1.Microchannel-based Electrochemiluminescence Sensor for Tetracycline Detection Using Luminol/Hydrogen Peroxide as Reporter System
Shao-Kun HUANG ; Xiu-Lin XIE ; Hua-Bin CAI ; Yan-Ling HUANG ; Yue LIN ; Zhen-Yu LIN
Chinese Journal of Analytical Chemistry 2025;53(3):356-363
A microchannel-based electrochemiluminescence(ECL)sensor was developed for detection of tetracycline(TC)utilizing luminol/H2O2 as ECL reporting system.The low excitation potential of luminol/H2O2 effectively mitigated the impact of clamping voltage,thereby enhancing the detection performance of the microchannel-based ECL sensor.The microchannel modified with TC aptamer selectively recognized and captured target TC.The positively charged TC reduced the surface charge density within the microchannel,thereby increasing the ionic current in the microchannel,leading to change of ECL signal of system.The experimental conditions such as electrolyte concentration,TC-aptamer concentration,and reaction time between TC and TC-aptamer were optimized.Under optimal conditions,the difference of ECL signal in the absence and presence of TC(?ECL)exhibited a good linear relationship with TC concentration in the range from 1.00 ng/mL to 200 ng/mL,with a detection limit as low as 0.69 ng/mL.The sensor had good selectivity and was successfully used in detection of TC in milk samples.
2.Experimental and Computational Investigation of pH-Dependent Urease Conformational Dynamics and Its Impact on MICP Efficiency
Qiu-Cai ZHANG ; Yi-Fei ZHENG ; Mei-Zhong HUANG ; Xiu-Kang SHEN ; Ling-Ling WU ; Zhi-Jun ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(6):879-894
The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(<0.5 ?),the longest hydrogen bond lifetime(>8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(~120 ?3)and moderate conformational coherence(correlation coefficient~0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.
3.Experimental and Computational Investigation of pH-Dependent Urease Conformational Dynamics and Its Impact on MICP Efficiency
Qiu-Cai ZHANG ; Yi-Fei ZHENG ; Mei-Zhong HUANG ; Xiu-Kang SHEN ; Ling-Ling WU ; Zhi-Jun ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(6):879-894
The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(<0.5 ?),the longest hydrogen bond lifetime(>8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(~120 ?3)and moderate conformational coherence(correlation coefficient~0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.
4.Research progress on biosynthesis of sesquiterpenoids in Atractylodes lancea.
Ling-Fang FENG ; Sheng WANG ; Cheng-Cai ZHANG ; Hong-Yang WANG ; Xiu-Zhi GUO ; Ye CAO ; Yi-Feng ZHANG ; Lan-Ping GUO
China Journal of Chinese Materia Medica 2024;49(21):5829-5834
The traditional Chinese medicine Atractlodis Rhizoma is the dried rhizome of the Asteraceae herbal plant Atractylodes lancea, and it has the functions of drying dampness and strengthening the spleen, removing wind and dissipating cold, and brightening the eyes. The sesquiterpenoids in A. lancea are the main ingredients of its pharmacological activities in clinical practice, including atractylone, β-eudesmol, and hinesol, which possess anti-inflammation, antibacterial, antiviral, and hepatoprotective effects. This study focused on the biosynthesis of sesquiterpenoids in A. lancea, summarized the proportion of the main active ingredients in A. lancea from the genuine region and the non-genuine region, elaborated on the research progress of genes related to biosynthesis pathways, and systematically sorted out the biotic and abiotic factors affecting their biosynthesis, so as to provide a theoretical basis for further research on the biosynthetic mechanism of sesquiterpenoids in A. lancea and development of high-quality medicinal materials of A. lancea.
Atractylodes/metabolism*
;
Sesquiterpenes/metabolism*
;
Drugs, Chinese Herbal/pharmacology*
;
Biosynthetic Pathways
5.A multicenter study of neonatal stroke in Shenzhen,China
Li-Xiu SHI ; Jin-Xing FENG ; Yan-Fang WEI ; Xin-Ru LU ; Yu-Xi ZHANG ; Lin-Ying YANG ; Sheng-Nan HE ; Pei-Juan CHEN ; Jing HAN ; Cheng CHEN ; Hui-Ying TU ; Zhang-Bin YU ; Jin-Jie HUANG ; Shu-Juan ZENG ; Wan-Ling CHEN ; Ying LIU ; Yan-Ping GUO ; Jiao-Yu MAO ; Xiao-Dong LI ; Qian-Shen ZHANG ; Zhi-Li XIE ; Mei-Ying HUANG ; Kun-Shan YAN ; Er-Ya YING ; Jun CHEN ; Yan-Rong WANG ; Ya-Ping LIU ; Bo SONG ; Hua-Yan LIU ; Xiao-Dong XIAO ; Hong TANG ; Yu-Na WANG ; Yin-Sha CAI ; Qi LONG ; Han-Qiang XU ; Hui-Zhan WANG ; Qian SUN ; Fang HAN ; Rui-Biao ZHANG ; Chuan-Zhong YANG ; Lei DOU ; Hui-Ju SHI ; Rui WANG ; Ping JIANG ; Shenzhen Neonatal Data Network
Chinese Journal of Contemporary Pediatrics 2024;26(5):450-455
Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75%(27/36);boys accounted for 64%(23/36).Among the 36 neonates,31(86%)had disease onset within 3 days after birth,and 19(53%)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61%)had left cerebral infarction and 13(36%)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75%)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72%)and seizures in 10 neonates(34%).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33%,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44%(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.
6.Comparison of Microdroplet Digital PCR Assays with Real-time Fluorescence Quantitative PCR for Clostridioides difficile Detection.
Cai Hong YIN ; Zhan Yun SONG ; Xing Xing LIU ; Xiao Mu WANG ; Ying WANG ; Cheng Cheng GAO ; Xiu Ling SONG ; Xin FENG
Biomedical and Environmental Sciences 2023;36(7):653-657
7.Multicenter Prospective Study of Different Induction Regimens of Azacytidine in Treatment of Elderly Patients with Acute Myeloid Leukemia.
Cai-Zhao WANG ; Xiao-Xia CHU ; Hong-Yan YU ; En-Qin YANG ; Ling WANG ; Xiu-Zhi DENG ; Xue-Hong RAN ; Li-Qing WANG ; Chun-Ting ZHAO ; Xiao-Dan LIU
Journal of Experimental Hematology 2023;31(4):1005-1013
OBJECTIVE:
To observe the efficacy and safety of different induction regimens of same total dosage of azacitidine (Aza), including standard dose (standard dose group) and low-dose long-term (adjusted dose group), in the treatment of elderly acute myeloid leukemia (AML).
METHODS:
A total of 103 elderly patients with AML (non-acute promyelocytic leukemia) from January 2020 to June 2021 were enrolled. Aza was administered at the standard dose of 75 mg/(m2·d) for 7 days in the standard dose group (50 cases), while at 100 mg/d for 7-12 days in the adjusted dose group (53 cases). The administration days in adjusted dose group was calculated based on the total standard dose of the patient's single course of treatment. The efficacy and safety between standard dose group and adjusted dose group were compared. Subgroup analysis were performed in the two groups for Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy for efficacy and safety.
RESULTS:
There were no significant differences in overall response rate (ORR), incidence of adverse reaction, and 1-year overall survival (OS) rate between standard dose group and adjusted dose group (P >0.05). The ORR of combination was higher than that of Aza alone (P < 0.05), while there was no significant difference in ORR between Aza combined with BCL-2 inhibitor and Aza combined with low-dose chemotherapy (P >0.05). The combination of BCL-2 inhibitor did not increase the incidence of adverse reactions compared wtih Aza alone. There was a higher risk of myelosuppression and pulmonary infection with a combination of low-dose chemotherapy than with a combination of BCL-2 inhibitor and Aza alone (P <0.05). No significant difference was observed in 1-year OS between Aza alone, Aza combined with BCL-2 inhibitor, and Aza combined with low-dose chemotherapy (P >0.05).
CONCLUSIONS
Both two induction regimens can be used in elderly AML patients who cannot tolerate intensive chemotherapy with similar overall effectiveness and safety. Aza combined with low-dose chemotherapy may result in increased ORR and an increased incidence of serious adverse reactions, and may not result in longer survival compared with Aza alone. Aza combined with BCL-2 inhibitor not only has similar effect in complete remission, objective response rate, and OS compared with Aza combined with low-dose chemotherapy, but also has higher safety.
Humans
;
Aged
;
Azacitidine/therapeutic use*
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Prospective Studies
;
Treatment Outcome
;
Antineoplastic Combined Chemotherapy Protocols
;
Leukemia, Myeloid, Acute/etiology*
;
Proto-Oncogene Proteins c-bcl-2
8.To compare the efficacy and incidence of severe hematological adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia.
Xiao Shuai ZHANG ; Bing Cheng LIU ; Xin DU ; Yan Li ZHANG ; Na XU ; Xiao Li LIU ; Wei Ming LI ; Hai LIN ; Rong LIANG ; Chun Yan CHEN ; Jian HUANG ; Yun Fan YANG ; Huan Ling ZHU ; Ling PAN ; Xiao Dong WANG ; Gui Hui LI ; Zhuo Gang LIU ; Yan Qing ZHANG ; Zhen Fang LIU ; Jian Da HU ; Chun Shui LIU ; Fei LI ; Wei YANG ; Li MENG ; Yan Qiu HAN ; Li E LIN ; Zhen Yu ZHAO ; Chuan Qing TU ; Cai Feng ZHENG ; Yan Liang BAI ; Ze Ping ZHOU ; Su Ning CHEN ; Hui Ying QIU ; Li Jie YANG ; Xiu Li SUN ; Hui SUN ; Li ZHOU ; Ze Lin LIU ; Dan Yu WANG ; Jian Xin GUO ; Li Ping PANG ; Qing Shu ZENG ; Xiao Hui SUO ; Wei Hua ZHANG ; Yuan Jun ZHENG ; Qian JIANG
Chinese Journal of Hematology 2023;44(9):728-736
Objective: To analyze and compare therapy responses, outcomes, and incidence of severe hematologic adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia (CML) . Methods: Data of patients with chronic phase CML diagnosed between January 2006 and November 2022 from 76 centers, aged ≥18 years, and received initial flumatinib or imatinib therapy within 6 months after diagnosis in China were retrospectively interrogated. Propensity score matching (PSM) analysis was performed to reduce the bias of the initial TKI selection, and the therapy responses and outcomes of patients receiving initial flumatinib or imatinib therapy were compared. Results: A total of 4 833 adult patients with CML receiving initial imatinib (n=4 380) or flumatinib (n=453) therapy were included in the study. In the imatinib cohort, the median follow-up time was 54 [interquartile range (IQR), 31-85] months, and the 7-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.2%, 88.4%, 78.3%, and 63.0%, respectively. The 7-year FFS, PFS, and OS rates were 71.8%, 93.0%, and 96.9%, respectively. With the median follow-up of 18 (IQR, 13-25) months in the flumatinib cohort, the 2-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.4%, 86.5%, 58.4%, and 46.6%, respectively. The 2-year FFS, PFS, and OS rates were 80.1%, 95.0%, and 99.5%, respectively. The PSM analysis indicated that patients receiving initial flumatinib therapy had significantly higher cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) and higher probabilities of FFS than those receiving the initial imatinib therapy (all P<0.001), whereas the PFS (P=0.230) and OS (P=0.268) were comparable between the two cohorts. The incidence of severe hematologic adverse events (grade≥Ⅲ) was comparable in the two cohorts. Conclusion: Patients receiving initial flumatinib therapy had higher cumulative incidences of therapy responses and higher probability of FFS than those receiving initial imatinib therapy, whereas the incidence of severe hematologic adverse events was comparable between the two cohorts.
Adult
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Humans
;
Adolescent
;
Imatinib Mesylate/adverse effects*
;
Incidence
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Antineoplastic Agents/adverse effects*
;
Retrospective Studies
;
Pyrimidines/adverse effects*
;
Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy*
;
Treatment Outcome
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Benzamides/adverse effects*
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Leukemia, Myeloid, Chronic-Phase/drug therapy*
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Aminopyridines/therapeutic use*
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Protein Kinase Inhibitors/therapeutic use*
9.Antimicrobial susceptibility of Gram-positive organisms:Results from China antimicrobial resistance surveillance trial(CARST)program,2021-2022
Yun LI ; Bo ZHENG ; Feng XUE ; Xiu-Zhen ZHANG ; Yun-Jian HU ; Yu-Fen JIN ; Jian-Hong ZHAO ; Shi-Yang PAN ; Wei GUO ; Feng ZHAO ; Yun-Song YU ; Xuan CAI ; Wen-En LIU ; De-Hua LIU ; Ying FEI ; Jia-Yun LIU ; Feng-Yan PEI ; Ling MENG ; Ping JI ; Jin TANG ; Kai XU ; Lei ZHU ; Cun-Wei CAO ; He-Ping XU ; Shan WANG ; Lan-Qing CUI ; Jia ZHANG ; Yao-Yao LIU
The Chinese Journal of Clinical Pharmacology 2023;39(23):3509-3524
Objective To investigate the Gram-positive coccus resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Methods All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 1 974 pathogenic Gram-positive coccus from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,the prevalence of methicillin resistant Stapylococcus aureus(MRSA)and methicillin resistant Stapylococcus epidermidis(MRSE)were 36.4%and 79.9%respectively.No vancomycin insensitivity Staphylococcus was detected.Staphylococcus aureus were 100%susceptibility to linezolid and teicoplanin.Antibiotic resistance rate of Enterococcus faecalis and Enterococcus faecium to ampicillin were 3.1%and 92.9%.The detectation rate of vancomycin resistant Enterococcus(VRE)was 1.6%.Nonsusceptibility rate of Enterococcus faecalis to linezolid was 32.2%,two consecutive monitoring rises and nonsusceptibility rate of Enterococcus faecium(12.5%)was also significantly increased.The prevalence of penicillin non-susceptible Streptococcus pneumoniae(PNSSP)was 0.8%based on non-meningitis and parenteral administration criterion,decrease of nearly 30 percentage points from the previous surveillance.While for cases of oral penicillin,the rate was 71.8%,showing similar to last time.The results indicated that the number of strains with higher MIC value of penicillin(MIC ≥4 mg·L-1)decreased significantly.There were no significant differences of resistance rates of Stapylococcus aureus,Stapylococcus epidermidis,Enterococcus faecalis,Enterococcus faecium and Streptococcus pneumoniae among various groups such as different department,age,or specimen source.Conclusion VRE detection ratio stablized at a relatively low level.The number of Streptococcus pneumoniae with higher MIC value of penicillin decreased significantly compared with the previous monitoring.The increase of linezolidin-insensitive Enterococcus was noteworthy.
10.Antimicrobial susceptibility of Gram-negative organisms:Results from China antimicrobial resistance surveillance trial(CARST)program,2021-2022
Yun LI ; Bo ZHENG ; Feng XUE ; Xiu-Zhen ZHANG ; Yun-Jian HU ; Yu-Fen JIN ; Jian-Hong ZHAO ; Shi-Yang PAN ; Wei GUO ; Feng ZHAO ; Yun-Song YU ; Xuan CAI ; Wen-En LIU ; De-Hua LIU ; Ying FEI ; Jia-Yun LIU ; Feng-Yan PEI ; Ling MENG ; Ping JI ; Jin TANG ; Kai XU ; Lei ZHU ; Cun-Wei CAO ; He-Ping XU ; Shan WANG ; Lan-Qing CUI ; Jia ZHANG ; Yao-Yao LIU
The Chinese Journal of Clinical Pharmacology 2023;39(23):3525-3544
Objective To investigate the Gram-negative bacteria resistance in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance.Method All the clinical isolates were collected from 19 hospitals and the minimal inhibitory concentrations(MICs)were tested using agar/broth dilution method recommended.Results A total of 4 066 pathogenic isolates from 19 tertiary hospitals in 19 cities nationwide over the period from July 2021 to June 2022 were studied.Based on the MIC results,Escherichia coli and Klebsiella pneumoniae showed extended spectrum β-lactamase(ESBLs)phenotype rates of 55.0%and 21.0%,respectively,ESBLs phenotype rate of Klebsiella pneumoniae keep going down.The ratios of carbapenems resistance Klebsiella pneumoniae increased by 5 percentage points compared with the previous monitoring.Carbapenems,moxalactam,sitafloxacin,β-lactam combination agents,fosfomycin trometamol,and amikacin displayed desirable antibacterial activity against Enterbacterales,susceptibal rates were above 75%.In addition,tigacycline,omacycline,colistin and fluoxefin maintained good antibacterial activity against their respective effective bacteria/species,and the bacterial sensitivity rates by more than 80%.Resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannnii to imipenem were 26.3%and 72.1%and multidrug-resistant(MDR)detection rates were 41.1%and 77.3%,extensively drug-resistant(XDR)were 12.0%and 71.8%,respectively.Comparison of drug resistance rates from different wards,ages and specimen sources indicated that the proportion of resistance in Klebsiella pneumoniae and Acinetobacter baumannii isolated from intensive care unit(ICU)were significantly higher than non-ICU.Carbapenem resistance rates of Klebsiella pneumoniae isolated from ICU were more than 35%.Resistance rates of Haemophilus influenzae isolated in children to β-lactam,macrolide,clindamycin and ESBLs detection rate in Klebsiella pneumoniae isolated from children were more than those from adults and the old people,so bacterial resistance in children is an important problem in China.Conclusion ESBLs detection rate of Escherichia coli increased slightly after years of continuous decline.The proportion of carbapenem resistant Pseudomonas aeruginosa was stable,but the resistance rate of Klebsiella pneumoniae and Acinetobacter baumannii to carbapenems was still increased,which should be paid more attention.

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