Objective:To investigate the clinical features, gene mutation and follow-up outcome of children with paroxysmal kinesigenic dyskinesia(PKD).Methods:Clinical data was collected at Beijing Tiantan Hospital Affiliated to Capital Medical University from November 2018 to November 2019.In total, seven children with PKD were recruited, and peripheral blood samples for gene study were collected from six patients and their parents.Mutation analysis of PRRT2 gene was performed by PCR sequencing in children and by Sanger sequencing in patients.Results:Of the seven patients, four were male and three were female, and the median age of onset was 11 years and 6 months, ranging from 5 to 14 years.Among them, two patients were family cases and the other five patients were sporadic cases.The presentation were abnormal involuntary movements provoked by sudden movements, without loss of consciousness.Five patients exhibited dystonia and two patients had dystonia and choreoathetosis.The duration of the attacks lasted for a few seconds to 40 seconds.The frequency ranged from 5 to 15 times per day.PRRT2 mutations, c.649_650insC(P.R217PfsX8), were found in two patients with PKD families and three sporadic PKD cases.Conclusion:The onset age of PKD is pre-school or school age.The attacks manifest as dystonia or mixed with dystonia and choreoathetosis.PRRT2 is the main pathogenic gene of PKD and mutation c. 649_650insC is the hotspot mutation.Low-dose Carbamazepine has good effects.

Innovative Experiment Competition of Preventive Medicine is a significant constitution of Guangdong Undergraduate Technique Competition of Preventive Medicine. Without the constriction of majors, students participate in group with 3 people, design their own experiments around the hot spots and practical problems in public health area and are awarded according to the grades of the experiment design and thesis defence. The most topics in the first and the second competitions are about environmental hygiene and occupational hygiene, and the infectious diseases are attracting increasing attention. More and more topics combine the method of experiment with investigation. Some tactics are also suggested that innovation, view of general population, autonomy and investigation should be included in topic selection for this contest.

OBJECTIVETo investigate the origin and the recombinant model of H7N9 virus prevailing in China by sequence analysis.

METHODSThe sequences of H7N9 virus were collected and analyzed with the software BLAST and MEGA 5.0. The phylogenetic trees were constructed after multiple sequences alignment. The homologous sequences of H7N9 segments were determined and the model was inferred according to the origin of H7N9 segments.

RESULTSThe most relevant sequences of HA, NA, NS and PB2 segments were located at one branch of the phylogenetic tree, while the closest relevant sequences of PB1, PA, NP and MP contained two H9N2 virus origins. According to the analysis of sequence origin, H7N9 viruses might be divided into 5 genotypes: namely A, B, A/Shanghai/1/2013-H7N9, A/Pigeon/Shanghai/S1069-H7N9 and A/Zhejiang/HZ1/2013-H7N9, and the genotype A consisted of A1 and A2 subtypes.

CONCLUSIONThe prevailing H7N9 virus might be derived from 5 different viruses after 4 times of recombination, which resulted in the two major types of A and B. The subtypes of A1 and A2 were two different derivatives from one reassortant. The A/Pigeon/Shanghai/S1069-H7N9 strain might be the recombinant of type A H7N9 virus with a local H9N2 virus during the H7N9 epidemics. The A/Zhejiang/HZ1/2013-H7N9 strain could be the re-arrangement of subtype A2 with type B H7N9 virus.

China ; Genome, Viral ; Genotype ; Humans ; Influenza A Virus, H7N9 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; virology ; Phylogeny ; Reassortant Viruses ; classification ; genetics ; isolation & purification ; Sequence Analysis, RNA ; Viral Proteins ; genetics

OBJECTIVETo construct enterohemorrhagic Escherichia coli (EHEC) O157: H7 ppk gene deletion strains and study its biological characteristics.

METHODSThe gene fragment of kanamycin resistance was amplified using a pair of homologous arm primers whose 5' and 3' ends were homologous with ppk gene and kanamycin resistance gene, respectively. EHEC O157: H7 EDL933w competent strains were prepared and transformed via electroporation with the amplification products. The ppk gene was replaced by kanamycin resistance gene using pKD46-mediated Red recombination system. The recombinant strain was confirmed by PCR and sequencing, and its morphology, growth ability and adhesion were assessed using Gram staining, OD600 value and Giemsa staining.

RESULTS AND CONCLUSIONWe established a ppk-deleted EHEC O157:H7 EDL933w strain with kanamycin resistance and compared the biological characteristics of the wild-type and mutant strains, which may facilitate further study of the regulatory mechanism of ppk gene.

DNA Primers ; Escherichia coli O157 ; genetics ; Escherichia coli Proteins ; genetics ; Gene Deletion ; Phosphotransferases (Alcohol Group Acceptor) ; genetics ; Polymerase Chain Reaction

OBJECTIVETo construct enterohemorrhagic Escherichia coli (EHEC) O157:H7 strains with delection espF gene and its nucleotide fragment and with espF gene complementation.

METHODSA pair of homologous arm primers was designed to amplify the gene fragment of kanamycin resistance, which was transformed into EHEC O157:H7 EDL933w strain via the PKD46 plasmid by electroporation. The replacement of the espF gene by kanamycin resistance gene through the PKD46-mediated red recombination system was confirmed by PCR and sequencing. The entire coding region of espF along with its nucleotide fragment was amplified by PCR and cloned into pBAD33 plasmid, which was transformed into a mutant strain to construct the strain with espF complementation. RT-PCR was used to verify the transcription of espF and its nucleotide fragment in the complemented mutant strain.

RESULTS AND CONCLUSIONWe established EHEC O157:H7 EDL933w strains with espF gene deletion and with espF gene complementation. Both espF and its nucleotide fragment were transcribed in the complemented mutant strain. The two strains provide a basis for further study of the regulatory mechanism of espF.

Carrier Proteins ; genetics ; DNA Primers ; Escherichia coli O157 ; genetics ; Escherichia coli Proteins ; genetics ; Gene Deletion ; Plasmids ; Polymerase Chain Reaction

Objective:To analyze the epidemiological characteristics of childhood infectious diseases in a single center in Beijing City from 2007 to 2021, and to provide scientific basis for the management of infectious diseases in hospitals.Methods:The clinical data of outpatients or inpatients aged<18 years old with infectious diseases recorded in the Nationwide Health Information-based Disease Control and Prevention Information System of Beijing Children′s Hospital, Capital Medical University from January 1, 2007 to December 31, 2021 were collected. Descriptive epidemiological methods were used to analyze the types of infectious diseases, population distribution, time distribution characteristics, as well as the etiological characteristics of major infectious diseases.Results:There were 219 260 cases reported, accounting for 5.73‰(219 260/38 295 800) of the total number of hospital cases, with two peaks of 25 469 and 22 928 cases in 2010 and 2019, respectively. The main category of infectious diseases was class C, accounting for 77.51%(169 947/219 260). According to the classification of transmission routes, fecal-oral transmission infectious diseases were the most common, with 144 712 cases (66.00%), followed by air and droplet transmission infectious diseases with 73 946 cases (33.73%), showing an increasing trend by year. The top five diseases in terms of incidence were hand, foot and mouth disease (114 864 cases), influenza (28 703 cases), varicella (22 190 cases), other infectious diarrheal diseases (21 040 cases) and scarlet fever (11 500 cases). Among the 219 260 children, there were 131 546 males and 87 714 females, with a male-to-female ratio of 1.5 to 1. Children aged≤6 years old comprised the majority, with a total of 189 593 cases (86.47%). The peak period of infectious diseases reporting was from May to July. Hand, foot and mouth disease was mainly caused by Coxsackie virus A16(35.02%(1 258/3 592)), while Coxsackie virus A6 had been increasing rapidly since 2017. The main pathogen of influenza was influenza A virus (62.18%(7 400/11 900)), while other infectious diarrhea was mainly caused by rotavirus (87.55%(4 283/4 892)).Conclusions:There is an intermittent outbreak in the incidence of childhood infectious diseases, and air and droplet transmission infectious diseases have shown an upward trend in recent years. Hand, foot and mouth disease, influenza, varicella, other infectious diarrheal diseases and scarlet fever are the main infectious diseases affecting children. Different diseases have the characteristics of age and onset season. The prevention and control of infectious diseases should be updated gradually according to the epidemic trend. Proper protection should be taken during peak seasons and for key populations.