BACKGROUND: Thoracolumbar fracture is commonly seen in spinal injuries, which causes loss of stability of the spine, as well as spinal cord and nerve compression, even deformity and paralysis. The diagnosis and treatment of thoracolumbar fracture remain controversial.OBJECTIVE: To summarize the mechanism of thoracolumbar fracture based on finite element method, its classification and transpedicular screw fixation.METHODS: The first author retrieved CNKI and PubMed databases for the relevant literature published between January 2000 and December 2016. The keywords were "finite element method, thoracolumbar spine fracture,transpedicular screw fixation" in Chinese and English, respectively.RESULTS AND CONCLUSION: (1) The finite element analysis method can simulate the mechanism of thoracolumbar fracture and provides a reference for the studies on the occurrence, development and treatment of thoracolumbar fracture. (2) The classification of thoracolumbar fracture is beneficial for planning a rational treatment strategy and evaluating prognosis. (3) Compared with the traditional screw fixation, the transpedicular screw fixation holds advantages in biomechanical stability and postoperative correction effect. (4) There are various classifications for thoracolumbar fracture; differences in severity and cartilage injury are difficult to simulate completely. (5) The finite element analysis method shows certain application limitations due to long learning curve and modeling time as well as complicated calculations.

OBJECTIVETo analyze the clinical characteristics of hospitalized pediatric patients infected with 2009 H1N1 influenza.

METHODSTotally 159 children (83 male and 76 female) with influenza A (H1N1) confirmed by the real-time reverse-transcriptase-polymerase-chain-reaction assay were admitted to a special ward of Capital Institute of Pediatrics from November 2009 to January 2010. Clinical manifestations, laboratory and therapy data from the hospitalized children were collected by designed case report form and analyzed.

RESULTSOut of 159 hospitalized patients, 139 (87.4%) were under the age of 5 years and 34.0% of them had at least one underlying medical conditions. Proportions of the severe cases, pneumonia and underlying medical diseases were similar between the 78 infants and 81 older children. All of these 159 cases had influenza-like symptoms at onset and the most common presentations were fever (115 cases, 72.3%) and cough (154 cases, 96.8%). Five severe cases presented dyspnea, cyanosis and hypoxemia. The virus easily invaded into the lower respiratory tract as indicated by that 61% of the cases had findings consistent with pneumonia by X-ray and/or CT and 21.6% had bacterial co-infection. Part of them had mycoplasma pneumonia (20 cases, 27.0%) or other respiratory viruses (5 cases, 3.1%) co-infection simultaneously. The duration of fever was similar between the H1N1 virus sole infection group and the co-infection group (t = 0.975, P > 0.05), but the average course of the disease and hospitalized days of the latter group were longer than the former (t = 3.182 and 3.190, P < 0.01). The proportion of children with pneumonia in the co-infection group was significantly higher than that in the H1N1 sole-infection group (χ(2) = 4.082, P < 0.05).

CONCLUSIONSMost of the H1N1 infected pediatric patients had mild respiratory symptoms, a few of them developed severe manifestations. Dyspnea and hypoxemia were the early signals for the developing severe cases. Rational and experienced treatment with antibiotics was important addition to the antiviral therapy for those co-infected with bacteria.

Child ; Child, Hospitalized ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; diagnosis ; epidemiology ; pathology ; therapy ; Male

OBJECTIVEThe fact that the acute lower respiratory infections (ALRI) are associated with a newly discovered virus, human metapneumovirus (hMPV), has been shown in several studies. The authors conducted this study to understand the etiological and clinical characteristics of bronchiolitis, one of the most common ALRI in infants, caused by hMPV.

METHODSNasopharyngeal aspirate specimens from 54 out of 126 infants with bronchiolitis admitted to the Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing from November 2002 to February 2003 were examined for hMPV gene fragments by reverse transcription-polymerase chain reaction (RT-PCR). Prior to the detection, the specimens were confirmed as negative for the common respiratory pathogens including RSV, influenza A and B, parainfluenza I, II, III, adenovirus, Mycoplasma pneumoniae by indirect immunofluorescence test, virus isolation and ELISA test. The clinical data of the patients diagnosed etiologically as hMPV infection analyzed included the infants' age, sex, the degree of fever, the severity of wheezing and clinical Lowell score, the findings of chest examination and chest X-ray, the white blood cell count and blood gas analysis, the course of the disease, the major treatments and the outcome of the disease.

RESULTSTwenty-one specimens showed the predicted 213 bp PCR products in agarose gel and the positive rate was 16.7% of all patients (21/126) and 39% of the patients with negative results for common respiratory pathogens detections (21/54). The range of patients' age was 2 - 15 months and the young infants with hMPV bronchiolitis (1 - 6 month of age) accounted for 62% and the male:female ratio was 3.2:1. The patients presented a low-medium grade fever (T < 39 degrees C) accounted for 86%; 81.0% of patients had a white blood cell count lower than 10.0 x 10(9)/L. The radiological findings were patchey opacity in both lungs (68%) and(or) hyperinflation (62%). Assessed by the Lowell score system, 5 out of 21 cases were considered as severe cases. The major clinical findings of hMPV bronchiolitis had no significant difference compared with that of subgroup A hRSV bronchiolitis, and showed longer course of disease than that of subgroup B hRSV bronchiolitis (P < 0.01).

CONCLUSIONSOf the infants with bronchiolitis hospitalized in our hospital from November of 2002 through February of 2003, 16.7% were caused by hMPV infection. These data showed that the major clinical characteristics and the outcome of treatment of hMPV bronchiolitis had no statistically significant difference compared to the cases with either subgroup A or subgroup B hRSV infection.

Bronchiolitis ; therapy ; virology ; China ; Female ; Humans ; Infant ; Male ; Metapneumovirus ; genetics ; Mucus ; virology ; Paramyxoviridae Infections ; therapy ; virology ; Prognosis ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVEA new respiratory virus, human metapneumovirus (HMPV) was recently identified by scientists in the Netherlands first and then in a few other countries. To investigate if this newly discovered virus is associated with the acute respiratory infections in pediatric patients in Beijing, tests were developed to detect HPMV gene fragments from nasopharyngeal aspirates collected from infants and young children hospitalized for acute respiratory infections from November 2002 to March 2003.

METHODSThe HMPV was screened by reverse transcription-polymerase chain reaction (RT-PCR). RNAs were extracted by Trizol from 247 specimens which had been determined as negative for conventional respiratory viruses including RSV, influenza A and B, parainfluenza I, II, III and adenovirus by indirect immunofluorescence test as well as virus isolation. The HMPV RNAs were detected by reverse transcription tests using random primer and M-MLV reverse transcriptase followed by PCR using the primers designed from the published sequence of the N protein-encoding gene from the first HMPV identified in the Netherlands. PCR products were visualized by 1.2% agarose gel electrophoresis. Selected positive PCR products were sequenced and the sequences of the nucleotides and deduced amino acids were compared with those in the GenBank.

RESULTSAmong those 247 specimens negative for common respiratory viruses, 74 (30.0%) showed the predicted 213 bp PCR products in agarose gel. Most of clinical diagnoses for these 58 patients were pneumonia (36, 48.6%), bronchiolitis (21, 28.4%), and bronchitis and asthma in some patients. Nearly 90 percent of positive specimens were from patients under 2 years of age. Ten out of 74 amplicons were randomly selected for sequence analysis. When compared with the sequences in the GenBank, the nucleotide sequences of these 10 amplicons shared high homology only with those of HMPVs. The nucleotide sequence identities of these 10 samples with those from the Netherlands and Canada were 87% - 99%. When compared with the nucleotide sequence from the first reported strain by Van den Hoogen (strain HMPV 00-1), the sequence identities of these 10 fragments ranged from 88.7% to 99.1%. Among the 10 amplicons from the specimens, the nucleotide identities were 87.3% - 100%. One of the 10 amplicons (No. 1816) shared lower identity with others (87.3% - 89.7%), whereas the other 9 shared higher identities (95.8% - 100%) with each other. The comparison of amino acids showed that these 10 amplicons showed high homology (95.8% - 100%). Again, amplicon No.1816 shared lower homology (95.8% - 97.2%) with others, whereas the other 9 shared higher homology (98.6% - 100%). The amino acid homology between No.1816 and HMPV 00-1 was 95.8%, whereas that of the other 9 with HMPV 00-1 was 98.6% - 100%.

CONCLUSIONThese data suggested that some of acute respiratory infections in pediatric patients in Beijing area are related to the newly identified human metapneumovirus. The HMPV circulating in Beijing may have different genotypes.

Acute Disease ; Child ; Child, Preschool ; China ; Female ; Fluorescent Antibody Technique, Indirect ; Humans ; Infant ; Male ; Metapneumovirus ; genetics ; Nucleocapsid Proteins ; genetics ; Paramyxoviridae Infections ; pathology ; virology ; RNA, Viral ; genetics ; Respiratory Tract Infections ; pathology ; virology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVEThe novel influenza A (H1N1) virus firstly detected in April 2009 in Mexico rapidly spread to many countries including the United States and Canada where humans were infected with the H1N1 virus and deaths were reported. The pandemic virus strain had never been detected in specimen of human beings and swine. It was so highly contagious and widely spread that threatened life of humans globally. This study aimed to analyze clinical data of hospitalized children patients with 2009 novel H1N1 influenza A virus infection confirmed by etiologic tests, and compared with that of seasonal influenza A.

METHODClinical manifestations, laboratory and therapy data from the hospitalized children were collected by designed case report form and analyzed. All patients were enrolled from Capital Institute of Pediatrics from January 2003 to 2010. There were 152 cases in seasonal influenza A group, which was composed of 100 boys and 52 girls. Other 93 boys and 86 girls formed 2009 novel influenza A group.

RESULTInfluenza A was dominate from 2003 to 2008 and the peak season was December and January, while the peak hospitalized time of 2009 novel H1N1 influenza was from November 2009 to January 2010. The median age of seasonal influenza group was 35 months, which was lower than that of novel influenza group (Z = -6.702, P<0.01). Besides, 80.9% of the patients in seasonal influenza group were infants, while the novel influenza A group was mainly composed of infants and pre-school children (chi2 = 40.725, P<0.01). The cases of both groups had influenza-like symptoms at onset and the most common presentations were fever and cough. The duration of fever was much longer in 2009 novel influenza group (Z = -7.173, P<0.01). Patients in two groups nearly had the same symptoms except cough was more frequently presented by novel influenza A group cases (chi2 = 4.109, P<0.05). In laboratory examination, the novel influenza group had more cases with abnormality in blood platelet, CRP, ALT, and CK-MB than that of seasonal influenza group (chi2 = 7.562, 17.245, 4.398, 6.217, P<0.01). Patients in novel influenza A group had more changes in electrocardiogram (chi2 = 24.461, P<0.01). More patients had common underlying medical condition in novel influenza groups than those in seasonal influenza group (chi2 = 12.553, P<0.01). Furthermore, the groups had different age distribution in underlying medical diseases (chi2 = 7.231, P<0.05). Children with 2009 novel H1N1 virus infection tended to catch pneumonia (chi2 = 8.661, P<0.01) and became the severe cases (chi2 = 10.595, P<0.01). They had much higher ICU admission rate (chi2 = 12.873, P<0.01) and longer hospital stay (Z = -2.764, P<0.01).

CONCLUSIONAs a new variant of influenza virus A, 2009 novel H1N1 influenza A had stronger pathogenicity. Children with underlying medical conditions had the high risk to be infected and developed severe manifestations.

Adolescent ; Child ; Child, Hospitalized ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Influenza A Virus, H1N1 Subtype ; Influenza A virus ; Influenza, Human ; epidemiology ; virology ; Male

OBJECTIVEThe severe acute respiratory syndrome (SARS) is a highly contagious infection caused by a newly discovered strain of coronavirus (SARS-CoV). During the outbreak of SARS in the first half of 2003, children appeared to be less susceptible to the SARS coronavirus and pediatric patients presented with a less aggressive clinical course than adult patients did, demonstrating the traits which were rarely observed in other viral contagious disease. The present study aimed to preliminarily examine the presence of serum specific antibodies against severe acute respiratory syndrome (SARS)-associated coronavirus virus (SARS-CoV) in pediatric SARS patients and explore the possibility of subclinical infection in children/adults through close association with SARS cases.

METHODS(1) Clinicians and nurses visited families and collected general and epidemiological information about the subjects using a standard questionnaire and took serum specimens. (2) Specific antibodies against SARS-CoV were assayed with two methods, indirect immunofluorescence assay (IFA) for detecting IgG antibodies and enzyme linked immunosorbent assay (ELISA) for mixed antibodies. Serum specimens tested included those from 21 clinically confirmed pediatric SARS cases (aged from 8 months to 14 years, 11 male and 10 female) and their 23 parents who had close contact with the children, 36 adult patients in convalescence stage of SARS, 24 children (aged 1.5 to 14 years) and other 34 adults who had close contact with infected adults.

RESULTS(1) The positive rates of specific IgG and mixed antibodies against SARS-CoV were 38% (8/21) and 33% (7/21) in pediatric cases; whereas the rates were 75% (27/36) and 69% (25/36) in adult patients. (2) The proportion of the patients who had close contact to SARS patients was 7/8 among the antibody-positive group vs. 1/13 for the antibody-negative group (P < 0.05). (3) The IgG antibody emerged in one of 24 children, whose mother, a nurse, had suffered from SARS (4%). (4) Among 23 parents of children with SARS, one was positive for IgG and the mixed antibodies, whose grandson and husband suffered from SARS; The IgG antibody and the mixed antibodies were also positive in another adult who had close contact with adult SARS cases (3%).

CONCLUSIONS(1) SARS-CoV infection was confirmed by serological methods in 38.1% of clinically diagnosed pediatric SARS cases, which leads to the assumption that correct diagnosis of pediatric SARS requires more accurate and efficient ways, for example, screening for antigen or gene of SARS-CoV. (2) The proportion of the patients who had close contact to SARS patients among antibody-positive cases was higher than that in antibody-negative cases. (3) It is possible that subclinical SARS CoV infection exists in children and adults, although the rate of occurrence is low. The data of the present study did not confirm that SARS had subclinical infection among adults who had close contact to pediatric SARS cases.

Adolescent ; Adult ; Antibodies, Viral ; blood ; immunology ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Fluorescent Antibody Technique, Indirect ; Humans ; Immunoglobulin G ; blood ; immunology ; Infant ; Male ; SARS Virus ; immunology ; Severe Acute Respiratory Syndrome ; blood ; epidemiology ; immunology

UNLABELLEDA Special "Fever and Cough" Clinic was set up at the Children's Hospital Affiliated to Capital Institute of Pediatrics for children with symptoms of fever and cough in late April when the severe acute respiratory syndrome (SARS) epidemic was at its peak in Beijing to separate the children with fever from others during their visit to the Outpatient Department.

OBJECTIVEFor patients with fever, normal or low count of white blood cell and with suspected pneumonia suggested by X-ray, it was urgent to determine the etiological agents of the diseases before they were admitted to the hospital.

METHODSThroat swabs or nasopharyngeal aspirate specimens were collected from those patients and common respiratory virus antigens including influenza virus A and B, respiratory syncytial virus, adenovirus, parainfluenza virus types I, II, and III were tested by indirect immunofluorescent assay. The patients with atypical pneumonia diagnosed by X-ray and evidences of common respiratory virus infection were admitted to the regular ward for children with respiratory diseases. Children with pneumonia demonstrated by X-ray and negative for common respiratory viruses were admitted to the isolated ward for suspected SARS patients for the first step and further viral etiological studies were requested. RT-PCR was performed for those patients to detect gene fragments of human metapneumovirus (HMPV), rhinovirus (RhV) and enterovirus (EV) in their specimens. Nested RT-PCR was also developed to detect SARS coronavirus gene fragment from the specimens. Primer sequences for SARS virus detection with the PCR were selected according to the primer sequences published online by WHO on April 18, 2003. All the primers derived from the sequence at the 1b frame of coronavirus replicase gene and products with a size of 368 or 348 bp were expected with 2 different primer pairs.

RESULTSAmplicons with the sizes of 368 bp and 348 bp were obtained from a throat swab specimen collected from a 17 years old girl, who was admitted to the isolated ward because of high fever (39.5 degrees C) for 7 days, cough for 2 days, low WBC count, and pneumonia shown by X-ray when she visited the "Fever and Cough" Clinic, and without known history of contact with probable SARS patient. Antigens for the common respiratory viruses were all negative, RT-PCR for HMPV, RhV and EV were also negative while RT-PCR with different primer pairs for SARS virus were all positive which indicated that SARS coronavirus gene fragments were amplified from the specimen from this girl. The amplified fragment with a size of 368 bp was sequenced and the sequence was compared with those in the GenBank. The sequence shared 100% homology with the sequences from 1b frame of replicase genes from all 17 of SARS coronaviruses published in the GenBank so far, and shared very low homology with 2 reference strains of human coronavirus as well as other animal coronaviruses. The serum collected before her discharge from the hospital (19 days after the onset of the disease) showed SARS specific IgM and IgG antibodies.

CONCLUSIONThese data indicate that the patient was a confirmed case of SARS. It is of great importance to differentiate SARS patients from those infected with common respiratory viruses during SARS epidemic, especially for pediatric patients, because most of the patients visiting the outpatient department present with the symptoms of fever, cough and normal WBC count. The data mentioned above indicate that antigen and gene detections for those common respiratory viruses are useful methods for the differentiation to avoid the spread of SARS.

Adolescent ; Amino Acid Sequence ; Antibodies, Viral ; analysis ; China ; Female ; Fluorescent Antibody Technique, Indirect ; Humans ; Molecular Sequence Data ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; immunology ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Severe Acute Respiratory Syndrome ; diagnosis ; virology

Human metapneumovirus (hMPV) is a recently identified respiratory virus more like human respiratory syncytial virus in clinical symptoms. Matrix protein (M) is one of the most important structural proteins. For further studying of hMPV, the full length of M genes from the recombinant plasmid pUCm-M1816 and pUCmM1817 were cloned by PCR and sub-cloned into the pET30a(+) vector, which is a prokaryotic expression vector, after dual-enzyme digestion with Bam HI and Xho I. The positive recombinated plasmids were transformed into E. coli BL21 (DE3) and expressed under the inducing of IPTG. Target proteins were characterized by SDS-PAGE and Western blotting. In this article, we' ve successfully constructed the recombinated plasmids pET30a-M1816 and pET30a-M1817 which have correct open reading frames confirmed by dual-enzyme digestion analysis and sequencing. The fusion proteins with 6 x His-N were highly produced after inducing by 1mmol/ L IPTG at 37 degrees C. A unique protein band with approximate 27.6 kD was characterized by SDS-PAGE. Most of the target protein existed in inclusion body. Western blot analysis showed that the target protein has specific binding reaction to rabbit antiserum against polypeptides of the matrix protein of hMPV. So the M genes were highly expressed in the prokaryotic system and the expressed M proteins have specific antigenic activities. It can be used for further studying of hMPV infections in Beijing.
Animals ; Antigens, Viral ; genetics ; immunology ; metabolism ; Blotting, Western ; China ; Gene Expression ; Genetic Vectors ; genetics ; Humans ; Immune Sera ; immunology ; Metapneumovirus ; genetics ; immunology ; metabolism ; Plasmids ; genetics ; Prokaryotic Cells ; metabolism ; Rabbits ; Species Specificity ; Viral Structural Proteins ; genetics ; immunology ; metabolism

OBJECTIVETo understand the seroprevalence of antibody against the newly identified human metapneumovirus (hMPV) in Beijing.

METHODSThe antigenic specificity of hMPV N protein cloned into vector pET30a and then expressed in E coli was verified by using SDS-PAGE and Western blotting in 116 serum specimens. The plasmid pET30a without insert was used as control. Totally 710 serum specimens collected from non-respiratory infection patients visited the Outpatient Departments of Children's Hospital affiliated to Capital Institute of Pediatrics and Xuanwu Hospital, Beijing from April 1996 to March 1997 were tested for specific IgG antibody against hMPV N protein.

RESULTSThe bands with expected molecular weight showed only on the membranes transferred by the expressed hMPV N protein and incubated with rabbit hyperimmune serum against hMPV N protein polypeptides as well as the collected human sera, indicating the specificity of the expressed hMPV N protein. Out of 710 specimens tested, 17.2% (122/710) were positive for antibody to N protein. Antibody positive rate was the lowest in 2 to 6 months old infants (3.1%); the rate declined from 13.2% in newborns to 6.1% in 1 to 2 months old infants, then to 3.1% in the 2 to 6 months group, and sustained at about 3.0% from 6 months group to 30 years of age, then increased to 28.1% in 30 to 39-year-old adults, 32.3% in 40 to 49-year-old adults and to 38.5% in the group over age of 50 years.

CONCLUSIONThe expressed hMPV N protein is reliable when it was used as antigen for testing specific IgG antibody against hMPV in human sera. The high seroprevalence of antibody against hMPV N protein and early age antibody acquisition suggest that hMPV has been circulating in Beijing and the importance of the virus as pathogen should be further analyzed.

Adolescent ; Adult ; Antibodies, Viral ; blood ; Antibody Specificity ; Child ; Child, Preschool ; China ; epidemiology ; Humans ; Immunoglobulin G ; blood ; Infant ; Metapneumovirus ; immunology ; Middle Aged ; Paramyxoviridae Infections ; epidemiology ; immunology ; Seroepidemiologic Studies ; Viral Proteins ; immunology ; Young Adult

OBJECTIVETo study the suppressive effect of LRRC4 gene on human glioma U251 cells and further investigate its biological functions.

METHODSH&E, DNA and AgNORs stainings were performed on LRRC4-transfected U251 cells, mock-transfected U251 cells and non-transfected U251 cells, respectively. Quantitative analysis including cell morphometry, DNA content, DNA ploidy, silver stained argyrophilic nucleolar organizer regions (AgNORs) were investigated by image analysis. Flow cytometry was employed to determine the difference of cell cycle distribution and MTT staining was used to elucidate the activity of the LRRC4-transfected U251 cells.

RESULTSThe morphological cell parameters such as area, perimeter and diameter, DNA content, chromosomal aneupoloidy, mean area of AgNORs particles and mean nucleus area of the LRRC4-transfected U251 cells were remarkably decreased compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). Meanwhile, significant accumulation of cells in G(0)/G(1) phase but decrease of cells in S and G(2)/M phase, was observed in transfected U251 cells compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). MTT staining showed that proliferation activity of both the mock- and non-trasfected U251 cells was significantly higher than that of the U251 cells transfected with LRRC4 gene (P < 0.01).

CONCLUSIONLRRC4 gene might be involved in tumor suppression by restraining DNA synthesis and the nucleoli organizer regions-associated proteins, keeping the cell cycles in phase G(0)/G(1) and reducing proliferation activity of the glioma cells. Morphometry combined with other techniques such as flow cytometry and MTT staining can well elucidate the biological function of novel genes.

Brain Neoplasms ; genetics ; pathology ; Chromosomes, Human, Pair 7 ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; physiology ; Glioblastoma ; genetics ; pathology ; Humans ; Nerve Tissue Proteins ; genetics ; physiology ; Transfection ; Tumor Cells, Cultured