1.National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria
Zhiying LIU ; Yunbo CHEN ; Jinru JI ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(1):42-57
Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period,9 035 strains of Gram-negative bacteria were collected from 51 hospitals,of which 7 895(87.4%)were Enterobacteriaceae and 1 140(12.6%)were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli( n=4 510,49.9%), Klebsiella pneumoniae( n=2 340,25.9%), Pseudomonas aeruginosa( n=534,5.9%), Acinetobacter baumannii complex( n=405,4.5%)and Enterobacter cloacae( n=327,3.6%). The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus spp. were 47.1%(2 095/4 452),21.0%(427/2 033)and 41.1%(58/141),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(58/4 510)and 13.1%(307/2 340);62.1%(36/58)and 9.8%(30/307)of CREC and CRKP were resistant to ceftazidime/avibactam combination,respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 59.5%(241/405),while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 18.4%(98/534). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions,with statistically significant differences in the prevalence of CRKP and CRPA( χ2=20.489 and 20.252, P<0.001). The prevalence of CREC,CRKP,CRPA,CRAB,ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals( χ2=11.953,81.183,10.404,5.915,12.415 and 6.459, P<0.01 or <0.05),while the prevalence of CRPA was higher in economically developed regions(per capita GDP ≥ 92 059 Yuan)than that in economically less-developed regions(per capita GDP <92 059 Yuan)( χ2=6.240, P=0.012). Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend,and Escherichia coli is ranked in the top,while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different,and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.
2.Survival time and influencing factors analysis of clinically diagnosed sporadic Creutzfeldt-Jakob disease patients in China from 2020 to 2022
Weiwei ZHANG ; Donglin LIANG ; Donghua ZHOU ; Yuan WANG ; Kang XIAO ; Wei ZHOU ; Xiaoping DONG ; Qi SHI
Acta Universitatis Medicinalis Anhui 2024;59(10):1842-1848
Objective To investigate the survival time of patients diagnosed with sporadic Creutzfeldt-Jakob disease in China between 2020 and 2022 and explore the associated factors influencing survival.Methods A retrospective analysis was conducted on clinically diagnosed cases with complete information on sporadic Creutzfeldt-Jakob dis-ease diagnosed by the China Creutzfeldt-Jakob disease surveillance network from 2020 to 2022,baseline information of patients was obtained from the case files,telephone follow-up was used to obtain the treatment and survival status of the patients after the diagnosis,life-table method was used for estimating the survival rate,Kaplan-Meier method was used for calculating the median survival time and the 95%CI,Cox regression model was used for univariate and multivariate analyses were used to screen for factors influencing survival time.Results The median survival time of the 300 patients was 5 months(95%CI:4.165-5.835).Univariate analysis revealed that factors such as age at onset,regional distribution,presence of corticobasal or extrapyramidal symptoms as initial manifestations,number of initial symptoms,presence of corticobasal or extrapyramidal functional abnormalities,number of major clinical manifestations,presence of typical electroencephalogram findings,and use of nasal feeding during the course of the disease were potential factors influencing survival time(P<0.1).Multivariate analysis showed that the risk of death in patients with onset age>65 years was 1.350 times higher than in patients with onset age ≤65 years(P=0.021,95.0%CI:1.046-1.742).Patients without pyramidal or extrapyramidal dysfunction had a 0.674-fold lower risk of death compared to those with these symptoms(P=0.020,95.0%CI:0.483-0.939).Patients who did not receive nasal feeding had a 1.817-fold higher risk of death compared to those who did(P<0.001,95.0%CI:1.406-2.349).Conclusion Age at onset,the presence of pyramidal or extrapyramidal functional abnormalities,and the use of nasal feeding during the disease course are factors influencing the survival time of pa-tients clinically diagnosed with sCJD.
3.Clinical features and risk factors analysis of patients with hyperthyroidism complicating atrial fibrillation
Chengwei ZHANG ; Qi WU ; Wei CHEN ; Xiaoping LI
Chongqing Medicine 2024;53(12):1772-1777
Objective To analyze the clinical characteristics and prognosis differences of the patients with hyperthyroidism complicating atrial fibrillation.Methods A retrospective analysis was adopted.The clinical data of 1 160 patients with hyperthyroidism admitted and treated in the Second Affiliated Hospital of Chengdu Medical College during 2004-2022 were collected.The patients were divided into the atrial fibrilla-tion group(n=581)and non-atrial fibrillation group(n=579)according to whether complicating atrial fibril-lation.Then the levels of thyroid functional indicators[free triiodothyronine(FT3),free tetraiodothyronine(FT4),thyroid-stimulating hormone(TSH)],cholesterol,brain natriuretic peptide(BNP),N-terminal brain natriuretic peptide precursor(NT-proBNP)and triglyceride(TG)as well as the hypertension history,diabetic history,smoking history,inner diameter of left and right atrium(ventricle),ejection fraction and NYHA grade were analyzed and compared between the two groups.The multivariate logistic regression analysis was per-formed for the above possible risk factors.Results There were statistically significant differences in the age,FT3,TSH,left atrial diameter,LVEF,NYHA grade,BNP and NT-proBNP between the two groups(P<0.05).The multivariate logistic regression analysis results showed that left atrial inner diameter rather large,TSH rather low and BNP rather high were the independent risk factors for atrial fibrillation occurrence in the patients with hyperthyroidism.The results of receiver operating characteristic(ROS)curve of above 3 indica-tor in predicting the occurrence of atrial fibrillation occurrence in the patients with hyperthyroidism showed that the area under the curve of left atrial inner diameter was significantly higher than that of TSH and BNP,and the differences were statistically significant(P<0.05).Conclusion When the left atrial inner diameter in the patients with hyperthyroidism is enlarged,TSH is decreased and BNP is increased,the risk of atrial fibril-lation occurrence is increased.
4.Effect of differences in health care situations on the survival of patients with sporadic Creutzfeldt-Jakob disease
Weiwei ZHANG ; Donghua ZHOU ; Yuan WANG ; Kang XIAO ; Donglin LIANG ; Wei ZHOU ; Xiaoping DONG ; Qi SHI
Chinese Journal of Experimental and Clinical Virology 2024;38(1):37-42
Objective:To understand the medical care of patients with sporadic Creutzfeldt-Jakob disease in China and its relationship with survival time.Methods:A retrospective analysis was performed on data of 150 patients with sporadic Creutzfeldt-Jakob disease diagnosed by China′s Creutzfeldt-Jakob Disease Surveillance Network during the period of January 1, 2021 to December 31, 2022 in this study, and telephone follow-up with family members was used to obtain information of the patients′ care, treatment, and survival after diagnosis. Survival was estimated by life table method, median survival time and 95% confidence interval ( CI) were calculated by Kaplan-Meier method, log-rank method was used to compare the difference in survival time between different groups, and multifactorial analysis was performed by COX proportional risk regression model regarding the influencing factors on patients′ survival time. Results:The median survival time of 150 patients with sporadic Creutzfeldt-Jakob disease was 6 months, and the cumulative lifetime survival rates at 2, 6, 12, and 18 months were 62%, 39%, 22%, and 9%, respectively. The result of univariate analysis showed that the differences in survival time between groups with the presence or absence of cortical blindness in the first symptom, the presence or absence of respiratory support (oxygen therapy), the presence or absence of adjunctive medication, and the presence or absence of tube feeding (nasogastric) were meaningful ( P<0.1). Multifactorial COX regression analysis showed that the risk of death in patients without adjuvant medication was 1.429 times higher than that in patients with adjuvant medication (95.0% CI: 1.014-2.014), and the risk of death in patients without tube feeding (nasal feeding) was 1.479 times higher than that in patients with tube feeding (nasal feeding) (95% CI: 1.052-2.081). Conclusions:Whether or not adjuvant medication is administered and whether or not tube feeding (nasogastric) is used are factors that affect survival time in patients with sporadic Creutzfeldt-Jakob disease, and the administration of appropriate adjuvant medication and tube feeding (nasogastric) may contribute to prolonging survival time in patients with sporadic Creutzfeldt-Jakob disease.
5.MAX germline mutation-associated pheochromocytoma-paraganglioma syndrome: multiple endocrine neoplasia type 5
Xiaoping QI ; Weiying CHEN ; Xudong FANG ; Bijun LIAN ; Hongyuan YU ; Junwei WANG
Chinese Journal of Surgery 2024;62(8):798-804
The individualized precision management of hereditary pheochromocytoma (PHEO) and paraganglioma (PGL) syndromes (PPGLs) based on molecular diagnosis and molecular subtype is becoming more popular. The newly discovered MAX germline mutation-associated PPGLs are autosomally dominant and rare. To raise awareness and explore the effective management of individual diagnosis and treatment, the relevant literature published between January 2011 and February was systematically reviewed. There were a total of 101 patients in the 77 families, involving all 5 exons, containing 44 types of MAX germline mutations and mostly concentrated in exons 3 and 4 (64.4%), the main mutations were nonsense mutations and missense mutations (72.3%), and some were large fragment deletions or insertions, intron variant, gene fusion mutations were relatively infrequent. Furthermore, about 10% of the patients had a paternal parent-of-origin effect. Among the 101 patients, 96 (95.0%) developed PHEO including 15 metastatic PHEO, 61 bilateral PHEO and 35 unilateral PHEO. The age of diagnosis was (31.7±10.9) years (range: 13 to 80 years). The male to female ratio was 1.2∶1. Eleven were accompanied with chest and abdominal PGL. Eight (7.9%) were accompanied by functional pituitary adenoma. And 12 (11.9%) developed other neuroendocrine tumors (NET), of which 8 were accompanied by PHEO, including 4 hyperparathyroidism, 1 gangliocytoma and neuroblastoma, 1 pancreatic NET, 1 medullary thyroid carcinoma and 1 C cell hyperplasia. Six presented concomitant non-NET, including 1 tongue squamous cell carcinoma, 1 papillary thyroid carcinoma, 1 prostate cancer, 1 renal oncocytoma, 1 breast cancer with renal oncocytoma, and 1 thoracic chondrosarcoma with multifocal adenocarcinoma of lung. The remaining 5 cases (5.0%), including 4 other NET (2 ganglioblastoma, 1 abdominal neuroblastoma and 1 pancreatic NET) and 1 asymptomatic child, did not present PHEO. The MAX germline mutation may cause a novel multiple endocrine neoplasia, which can be described as type 5. A comprehensive baseline assessment of neural crest cell-derived diseases such as PPGL, pituitary adenoma, hyperparathyroidism, and/or gangliocytoma (neuroblastoma) was recommended for all people with MAX germline mutations, and the risk of bilateral and/or metastatic PHEO should also be considered. In contrast, patients with PPGLs combined with other NET, such as functional pituitary adenoma, should undergo genetic testing and pedigree screening that includes at least the MAX gene.
6.Comparison of the predictive value of multiparametric MRI and prostate-specific membrane antigen PET/CT for pelvic lymph node metastasis in prostate cancer
Wei TANG ; Yi CAI ; Yongxiang TANG ; Xiaoping YI ; Xiaomei GAO ; Lin QI
Chinese Journal of Surgery 2024;62(11):1008-1015
Objective:To compare the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) PET/CT in detecting pelvic lymph node metastasis in prostate cancer.Methods:This is a retrospective case series study. A retrospective analysis was conducted on the data of 115 prostate cancer patients who underwent both mpMRI and PSMA PET/CT before undergoing radical prostatectomy and extended pelvic lymph node dissection at the Department of Urology, Xiangya Hospital, Central South University, between March 2020 and September 2023. The age ( M(IQR)) was 67(10) years (range: 45 to 84 years), and the body mass index was 24(4) kg/m 2 (range: 18 to 30 kg/m 2). Pathological and imaging data were obtained from the patients. Lymph node pathology results were used as the gold standard to evaluate the diagnostic performance of mpMRI and PSMA PET/CT for detecting pelvic lymph node metastasis in PCa through diagnostic evaluation tests. Comparisons between groups were performed using independent samples t-test, Mann-Whitney U test, or χ2 test. Results:The positive rate for detecting pelvic lymph node metastasis was 18.3% (21/115) with mpMRI and 25.2% (29/115) with PSMA PET/CT. The pathological positive rate for lymph nodes was 28.7% (33/115). In patient-based analysis, the diagnostic sensitivity of PSMA PET/CT was significantly higher than that of mpMRI (63.6% vs. 30.3%, χ2=7.36, P=0.007). In lesion-based analysis, both the sensitivity and positive predictive value of PSMA PET/CT were significantly higher than those of mpMRI (sensitivity: 68.0% vs. 21.6%, χ2=42.20, P<0.01; positive predictive value: 50.0% vs. 23.1%, χ2=7.54, P=0.006). Conclusions:PSMA PET/CT and mpMRI both demonstrates good specificity in predicting pelvic lymph node metastasis in prostate cancer. However, PSMA PET/CT is significantly superior to mpMRI in terms of sensitivity and the detection rate of pathologically positive lymph nodes.
7.Investigation of the inhibitory potential of caffeic acid phenethyl ester on prion replication, amplification, and fibril formation in vitro
Zhiyue CHAO ; Xiaoxi JIA ; Jiafeng ZENG ; Yuezhang WU ; Kang XIAO ; Liping GAO ; Qi SHI ; Xiaoping DONG ; Cao CHEN
Chinese Journal of Preventive Medicine 2024;58(7):1011-1019
Objective:To investigate the effects and possible mechanisms of caffeic acid phenethyl ester (CAPE) on the replication, amplification, and fibre formation of prions (PrP Sc). Methods:The CCK8 assay was used to detect the cell viability of the prion-infected cell model SMB-S15 after CAPE treatment for 3 days and 7 days and the maximum safe concentration of CAPE for SMB-S15 was obtained. The cells were treated with a concentration within a safe range, and the content of PrP Sc in the cells before and after CAPE treatment was analyzed by western blot. Protein misfolding cycle amplification (PMCA) and western blot were used to assess changes in PrP Sc level in amplification products following CAPE treatment. Real-time-quaking induced conversion assay (RT-QuIC) technology was employed to explore the changes in fibril formation before and after CAPE treatment. The binding affinity between CAPE and murine recombinant full-length prion protein was determined using a molecular interaction assay. Results:CCK8 cell viability assay results demonstrated that treatment with 1 μmol/L CAPE for 3 and 7 days did not exhibit statistically significant differences in cell viability compared to the control group (all P<0.05). However, when the concentration of CAPE exceeded 1 μmol/L, a significant reduction in cell viability was observed in cells treated with CAPE for 3 and 7 days, compared to the control group (all P<0.05). Thus, 1 μmol/L was determined as the maximum safe concentration of CAPE treatment for SMB-S15 cells. The western blot results revealed that treatment with CAPE for both 3 and 7 days led to a detectable reduction in the levels of PrP Sc in SMB-S15 cells (all P<0.05). The products of PMCA experiments were assessed using western blot. The findings revealed a significant decrease in the levels of PrP Sc (relative grey value) in the PMCA amplification products of adapted-strains SMB-S15, 139A, and ME7 following treatment with CAPE, as compared to the control group (all P<0.05). The RT-QuIC experimental results demonstrated a reduction in fibril formation (as indicated by ThT peak values) in CAPE-treated mouse-adapted strains 139A, ME7, and SMB-S15, as well as in SMB-S15 cells infected with prions. Furthermore, CAPE exhibited varying degrees of inhibition towards different seed fibrils formation, with statistically significant differences observed (all P<0.05). Notably, CAPE exhibited a more pronounced inhibitory effect on ME7 seed fibrils. Molecular interaction analyses demonstrated significant binding between CAPE and murine recombinant prion protein, and the association constant was (2.92±0.41)×10 -6 mol/L. Conclusions:CAPE inhibits PrP Sc replication, amplification, and fibril formation in vitro possibly due to specific interactions with the prion protein at the molecular level.
8.MAX germline mutation-associated pheochromocytoma-paraganglioma syndrome: multiple endocrine neoplasia type 5
Xiaoping QI ; Weiying CHEN ; Xudong FANG ; Bijun LIAN ; Hongyuan YU ; Junwei WANG
Chinese Journal of Surgery 2024;62(8):798-804
The individualized precision management of hereditary pheochromocytoma (PHEO) and paraganglioma (PGL) syndromes (PPGLs) based on molecular diagnosis and molecular subtype is becoming more popular. The newly discovered MAX germline mutation-associated PPGLs are autosomally dominant and rare. To raise awareness and explore the effective management of individual diagnosis and treatment, the relevant literature published between January 2011 and February was systematically reviewed. There were a total of 101 patients in the 77 families, involving all 5 exons, containing 44 types of MAX germline mutations and mostly concentrated in exons 3 and 4 (64.4%), the main mutations were nonsense mutations and missense mutations (72.3%), and some were large fragment deletions or insertions, intron variant, gene fusion mutations were relatively infrequent. Furthermore, about 10% of the patients had a paternal parent-of-origin effect. Among the 101 patients, 96 (95.0%) developed PHEO including 15 metastatic PHEO, 61 bilateral PHEO and 35 unilateral PHEO. The age of diagnosis was (31.7±10.9) years (range: 13 to 80 years). The male to female ratio was 1.2∶1. Eleven were accompanied with chest and abdominal PGL. Eight (7.9%) were accompanied by functional pituitary adenoma. And 12 (11.9%) developed other neuroendocrine tumors (NET), of which 8 were accompanied by PHEO, including 4 hyperparathyroidism, 1 gangliocytoma and neuroblastoma, 1 pancreatic NET, 1 medullary thyroid carcinoma and 1 C cell hyperplasia. Six presented concomitant non-NET, including 1 tongue squamous cell carcinoma, 1 papillary thyroid carcinoma, 1 prostate cancer, 1 renal oncocytoma, 1 breast cancer with renal oncocytoma, and 1 thoracic chondrosarcoma with multifocal adenocarcinoma of lung. The remaining 5 cases (5.0%), including 4 other NET (2 ganglioblastoma, 1 abdominal neuroblastoma and 1 pancreatic NET) and 1 asymptomatic child, did not present PHEO. The MAX germline mutation may cause a novel multiple endocrine neoplasia, which can be described as type 5. A comprehensive baseline assessment of neural crest cell-derived diseases such as PPGL, pituitary adenoma, hyperparathyroidism, and/or gangliocytoma (neuroblastoma) was recommended for all people with MAX germline mutations, and the risk of bilateral and/or metastatic PHEO should also be considered. In contrast, patients with PPGLs combined with other NET, such as functional pituitary adenoma, should undergo genetic testing and pedigree screening that includes at least the MAX gene.
9.Comparison of the predictive value of multiparametric MRI and prostate-specific membrane antigen PET/CT for pelvic lymph node metastasis in prostate cancer
Wei TANG ; Yi CAI ; Yongxiang TANG ; Xiaoping YI ; Xiaomei GAO ; Lin QI
Chinese Journal of Surgery 2024;62(11):1008-1015
Objective:To compare the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) PET/CT in detecting pelvic lymph node metastasis in prostate cancer.Methods:This is a retrospective case series study. A retrospective analysis was conducted on the data of 115 prostate cancer patients who underwent both mpMRI and PSMA PET/CT before undergoing radical prostatectomy and extended pelvic lymph node dissection at the Department of Urology, Xiangya Hospital, Central South University, between March 2020 and September 2023. The age ( M(IQR)) was 67(10) years (range: 45 to 84 years), and the body mass index was 24(4) kg/m 2 (range: 18 to 30 kg/m 2). Pathological and imaging data were obtained from the patients. Lymph node pathology results were used as the gold standard to evaluate the diagnostic performance of mpMRI and PSMA PET/CT for detecting pelvic lymph node metastasis in PCa through diagnostic evaluation tests. Comparisons between groups were performed using independent samples t-test, Mann-Whitney U test, or χ2 test. Results:The positive rate for detecting pelvic lymph node metastasis was 18.3% (21/115) with mpMRI and 25.2% (29/115) with PSMA PET/CT. The pathological positive rate for lymph nodes was 28.7% (33/115). In patient-based analysis, the diagnostic sensitivity of PSMA PET/CT was significantly higher than that of mpMRI (63.6% vs. 30.3%, χ2=7.36, P=0.007). In lesion-based analysis, both the sensitivity and positive predictive value of PSMA PET/CT were significantly higher than those of mpMRI (sensitivity: 68.0% vs. 21.6%, χ2=42.20, P<0.01; positive predictive value: 50.0% vs. 23.1%, χ2=7.54, P=0.006). Conclusions:PSMA PET/CT and mpMRI both demonstrates good specificity in predicting pelvic lymph node metastasis in prostate cancer. However, PSMA PET/CT is significantly superior to mpMRI in terms of sensitivity and the detection rate of pathologically positive lymph nodes.
10.Investigation of the inhibitory potential of caffeic acid phenethyl ester on prion replication, amplification, and fibril formation in vitro
Zhiyue CHAO ; Xiaoxi JIA ; Jiafeng ZENG ; Yuezhang WU ; Kang XIAO ; Liping GAO ; Qi SHI ; Xiaoping DONG ; Cao CHEN
Chinese Journal of Preventive Medicine 2024;58(7):1011-1019
Objective:To investigate the effects and possible mechanisms of caffeic acid phenethyl ester (CAPE) on the replication, amplification, and fibre formation of prions (PrP Sc). Methods:The CCK8 assay was used to detect the cell viability of the prion-infected cell model SMB-S15 after CAPE treatment for 3 days and 7 days and the maximum safe concentration of CAPE for SMB-S15 was obtained. The cells were treated with a concentration within a safe range, and the content of PrP Sc in the cells before and after CAPE treatment was analyzed by western blot. Protein misfolding cycle amplification (PMCA) and western blot were used to assess changes in PrP Sc level in amplification products following CAPE treatment. Real-time-quaking induced conversion assay (RT-QuIC) technology was employed to explore the changes in fibril formation before and after CAPE treatment. The binding affinity between CAPE and murine recombinant full-length prion protein was determined using a molecular interaction assay. Results:CCK8 cell viability assay results demonstrated that treatment with 1 μmol/L CAPE for 3 and 7 days did not exhibit statistically significant differences in cell viability compared to the control group (all P<0.05). However, when the concentration of CAPE exceeded 1 μmol/L, a significant reduction in cell viability was observed in cells treated with CAPE for 3 and 7 days, compared to the control group (all P<0.05). Thus, 1 μmol/L was determined as the maximum safe concentration of CAPE treatment for SMB-S15 cells. The western blot results revealed that treatment with CAPE for both 3 and 7 days led to a detectable reduction in the levels of PrP Sc in SMB-S15 cells (all P<0.05). The products of PMCA experiments were assessed using western blot. The findings revealed a significant decrease in the levels of PrP Sc (relative grey value) in the PMCA amplification products of adapted-strains SMB-S15, 139A, and ME7 following treatment with CAPE, as compared to the control group (all P<0.05). The RT-QuIC experimental results demonstrated a reduction in fibril formation (as indicated by ThT peak values) in CAPE-treated mouse-adapted strains 139A, ME7, and SMB-S15, as well as in SMB-S15 cells infected with prions. Furthermore, CAPE exhibited varying degrees of inhibition towards different seed fibrils formation, with statistically significant differences observed (all P<0.05). Notably, CAPE exhibited a more pronounced inhibitory effect on ME7 seed fibrils. Molecular interaction analyses demonstrated significant binding between CAPE and murine recombinant prion protein, and the association constant was (2.92±0.41)×10 -6 mol/L. Conclusions:CAPE inhibits PrP Sc replication, amplification, and fibril formation in vitro possibly due to specific interactions with the prion protein at the molecular level.


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