, and 57 (35%) patients were female. This result indicated that boys were more susceptible to infectious diseases (χ²=14.73, P<0.01). Analysis of inflammatory factors in serum among 103 patients, interleukin (IL)-6 level in 40 infectious diseases patients (9 (2, 38) ng/L) was significantly lower than those of 6 tumor patients (89 (64, 599) ng/L) and 57 non-infectious inflammatory diseases patients (25 (8, 78) ng/L, U=51.05, 15.70, both P<0.05), no significant difference was observed in IL-2, IL-4, IL-10, tumor necrosis factor α and interferon among the groups (all P>0.05). The patients grouped into those aged 1-<3 years and 3-<6 years were more likely to be attacked by infectious diseases (51.3% (59/115) and 57.1% (40/70)), while patients grouped into those aged 6-<12 years and 12-<18 years were more likely to be attacked by non-infectious inflammatory diseases (55.6% (65/117) and 72.4% (21/29)). Conclusions: Infectious disease is still the main cause of FUO in children and the boys are more susceptible to infectious diseases. However, the morbidity of non-infectious inflammatory diseases increases to number 1 in FUO of children over 6 years of age.

Objective: To investigate the diagnostic value of rapid antigen test based on colloidal gold immunochromatographic assay for the detection of SARS-CoV-2 infection in symptomatic patients. Methods: From May 20 to June 5 2022, 76 hospitalized children and their 55 accompanying family members with confirmed SARS-CoV-2 infection in the COVID-19 isolation unit of the Children's Hospital of Fudan University (designated referral hospital for SARS-CoV-2 infection in Shanghai) enrolled. Their nasopharyngeal swab specimens were consecutively collected. The samples were tested for SARS-CoV-2 nucleic acid by real-time quantitative. SARS-CoV-2 antigen was tested by immunochromatography. The correlation between the antigen detection results and the change of the cycle threshold (Ct) values were evaluated, as well as the sensitivity and specificity of SARS-CoV-2 antigen detection at different periods after the onset of the disease. Kappa consistency test was conducted to investigate the consistency between the 2 diagnostic methods. Results: Of the enrolled SARS-CoV-2 symptomatic infections, 76 were children, including 41 males and 35 females, with an age of 5 (2, 9) years; 55 were accompanying families, including 8 males and 47 females, with an age of 38 (32, 41) years. All 478 samples were simultaneously tested for SARS-CoV-2 antigen and nucleic acid. In any period from disease onset to negative conversion of viral nucleic acid, the overall sensitivity of the rapid antigen test was 48.2% (119/247), the specificity was 98.3% (227/231), and antigen test and nucleic acid test showed moderate consistency (κ=0.46, P<0.05). The sensitivity of antigen test was 100% (82/82) when the Ct value was ≤25. And the sensitivity of antigen test was 8/10, 4/15 and 8.3% (3/36) when the Ct value was 26, 30 and 35, respectively. All antigen tests were negative when Ct value was >35. During the period of 1-2 days, 3-5 days, 6-7 days, 8-10 days and >10 days after onset, the sensitivity and specificity of SARS-CoV-2 antigen test were 5/8 and 5/5, 90.2% (37/41) and 5/5, 88.9% (24/27) and 2/5, 45.0% (36/80) and 94.1% (32/34), 18.7% (17/91) and 98.9% (183/185) respectively. The Ct values of nasopharyngeal swabs were<26 during 2 to 7 days after onset, 28.7±5.0 on day 8, 34.5±2.9 on day 13 and > 35 after 14 days, respectively. Conclusion: SARS-CoV-2 antigen test in the patients with SARS-CoV-2 infection shows acceptable sensitivity and specificity within 7 days after onset of disease, and the sensitivity was positively correlated with viral load and negatively correlated with onset time.

Heterotaxy syndrome (HTX) is characterized by left-right (LR) asymmetry disturbances associated with severe heart malformations. However, the exact genetic cause of HTX pathogenesis remains unclear. The aim of this study was to investigate the pathogenic mechanism underlying heterotaxy syndrome. Targeted next-generation sequencing (NGS) was performed for twenty-two candidate genes correlated with LR axis development in sixty-six HTX patients from unrelated families. Variants were filtered from databases and predicted in silico using prediction programs. A total of twenty-one potential disease-causing variants were identified in seven genes. Next, we used Sanger sequencing to confirm the identified variants in the family pedigree and found a novel hemizygous mutation (c. 890G > T, p. C297F) in the ZIC3 gene in a male patient that was inherited from his mother, who was a carrier. The results of functional indicated that this ZIC3 mutation decreases transcriptional activity, affects the affinity of the GLI-binding site and results in aberrant cellular localization in transfected cells. Moreover, morpholino-knockdown experiments in zebrafish demonstrated that zic3 mutant mRNA failed to rescue the abnormal phenotype, suggesting a role for the novel ZIC3 mutation in heterotaxy syndrome.

Abnormal level of Cx43 expression could result in CHD. Epigenetic modification and disease-associated, non-coding SNPs might influence gene transcription and expression. Our study aimed to determine the role of histone modification and an rSNP (rs2071166) in the Cx43 promoter in patients with TOF. Our results indicate that H3K18ac bind to Cx43 promoter and that their levels are reduced in TOF patients relative to controls. The relationship between the non-coding SNP in the Cx43 gene and TOF patients was evaluated in 158 patients and 300 controls. The C allele of rs2071166 was confirmed to result in an increased risk of TOF (OR = 1.586, 95%CI 1.149–2.189). Individuals with the CC genotype at rs2071166 also showed a significant susceptibility to TOF (OR = 2.961, 95%CI 1.452–6.038). The mRNA level in TOF who were CC genotype was lower than that in patients with the AA/AC genotype. Functional analysis in cells and transgenic zebrafish models showed that rs2071166 decreased the activity of the promoter and could block the interaction between RXRα and RARE. This is the first study to illustrate that epigenetic modification and an rSNP in the Cx43 promoter region play a critical role in TOF by impacting the transcriptional activity and expression level of Cx43.

目的 通过改变组蛋白H3K27和S28位点整体修饰水平并检测心脏发育相关基因表达,初步探索位点修饰对基因表达的影响,阐明位点修饰在先天性心脏病(CHD)发病中的可能机制.方法 ①使用丁酸钠、姜黄素、佛波酯处理培养的C2C12细胞;Western Blot检测组蛋白H3K27乙酰化(H3K27ac)和H3S28磷酸化(H3S28ph)水平;实时荧光定量PCR检测心脏相关基因表达情况.②对培养细胞行丁酸钠和姜黄素浓度梯度处理,检测位点修饰及表达差异相关心脏基因表达.采用Pearson相关检验位点修饰与基因表达的关系.结果 ①丁酸钠处理后的C2C12细胞H3 K27 ac水平较对照组明显上调[(1.90±0.04)vs(1.09±0.01),P＜0.05],伴H3S28ph水平明显下调[(0.04±0.01)vs(0.73±0.01),P＜0.05)];姜黄素组H3 K27 ac水平(0.04±0.00)较对照组明显下调(P＜0.05),伴H3S28ph水平上调[(0.97 ±0.06)vs(0.73 ±0.01),P＜0.05)];佛波酯组H3S28ph(1.67 ±0.00)和H3 K27 ac水平(1.58±0.03)较对照组上调(P＜0.05).②丁酸钠与姜黄素浓度梯度处理后,H3K27ac、H3S28ph水平与给药浓度的指数有显著的相关性(R2分别为0.993和0.966).在检测的8个心脏相关基因中,药物处理后均产生了表达改变,差异有统计学意义(ANOVAP＜0.05);丁酸钠梯度处理的细胞cTnT、Cx43和Six1基因表达与H3 K27ac水平呈负相关(R2分别为0.709、0.713和0.651),与H3S28 ph水平呈正相关(R2分别为0.866、0.822和0.766).姜黄素梯度处理未有显著的相关性(R2＜0.5).结论 组蛋白H3K27和H3S28位点修饰状态的变化影响心脏发育相关基因的表达,可能是CHD的潜在发病机制.

OBJECTIVETo study the expression of histone acetyltransferases (HATs) and histone deacetylases (HDACs) in children with tetralogy of Fallot (TOF), and to investigate the role of histone acetylation and acetylation-related enzymes in the pathogenesis of TOF.METHODSMyocardial tissue samples in the TOF group were obtained from 46 children with TOF who underwent radical operation, and myocardial tissue samples in the control group were obtained from 16 children who suffered accidental deaths and had no cardiac anomalies as shown by autopsy. The acetylation of H3K9, H3K18 and H3K27 was evaluated by immunohistochemistry. The mRNA expression of HATs and HDACs in the myocardium was measured by real-time PCR. The correlation between mRNA expression of HATs and HDACs and histone acetylation was analyzed.RESULTSCompared with the control group, the TOF group showed significantly increased acetylation of H3K9 (P=0.0165) and significantly decreased acetylation of H3K18 (P=0.0048) and H3K27 (P=0.0084). As to 4 HATs and 6 HDACs, the mRNA expression of EP300 and CBP was significantly higher in the TOF group than in the control group (P=0.025; P=0.017), and there was no significant difference in the mRNA expression of other HATs and HDACs between the two groups. The correlation analysis revealed a positive correlation between H3K9 acetylation and mRNA expression of EP300 (r=0.71, P<0.01) and CBP (r=0.72, P<0.01).CONCLUSIONSUpregulated mRNA expression of EP300 and CBP may be associated with increased H3K9 acetylation, suggesting that EP300 and CBP might affect cardiac development by regulating H3K9 acetylation.

先天性心脏病是指心脏及大血管的结构异常,全世界的发病率为0.8％ ～1％,无明显地区及种族特异性,在先天畸形的发病中排首位,因其发病率高,后果严重,而受到人们的广泛重视.目前认为先天性心脏病是受环境和遗传共同作用的多基因疾病,但其发病机制及如何相互作用目前仍不清楚. 越来越多的研究发现,先天性心脏病患儿基因突变的发生率极低,仅能解释小部分先天性心脏病的发生,对于大部分的先天性心脏病来说并未出现致病性的基因改变.近期大量的研究发现"表观遗传"极有可能参与先天性心脏病的发病并起重要的作用[1].