DiGeorge(DGS)syndrome is an autosomal dominant disorder caused by 22q11.2 microdeletions,most patients developed the disease in childhood.22q11.2 deletion syndrome,and the mutation types are dominated by haploid deletion of this gene.We report a young patient with hypoparathyroidism(parathyroidism)induced by DGS syndrome combined with hypocalcemic heart failure.Genetic testing revealed pathogenic copy number variants associated with the clinical phenotype of the subject.About 2 674 kb of deletion variation was detected at q11.21 position on chromosome 22,which contained the TBX1 gene and was a pathogenic mutation.This paper discusses the clinical features,pathogenesis and current treatment of DGS,and emphasizes the importance of early screening,early diagnosis and treatment,and regular follow-up of heart failure,aiming to enhance the awareness of clinicians and geneticists on DGS syndrome.

Objective:To investigate the clinical characteristics of non-typhoidal Salmonella（NTS）enteritis in children and the drug resistance of NTS strains.Methods:The clinical data of 138 children who were hospitalized in Children's Hospital Affiliated to Xi'an Jiaotong University from 2022 to 2023 with diarrhea as the main complaint and NTS detected in stool culture were analyzed retrospectively, and the clinical characteristics and drug resistance were summarized.Results:Among 138 children with NTS enteritis，89 were males and 49 were females，with a male-to-female sex ratio of 1.81∶1 and an average age of 1.9（1.0,3.6）years，with a high incidence rate in June,July and August.Seventeen（12.31%）cases had a history of suspected unclean diet before illness.All the children had diarrhea symptoms with changes in fecal frequency and character，including 74 cases of pus and bloody stool，119 cases of mucus stool，and 70 cases of watery stool.One hundred and twenty-five（90.57%）cases had fever.Among 138 cases of fecal culture,there were 47 (34.05%) strains of Salmonella typhimurium,36(26.09%) strains of Salmonella enteritidis,and 55(39.85%) strains of other serotypes of Salmonella .One hundred and twenty-two（88.40%）NTS strains were resistant to more than one antimicrobial agent，and 29（21.01 %）were multi-drug resistant.The resistance rates to ampicillin，ampicillin/sulbactam，ceftriaxone，trimethoprim/sulfamethazole，ceftazidime，cefepime and piperacillin/tazobactam were 73.91%，71.01%，29.71%，29.71%，23.19%，11.59%，and 3.62%，respectively.All strains were sensitive to carbapenem antibiotics（meropenem，imipenem，and ertapenem）.The drug resistance rates of Salmonella typhimurium to ceftazidime and trimethoprim/sulfamethoxazole were higher than those of Salmonella enteritidis（38.30% vs 8.33%），the difference was statistically significant ( P < 0.05). Conclusion:Infants and young children are the high-incidence group of NTS enteritis，with the peak incidence period being from June to August each year，manifested by mucus-pus-blood stools, abdominal pain, vomiting，fever and other symptoms.Reasonable selection of antibiotics in time according to the local epidemic strains,changes of antimicrobial resistance and the results of drug sensitivity test of strains can effectively resist infection and reduce the production of drug-resistant beads.

DiGeorge(DGS)syndrome is an autosomal dominant disorder caused by 22q11.2 microdeletions,most patients developed the disease in childhood.22q11.2 deletion syndrome,and the mutation types are dominated by haploid deletion of this gene.We report a young patient with hypoparathyroidism(parathyroidism)induced by DGS syndrome combined with hypocalcemic heart failure.Genetic testing revealed pathogenic copy number variants associated with the clinical phenotype of the subject.About 2 674 kb of deletion variation was detected at q11.21 position on chromosome 22,which contained the TBX1 gene and was a pathogenic mutation.This paper discusses the clinical features,pathogenesis and current treatment of DGS,and emphasizes the importance of early screening,early diagnosis and treatment,and regular follow-up of heart failure,aiming to enhance the awareness of clinicians and geneticists on DGS syndrome.

Objective:To investigate the clinical characteristics of non-typhoidal Salmonella（NTS）enteritis in children and the drug resistance of NTS strains.Methods:The clinical data of 138 children who were hospitalized in Children's Hospital Affiliated to Xi'an Jiaotong University from 2022 to 2023 with diarrhea as the main complaint and NTS detected in stool culture were analyzed retrospectively, and the clinical characteristics and drug resistance were summarized.Results:Among 138 children with NTS enteritis，89 were males and 49 were females，with a male-to-female sex ratio of 1.81∶1 and an average age of 1.9（1.0,3.6）years，with a high incidence rate in June,July and August.Seventeen（12.31%）cases had a history of suspected unclean diet before illness.All the children had diarrhea symptoms with changes in fecal frequency and character，including 74 cases of pus and bloody stool，119 cases of mucus stool，and 70 cases of watery stool.One hundred and twenty-five（90.57%）cases had fever.Among 138 cases of fecal culture,there were 47 (34.05%) strains of Salmonella typhimurium,36(26.09%) strains of Salmonella enteritidis,and 55(39.85%) strains of other serotypes of Salmonella .One hundred and twenty-two（88.40%）NTS strains were resistant to more than one antimicrobial agent，and 29（21.01 %）were multi-drug resistant.The resistance rates to ampicillin，ampicillin/sulbactam，ceftriaxone，trimethoprim/sulfamethazole，ceftazidime，cefepime and piperacillin/tazobactam were 73.91%，71.01%，29.71%，29.71%，23.19%，11.59%，and 3.62%，respectively.All strains were sensitive to carbapenem antibiotics（meropenem，imipenem，and ertapenem）.The drug resistance rates of Salmonella typhimurium to ceftazidime and trimethoprim/sulfamethoxazole were higher than those of Salmonella enteritidis（38.30% vs 8.33%），the difference was statistically significant ( P < 0.05). Conclusion:Infants and young children are the high-incidence group of NTS enteritis，with the peak incidence period being from June to August each year，manifested by mucus-pus-blood stools, abdominal pain, vomiting，fever and other symptoms.Reasonable selection of antibiotics in time according to the local epidemic strains,changes of antimicrobial resistance and the results of drug sensitivity test of strains can effectively resist infection and reduce the production of drug-resistant beads.

Objective:To understand the epidemiological and clinical characteristics of children with severe and critical hemorrhagic fever with renal syndrome(HFRS), and to accumulate experience in the diagnosis and treatment of severe and critical HFRS in children.Methods:A retrospective analysis method was used to collect the clinical data of 49 children diagnosed with HFRS, who were admitted to the Department of Infectious Diseases, Children′s Hospital Affiliated to Xi′an Jiaotong University from January 2019 to December 2021 and classified as severe or critical group.The epidemiological data, characteristics, clinical manifestations, laboratory examinations, diagnosis and treatment outcomes of the children were analyzed.Results:Among the 49 children with severe HFRS, the ratio of male∶female was 3.45∶1(38∶11), the median age was 10 years and 8 months old, and the highest proportion was 6-12 years old.The peak incidence was in November and December(75.51%).Most of them lived in rural areas, with a total of 39 cases(79.59%).All patients had fever onset, gastrointestinal symptoms(vomiting, abdominal pain, diarrhea, 81.63%)and hyperemia of skin and mucous membranes(77.55%)were common, but typical headache, backache pain and orbital pain(three pains)only accounted for 15 cases(30.6%).Laboratory test results: the white blood cells in routine blood increased in 42 cases(85.71%), while the platelets decreased in 47 cases(95.91%).The procalcitonin was increased in 48 cases(97.95%).The alanine aminotransferase was elevated in 49 cases(100%), while the albumin of 38 cases(77.55%)were lower than 30 g/L.The urea nitrogen increased in 34 cases(69.38%), and the creatinine increased in 47 cases(95.91%).The creatine kinase isozyme was elevated in 41 cases(83.67%).Forty-nine children had different degrees of electrolyte imbalance, among which low sodium(91.83%)and low calcium(85.71%)were the most common.The urine protein was positive in 47 cases(95.91%), and the urine red blood cell was positive in 38 cases(77.55%).Ultrasonography of the urinary system revealed abnormalities in the kidneys and surrounding kidneys in 43 cases(91.48%).Twenty-eight(58.33%)patients had abnormal electrocardiogram.All the 49 patients were clinically cured.Conclusion:Severe HFRS is mainly in rural male children aged 6-12 years, mainly with fever and gastrointestinal symptoms, lack of typical three pain symptoms.When white blood cell count and procalcitonin significantly increased, platelet count significantly decreased, liver and kidney function impaired and electrolyte imbalance, severe cases should be highly suspected.Early identification of critically ill children and active treatment are critical to their prognosis.

Objective:To summarize the clinical characteristics, causes of misdiagnosis and preventive measures of infectious mononucleosis (IM) in children, and to improve the ability of clinicians in early diagnosis of IM in children.Methods:The clinical data of 468 children with IM in Xi′an Children′s Hospital from January 2018 to December 2021 were retrospectively analyzed, including general situation, disease onset, diagnosis and misdiagnosis.Results:Among the 468 children, 33 cases were clinically diagnosed and 435 cases were a definitely diagnosed; 281 males (60.04%) and 187 females (39.96%); the incidence rate was highest in preschool children (43.80%, 205/468) and in autumn (33.12%, 155/468). The first symptoms were fever (52.99%, 248/468), eyelid edema (15.38%,72/468) and neck mass (14.96%, 70/468). The fever rate was 90.38% (423/468), and the median time of first fever appearance was on the first (first, second) day of disease course, and the median duration of fever was 6 (4, 8) d. The median time of first visit was on the third (first, fifth) day of disease course, and the time of diagnosis was on the seventh (fifth, ninth) day of disease course. Blood routine examination showed that the proportion of white blood cell count increased was 51.92% (243/468), the proportion of lymphocytes increased was 61.75% (289/468), and the proportion of abnormal lymphocytes increased (≥10%) in peripheral blood was 58.97% (276/468). The lymphocyte subsets of 364 children were detected, the rate of helper T lymphocytes (Th cells) decreased was 80.22% (292/364), the rate of suppressor T lymphocytes (Ts cells) increased was 99.45% (362/364), the value and decreased rate of Th cells/Ts cells were 0.24 (0.16, 0.40) and 100.00% (364/364), rate of B lymphocytes decreased was 93.96% (342/364), rates of natural killer cells decreased and increased were 35.16% (128/364) and 0.55% (2/364). The misdiagnosis rate was 55.13% (258/468), and the misdiagnosis time was on the fifth (fourth, seventh) day of disease course. Among the 258 misdiagnosed children, 105 cases (40.70%) were misdiagnosed as upper respiratory tract infection, 65 cases (25.19%) as acute suppurative tonsillitis, 27 cases (10.47%) as acute cervical lymphadenitis or neck mass.Conclusions:Due to the complex and diverse clinical manifestations of IM in children, it is easy to be misdiagnosed in the early stage of the disease. So, it is necessary for clinicians to master the clinical characteristics of IM in children, constantly improve the level of diagnosis and treatment, and reduce the misdiagnosis rate.

Objective:To study the clinical and genetics features of two families with dentatorubral-pallido-luysian atrophy (DRPLA), and to summarize the correlation between genotypes and phenotypes.Methods:The peripheral blood, clinical data and auxiliary examination results of probands and related members in 2 families with hereditary epilepsy and ataxia were collected from July 2018 to March 2019 in Peking University First Hospital.By whole exome sequencing and detecting the cytosine-adenine-guanine (CAG) repeats with capillary electrophoresis and fragment analysis, the genetic testing was conducted on the probands and their family members.The clinical and genetic characteristics of all affected members in the 2 families were also analyzed.Results:Two families were diagnosed with DRPLA.All 11 patients presented with psychomotor retardation, and 7 of them had seizures (including myoclonus, focal seizures and generalized tonic-clonic seizures, etc.). There were significant differences in clinical manifestations among different patients in the same family, and the filial generation had seizures at an earlier age with a more severe phenotype than the parental generation.The youngest onset age was 2 years old, and the largest was 45 years old.Five cases had seizures in childhood.Of the 11 patients, 5 cases were deceased, and the cause of death included seizure attacks, sudden unexpected death in epilepsy (SUDEP) and disease progression.The number of CAG repeat times in the fifth exon of the ATN1 gene were found abnormal in 6 surviving patients.The grandfather of the proband in pedigree 2 had normal clinical manifestations, but he also showed abnormal CAG repeats in the fifth exon of the ATN1 gene, which might be an intermediate allele. Conclusions:DRPLA is mainly featured by epilepsy, ataxia, psychomotor retardation and anticipation in clinical.This disease is rare in children with seizures as the first symptom, and has poor prognosis.An early diagnosis can facilitate genetic counseling.

Objective:To explore the association between resting heart rate(RHR) and all-cause mortality among the Chinese oldest-old aged more than 80.Methods:Using a total of seven surveys or follow-ups data (1998, 2000, 2002, 2005, 2008, 2011 and 2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 17 886 elderly over 80 years old were selected as subjects, their resting heart rate were measured though baseline survey and the survival outcome and death time of the subjects were followed up. The subjects were divided into 6 groups according to their resting heart rate. Cox regression model was used to estimate the effect of resting heart rate on mortality risk. The interaction of age, gender and resting heart rate was also analyzed by likelihood ratio test.Results:The age of subjects M( P25, P75) was 92 (86, 100) years old, including 10 531 females (58.9%) and there were 13 598 participants died, the mortality rate was 195.5 per 1 000 person-years. Multivariate Cox regression analysis showed that compared to the control group (60-69 pbm/min), the hazard ratio of the elderly are 1.06 (95% CI: 1.02, 1.11), 1.09 (95% CI: 1.04, 1.15), 1.23 (95% CI: 1.14, 1.34), 1.25 (95% CI: 1.08, 1.44) in the group of RHR between 70-79, 80-89, 90-99 and ≥100 pbm/min and Pvalues are all less than 0.05. Likelihood ratio test showed that RHR and age had an interaction effect. ( P for interaction=0.011). Conclusion:The risk of all-cause death increased with the increase of resting heart rate and this relationship was stronger between the 80-89 years old people.

Objective:To analyze the sensitivity and specificity of SARS-CoV-2 nucleic acid testing in 20 348 close contacts of COVID-19 cases in different prevention and control stages in Guangzhou and to provide scientific evidence for optimizing epidemic response strategies.Methods:A total of 20 348 close contacts of COVID-19 cases in Guangzhou were traced between February 21 and September 22,2020. All the close contacts were tested for the nucleic acid of SARS-CoV-2. The sensitivity and specificity of nucleic acid testing and diagnosis in the different prevention and control stages were compared.Results:In 20 348 close contacts, 12 462 were males (61.24%), the median ( P 25, P 75) of age of them was 31.0 years (23.0,43.0), the median number ( P 25, P 75) of nucleic acid testing for them was 2.0 (1.0,3.0), and the median ( P 25, P 75) of their quarantine days was 12.0 (8.0,13.0) days, respectively. A total of 256 COVID-19 cases were confirmed in the close contacts after seven nucleic acid tests. In the 1 st, 2 nd, 3 rd and 7 th nucleic acid testing, the sensitivity and specificity were 69.14% and 99.99% (177 cases confirmed), 89.84% and 99.99% (230 cases confirmed), 97.27% and 99.99% (249 cases confirmed), and 100.00% and 99.98%, respectively. In the three stages of COVID-19 prevention and control in China: domestic case stage, imported case stage, and imported case associated local epidemic stage, the sensitivity of the 1 st nucleic acid testing was 70.68%, 68.00% and 67.35%, and the specificity was 99.98%, 100.00% and 100.00%, respectively. Conclusions:The sensitivity of nucleic acid testing in the close contacts at the different stages were consistent with slight decrease, which might be related to the increased proportion of asymptomatic infections in the late stage of epidemic prevention and control with COVID-19 in Guangzhou. It is suggested to give three nucleic acid tests to improve the sensitivity and reduce false negative risk.

Objective:To explore the association between resting heart rate(RHR) and all-cause mortality among the Chinese oldest-old aged more than 80.Methods:Using a total of seven surveys or follow-ups data (1998, 2000, 2002, 2005, 2008, 2011 and 2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 17 886 elderly over 80 years old were selected as subjects, their resting heart rate were measured though baseline survey and the survival outcome and death time of the subjects were followed up. The subjects were divided into 6 groups according to their resting heart rate. Cox regression model was used to estimate the effect of resting heart rate on mortality risk. The interaction of age, gender and resting heart rate was also analyzed by likelihood ratio test.Results:The age of subjects M( P25, P75) was 92 (86, 100) years old, including 10 531 females (58.9%) and there were 13 598 participants died, the mortality rate was 195.5 per 1 000 person-years. Multivariate Cox regression analysis showed that compared to the control group (60-69 pbm/min), the hazard ratio of the elderly are 1.06 (95% CI: 1.02, 1.11), 1.09 (95% CI: 1.04, 1.15), 1.23 (95% CI: 1.14, 1.34), 1.25 (95% CI: 1.08, 1.44) in the group of RHR between 70-79, 80-89, 90-99 and ≥100 pbm/min and Pvalues are all less than 0.05. Likelihood ratio test showed that RHR and age had an interaction effect. ( P for interaction=0.011). Conclusion:The risk of all-cause death increased with the increase of resting heart rate and this relationship was stronger between the 80-89 years old people.