1.Staphylococcus aureus DNA in human venous blood detected by real-time quantitative PCR assay
Junren KANG ; Enling MA ; Jiabin FANG ; Xizeng CUI
Chinese Journal of Clinical Nutrition 2014;22(2):101-105
Objective To establish a rapid real-time quantitative polymerase chain reaction (RQ-PCR)assay in quantifying and detecting Staphylococcus aureus DNA from human venous blood samples,so as to quantificationally evaluate the systemic infection caused or deteriorated by intestinal bacteria translocation.Methods Totally 26 clinical blood samples and 15 simulation blood samples were detected.The primers and TaqMan probe were designed targeting the highly conserved house-keeping femA gene of Staphylococcus aureus,and a 20 μl RQ-PCR amplification reaction system was established.The standard curve was built based on the recombinant plasmid DNA containing the amplicon of the target gene,and genomic DNA was extracted using QIAamp DNA Blood Mini Kit.Results The specificity of primers and probe was excellent,the detecting limit was 100 copies/μl (103 CFU/ml),the sensitivity was 99.7%,and the specificity was 94.6%.The correlation coefficient of the standard curve was between 0.9918 and 0.9997.For samples with different Staphylococcus anreus concentrations,the average accuracy of the RQ-PCR assay was (96.25 ± 2.26) % ; the intra-and interassay coefficients of variation were (8.06 ±0.07)% and (10.01 ±4.40)%,respectively.The average recovery rate of Staphylococcus aureus DNA in blood samples was (111.72 ± 20.72) %.In clinical blood samples,the positive rate of Staphylococcus aureus DNA was 15.4% (4/26),while the blood culture of these samples all produced negative result for Staphylococcus aureus.Conclusion RQ-PCR assays is a rapid,sensitive,and specific method with good repetitiveness and can be used in the quantitative detection of Staphylococcus aureus in whole blood samples.
2.Multiplex real-time quantitative polymerase chain reaction for simultaneous detection of Escherichia coli and Candida albicans genes in human whole blood
Jiabin FANG ; Junren KANG ; Enling MA ; Guangliang GUO ; Xizeng CUI
Chinese Journal of Clinical Nutrition 2015;23(3):170-175
Objective To establish a multiplex real-time quantitative polymerase chain reaction (MRQPCR) assay for fast and simultaneous detection of Escherichia coli (E.coli) and Candida albicans (C.albicans) genes in human whole blood,in order to facilitate differentiation of the types of microorganism and evaluation of the severity of bacterial or fungi translocation due to impaired gut barrier,hence providing help to select specific antimicrobial agents.Methods The β-D-galactosidase gene of E.coli and ITS2 gene of C.albicans were selected as the target genes for designing primers and probes.E.coli and C.albicans genomes were extracted with QIAamp(R) DNA Blood Mini Kit,and the 25 μl TaqMan MRQ-PCR amplification reaction system was established.18 simulated human whole blood samples and 10 whole blood samples from febrile surgical patients were detected for E.coli and C.albicans genes using MRQ-PCR.Results The specificity of the primers and probes were excellent.The correlation coefficients of the standard curves of E.coli and C.albicans were 0.994-0.999 and 0.994-0.998,respectively;and the efficiency of amplification were 0.894-1.022 and 0.905-1.028,respectively.In the standard samples,the lowest detection limits of E.coli and C.albicans were 13.9 copies/μl and 0.8 cfu/μl,respectively;the sensitivity was 100% and 99.69%,the specificity was 100% and 94.73%,respectively;the average recovery rates were (101.89 ± 5.69)% and (103.74 ± 4.64)% respectively;the intra-batch coefficients of variance (CV) in detecting the genes were (13.14 ± 10.27)% and (19.18 ± 8.54)%,respectively,and the inter-batch CV were (14.35 ± 9.34)% and (18.31 ± 10.25) %,respectively.In human whole blood,the lowest detection limits of E.coli and C.albicans were 12 455.2 copies/ml and 800.3 cfu/ml,respectively;the average recovery rates were (111.60 ± 11.06) % and (99.96 ± 6.16) %,respectively;the intra-batch CV in detecting the genes were (11.02 ± 5.65) % and (8.14 ± 7.29)%,respectively,and the average inter-batch CV were (12.88 ± 7.59)% and (18.62 ± 9.14)%.Conclusions MRQ-PCR is a rapid,sensitive,specific,accurate,and reproducible method for simultaneous detection of E.coli and C.albicans genes in human whole blood,with sample-,cost-,and time-saving advantages.It is a promising technique for rapid differentiation between fungi and bacteria,which could help targeted administration and evaluation of antimicrobial agents,and help to assess the consequence of gut barrier damage and the efficacy of treatment.
3.Detection of Aspergillus fumigatus genome load in human whole blood samples by real-time quantitative polymerase chain reaction and its clinical application
Xizeng CUI ; Enling MA ; Junren KANG ; Guangliang GUO ; Jiabin FANG ; Yunfei XU
Chinese Journal of Clinical Nutrition 2011;19(3):154-158
Objective To establish a real-time quantitative polymerase chain reaction (RQ-PCR) assay for fast detection of Aspergillus fumigatus genome in human whole blood samples and explore its clinical application.Methods The primers and the TaqMan-probe were designed on the basis of the multi-copy ITS1-5. 8S region of the rDNA of Aspergillus fumigatus. The Aspergillus fumigatus genomic DNA were extracted with QIAamp(R) DNA Blood Mini Kit.A 20 μl RQ-PCR amplification system was established, and the simulated blood samples containing various given load of Aspergillus fumigatus genome and the 66 whole blood samples of the surgical febrile patients were examined. Results The detection limit of the RQ-PCR instrument is 10-1 genomes/μl DNA sample,namely 78 CFU/ml whole blood. The specificity and the sensitivity were 94. 25% and 99. 04% respectively; and the positive predictive value and negative predictive value were 97. 63% and 97. 62% respectively. The average relative error of the quantitative results was (3. 67 ±13. 19)%, and the intra- and the inter-assay average coefficients of variation were (12.38 ± 1. 53)% and (16. 27 ±2. 72)% , respectively. The average recovery rate of Aspergillus fumigatus genomic DNA in human whole blood samples was (107. 81 ±25. 92)% , and the average coefficient of variation of the average recovery rate was (26. 24 ± 5.62) % . No Aspergillus fumigatus genomic DNA was detected among the 66 blood samples of the surgical febrile patients. Conclusions The RQ-PCR assay for fast quantitative detection of Aspergillus fumigatus genome in human whole blood samples is of high sensitivity, specificity,accuracy and precision. The Aspergillus fumigatus genome was not detected in this group of surgical febrile patients.
4.Detection of Candida albicans in the venous blood of the surgical febrile patients by real-time quantitative PCR
Guangliang GUO ; Enling MA ; Junren KANG ; Jiabin FANG ; Xizeng CUI ; Xiuli XIE
Chinese Journal of Clinical Nutrition 2009;17(5):284-289
Objective To establish the real-time quantitative PCR (RQ-PCR) assay for detecting Candida albicans (C.albicans) in whole blood and its clinical application in the febrile surgical patients who may develop gut barrier damage and gut microorganism translocation.Methods The NAG1 gene,which is a single copy in C.albicans genome,was selected as the target gene for designing the primers and probe.The plasmid was fabricated and produced as standard samples.C.albicans genomes were extracted with QIAamp(R) DNA Blood Mini Kit,and the total 20 μl TaqMan RQ-PCR amplification reaction system was established.The 74 venous blood samples from the surgical febrile patients were detected for C.albicans load.Results The specificities of the primers and probe were excellent,the correlation coefficients of the standard curves were between 0.9918 and 0.9985,and the efficiency of amplification was 0.88-1.027 for the samples above the lowest detection limit (100 copies/μl examine fluid,or nearly 1.1 × 103 cfu/ml whole blood).The average accuracy of the RQ-PCR equipment was (99.64±2.08) %,the sensitivity was 97.46%,the specificity was 100%,and the average coefficients of variation (CV) of the intra-and inter-assay were (14.76±2.64)% and (17.85±3.53)%,respectively.The average recovery rate of C.albicans DNA in whole blood samples was (88.60±5.73) %,and the average CV of recovery rate was (11.70 ±5.36) %.The number of copies of C.albicans genes per unit blood was not significantly different among the same original blood samples stored separately under-20℃ for 3 or 6 months when compared with its freshly collected blood (P = 0.267).In the 74 whole blood samples obtained from the febrile surgical patients,the positive rate of C.albicans genes was 2.7% and the highest load was 4.42×103 cfu/ml.Conclusions RQ-PCR is a rapid,sensitive,highly specific,and reproducible method in detecting C.albicans NAG1 gene.Clinically it can be used to quantitatively evaluate the numbers of C.albicans in the whole blood.A small percentage of the febrile surgical patients may develop blood infection of C.albicans.
5.A comparative study on preoperative ICGR15 dye excretion detection and liver function indexes in patients with primary liver cancer
Yubing XU ; Meng FANG ; Jie ZHANG ; Jiabin SHEN ; Chunmei RAO ; Chunfang GAO
Chinese Journal of Laboratory Medicine 2015;38(11):733-736
Objective To study the correlation between preoperative dye exclusion test and liver function in patients with primary hepatic carcinoma.Methods This was a cross sectional survey.A total of 192 cases of primary liver cancer patients were recruited from May 2014 to March 2015 at the Second Military Medical University Affiliated Eastern Hepatobiliary Surgery Hospital.Hereinto, 160 cases were male and 32 females, the male to female ratio was 5: 1.The age of the patients ranged from 26 to 72 years old, and the average age was 50.5 years old.ICG 15 minutes retention rate of ICG clearance test was determined by PDD method in 192 cases of primary liver cancer patients.ICGR15 value was stratified into three stages: ICGR15 < 10% , ICGR1510%-20% , and ICGR15 > 20%.The ICGR15 stage of patients with different ChildPugh grades was analyzed.The biological liver function indexes of patients were simultaneous detected including TBIL, TBA, TP, ALB, PA, ALT, AST, PT-INR, HA, LN, Ⅲ, Ⅳ, APRI, PLT etc.The correlations of ICGR15 and biological indexes of liver function were analyzed using Spearman nonparametric correlation analysis.Results (1) ICGR15 was positively correlated with Child-Pugh grade (r =0.477, P < 0.01) in the 192 cases of HCC.The hierarchical analysis showed that there were significant differences between ICGR15 and different Child-Pugh grades (P < O.05).(2) Child-Pugh classification and ICGR15 comparison further showed that, ICGR15 increased with Child-Pugh grade.While ICG plasma clearance rate (ICGK) and effective hepatic blood flow (EHBF) reduced (P < 0.05).(3) The correlation analysis between ICGR15 and biological indexes of liver function showed that: ICGR15 was positively correlated with TBIL,TBA, ALT, AST, AFU, GGT, PT-INR, HA, LN, Ⅲ, Ⅳ and APRI index [(AST/ULN) × 100/ PLT (× 109/L)] (r =0.422, 0.389, 0.219, 0.301, 0.219, 0.244, 0.325, 0.652,0.403, 0.523, 0.519, 0.434, P < 0.05);and was negatively correlated with TP, ALB, PA, SOD, WBC, PLT (r =-0.290,-0.532, 0.546, 0.531, 0.256, 0.327, P< 0.05).Conclusions ICGR15 as a indicator for liver reserved and dynamic function can comprehensively reflect the liver reserve function is associated with the existing Child-Pugh grades and liver function biochemical indexes.Therefore, ICGR15 could be served as a sensitive index reflecting the preoperative liver reserve function.
6.Expression of nerve growth factor and neurotrophin 3 after transplantation of human umbilical cord blood stem cells combined with electroacupuncture stimulation in rats with spinal cord injuries
Zhaozhong SUN ; Rui LI ; Qingmin FANG ; Guanglin WANG ; Xiaopeng GENG ; Jiabin REN ; Cheng YANG
Chinese Journal of Tissue Engineering Research 2015;(1):61-66
BACKGROUND:Studies have shown that umbilical cord blood stem cel transplantation promote the recovery of spinal cord injury, and electroacupuncture also can inhibit the proliferation of astrocytes to reduce damage to scar formation, suggesting that a combination of umbilical cord blood stem cel transplantation and electroacupuncture may play an important role in the treatment of acute spinal cord injuries. OBJECTIVE:To observe the influence of transplantation of human umbilical cord blood stem cels combined with electroacupuncture at theDu channel on expression of nerve growth factor and neurotrophin 3 in rats with spinal cord injuries. METHODS: Seventy-two female Sprague-Dawlay rats were randomly divided into control group, injury group, transplantation group and combined therapy group. In the control group, only an incision on the back was sutured;in the injury group, a piece of saline-infiltrated gelatin sponge, 1 mm×2 mm×2 mm, was placed into the transected spinal cord at T10 level; in the transplantation group and combined therapy group, a piece of gelatin sponged infiltrated in the suspension of human umbilical cord blood stem cels was placed into the transected spinal cord, respectively, and then, electroacupuncture stimulation at the Duchannel was performed in the combined therapy group at 1 hour after modeling. Specimens were taken at 7, 14, 28 days after modeling in each group, and then immunohistochemistry, western blot and real time-PCR methods were used to detect the expression of nerve growth factor and neurotrophin 3. RESULTS AND CONCLUSION:Compared with the transplantation group, the expression of nerve growth factor and neurotrophin 3 was lower in the injury group but higher in the combined therapy group at 7, 14, 28 days after modeling (P < 0.05). The results of western blot and real time-PCR were consistent with those of immunohistochemical detection. Findings show that human umbilical cord blood stem cel transplantation combined with electroacupuncture has a remarkable synergistic effect in the treatment of spinal cord injury that can significantly up-regulate the expression of nerve growth factor and neurotrophin 3, and contribute to injured spinal cord repair, regeneration and functional recovery after spinal cord injury.
7.Research of 24-hour dynamic sleep monitoring and melatonin changes in patients with delirium in intensive care unit
Ting SUN ; Fang HAN ; Yunliang SUN ; Jianghua LIU ; Jiabin YANG ; Xiaozhi WANG
Chinese Critical Care Medicine 2014;(10):726-729
Objective To dynamic monitor and analyze the characteristic of polysomnography (PSG)and melatonin levels of delirium patients in intensive care unit (ICU). Methods A prospective observational study was performed from December 2013 to April 2014. The patients admitted to ICU of Affiliated Hospital of Binzhou Medical College for more than 72 hours were evaluated with confusion assessment method for the ICU (CAM-ICU),and were divided into delirium group and non-delirium group. Sleep patterns of all the patients underwent continuous PSG for up to 24 hours were evaluated. Melatonin levels were determined every 4 hours with enzyme linked immunosorbent assay (ELISA)duration sleep monitoring. Results Eighteen patients were enrolled,and 9 were delirium patients. All the patients had sleep disorders:a decrease in rapid eye movement (REM)sleep 〔(5.91±5.26)%〕,an increase in the sleep fragmentations 〔arousal index was (15.40 ±12.79)times/h〕,and the N3 sleep stage was on the lower limit of normal 〔(14.67 ±11.10)%〕. Compared with non-delirium group,the REM sleep was significantly decreased in delirium group〔(0.10±0.20)%vs.(8.83±3.81)%,t=4.782,P=0.001〕. Melatonin levels lost rhythm between day and night,and there was no difference in melatonin between delirium group and non-delirium group (time effect:F=1.370,P=0.287;between-group effect:F=1.646,P=0.250;interaction effect:F=1.558,P=0.247). The peak of melatonin levels of delirium group appeared on 06:00 〔(137.84±62.21)ng/L〕and 14:00 〔(148.24±58.8)ng/L〕, the minimum value on 22:00 〔(64.47 ±26.97) ng/L〕. But in non-delirium group,the peak of melatonin levels appeared on 02:00 〔(63.52 ±39.75)ng/L〕,the minimum value on 10:00 〔(44.87 ±11.19)ng/L〕. Conclusions ICU patients have sleep disorders,and the delirium patients have less REM stage. Normal rhythmic melatonin secretion changes of ICU patients were lost. The delirium peak of patients appears in the daytime.
8.Metal Organic Nanotubes-based Dispersive Solid Phase Extraction-Gas Chromatography-Tandem Mass Spectrometry for SensitiveAnalysis of Polychlorinated Biphenyls in Environmental Water Samples
Fang HUANG ; Xiaokun SHE ; Jiabin ZHOU ; Xia WANG ; Xiaoli WANG ; Shanshan WANG ; Rusong ZHAO
Chinese Journal of Analytical Chemistry 2017;45(6):856-861
A method of metal organic nanotubes-based dispersive solid phase extraction-gas chromatography-tandem mass spectrometry was developed for sensitive analysis of polychlorinated biphenyls in environmental water samples.Related important factors influencing enrichment efficiency, such as ionic strength, extraction time and amount of adsorbent, were investigated.Response surface methodology was used to optimize these factors in detail.Under the optimal conditions such as 4.92% (w/V) NaCl, 4.5 min of extraction time, 62.5 mg of adsorbent, and n-hexane as desorption solvent, wide linearity (2-1000 ng/L or 5-1000 ng/L), and low limits of detection (0.26-0.82 ng/L) were achieved.The intra-day and inter-day relative standard deviations were 0.8%-5.5% (200 ng/L, n=6)and 2.7%-7.4% (200 ng/L, n=6), respectively.Finally, this method was successfully applied to the sensitive analysis of 6 kinds of PCBs in environmental water samples, with satisfactory recoveries of 78.9%-113.3%.
9.Preliminary Practice in Electron Microscope Technique Course for the Undergraduates of Laboratory Medicine
Huidan ZHANG ; Jin FANG ; Fuhui ZHANG ; Jiabin LI ; Yanni ZHAO ; Ruoping SU
Chinese Journal of Medical Education Research 2005;0(06):-
In China Medical University,20-teaching-hour electron microscope technique course has been arranged for the undergraduates of Laboratory Medicine.The purpose is to let the students master the specialized skill and essential scientific research ability through studying the relative basic knowledge and operation of the electron microscope.The questionnaire results show that the attitude of students is positive and 83% of them are satisfied in general.This paper summarizes the experiences of the practice.
10.Effect of curcumin on radiosensitization of radioresistantnasopharyngeal carcinoma cell line CNE-2R and its mechanism
Daoqi ZHU ; Mu HUANG ; Zhaoru LIU ; Aiwu LI ; Meng SHAO ; Yuanliang LIU ; Miao FANG ; Jiabin YANG ; Ying LYU ; Zhixian MO ; Qin FAN
Chinese Pharmacological Bulletin 2017;33(8):1086-1091
Aim To investigate the effect of curcumin on radiosensitivity of radioresistant nasopharyngeal carcinoma cell line CNE-2R and its mechanism.Methods The concentration of curcumin was screened by MTT assay.Dose-survival curves were obtained according to the colony forming test for L-Q matching and multitarget-single hitting matching,while SF2 and the correlation parameters of radiation biology were calculated.The changes of cell cycle in CNE-2R cells caused by curcumin were also tested by flow cytometry(FCM).The differential expression of genes related to cell cycle and DNA damage repair were detected by RT-qPCR.Results CNE-2R cells could not be inhibited by 10 μmol·L-1 curcumin.Dealt with 10 μmol·L-1 curcumin for 24 h,the value of α/β increased to 1 596 from 6.56;the value of SF2 decreased to 0.361 Gy from 1.93 Gy;the value of N decreased to 1.06 from 1.60;the value of D0 decreased to 2.12 from 3.27;the value of Dq decreased to 0.12 from 1.53.FCM showed that the cells in G2 phase had a significant increase and the cells in S phase had a significant decrease after dealt with 10 μmol·L-1 curcumin for 24 h.The expression of CDK4 was significantly up-regulated and GADD45g,BRCA1 were significantly down-regulated.Conclusion Curcumin radiosensitizes nasopharyngeal carcinoma cell line CNE-2R by changing cell cycle and affecting DNA damage repair through regulating the expression of CDK4,GADD45 g and BRCA1.