1.Preparation and characterization of methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold
Xun YUAN ; Zhengang DING ; Liwei FU ; Jiang WU ; Yazhe ZHENG ; Zhichao ZHANG ; Guangzhao TIAN ; Xiang SUI ; Shuyun LIU ; Quanyi GUO
Chinese Journal of Tissue Engineering Research 2024;28(22):3517-3523
BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P<0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P<0.05,P<0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.
2.Study on the anti-inflammatory mechanism of active ingredients of Gubi Formula in the treatment of osteoarthritis
Peng DING ; Feng-Xiang TIAN ; Li XU ; Yu GE ; Fu-Rong WANG ; Yu-Jie BAO ; Ling-Ling ZHOU
The Chinese Journal of Clinical Pharmacology 2024;40(14):2053-2057
Objective To explore the anti-inflammatory mechanism of the active ingredients of Gubi Formula in treating osteoarthritis.Methods Normal human chondrocytes were cultured in vitro,and lipopolysaccharide(LPS)stimulated inflammation.The cells were divided into control group(normal culture),model group(10 μg·mL-1 LPS),quercetin group(10 μg·mL-1 LPS+8 μmol·L-1 quercetin),formononetin group(10 μg·mL-1 LPS+50 μmol·L-1 formononetin),naringin group(10 μg·mL-1 LPS+10 μmol·L-1 naringin),asperosaponin Ⅵ group(10 μg·mL-1 LPS+50 pmol·L-1 asperosaponin Ⅵ),β-ecdysterone group(10 μg·mL-1 LPS+50 μmol·L-1β-ecdysterone).Cell counting kit-8(CCK8)was used to detect the viability of chondrocytes.Western blot was used to detect the expression of nuclear factor NF-kappa-B p65 subunit(p65),nuclear factor erythroid 2-related factor 2(Nrf2)nuclear protein.Results The cell viability of control group,model group,quercetin group,formononetin group,naringin group,Dipsacoside Ⅵ group,β-ecdysterone group were(103.10±8.55)%,(62.41±2.35)%,(76.92±1.74)%,(77.01±0.60)%,(80.39±3.06)%,(79.43±0.94)%,(55.20±0.99)%;the relative expression of Nrf2 protein were 1.00±0.00,1.01±0.09,1.30±0.15,0.91±0.15,1.23±0.25,0.71±0.19,1.51±0.13,1.26±0.15;the relative expression of P65 protein were 1.00±0.00,2.24±0.85,0.74±0.33,1.49±0.29,0.97±0.06,1.33±0.07,1.67±0.22,1.52±0.17;the relative expression of inflammatory mediators iNOS were 1.00±0.00,1.52±0.27,1.07±0.24,1.25±0.12,1.01±0.30,1.44±0.12,1.07±0.18,1.11±0.16.The above indexes in quercetin group,formononetin group and naringin group were significantly different from those in model group(P<0.05,P<0.01 and P<0.001).Compared with the model group,there was no significant difference in the above indexes between the Asperosaponin Ⅵ group and theβ-ecdysterone group(all P>0.05).Conclusion The active components of Gubi Formula,including quercetin,mangiferin,and naringin,can activate Nrf2-HO-1 signaling and inhibit the activation of the Nuclear factor-κB(NF-κB)pathway plays an anti-inflammatory role in alleviating osteoarthritis.
3.Clinical trial of naratinib combined with capecitabine in the treatment of advanced breast cancer patients with HER2 positive
Tuan-Jie ZHANG ; Fu-Yu GONG ; Yu-Ning LU ; Liang DING ; Xiang LI
The Chinese Journal of Clinical Pharmacology 2024;40(17):2474-2478
Objective To observe the clinical efficacy and safety of naratinib maleate tablets combined with capecitabine tablets in the treatment of advanced breast cancer patients with human epidermal growth factor receptor 2(HER2)positive.Methods The advanced breast cancer patients with HER2 positive were randomly divided into control group and treatment group.The control group was given 1 250 mg·m-2 capecitabine tablets,bid,orally administered,and stopped for 1 week after 2 weeks of treatment.On the basis of treatment in the control group,the treatment group was treated with a combination of naratinib maleate tablets 240 mg,qd,orally.Both groups of patients continued to take medication until the disease progressed or the patient could not tolerate it,with one course of treatment every three weeks.The clinical efficacy,tumor marker levels,survival status,and the safety was evaluated.Results Treatment group were enrolled 55 cases,1 case dropped out,and 54 cases were finally included in the statistical analysis.Control group were enrolled 55 cases,2 cases dropped out,and 53 cases were finally included in the statistical analysis.After treatment,the disease control rates of treatment and control groups were 64.81%(35 cases/54 cases)and 35.85%(19 cases/53 cases);the objective response rates were 37.04%(20 cases/54 cases)and 18.87%(10 cases/53 cases);the differences were statistically significant(all P<0.05).After treatment,the levels of carcinoembryonic antigen in the treatment and control groups were(14.88±1.96)and(17.25±2.01)ng·mL-1;the levels of carbohydrate antigen 15-3 were(28.42±4.27)and(32.56±4.85)U·mL-1;the levels of tissue peptide specific antigen were(101.76±10.64)and(106.23±11.16)U·L-1;the overall one-year survival rates were 31.48%and 15.09%;the progression free survival time was 7.00 and 6.00 months;the total survival time was 9.00 and 8.00 months,respectively.The differences of above indexes were statistically significant(all P<0.05).The adverse drug reactions of two groups were mainly diarrhea,leukopenia,hand foot syndrome,nausea and abdominal pain.The incidences of diarrhea in the treatment and control groups were 79.63%and 60.38%with significant difference(P<0.05);and there were no significant differences in the incidence of other adverse drug reactions between two groups(all P>0.05).Conclusion The clinical efficacy of naratinib maleate tablets combined with capecitabine tablets in the treatment of the advanced breast cancer is better than that of capecitabine alone;the former can better reduce the levels of tumor markers,prolong the survival time,and improve the short-term survival rate.
4.Environmental contamination related to the first patient with carbapenem-resistant Acinetobacter baumannii infection and the infection status of pa-tients in the intensive care unit in Tibetan areas
Cuo-Ta QIE ; Ding-Ying HE ; Fu-Yan LONG ; Xiao-Hua ZHANG ; Chun-Hua PENG ; Xiang-Xiang JIANG ; Ming-Lei DENG ; Cong FU ; Guo-Ping ZUO
Chinese Journal of Infection Control 2024;23(2):220-224
Objective To investigate the environmental contamination related to first patient with carbapenem-re-sistant Acinetobacter baumannii(CRAB)infection and the infection status of relevant patients in a newly established intensive care unit(ICU)of a hospital in Tibetan area,and analyze the transmission risk.Methods From the ad-mission in ICU of a patients who was first detected CRAB on November 15,2021 to the 60th day of hospitalization,all patients who stayed in ICU for>48 hours were performed active screening on CRAB.On the 30th day and 60th day of the admission to the ICU of the first CRAB-infected patient,environment specimens were taken respectively 2 hours after high-frequency diagnostic and therapeutic activities but before disinfection,and after disinfection but before medical activities.CRAB was cultured with chromogenic culture medium.Results Among the 13 patients who were actively screened,1 case was CRAB positive,he was transferred from the ICU of a tertiary hospital to the ICU of this hospital on November 19th.On the 40th day of admission to the ICU,he had fever,increased frequency for sputum suction,and CRAB was detected.The drug sensitivity spectrum was similar to that of the first case,and he also stayed in the adjacent bed of the first case.64 environmental specimens were taken,and 9 were positive for CRAB,with a positive rate of 14.06%,8 sampling points such as the washbasin,door handle and bed rail were positive for CRAB after high-frequency diagnostic and therapeutic activities.After routine disinfection,CRAB was detected from the sink of the washbasin.Conclusion For the prevention and control of CRAB in the basic-level ICU in ethnic areas,it is feasible to conduct risk assessment on admitted patients and adopt bundled prevention and con-trol measures for high-risk patients upon admission.Attention should be paid to the contaminated areas(such as washbasin,door handle,and bed rail)as well as the effectiveness of disinfection of sink of washbasin.
5.Correlation analysis of phase angle with nutritional risk and clinical outcomes in patients with severe acute pancreatitis
Lan DING ; Yue FU ; Ze-Hua ZHAO ; Hong-Lin YAO ; Xiang-Hong YE
Parenteral & Enteral Nutrition 2024;31(4):252-256
Objective:To investigate the relationship between phase angle (PA) and nutritional status,duration of mechanical ventilation,length of intensive care unit (ICU) stay,and clinical outcomes in patients with severe acute pancreatitis (SAP) complicated with ARDS. Methods:The clinical data of patients with SAP complicated with ARDS admitted to the surgical ICU,Jinling hospital,medical school of Nanjing University,from July 2023 to March 2024 were retrospectively collected. Patients are divided into low-PA group and normal-PA group based on phase angle. The correlation analysis between phase angle,nutritional status,and clinical outcomes,and evaluation of risk factors for mortality in patients with SAP combined with ARDS were performed. Result:A total of 83 patients with SAP complicated with ARDS were included in this study. PA was negatively correlated with nutritional risk scores (rs=-0.352,P=0.001),duration of mechanical ventilation (rp=-0.475,P<0.001),length of ICU stay (rp=-0.313,P=0.004),and mortality (rs=-0.371,P=0.001). Univariate analysis showed statistically significant differences in age,PA value,and duration of mechanical ventilation for predicting mortality (P<0.05);Multivariate analysis showed that the PA value was an independent risk factor for mortality (P<0.05). Conclusion:PA is significantly correlated with clinical outcomes,such as nutritional risk,duration of mechanical ventilation,length of ICU stay and mortality,and may be a promising biomarker in future.
6.A retrospective study of occlusal reconstruction in patients with old jaw fractures and dentition defects
Ming-Chao DING ; Bo-Ya JING ; Jin SHI ; Liu YANG ; Xiang-Dong LIU ; Jing-Fu WANG ; Shuang QU ; Jia-Wu LIANG ; Zi-Hao TANG ; Jin-Long ZHAO ; Lei TIAN
Chinese Journal of Traumatology 2024;27(5):272-278
Purpose::This study evaluated the methods and clinical effects of multidisciplinary collaborative treatment for occlusal reconstruction in patients with old jaw fractures and dentition defects.Methods::Patients with old jaw fractures and dentition defects who underwent occlusal reconstruction at the Third Affiliated Hospital of Air Force Military Medical University from January 2018 to December 2022 were enrolled. Clinical treatment was classified into 3 phases. In phase I, techniques such as orthognathic surgery, microsurgery, and distraction osteogenesis were employed to reconstruct the correct 3-dimensional (3D) jaw position relationship. In phase II, bone augmentation and soft tissue management techniques were utilized to address insufficient alveolar bone mass and poor gingival soft tissue conditions. In phase III, implant-supported overdentures or fixed dentures were used for occlusal reconstruction. A summary of treatment methods, clinical efficacy evaluation, comparative analysis of imageological examinations, and satisfaction questionnaire survey were utilized to evaluate the therapeutic efficacy in patients with traumatic old jaw fractures and dentition defects. All data are summarized using the arithmetic mean ± standard deviation and compared using independent sample t-tests. Results::In 15 patients with old jaw fractures and dentition defects (an average age of 32 years, ranging from 18 to 53 years), there were 7 cases of malocclusion of single maxillary fracture, 6 of malocclusion of single mandible fracture, and 2 of malocclusion of both maxillary and mandible fractures. There were 5 patients with single maxillary dentition defects, 2 with single mandibular dentition defects, and 8 with both maxillary and mandibular dentition defects. To reconstruct the correct 3D jaw positional relationship, 5 patients underwent Le Fort I osteotomy of the maxilla, 3 underwent bilateral sagittal split ramus osteotomy of the mandible, 4 underwent open reduction and internal fixation for old jaw fractures, 3 underwent temporomandibular joint surgery, and 4 underwent distraction osteogenesis. All patients underwent jawbone augmentation, of whom 4 patients underwent a free composite vascularized bone flap (26.66%) and the remaining patients underwent local alveolar bone augmentation. Free gingival graft and connective tissue graft were the main methods for soft tissue augmentation (73.33%). The 15 patients received 81 implants, of whom 11 patients received implant-supported fixed dentures and 4 received implant-supported removable dentures. The survival rate of all implants was 93.82%. The final imageological examination of 15 patients confirmed that the malocclusion was corrected, and the clinical treatment ultimately achieved occlusal function reconstruction. The patient satisfaction questionnaire survey showed that they were satisfied with the efficacy, phonetics, aesthetics, and comfort after treatment.Conclusion::Occlusal reconstruction of old jaw fractures and dentition defects requires a phased sequential comprehensive treatment, consisting of 3D spatial jaw correction, alveolar bone augmentation and soft tissue augmentation, and implant-supported occlusal reconstruction, achieving satisfactory clinical therapeutic efficacy.
7.Analysis of the current status of cancer incidence and mortality in Shanghai,2017 and trends of 2002-2017
Kai GU ; Yi PANG ; Chunxiao WU ; Chunfang WANG ; Liang SHI ; Yongmei XIANG ; Yangming GONG ; Peng PENG ; Jianming DOU ; Mengyin WU ; Xiaocong ZHANG ; Ganling DING ; Jianying YAN ; Yan SHI ; Chen FU
Tumor 2023;43(4):241-256
Background and purpose:The Shanghai Municipal Center for Disease Control and Prevention provides annual updates on cancer occurrence and trends in Shanghai.This study aimed to investigate the cancer incidence and mortality in 201 7 and their trends from 2002 to 2017 in Shanghai. Methods:Data of new cancer diagnoses and deaths from 2002 to 2017 were obtained from the Shanghai Municipal Center for Disease Control and Prevention population-based cancer registry and Vital Statistics System.Cancer incidence and mortality stratified by year of diagnosis or death,gender and age group were analyzed.Number,proportion,crude rate,age-specific rate,age-standardized rate and others were calculated.The number,proportion and rates of common cancers in different groups were also calculated.Trends in age-standardized rate of incidence and death rates for all cancers combined and for the common cancer types by gender were estimated by joinpoint analysis and characterized by the annual percent change(APC)and average annual percent change(AAPC).Segi's 1960 world standard population was used for calculating age-standardized incidence and mortality. Results:The new cancer cases and deaths were 79 378 and 37 186 in Shanghai in 2017.The crude rate of incidence was 546.55/105,and the age-standardized rate was 246.31/105.The age-standardized rate of incidence was higher among females than among males.The crude rate of mortality was 256.04/1 05,and the age-standardized rate was 88.41/105.The age-standardized rate of mortality was higher among males than among females.The age-specific numbers and rates of incidence and mortality increased with age.The age-specific number and rate of incidence reached the peak at the age groups of 60-64 years and older than 85 years,and those of mortality among males reached the peak at the age groups of 60-64 years and older than 85 years,and those of mortality among females reached the peak at the age groups of older than 85 years,respectively.The sites of top 10 common cancer types sorted by the number of incidence cases among males were lung,colorectum,stomach,prostate,liver,thyroid,pancreas,bladder,kidney and oesophagus,and among females were lung,breast,thyroid,colorectum,stomach,pancreas,liver,brain,central nervous system(CNS),cervix uteri and gallbladder,the sites of those sorted by the number of deaths among males were lung,stomach,colorectum,liver,pancreas,prostate,oesophagus,bladder,lymphoma and gallbladder,among females were lung,colorectum,breast,stomach,pancreas,liver,gallbladder,brain,CNS,ovary and lymphoma.The top 10 common cancer types stratified by gender and the top 5 common cancer types stratified by common age groups merged of incidence and mortality had wide variations.Overall,the age-standardized rates of incidence were stable from 2002 to 2009,and increased 2.88%on average per year from 2009 to 201 7.The age-standardized rates of mortality were stable from 2002 to 2011,and decreased 2.66%on average per year from 2011 to 201 7.The trends differed by gender and cancer type. Conclusion:Lung cancer,colorectal cancer,pancreatic cancer,thyroid cancer,female breast cancer,cervical cancer and male prostate cancer are the most common cancers in Shanghai,the appropriate screening technical scheme should be formulated according to the current situation of malignant tumors in Shanghai,promote cancer opportunistic screening,promote appropriate technologies for intervention and management of cancer patients in the community,reduce the disease burden of malignant tumors.
8.Survival analysis of cancer cases diagnosed during 2002-2013 in Shanghai:a population-based study
Chunxiao WU ; Kai GU ; Yi PANG ; Chunfang WANG ; Liang SHI ; Yongmei XIANG ; Yangming GONG ; Peng PENG ; Jianming DOU ; Mengyin WU ; Xiaocong ZHANG ; Ganling DING ; Jiaying YAN ; Yan SHI ; Chen FU
Tumor 2023;43(4):257-265
Objective:To investigate the survival of cancer cases diagnosed during 2002-2013 in Shanghai. Methods:Data on new cancer cases with dead and follow-up information were obtained from the population-based cancer registry and vital statistics system of Shanghai Municipal Center for Disease Control and Prevention.Survival indicators stratified by year of diagnosis,gender,site and age were analyzed.Number of cases and proportion were calculated.The observed survival rates were calculated based on the life table.The probabilities of surviving from 0 to 99 years old were estimated according to the Elandt-Johnson model,and then the cumulative expected survival rates were calculated according to the Ederer Ⅱ method.Finally,the relative survival rates and average annual percent changes of their trends were calculated.The age-standardized relative survival rates adjusted by International Cancer Survival Standard weights were calculated. Results:Total 644 520 new cancer cases were diagnosed during 2002-2013 in Shanghai,accounting for 643 545(99.85%)cases included in the observed cohort for survival analysis.The 5-year observed survival rate increased from 37.61%to 46.47%.The 5-year relative survival rate increased from 42.1 8%to 51.11%.The 5-year age-standardized relative survival rate increased from 40.57%to 49.80%.Among the 5-year relative survival rates of cases diagnosed during 2011 to 2013,99.43%of thyroid cancer was the highest,followed by female breast cancer(88.35%)and corpus uteri cancer(85.56%);5.87%of pancreas cancer was the lowest,followed by gallbladder cancer(13.64%)and oesophagus cancer(17.72%).the rate of lung cancer with the largest number of cases was 23.59%,followed by colorectal cancer(59.82%)and stomach cancer(38.65%).The 5-year relative survival rate of total cases of all sites increased from 40.55%in 2002 to 52.77%in 2013,with an average annual percent change of 2.40%.13 cancer types showed increasing trends,such as liver cancer and lung cancer,while the trends of other cancer types were not statistically significant,such as pancreatic cancer and gallbladder cancer. Conclusion:The diagnostic levels and survival rates of cancer cases have been improved continuously in Shanghai.The trends of different cancer types were varied.
9.Reliability and reproducibility of three classification systems for distal humeral coronal fractures
Gang FU ; Changrun LI ; Ting LI ; Xiang YU ; Zhaoning LI ; Liang DING ; Zhijian SUN ; Meng MI
Chinese Journal of Orthopaedic Trauma 2023;25(9):799-804
Objective:To investigate the reliability and repeatability of 3 classification systems for coronal fractures of distal humerus.Methods:Included were the imaging data (X-ray and CT scan) of the 64 patients with distal humeral coronal fracture who had been admitted to the outpatient and emergency departments of Beijing Jishuitan Hospital from January, 2015 to December, 2021. Four orthopedic surgeons (1 chief surgeon, 1 associate chief surgeon, 1 attending surgeon, and 1 resident surgeon) served as observers who classified the fractures by their imaging data respectively according to the Bryan-Morrey, Ring and Dubberley classifications. Four weeks later when the imaging data of 64 patients were renumbered, the 4 orthopedic surgeons performed the same classifications again. Inter-observer and intra-observer Kappa values were calculated for the 3 classifications. Landis and Koch Kappa's Benchmark Scale was used to interpret the results.Results:Interobserver confidence: The average agreement of the Bryan-Morrey classification was 75.0%, and its Kappa value was 0.546, indicating moderate agreement. The average consistency of Ring classification was 74.7%, and its Kappa value was 0.702, indicating high consistency. The average consistency of Dubberley classification was 84.1%, and its Kappa value was 0.785, indicating high consistency. Intra-observer repeatability: The average consistency of Bryan-Morrey classification was 89.9% and its Kappa value was 0.824 for the same observer. The average consistency of Ring classification was 91.0%, and its Kappa value was 0.884. The average consistency of Dubberley classification was 91.8%, and its Kappa value was 0.888.Conclusions:The 3 classification systems for distal humeral coronal fractures all demonstrate high reproducibility. As the Dubberley classification system is relatively more reliable, it has a certain guiding value for the treatment of coronal fractures of the distal humerus. However, in clinical practice, an optimal surgical strategy should take into account various factors that may affect fracture typing.
10.Influencing factors of viral RNA shedding time in patients with SARS-CoV-2 infection
Xin ZOU ; Ke XU ; Qigang DAI ; Jianguang FU ; Songning DING ; Yin WANG ; Shenjiao WANG ; Haodi HUANG ; Jianli HU ; Yang ZHOU ; Xiang HUO ; Qingxiang SHANG ; Changjun BAO
Chinese Journal of Experimental and Clinical Virology 2023;37(3):296-302
Objective:To understand the relationship between the RNA shedding time of SARS-CoV-2 infected persons and the single nucleotide mutation of the virus, the population of infected persons, underlying diseases and other factors, so as to provide more clues for the study of SARS-CoV-2 infection dynamics.Methods:The data of epidemiology, clinical manifestations, and underlying diseases of infected persons in a cluster epidemic of COVID-19 in Jiangsu province from July to September 2021 were collected. Nasopharyngeal swab samples of cases were collected, and the whole genome of the virus was sequenced by second-generation sequencing technology. The online analysis platform was used to judge the virus type and analyze the mutation site, and Cox proportional risk model was used to analyze the relationship between the RNA shedding time of SARS-CoV-2 and various research factors.Results:There were 350 persons who finally obtained the whole genome sequence of the virus in this COVID-19 outbreak, of which 60.3% were female, the median age was 49 years old (interquartile range, IQR: 37-65 years old)), and the median time of virus shedding was 33 days ( IQR, 26-44 days). The whole-genome sequencing analysis showed that compared with the Wuhan reference strain sequence, the infected persons’ sequence had 34~41 nucleotide mutation sites, belonging to VOC/Delta variant (B.1.617.2 evolutionary branch), and C346T, C1060T, T2803C, T7513C, A29681C were the main single nucleotide polymorphisms (SNPs) of this epidemic. Cox regression analysis showed that age, underlying disease, clinical classification, vaccination, SNP T2803C and T7513C had an impact on the RNA shedding time of SARS-CoV-2. The adjusted multivariate Cox regression result showed that age [ HR=0.73, 95% CI (0.55, 0.95)] and T7513C [ HR=0.37, 95% CI (0.18, 0.77)] were still the risk factors for the extension of SARS-CoV-2 RNA shedding time. Conclusions:This study analyzed the effects of the individual factors and viral single nucleotide variations on the time of viral RNA shedding. Those who were older, suffered from hypertension, had more severe clinical symptoms, were not vaccinated or incompletely vaccinated, and had T7513C mutation in the infected virus, had a risk of a long RNA shedding time of SARS-CoV-2, which should be given special attention and follow-up after rehabilitation.

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