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Objective:To investigate the epidemiological characteristics, genotypes and genetic evolution of respiratory syncytial virus (RSV) isolated in Shanghai from April 2020 to December 2021, which was a period from the COVID-19 outbreak to the phase of regular epidemic prevention and control.Methods:This retrospective study collected the nasopharyngeal secretions or nasopharyngeal aspirates of children with acute respiratory tract infection (ARTI) admitted to the Shanghai Children′s Hospital from April 2020 to December 2021. PCR-capillary electrophoresis and RT-PCR were used for virus identification and the amplification of the gene fragment of the second hypervariable region of RSV G protein. Homology analysis and phylogenetic analysis were conducted using bioinformatics software. Chi-square test was used to compare the detection rates of RSV. Results:A total of 6 211 samples were collected and 13.62% (846/6 211) of them were positive for RSV. The positive rates of RSV in male and female patients were 14.07% (503/3 574) and 13.01% (343/2 637), respectively, with no significant gender difference (χ 2=1.467, P=0.226). The highest detection rate of RSV was found in children ≤6 months of age, and the rate of RSV infection decreased gradually with age (χ 2=352.942, P<0.001). No RSV-positive specimens were detected from April 2020 to August 2020, after which the detection rate of RSV gradually increased with two epidemic peaks occurring from December 2020 to February 2021 and from August to October 2021. The predominant epidemic subtype was RSV subtype B in 2020 and the first 9 months of 2021, which was gradually replaced by RSV subtype A in the last 3 months of 2021. The 176 strains of RSV subtype A obtained in this study were all ON1 genotype, and the nucleotide homology of the Shanghai epidemic strains was 90.20%-99.50%. All of the 250 strains of RSV subtype B were BA9 genotype, and the nucleotide homology of the Shanghai epidemic strains was 90.10%-100.00%. Conclusions:From April 2020 to December 2021, with the regular prevention and control of COVID-19, there is a change in the epidemic season of RSV. The prevalent genotypes of RSV subtypes A and B are ON1 and BA9, respectively, and the subtype A gradually replaces subtype B as the most prevalent subtype.
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Objective:To investigate the genetic characteristics of norovirus (NoV) in children with acute gastroenteritis in Shanghai.Methods:A total of 709 stool specimens were collected from outpatients with acute gastroenteritis in Children′s Hospital of Shanghai from October 2018 to September 2019. Real-time RT-PCR was used for qualitative detection of NoV, and RT-PCR was used to identify the genotypes of NoV with the primers of VP1 gene, RdRp region and RdRp-VP1 region. SPSS20.0 statistical software was used for data processing and bioinformatics software was used for homology, phylogenetic and recombination analysis of NoV gene sequences.Results:NoV was detected in 265 out of the 709 stool specimens with a positive rate of 37.4%. Sequence analysis of RdRp region and VP1 gene showed that seven different genotypes including GⅡ.P16-GⅡ.2, GⅡ.P12-GⅡ.3, GⅡ.Pe-GⅡ.4_Sydney 2012, GⅡ.P7-GⅡ.6, GⅡ.P8-GⅡ.8, GⅡ.P21-GⅡ.13 and GⅡ.P17-GⅡ.17 were detected from 111 NoV-positive specimens. The predominated genotype was GⅡ.P16-GⅡ.2 (30.6%, 34/111), followed by GⅡ.Pe-GⅡ.4_Sydney 2012 (27.0%, 30/111) and GⅡ.P12-GⅡ.3 (24.3%, 27/111). Two new NoV recombinant strains belonging to GⅡ.P21-GⅡ.13 genotype were identified and the recombination site was in the junction region of ORF1 and ORF2. NoV infection occurred every month, but the predominant genotype was different. No significant difference in the positive rates of NoV was found between male and female patients ( P=0.329). However, there were significant differences between different age groups ( P=0.011) and the children in the age groups of >11-12 years old and >2-3 years old had higher rates of NoV infection. Conclusions:The predominated recombinant NoV strains belonged to GⅡ.P16-GⅡ.2, GⅡ.Pe-GⅡ.4_Sydney 2012 and GⅡ.P12-GⅡ.3 genotypes, and two new recombinant NoV strains (GⅡ.P21-GⅡ.13) were found in Shanghai during October 2018 to September 2019. Gene sequencing across ORF1 and ORF2 was conducive to better understanding the NoV genotypes and recombination.
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Objective@#To analyze the clinical characteristics of hand, foot and mouth disease (HFMD) caused by coxsackievirus A6 (CV-A6) in different age groups.@*Methods@#From January 2015 to December 2017, throat swabs were collected from children with or suspected of having HFMD then quantitative real-time PCR was performed to detect enterovirus nucleic acid. HFMD cases caused by CV-A6 were divided into different groups according to age for comparison.@*Results@#In total, there were 467 cases of HFMD caused by CV-A6 with the age ranging from 3 months to 16 years. There were 273 cases in the infants and young children group (< 3 years old), 131 cases in the pre-school group (3-6 years old), and 63 cases in the school-age group (> 6 years old). The peak incidence was found between May and November.Fever was the common symptom, and the rate of fever in infant group was the highest (220/273, 80.5%); The proportion of cases with leucocyte elevation in the infant group was the highest (127/273, 46.5%) than that in the school-age group (17/63, 27.0%) with a statistical significance. The skin erythra of the HFMD caused by CV-A6 were diverse in forms. Over two forms of skin erythra accounted for 53.9% (257/476) of all cases, and the cases in the infant group showing more forms of skin erythra (163/273, 59.7%). The oral herpes were mainly distributed in the upper palate and pharyngeal isthmus, but the school age group had the least number of distribution sites (0.89±0.86). The cases in the infant group showed higher incidence of skin rash at the elbow joint (109/273, 39.9%), knee (88/273, 32.6%), thigh (112/273, 41%), buttock (122/273, 44.7%) than the other two groups, However, the school age group showed lower incidence of skin rash in the lower leg (0/63, 0%) and thigh (6/63, 9.5%) than the other two groups. The differences between groups were statistically significant. All cases were cured clinically, no severe cases occurred. Among the 288 cases followed up for 6 months, 33 (33/288, 11.5%) suffered from nail exfoliation.@*Conclusions@#Different age groups of HFMD caused by CV-A6 had different clinical manifestations. In the infant group, more cases had fever and the erythra were more diverse in forms and wider in distribution. In addition, the increased leukocytes in routine blood test was also more common in the infant group.
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Objective@#To understand the epidemiological and etiological characteristics of enterovirus (EV)-associated diseases among children in Beijing from 2010 to 2016.@*Methods@#This was a repeated cross-sectional study. The throat swabs were collected from children with probable EV-associated diseases at the Children' s Hospital Affiliated to Capital Institute of Pediatrics from 2010 to 2016. The samples were sent for pan-EV, enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) detection by real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR) . The viral types of non-EV-A71 and non-CV-A16 EV-positive samples were identified using modified RT-PCR and sequencing with CV-A6, EV-A/B group and 5 'UTR universal primers. The constituent ratios of the prevalence of different EV types in different age and gender groups were compared.@*Results@#Of the 2 703 throat swabs, 1 992 (73.7%) samples were positive for EV, including EV-A71 (19.1%, 516/2 703), CV-A16 (24.3%, 658/2 703), CV-A6 (22.2%, 600/2 703), CV-A10 (4.5%, 122/2 703) and other types of EV (3.5%, 95/2 703). There was 1 case of EV-A71 and CV-A16 co-infection. The positive detection rate of EV-A group (excluding EV-A71, CV-A16, CV-A6 and CV-A10) increased from 11.3% (7/62) to 95.2% (59/62) after using the modified VP1-specific primers and PCR amplification conditions. During the period between 2010 and 2012, CV-A16 and EV-A71 predominated in EV-positive samples. However, CV-A6 accounted for 60.7% (68/112) in 2013, much higher than CV-A16 (23.2%, 26/112) and EV-A71 (12.5%, 14/112). In 2014, EVs were mainly of CV-A16 and EV-A71, but CV-A6 was the predominant type in 2015 (68.2%, 232/340) and in 2016 (38.6%, 151/391). The epidemic season of EVs was mostly from April to August, but CV-A6 showed a small epidemic peak from October to November. The male-to-female ratio of EV-positive patients was 1.50∶1, and EV-associated diseases mostly occurred in children under 5 years of age. Younger children were more susceptible to CV-A6 than to EV-A71 and CV-A16.@*Conclusions@#From 2010 to 2016, there was a significant change in the spectrum of EVs in children with EV-associated diseases in Beijing. Since 2013, non-EV-A71 and non-CV-A16 increased, and CV-A6 gradually became one of the major pathogens of EV-associated diseases. The modified PCR primers and amplification conditions can effectively improve the reliability of test results.
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BACKGROUND:Among various seed cel s, synovial mesenchymal stem cel s have unique advantages in the repair of articular cartilage injury. OBJECTIVE:To review the progress of synovial mesenchymal stem cel s and its intra-articular injection in the treatment of articular cartilage injury. METHODS:The first author searched PubMed and CNKI by computer to retrieve articles published from January 2004 to December 2004 using the keywords of“synovial mesenchymal stem cel s;intra-articular injection;cartilage repair”in English and Chinese, respectively. Final y, 57 articles were included in result analysis. RESULTS AND CONCLUSION:It is easy to isolate and culture synovial mesenchymal stem cel s, which has great advantages in cartilage repair. What’s more, intra-articular injection therapy for articular cartilage injury is feasible and safe. Intra-articular injection of synovial mesenchymal stem cel s is a very promising treatment for cartilage damage, but there are stil many problems to be solved in the future.
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Objective To investigate the pathological change in articular cartilages after firearm injury.Methods Four rabbits from 28 New Zealand healthy rabbits were chosen as control group and subjected to joint capsule incision only. Another 24 rabbits were equally divided into 6 experimental groups( groups B to G) and subjected to medial femoral condyle cartilage surface damage by the nail gun.After the operation, their specimens were collected after 6 h,3 d,7 d,14 d,28 d and 56 d, respectively.Tissue sections were observed and stained by HE staining and toluidine blue staining.The histolopathological changes in articular cartilage after firearm injury were detected.Results The color of articular cartilages in experimental groups became lighter, the cell number increased but then decreased, the articular cartilage layer disappeared, the cell shape became uneven, cells began to cluster and the Mankin score increased, and the statistical differences between experimental groups and control group were significant.Conclusion The histological pathological changes in articular cartilages after fiream injury seem to follow some pattern.The degeneration seems obvious after 7 days and then becomes heavier.
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Objective To investigate the effects of transforming growth factor-?1(TGF-?1), fibroblast growth factor-2 (FGF-2), platelet derived growth factor-bb(PDGF-bb) and hepatocyte growth factor(HGF) on adult human articular chondrocytes(AHAC) proliferation and phenotype maintaining. Methods Isolated AHAC were cultured in DMEM/F-12 supplemented with 10% human AB serum, 50 ?g/ml ascorbic acid-2-phosphate, 0.4 mmol/L proline, 5 ?g/ml insulin and 1 mmol/L non-essential amino acids (NEAA). The cells of 2nd passage were used for proliferation kinetics studying: 2.0?103 cells/well were seeded on 96-well plate, 24 h later, the cells were stimulated with various growth factors or combinations of these growth factors respectively, and the proliferation kinetics were analyzed by MTT colorimetric method. The passaged chondrocytes' phenotype were assessed by safranine O staining and immunostaining for type Ⅰ,Ⅱcollagens and aggrecan. Results All four growth factors: FGF-2, TGF-?1, PDGF-bb and HGF, could promote the proliferation of AHAC, and the optimal concentrations,when used separately, were 50 ng/ml, 1 ng/ml, 1 ng/ml, 20 ng/ml respectively. While 5 ng/ml FGF-2 combined with 1 ng/ml TGF-?1 could achieve the best proliferation effect, additionally adding PDGF-bb, HGF or both could not enhance more. With the combination of FGF-2 and TGF-?1, the AHAC could expand over 2000-fold and passage over 10 times. Chondrocytes of 9th passage still excreted type Ⅱcollagen and glycosaminoglycan(GAG). Conclusion 5 ng/ml FGF-2 combined with 1 ng/ml TGF-?1 is a very appropriated circumstance for in vitro expanding of AHAC.
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Objective To investigate the radiographic characteristics of degenerative lumbar scoliosis (DLS) and its relationship to osteoporosis. Methods 229 cases (83 males, 146 females) of DLS from January 1998 to June 2005 were reviewed. The mean age was 56.8 years (ranged from 40 to 74 years). The Cobb angle and vertebral stability in coronal plane were measured in anteroposterior radiographs and the changes of lordosis in sagittal plane were observed in lateral radiographs. The bone mineral density(BMD) and T-Score of lumbar spine (L2-L4) were measured using Dual Energy X-ray Absorptiometry. Results The mean Cobb angle is 9.45??4.79?, 151 cases(66%) with the angle less than 10?, 60 cases (26%) with 10?-20?, and 18 cases (8%) with more than 20?. Right side scoliosis were found in 52% (120 cases), left side in 48% (109 cases). 159 cases (69%) companied with gradeⅠ(Nash-Moe) vertebra rotation, 54 cases (24%) with grade Ⅱ. And the vertebra rotation was most evident on scoliosis apex. There were 20 cases (9%) with more than 4 mm lateral translation between the lumbar vertebrae which were usually the apex vertebrae with the most degenerative changes. The physical lordosis decreased in most cases in which 16 cases (7%) developed lumbar or thoracolumbar kyphosis. And the kyphosis degree was not relevant to scoliosis Cobb angle. The mean T-Score of BMD measurement was -1.88?0.17, which was -1.49?0.14, -2.56?0.24, -2.89?0.50 for the groups of with Cobb angle 20? respectively. There were 153 cases (67%) with T10?), and 98 cases (43%) with T