1.The state of non-culture-based laboratory diagnostic assays of invasive aspergillosis
Journal of Medical Postgraduates 2003;0(12):-
In high-risk patients,such as patients with hematologic malignancies,or patients after allogeneic stem-cell or solid-organ transplantation,early diagnosis of invasive aspergillosis(IA) is essential,as missing or delayed diagnosis of IA results in increasing rates of mortality.However,diagnosis of IA is difficult because classic tests have low sensitivity and specificity.The limited sensitivity and specificity of conventional assays for the detection of IA and the growing number of IA patients have led to the development of new assays.These methods include antigen detection systems,such as galactomannan(GM) assay,and different molecular methods(PCR assays).The GM assay is commercially available.However,it still need to be evaluated in large patient cohorts,especially children.A range of different PCR assays have been developed,targeting different gene regions,including a variety of amplicon detection methods.These molecular assays provide high potential in terms of sensitivity and specificity,but vary widely in their feasibility and up to now have not been standardised.Taken together,new non-culture-based diagnostic assays are noninvasive,simple,rapid and highly sensitive.Thus,they might be valuable tools to make early diagonosis,to reduce empirical antifungal therapy and to monitor the therapy.
2.Study on purification and properties of lactate dehydrogenase from human erythrocyte
Lingxiang MAO ; Ze MENG ; Lining SHI
Chinese Journal of Clinical Laboratory Science 2001;19(1):4-7
Objective To preparing the reference material(RM) of lactate dehydrogenase(LD),we purification of LD from human erythrocyte(RBC)and studied its properties.Methods Using a modified procedure which including complete hemolysis of the RBC,hydroxyapatite treatment,(NH4)2 SO 4 Precipitation,CM- Sephadex C 50,Sephadex G100 and 5'- AMP- Sepharose 4B affinity chromatography.Results The purified LD has a sepecific activity of 163.0 kU/g protein.It is almost free of contaminating enzymes.Two corresponding bands were observed on both PAG plates stained for either protein or LD activity after electrophresis had been done.The apparent Michaelis constants were of 1.000 and 0.179 mmol/L for L-lactate and NAD and of 0.119 mmol/L 0.062 mmol/L for pyruvate and NADH respectively.Conclusion The final purified LD was found to be very similar to that in human serum in catalytic properties.It is intended to be a fundament to prepare a RM for the measurement of LD.
3.Purification and properties of alkaline phosphatase from porcine kidney
Lining SHI ; Ze MENG ; Chunni ZHANG
Journal of Medical Postgraduates 2003;0(08):-
Objective: For preparing the reference material of alkaline phosphatase(ALP), the purification and properties of ALP from porcine kidney were studied. Methods: The ALP purification procedure included isolation microvillus of porcine kidney cortices by solubilization the membrance-binding enzymes with 1-butanol, precipitation with ammonium sulfate, chromatography on DEAE-Sephacel,ConA-Sepharose,Sephadex G-200 and a immuno-affinity column of anti-GGT antibodies. Results: The purified enzyme had a specific activity of 402 kU/g protein at 37℃and was almost free of contaminating enzymes. The apparent Michaelis constants was 1.35 mmol/L, and the optimum pH was 10.40. Conclusion: The kinetic properties of the preparation were very close to those of the enzyme present in the human serum, The product was suitable as enzyme preparation for producing the enzyme reference material.
4.Re-expression of RASSF1A by 5-Aza-CdR induced demethylation of the promoter region in human biliary tract carcinoma cells.
Shi, ZUO ; Yongjun, CHEN ; Lining, XU ; Qibin, TANG ; Shengquan, ZOU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2007;27(3):281-4
Hypermethylation of the promoter region is an important mean for the transcriptional repression of a number of cancer-associated genes, and over-expression and/or increased activity of DNA methyltransferase are considered to be the main cause of promoter hypermethylation. In order to further explore the epigenetic mechanism of tumor suppressor gene RASSF1A inactivation, 5-aza-2'-deoxycytidine (5-Aza-CdR), a DNA methyltransferase inhibitor, was used to treat the human biliary tract carcinoma cell line QBC-939 at the concentration of 5 micromol/L for 24 h in this study. After the chemical intervention with 5-Aza-CdR, the methylation status in the promoter region of RASSF1A gene was detected by methylation specific PCR (MS-PCR), and the expression alteration of RASSF1A mRNA and protein were observed by RT-PCR and Western Blot respectively. Following the treatment with 5-Aza-CdR, methylation status in the promoter region of RASSF1A gene was reversed from methylation to unmethylation. A 280 bp DNA band which represented RASS1FA expression at transcriptional level and a 40 kDa (1 kDa=0.9921 ku) protein band which represented RASSF1A expression at protein level were detected by RT-PCR and Western Blot respectively in the experimental group cells and there were no corresponding bands in the control group cells. The experimental results suggest that 5-Aza-CdR can induce demethylation in the promoter region of RASSF1A. It can also reverse epigenetic transcriptional silencing caused by DNA methylation and induce the re-expression of RASSF1A in QBC-939. This study also suggest that the mechanism of RASSF1A inactivation is very closely related to the methylation of the promoter region, which may provide a new epigenetic understanding for tumor related gene inactivation and the pathogenesis of biliary tract carcinoma.
5.A study of PET-CT SUV range for dose verification in carbon ion radiation therapy
Lining SUN ; Weigang HU ; Songtao LAI ; Leijun SHI ; Junchao CHEN
Chinese Journal of Radiation Oncology 2017;26(7):781-785
Objective The positron generated at the dose deposition site by using high-energy carbon ions to hit the material annihilate with the negative electron in the material to release the gamma photon.The positron-emitting isotope (PEI) distributions in the target volume are activated significantly by carbon ions.Therefore, the mean values of positron emission tomography (PET) activity could be related to the delivered doses to the clinical target volume from carbon ion.This specialty can be used for the image registration fusion of the carbon ion treatment planning computed tomography (CT) and treatment verification PET-CT.After radiation in the almost same decay period, the relationship between the different target volume and the PET-CT SUV of different every single fraction dose can be found, then the range of SUV for the radiation target could be decided.So this PET-CT standardized uptake value (SUV) range can also provide a reference for the correlation and consistency in planning target dose verification and evaluation for the clinical trial.Methods The head phantom was used as a simulation of the real human body, the 1 cc, 4 cc, and 10 cc cube volume target contouring were done in the TPS, the 90 degree fixed carbon ion beams were delivered in different single fraction effective dose of 2.5 GyE, 5 GyE, and 8 GyE.After the beam delivery, later the PET-CT scanning was performed and parameters of scanning followed the trial regulation.The MIM Maestro software was used for the image processing and fusion to determine the maximum, minimum, average, and total values of SUV in the virtual clinical target volumes for the different single fraction dose.Results The results showed that for the same target volume, the SUV range of target had an approximate linear correlation with effective dose of target (P=0.000).The same effective dose for the different target volumes got the same SUV range (P>0.05).Conclusions For the carbon ion treatment plan, the SUV range from image registration and fusion of planning CT and PET-CT after treatment can be used to make an evaluation for accuracy of the dose distribution.And this method also could be used in the hyper-fraction treatment plan.In the SUV range research of different decay periods, the similar method can be performed for the exploration.
6.Study on the Mechanism of Quinolone Resistance in Pseudomonas Aeruginosa
Ying WANG ; Mei HUANG ; Haiyan XI ; Linghui LI ; Lining SHI ; Weiping WANG ; Haifeng SHAO
Journal of Modern Laboratory Medicine 2014;(6):18-20,24
Objective 30 Pseudomonasaeruginosa mechanism of resistance to quinolones.Methods For the determination of ciprofloxacin MIC by agar dilution method.Used PCR on DNA gyrase and topoisomerase Ⅳ,resistance genes gyrA,gyrB, parC and parE were amplified,and BLAST,to determine whether there was resistance to bits mutation point;using pulsed-field gel electrophoresis (PFGE)of these 30 strains homology analysis.Results The 28 bacterial strains gyrA gene ampli-fied fragment of 137 points were C→T mutation causes T83I;17 strains gyrB gene amplified fragment of 351 G→C lead to G466A;parC gene amplification 21 bacteria fragment 277 point increase with C→U mutation causes S87L change two differ-ent strains parE gene locus C→U mutation A425V and A473V cause change.PFGE results:30 Pseudomonas aeruginosa could be divided into six clones,Aclone 4,B clone 7,C clone 3,D clone 14,and two other single clones.Conclusion The tar-get mutant strains closely related to the epidemic clone type,the same changes in the same pop-type strains of drug targets, and proportional to the level of ciprofloxacin MICs value,the more the number of mutated genes,MICs value higher.GyrA gene most prone to mutation,the mutation was also the first to be discovered,more than any other target of the mutation mutations on binding of drugs and targets that would be the focus of concern.
7.Development of an immunomagnetic bead assay for quantitative detection enolase of Candida albicans
Yuan HU ; Lining SHI ; Fangqiu LI ; Wei LI ; Chunfang MA ; Na NIAN
Journal of Medical Postgraduates 2014;(6):568-572
Objective To develop an immunomagnetic bead ( IMB) assay for quantitative detection enolase ( Eno) of Candi-da albicans, and to improve the diagonosis of invasive candidiasis . Methods The immunomagnetic bead was prepared by conjuga-ting with Anti Eno of Candida albicans monoclonal antibody .HRP-conjugated goat polyclonal antibody against Candida albicans Eno was employed as detecting antibody .The performance parameters of the IMB assay including precision , specificity, linear range and limit of detection were verified by using recombinant Candida albicans Eno.Then the developed assay was applied to determine Eno levels in supernatant of pathogenic fungi cultures . Results The intra and inter-coefficient of variation was 4.54%, 5.87% and 5.26%, 8.82%at the concentration of 25 ng/mL and 5 ng/mL, respectively.The limit of detection was 0.5 ng/mL.The linear range was(0.5-50) ng/mL.The level of Eno in Candida albicans culture after incubated in 37℃for 24 h was 3.89 ng/mL and gradually in-creased to 37.89 ng/mL at 120 h.There was a positive correlation between the level of Eno and growth hyphae of Candiad albicans. There was weak cross reaction with Candida parapsilosis and no cross reaction with Candida tropicalis, Candida guilliermondii, Candida glabrata, Cryptococcus neoformans and Saccharomyces cerevisiae. Conclusion An IMB assay for quantitative detection Eno of Candida albicans was developed , which was more sensitive , rapid and reliable than previous qualitative ELISA .The IMB assay has the potential to be applied to the research in invasive candidasis .
8.Detection of Aspergillus fumigatus thioredoxin reductase GliT antigen-specific T cells by ELISPOT assay in healthy individuals and result evaluation
Lining SHI ; Yuan HU ; Hong LIAO ; Xue HAN ; Dandan HAN ; Xiaojun LI ; Fangqiu LI
Journal of Medical Postgraduates 2014;(12):1286-1289
Objective The purpose of this study was to evaluate the protective potential of the Aspergillus fumigatus thiore -doxin reductase GliT ( TR) antigen by establishing and optimizing ELISPOT assay for TR antigen-specific T cells ( TR/AST) secreting IFN-γand IL-4 in peripheral blood mononuclear cells ( PBMCs ) and explore the role of TR/AST in invasive aspergillosis ( IA ) . Methods We optimized the reaction conditions of ELISPOT by preliminary checkerboard titration and determined the frequencies of positive spot-forming cells ( SFCs) specifically secreting IFN-γand IL-4 in the PBMCs of 20 healthy individuals with TR as specific stimulant and with PHA and PMA as positive controls ,. Results Checkerboard titration demonstrated the best result of ELISPOT with the TR antigen at the final concentration of 10μg/well and PBMCs at 3 ×105/well.The median frequency of IFN-γSFCs was sig-nificantly higher (15 [3.5, 59.5]) than that of IL-4 SFCs (0 [0, 0]) (P<0.001).TR induced IFN-γresponses in all the 20 healthy donors, including 9 cases of strong IFN-γresponse (SFCs>20/3 ×105 PBMCs), accounting for 45%, but failed to induce IL-4 response in 19 of the healthy individuals . Conclusion The Aspergillus fumigatus TR antigen could induce an immunodominant Th1 response , and therefore might be a potential protective antigen .
9.Candesartan early or late treatment reduced advanced glycation end-products accumulation and the receptor for AGE (RAGE) expression in type 2 diabetic KK/Ta mice kidney
Qiuling FAN ; Xiaoming ZHAO ; Shi PU ; Sali LI ; Gang YANG ; Congxiao ZHANG ; Yi JIANG ; Lining WANG
Journal of Chinese Physician 2012;14(2):145-150
Objective The effects of candesartan,an angiotensin Ⅱ type 1 receptor blocker (ARB) were investigated on advanced glycation end-products accumulation and the receptor for AGE (RAGE) expression in type 2 diabetic KK/Ta mouse kidneys.MethodsKK/Ta mice(n=72)were random divided into three groups(n=24) and it was treated with candesartan [4 mg/(kg·d)] or vehicle from 6 or 12 to 28 weeks of age.BALB/c mice(n=24) treated with vehicle were used as controls.Body weight,blood pressure,blood glucose,urinary microalbumin,urinary creatinine and serum creatinine were measured every four weeks.At 28 weeks,renal expressions of carboxymethyllysine and RAGE were evaluated by immunohistochemistry and/or competitive RT-PCR.Results KK/Ta mice developed high body weight,high blood glucose,and high urinary microalbumin/creatinine ratio in KK/Ta mice at 28 weeks of age,and it was significantly higher than that of BALB/c mice [(427.49±89.37)mg/g vs (9.54±3.25)mg/g,P<0.01 ].Protein and mRNA expressions of RAGE were upregulated in KK/Ta kidneys with increased immunostaining intensities of carboxymethyllysine.Candesartan treatment has markedly reduced urinary microalbumin/creatinine ratio [Early treatment group (32.18±9.41)mg/g,Late treatment group (53.20±7.26)mg/g,P<0.01 ].Treatment with candesartan down-regulated the protein and mRNA expressions of RAGE and reduced the accumulation of carboxymethyllysine.There were no significant differences between the two treatment groups (from 6 or 12 weeks).ConclusionsThe results suggest that candesartan,an ARB,reduces advanced glycation end-products accumulation and subsequent albuminuria by down-regulating RAGE expression in type 2 diabetic KK/Ta mouse kidneys.
10.Detection and analysis of plasmid-mediated carbapenem-hydrolyzing enzyme KPC-2 in carbapenem-resistant Escherichia coli
Shougang KUAI ; Haifeng SHAO ; Weiping WANG ; Lining SHI ; Xiaowei ZHANG ; Ming FAN
Chinese Journal of Laboratory Medicine 2009;32(10):1120-1123
Objective To study molecular epidemiology and carbapenem-resistance mechanism of four Escherichia coli strains isolated from general surgery wards. Methods Antibiotic susceptibility was carried out by K-B gar diffusion and agar dilution methods. Carbapenemases were screened by three dimensional test and EDTA-Na_2-disk synergy test. Pulsed-field gel electropboresis (PFGE) was performed to analyze molecular epidemiology of isolates. Plasmid was extracted by using an alkalinelysis technique. Conjunction experiment, transformation assay, specific PCR and DNA sequencing were performed to confirm carbapenemase genotype and its transmission mechanism Results Four Escherichia coli isolates were resistant to most antimicrobials including carbapenem. PFGE showed that the four isolates belong to four different clonal strains. Specific PCR and DNA sequence analysis identified that carbapenem resistance in four clinical isolates was mediated by KPC-2 encoded on an approximately 56 000 bp plasmid, and this plasmid did not harbor aminoglycosides and fluorquinolones resistant genes. Conclusion Four Escherichia coli isolates with carbapenem resistance are obtained from our hospital, and KPC-2 plasmid is main cause of carbapenem resistance in these isolates.