Domestic and foreign literatures related to the persistence of SARS-CoV-2 and the re-positive cases infected with SARS-CoV-2 were reviewed, and the characteristics and infectivity of the re-positive cases were analyzed to provide scientific evidence for the improvement of case management and the development of measures to stop the spread of SARS-CoV-2. Existing studies have shown that re-positive rate of SARS-CoV-2 ranged from 2.4% to 19.8%, the median of interval between re-positive detection and discharge was 4-15 days. Following the second course of the disease, the anti-SARS-CoV-2 IgM, IgG and IgA positive rates of the cases were 11.11%-86.08%, 52.00%-100.00% and 61.54%-100.00% respectively, the total antibody and neutralizing antibody positive rates were 98.72% and 88.46%. The viral load of the re-positive cases was lower than that in the initial infection. At least 3 380 re-positive cases have been reported globally. SARS-CoV-2 strains were isolated from the samples of 3 re-positive cases (1 immunodeficiency case and 2 cases with abnormal pulmonary imaging). There were close contacts that were infected by an asymptomatic case taking immunosuppressive agents. In conclusion, the infectivity of re-positive cases infected with SARS-CoV-2 is generally very low. Rare re-positive cases infected with SARS-CoV-2 might cause further transmission. The management approach for the re-positive cases can be based on the assessment of the individual transmission risk according to the pathogen detection results.
Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Humans ; Immunoglobulin M ; SARS-CoV-2

Objective:To evaluate the measurement agreement of Roche 25(OH)D immunoassay(evaluation method) with LC-MS/MS (reference method).Methods:A total of 909 residual serum samples from routine health check participants were collected from May to June in 2019. 25(OH)D concentrations were measured by evaluation method and LC-MS/MS, respectively. Passing-bablok regression, intraclass correlation coefficient (ICC), Bland Altman plots and Kappa test were used to analyze the consistency and bias on the results derived from the two measurement methods.Results:The 25(OH)D concentration derived from evaluation method was significantly different from those from LC-MS/MS method ( P<0.001). Slope of regression for evaluation method and LC-MS/MS was 0.962(95% CI 0.919-1.007), while intercept was -0.185 (95% CI -1.191-0.745). The ICC was 0.765 (95% CI 0.735-0.792). Altman plot showed that the average deviation between evaluation method and LC-MS/MS was -0.902 ng/ml (0.300%). The coincidence rate of evaluation method′s judgment of vitamin D sufficiency, insufficiency and deficiency with LC-MS/MS was 83.39%, and the weighted Kappa values was 0.790. Conclusion:Roche automatic 25(OH)D immunoassay shows acceptable correlation and agreement with LC-MS/MS, however, it is to note that the deviation between immunoassay and LC-MS/MS may lead to wrong judgment of vitamin D nutritional status. It is recommended that each laboratory should establish own corresponding reference values for 25(OH)D concentrations derived from these two methods.

Objective:To explore the strategies and complications of the submucosal tunneling endoscopic resection (STER) in the treatment of esophageal duplicated cyst (EDC).Methods:From January 2013 to December 2019, at Department of Gastroenterology, Taizhou Hospital of Zhejiang Province, the clinical data of 11 hospitalized patients with EDC diagnosed by pathological examination who underwent STER were collected. The clinical featured, computed tomography (CT) findings, endoscopic findings, postoperative efficacy, complications and pathological results after operation were summarized.Results:Among the 11 patients, there were 6 males and 5 females, the age ranged from 13 to 67 years, and the mean age was (43.0±18.2) years. One case presented with swallowing obstruction, 1 case with belching, 4 cases with upper abdominal pain, and the remaining 5 cases had no specific clinical symptoms. Under endoscopy, the lesions of 11 patients were hemispherical or mound-shaped with smooth surface submucosal masses in the esophageal cavity, which were soft to touch. Under endoscopic ultrasonography, they all appeared as hypoechoic masses with clear boundary located in the esophageal muscularis propria. The results of CT scan of 9 patients showed round low-density cystic masses, among them 7 cases showed mild enhancement. The maximum diameter of the cysts was 1.5 to 4.4 cm, with mean maximum diameter being (2.8±0.8) cm, and the maximum diameter of most patients (7 cases) were 2 to 3 cm. The other two patients showed only slightly thickened esophageal wall on CT. Five lesions occurred in the horizontal mediastinum of the lower esophagus. All the 11 patients underwent STER operation successfully, among them 6 patients received simple STER and the cysts were completely resected, and the other 5 patients received STER and cauterization with argon ion for the residual cyst wall. The pathological results after operation indicated that 6 cases were congenital esophageal cysts and 5 cases were bronchogenic cysts. The median follow-up time (range) of 11 patients was 42 months (12-86 months). Ten patients recovered well after the operation, and local recurrence, malignant transformation or metastasis were not found. One case had recurrence, and was treated with STER and cauterization with argon ion for residual cyst wall and cured. No complications such as bleeding, fistula, mediastinal infection or death occurred during and after operation in all the 11 patients.Conclusions:STER is a minimally invasive, safe and effective treatment for EDC, and may be a new treatment for EDC.

Objective To explore the pathologic features and distribution characteristics of upper gastrointestinal submucosal tumors (SMT).Methods From January 2013 to December 2017,at Department of Gastroenterology of Taizhou Hospital Affiliated to Wenzhou Medical University,clinical data of 1 182 hospitalized patients with 1 237 upper gastrointestinal SMT who underwent endoscopic therapy and diagnosed by pathology and immunohistochemistry was retrospectively analyzed including the pathological types,tumor of locations,endoscopic findings,layer of origin and tumor size.Results There were 473 esophageal SMT,including 387(81.8％) leiomyomas,located in the mucosal muscularis or muscularis propria;and 59(12.5％)cysts located in the submucosa or mucosal muscularis.There were 138(29.2％) lesions,159(33.6％) lesions and 176(37.2％) lesions in the upper,middle and lower esophagus respectively,and the most common type was leiomyoma.A total of 723 tumors were gastric SMT,among them 284 (39.3％) lesions were gastrointestinal stromal tumors (GIST) and 273(37.8％) lesions were leiomyomas,and all located in the muscularis propria.A total of 69(9.5％) lesions located at cardia,the common types were leiomyoma (55 lesions,79.7％) and GIST (nine lesions,13.0％).A total of 239 (33.1％) lesions located at gastric fundus,the common types were GIST (152 lesions,63.6％) and leiomyoma (79 lesions,33.1％).A total of 280 (38.7％) lesions located at gastric body,the common types were leiomyoma (138 lesions,49.3％) and GIST (111 lesions,39.6％).A total of 127 (17.6％) lesions located at gastric antrum,the common types were heterotopic pancrease (71 lesions,55.9％) and lipoma (26 lesions,20.5％),and all were located in the submucosa,some involved the muscularis propria.There were six (0.8％) lesions at gastric angle,and two (0.3％) at gastrointestinal anastomosis.Forty-one lesions were duodenal SMT,among them 23(56.1％) located at duodenal bulb,the common types were cyst (10 lesions,43.5％),lipoma (five lesions,21.7％) and heterotopic pancrease (five lesions,21.7％).A total of 18(43.9％) lesions located at descending duodenum,the common types were lipoma (nine lesions,50.0％) and cyst (five lesions,27.8％),and all lesions located in the submucosa.Conclusions The most common type of SMT in the esophagus and cardia is leiomyoma,however the SMT in gastric fundus and body are mostly leiomyomas and GIST,while in gastric antrum,most SMT are heterotopic pancreases and lipomas.In duodenal bulb and descending duodenum,the common types of SMT are cyst and lipoma.

Objective To explore the impact of butylphthalide soft capsules on the related factors and quality of life of Parkinson patients with dementia.Methods 90 Parkinson patients with dementia were selected,and they were divided into the study group and the control group by the random number table method,45 cases in each group.The control group was treated with donepezil hydrochloride combined with routine nursing method,and the study group was treated with butylphthalide soft capsules based on the treatment of the control group.Before and after treatment,the serum C-reactive protein(CRP),recombinant human Parkinson disease protein 7 (PARK7),neurotrophic factor -3 (NT-3) levels of all patients were detected.And the quality of life of patients at admission and discharge were evaluated by the scale of disease self management efficiency and quality of life scale WHO (WHO QOL-BREF),quality of life of the two groups was compared before and after treatment.The Parkinson's Disease Rating Scale (UPDRS) scores was compared between the two groups before and after treatment.Results Before treatment,the dementia related factors and quality of life score,UPDRS score of the two groups had no statistically significant differences (all P ＞ 0.05).After treatment,the dementia related factors of the two groups were all improved,which of the study group improved significantly [CRP:(3.24 ± 0.78) mg/L vs.(6.02 ± 0.95) mg/L,PARK7:(13.15 ± 1.51) μg/L vs.(24.93 ±2.02)μg/L,NT-3:(34.16 ± 3.47) μg/L vs.(26.23 ± 2.97) μg/L,all P ＜0.05].After treatment,the quality of life(QOL) and UPDRS score of the study group were significantly higher than those of the control group [(80.5 ± 12.5) points vs.(66.0 ± 10.3) points,(33.28 ± 2.18) points vs.(41.26 ± 2.54) points,all P ＜ 0.05].Conclusion Butylphthalide soft capsules can effectively improve the dementia related factor of Parkinson patients with dementia,and enhance the quality of life with good effect.

Objective To set up a computer-assisted polyp detection system under colonoscopy,and to preliminarily verify its effectiveness.Methods Based on Faster R-CNN algorithm and the open source implementation of the open source framework tensorflow and Faster R-CNN,a computer-assisted polyp detection system under colonoscopy was constructed.According to the size and difficulty of the training set,five test groups were set up:test group one,two,three and four contained 1 000,2 000,4 000 and 6 000 training samples,respectively.Test group five increased the probability of selecting the difficult samples based on 6 000 training samples.In different training sets,the sensitivity,specificity,other classification evaluation parameters,and the evaluation parameters of target detection such as recall and precision of this polyps detection system were calculated.Results Classification evaluation parameters showed that the sensitivities of test group one,two,three,four and five were 90.1％,93.3％,93.3％,93.3 ％ and 93.5 ％,respectively,and the difference was statistically significant (x2 =25.324,P＜0.01).The sensitivities of test group two,three,four and five were all higher than that of test group one,and the differences were statistically significant (x2 =13.964,13.508,13.508 and 13.386,all P＜ 0.006 25).There were no significant differences in specificity and positive predictive value among test groups (both P＞0.05).The negative predictive values of test group one,two,three,four and five were 90.4％,93.3％,93.3％,93.3％ and 93.5％,respectively,and the differences were statistically significant (x2 =21.862,P＜0.01).The negative predictive values of test group two,three,four and five were higher than that of test group one,and the differences were statistically significant (x2=11.447,11.564,11.755,13.760;all P＜0.006 25).As the training sample size increased from 1 000 to 2 000,the area under curve (AUC) increased by 2％,and further increased the sample size to 6 000,AUC increased by less than 1 ％.At this point maintaining the same sample size while increasing the proportion of difficult samples,AUC increased by 0.4％.The results of evaluation parameters of target detection showed that the recall rate of each test group was 73.6％,79.8％,79.5％,79.8％ and 83.3％,respectively,and the differences were statistically significant (x2 =71.936,P＜0.01).Among them,the recall rates of test group two,three and four were higher than that of test group one,and the differences were statistically significant (x2 =25.960,23.492 and 25.960,all P＜0.006 25),and the recall rate of test group five was higher than those of test group one,two,three and four,and the differences were statistically significant (x2=67.361,9.899,11.527 and 9.899;all P＜0.006 25).In addition,the precision rates of test group one,two,three,four and five were 87.9％,85.3％,90.2％,91.4％ and 89.2％,respectively,and the difference was statistically significant (x2=48.194,P＜0.01).The precision rates of test group three and five were higher than that of test group two,and the differences were statistically significant (x2 =24.508 and 15.223,both P＜0.006 25),and the precision rate of test group four was higher than those of test group one and two,and the differences were statistically significant (x2=13.524 and 39.120,both P＜0.006 25).As samples size and training difficulty increased,the values of F1-score and mean average precision increased steadily.Conclusions This study initially constructed a computer-assisted polyp detection system under colonoscopy.Currently the maximum sensitivity reached 93.5％,and the maximum recall rate reached 83.3％.Increasing the training set size may improve the polyp detection result to a certain degree,however it will reach a bottleneck.At this time,increasing the training difficulty can further improve the detection scores,especially the recall rate.

Objective To summarize the endoscopic appearance,endoscopic ultrasound findings and histopathological characteristics of gastric inflammatory fibroid polyp (IFP) in order to improve diagnosis of IFP.Methods From September 2011 to November 2016,49 patients with pathologically comfirmed gastric IFP,who underwent endoscopy in Taizhou Hospital of Zhejiang Province,were enrolled.The medical history,endoscopic examination,treatment and follow-up were retrospectively enalyzed.Results Among 49 patients with gastric IFP (16 males and 33 females;average age 54 years) the maximum diameter of 33 cases (67.3％) was between 1.0 cm and 2.0 cm.Forty-eight cases had single lesion and one case had multiple lesions.The lesions of 17 cases (34.7％) were located at the anterior wall of gastric antrum,the lesions of seven cases (14.3％) were at the posterior wall of gastric antrum,the lesions of seven cases (14.3％) were at the lesser curvature of gastric antrum and the lesions of seven cases (14.3％) were at the great curvature of gastric antrum.Among the lesions of 41 patients who received endoscopic ultrasonography,28 lesions were located in the submucosa of stomach,13 lesions were located in mucosa and muscularis mucosa.The rate of misdiagnosis of endoscopic ultrasonography was 29.3％ (12/41).The endoscopic ultrasound findings of the lesions included 26 hypoechoic structures,11 hyperechoic structures and four slightly hypoechoic structures.The lesions of all the patients were successfully removed by endoscopic polypectomy without any complication.Thirty-seven lesions were treated by endoscopic submucosal dissection (ESD) and 12 lesions by endoscopic mucosal resection (EMR).All the patients were not clearly diagnosed before operation and were finally diagnosed by pathological examination.Postoperative pathological examination showed that in the suhmucosa and mucosa lamina propria,spindle-shaped cells proliferated and arranged in an interwoven pattern or cells around vessels or mucosal glands formed vortex-like or onion skin like pattern.Forty-seven patients were followed up and the median follow-up time was 31 months.All patients survived withont recurrence or metastasis until the submission of this paper.Conclusions The rate of misdiagnosis of gastric IFP is high before operation,and the diagnosis is depended on histopathological examination.Endoscopic resection is the first choice because the diameter of most lesions are less than 5 cm.

Objective To investigate the differential diagnostic value of 18 F‐DG PET/CT imaging on gastric malignancies and primary gastric lymphoma(PGL) .Methods A total of 93 cases of gastric cancer (23 cases of mucinous adenocarcinoma and 70 ca‐ses of non mucinous adenocarcinoma ) ,58 cases of PGL and 31 cases of Diffuse Large b Cell Lymphoma (DLBCL ) and 27 cases of Mucosa associated tissue lymphoma (MALT) treated in our hospital from Jun 2012 to Jun 2015 were involved in this study .Their clinical data ,SUVmax ,maximum lesions thickness ,CT value ,lesion shape ,merge splenomegaly and lymph node metastasis were compared .The relation between SUVmax and maximum lesions thickness were analyzed with Pearson analysis .Results The aver‐age age and the lesions involve cardiac orifice rate of the gastric cancer group were significantly higher than that of PGL group (P<0 .05) .The occurence rate of SUVmax and splenomegaly in the gastric cancer group were significantly lower than that of PGL group (P<0 .05) .From the perspective of lesion shape ,type Ⅱand Ⅲ were mostly found in gastric cancer group ,while type ⅠandⅡwere mostly seen in PGL group ,the difference was significant(P<0 .05) .Further analysis showed that the SUVmax of DLBCL was significantly higher than other type(P<0 .05);the maximum lesions thickness of DLBCL was significantly higher than gastric mucous adenocarcinoma and MALT (P<0 .05) .Pearson analysis showed that there was no significant difference between SUVmax of different pathological type and the maximum lesions thickness (P>0 .05) .Conclusion The diagnostic value of 18 F‐FDG PET/CT in gastric malignancies was high ,and patients with different cancer and pathological type were different in SUVmax ,maximum le‐sions thickness and lesion shape .

Objective To evaluate the safety and effectiveness of three endoscopic methods for re-moval of common bile duct stones (CBDs)accompanied with periampullary diverticula(PAD).Methods A total of 154 patients hospitalized at Taizhou Hospital and Taizhou No.1 People′s Hospital of Zhejiang prov-ince from December 2012 to July 2013 were divided randomly into three groups,i.e.,EST,EPBD and ES-BD group,and received the treatment of EST,EPBD and limited EST plus EPBD (ESBD)to extract CBDs, respectively.After 12 months of follow-up,the rate of full stone clearance,stones clearance rate in one time,the rate of mechanical lithotripsy,the rate of urgent lithotripsy,the average procedures,the average removal time and the complication incidence among three groups were compared.Results The rates of stone clearance in one time in group ESBD was higher than those of group EST and group EPBD (94.12% VS 78.43%,73.08%;P <0.05)with significant difference.The average procedures in group ESBD was lower than that of group EPBD (1.08 VS 1.31,P <0.05),which also showed significant difference.The occur-rence rates of early complication in group ESBD was lower than that of group EPBD (15.69% VS 34.61%, P <0.05).The occurrence rates of post-ERCP hyperamylasemia in group ESBD was lower than that of group EPBD (5.88% VS 21.15%)with significant difference (P <0.05).The incidence of pneumobilia in group EST was higher than those of group EPBD (52.27% VS 26.19%,P =0.013)and group ESBD (52.27%VS 27.66%,P =0.016).Conclusion The stone extraction efficiency of ESBD is better than that of EST and EPBD.Compared with conventional EST,ESBD shows similar safety level,and is safer than EPBD.So ESBD is a safe and effective method to remove CBDs with PAD.

Spinosad represents a new class of insecticides produced by Saccharopolyspora spinosa. To understand the transcription of the spinosad biosynthetic gene cluster, two promoter detection plasmids based on different reporter genes were constructed and used to detect 9 promoters in the spinosad biosynthetic gene cluster. In addition, the temporal transcriptional profiles of the corresponding genes controlled by the 9 promoters, together with 4 genes outside of the spinosad cluster but are required for the synthesis of sugars in spinosad, were examined by real-time PCR. The results indicate that the 9 spinosad biosynthetic genes were highly expressed at the stationary phase, which coincides with the accumulation of spinosad in the fermentation broth. Of particular note is that the transcription of the 4 sugar synthetic genes showed higher level at the exponential phase, suggesting the expression of sugar synthetic genes is not correlated with the spinosad synthetic genes. The data suggest that spinosad biosynthesis could be improved by engineering the expression pattern of the sugar synthetic genes that lie outside the spinosad gene cluster.
Drug Combinations ; Insecticides ; metabolism ; Macrolides ; metabolism ; Multigene Family ; Plasmids ; Promoter Regions, Genetic ; Real-Time Polymerase Chain Reaction ; Saccharopolyspora ; genetics ; metabolism