2.Leak subtraction analysis of Axon patch clamp system.
Zhen-Wei LIU ; Li-Jun LI ; Chuan-Gui LIU
Chinese Journal of Applied Physiology 2003;19(1):98-101
AIM AND METHODSUsing blind whole-cell recording techniques on rat hippocampal slices, the function and mechanisms of several leak subtraction methods of Axon patch clamp system (Axopatch amplifier and pClamp software) were analyzed. That how to select and use scaled P/N leak subtraction, patch clamp amplifier leak subtraction and Clampfit leak subtraction were emphasized in our present study.
RESULTSThe noise induced by scaled P/N leak subtraction of Clampex soft ware was smaller than that of P/N leak subtraction. Axon patch clamp amplifier leak subtraction could subtract the leak current produced by single depolarizing pulse but not the leak current produced by a series of different step depolarizing pulses. Due to its assumption that leak current would be produced if only potential difference arises across membrane, Clampfit leak subtraction was not suitable to subtracting the steady-state leak current while recording voltage-gated channel currents.
CONCLUSIONP/N- and scaled P/N leak subtraction, but not Clampfit leak subtraction, cad be used to subtract steady-state leak current while recording voltage-gated channel currents.
Amplifiers, Electronic ; Animals ; Hippocampus ; physiology ; Male ; Patch-Clamp Techniques ; methods ; Rats ; Rats, Wistar ; Software
3.Development and validation of a liquid chromatography-isotope dilution tandem mass spectrometry for determination of olanzapine in human plasma and its application to bioavailability study.
Mengqi ZHANG ; Jingying JIA ; Chuan LU ; Gangyi LIU ; Chengyin YU ; Yuzhou GUI ; Yun LIU ; Yanmei LIU ; Wei WANG ; Shuijun LI ; Chen YU
Acta Pharmaceutica Sinica 2010;45(6):767-71
A simple, reliable and sensitive liquid chromatography-isotope dilution mass spectrometry (LC-ID/MS) was developed and validated for quantification of olanzapine in human plasma. Plasma samples (50 microL) were extracted with tert-butyl methyl ether and isotope-labeled internal standard (olanzapine-D3) was used. The chromatographic separation was performed on XBridge Shield RP 18 (100 mm x 2.1 mm, 3.5 microm, Waters). An isocratic program was used at a flow rate of 0.4 m x min(-1) with mobile phase consisting of acetonitrile and ammonium buffer (pH 8). The protonated ions of analytes were detected in positive ionization by multiple reactions monitoring (MRM) mode. The plasma method, with a lower limit of quantification (LLOQ) of 0.1 ng x mL(-1), demonstrated good linearity over a range of 0.1 - 30 ng x mL(-1) of olanzapine. Specificity, linearity, accuracy, precision, recovery, matrix effect and stability were evaluated during method validation. The validated method was successfully applied to analyzing human plasma samples in bioavailability study.
4.Difference in action sites between mecamylamine and hexamethonium on nicotinic receptors of sympathetic neurons.
Wei LIU ; Jian-Quan ZHENG ; Zhen-Wei LIU ; Li-Jun LI ; Qin WAN ; Chuan-Gui LIU
Acta Physiologica Sinica 2002;54(6):497-500
To compare the difference in action sites between mecamylamine (MEC) and hexamethonium (HEX) on nicotinic receptors of sympathetic neurons, we investigated the effects of MEC and HEX on the nicotine-induced currents in cultured superior cervical ganglion neurons by whole-cell patch clamp technique. The IC(50) of MEC and HEX for antagonizing the effect of 0.08 mmol/L nicotine was 0.0012 and 0.0095 mmol/L, respectively. Both MEC and HEX accelerated the desensitization of nicotinic receptors. Furthermore, by comparing their effects at holding potentials 30, 70 and 110 mV, it was indicated that their suppressing effect on the nicotine-induced currents was voltage-dependent. However, different from that of HEX, the inhibitory effect of MEC increased with administering the mixture of MEC and nicotine at intervals of 3 min, indicating a use-dependent effect of MEC. It is concluded that the action site of MEC on nicotinic receptors of sympathetic neurons is different from that of HEX.
Animals
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Animals, Newborn
;
Cells, Cultured
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Hexamethonium
;
pharmacology
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Mecamylamine
;
pharmacology
;
Neurons
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drug effects
;
physiology
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Nicotinic Antagonists
;
pharmacology
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Patch-Clamp Techniques
;
Rats
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Rats, Wistar
;
Receptors, Nicotinic
;
drug effects
;
physiology
;
Superior Cervical Ganglion
;
cytology
;
physiology
5.A report of manipulative reduction for the proximal humeral epiphyseal fracture with shoulder dislocation.
Gui-Yang REN ; Qi-Yi CHEN ; Xiao-Chuan HU ; Xin LIU ; Rong-Xia YUAN
China Journal of Orthopaedics and Traumatology 2011;24(12):986-987
Child
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Epiphyses
;
injuries
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Female
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Humans
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Manipulation, Orthopedic
;
methods
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Shoulder Dislocation
;
therapy
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Shoulder Fractures
;
therapy
6.Remarks on the research of specificities of acupoints.
Huan-gan WU ; Wei YAO ; En-hua ZHOU ; Gui-rong DONG ; Chuan-tao ZUO ; Hui-rong LIU
Chinese Acupuncture & Moxibustion 2007;27(1):59-62
The scholars at home and abroad pay great attention to the studies of specificities of acupoints, but the studies were superficial and non-systemic because of lacking to application of modern sciences and technology. There are not persuasive conclusive achievements for the specificities of acupoints and the key factors influencing the effect of acupuncture. The study of the specificities of acupoints should be concentrate on the diseases for which acupuncture and moxibustion are effective. And multiple modern sciences and techniques should be adopted to resolve the key problems about biological and physical characteristics, pathological response, effects and law of compatibility of acupoints usually selected for the diseases, and then to create the model of the theory about the specificities of acupoints and to richen and develop the theory of the specificity of acupoints.
Acupuncture Points
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Humans
;
Research
7.Study on expression of genes in Tamarix androssowii under NaHCO3 stress using gene chip technology.
Chuan-Ping YANG ; Yu-Cheng WANG ; Gui-Feng LIU ; Jing JIANG ; Guo-Dong ZHANG
Chinese Journal of Biotechnology 2005;21(2):220-226
Gene chip technology was employed to study gene expression in Tamarix androssowii under NaHCO3 stress. cDNAs from T. androssowii treated with NaHCO3 solution and that from control group were labeled with fluorescent dye CyS and Cy3 respectively. The two fluorescent cDNA probes were mixed and hybridized to gene chips containing T. androssowii genes, and the chips were scanned using biochip scanning system. Differential expression of genes was analyzed through calculation of the ratio of Cy5 to Cy3 signal intensities. Total of 89 genes differentially expressed were identified, among them, 27 showed down regulated expression and 62 showed up regulated expression. Blastx analysis showed that the function of the differentially expressed genes could be grouped into some categorizations such as photosynthesis, reactive oxygen species eliminated, regulation of osmotic potential, regulation of gene expression and signal transduction, metabolism, development, ribosomal protein, protein breakdown and recycling, transporter, water channel proteins and so on. Based on this research, some function-unknown or novel unreported genes that respond to salt stress were also identified, and these genes may have important functions in salt resistance of T. androssowii. Some important pathways of salt resistance in T. androssowii are revealed, and the gene expression profiling of T. androssowii under salt stress and without stress is obtained in this study.
DNA, Complementary
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genetics
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Gene Expression Profiling
;
methods
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Genes, Plant
;
genetics
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Oligonucleotide Array Sequence Analysis
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Sodium Bicarbonate
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pharmacology
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Stress, Physiological
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Tamaricaceae
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drug effects
;
genetics
8.Evaluation of genotyping of human papilomavirus by a new DNA liquid chip based on Luminex XMAP.
Xiao-mei DENG ; Min LIU ; Gui-xi ZHENG ; Chuan-xin WANG ; Jian ZHANG ; Wei LI
Chinese Journal of Experimental and Clinical Virology 2009;23(6):476-478
OBJECTIVETo evaluate the diagnostic value of Luminex XMAP liquid chip for HPV detection.
METHODSDetect HPV DNA with the liquid chip and HC II in 264 cases, including 231 of cervical cancer and 33 of cervical scrapes. The accordance of two methods were compared and DNA sequencing was performed in conflicting samples and single (infection samples.
RESULTSThere is an excellent agreement between the methods. The overall incidence of HPV was 82.95%, the most common genotypes were HPV 16, 52, 58, 18, 11, 31, 6, 39, 33, 56, 70. Among all the positive types, 117 were single type and 102 were multiple types, and 87.43% were high-risk HPV genotypes and 12.57% were low-risk genotypes. Based on the criteria of histology and pathology, the sensitivity, specificity, positive and negative-predictive value of HPV liquid chip and HC II for detecting all cases of CIN II, III and carcinomas were respectively 93.07%, 87.88%, 98.17%, 64.44% and 94.81%, 87.88%, 98.21%, 70.73%.
CONCLUSIONThe common types of HPV infection are 16, 52, 58, 18, 11, 6, 56 and 31. Multiplex HPV genotyping by Luminex XMAP liquid chip appears to be highly suitable for diagnostic screening and large-scale epidemiological studies.
Adult ; Aged ; Alphapapillomavirus ; classification ; genetics ; isolation & purification ; Female ; Genotype ; Humans ; Middle Aged ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; methods ; Papillomavirus Infections ; diagnosis ; virology ; Phylogeny ; Uterine Cervical Neoplasms ; diagnosis ; virology ; Young Adult
9.Clinical observation on long-term survival in patients after simultaneous kidney-pancreas transplantation(report of 6 cases)
Li-Xin YU ; Yu-Ming YU ; Wen-Feng DENG ; Jian XU ; Shao-Jie FU ; Chuan-Fu DU ; Yi-Bin WANG ; Gui-rong YE ; Xiao-you LIU ; Yun MIAO ; Chuan-jiang LI ; Jun-sheng YE
Chinese Journal of Urology 2001;0(07):-
Objective To summarize the experience of long-term survival in patients after simulta- neous kidney-pancreas transplantation(SKPT)with modified enteric drainage(ED).Methods From October 2001 to July 2004,6 patients with end-stage renal disease due to Type 1 diabetes underwent SKPT with modified ED,ie,side-to-side anastomosis between the duodenum of donors and jejunum of recipients. The medication regimen included:mycophenolic acid 500 mg and tacrolimus 2 mg before operation;methyl- prednisolone(MP)1.0 during operation;and 2-dose anti-IL-2 receptor monoclonal antibody(2 cases)or antihuman thymocyte globulin(ATG)(4 cases)for immune induction therapy;MP was used on the first 3 d after transplantation,triple immunosuppressive therapy(tacrotimus,mycophenolic acid and prednisone)was used on the second d after transplantation.Anticoagulants such as low molecular heparin or alprostadil were used for 7-10 d to prevent thrombosis in pancreas graft.Somatostatin was used as prophylaxis for graft pan- creatitis.Ganciclovir was used to prevent cytomegalovirus infection when renal graft gradually recovered 3 to 5 d after transplantation.The follow-up was from 1 year and 3 months to 4 years and 1 month.Results Transplantation was successful in all 6 cases.The blood sugar levels were 6-16 mmol/L.Low-dose insulin was used for 5-10 d,then the blood sugar levels returned to normal range.One of 6 patients experienced nephrotoxicity because of high tacrolimus blood concentration at 7 d after operation;after 3 dialyses and re- duction of tacrolimus dose,the renal allograft regained normal function.Three cases experienced alimentary tract hemorrhage at 14,20 and 22 d,respectively,after operation;the bleeding was stopped after treatment. There were no complications such as pancreatic fistula,intestinal fistula and thrombosis early after operation. All the patients are now alive,specifically,1 survived over 4 years,3 over 3 years,1 over 2 years,and 1 over 1 year.All had normal blood sugar free of insulin use.Five cases had normal renal graft function,with normal sCr,and 1 had sCr>400?mol/L. Two cases were admitted to hospital due to upper respiratory infection and furuncles in the skin of head 6 months and 2 years,respectively,after operation.They were both cured.No complications such as urinary infection,metabolic acidosis and dehydration occurred.Conclusions SKPT is effective for the treatment of end-stage renal disease due to Type 1 diabetes.SKPT with modified ED are relatively simple with physiological compatibility and fewer complications.High quality of donated organs, HLA matching,pancreatic drainage pattern,rational periopcrative medications and infection late after trans- plantation are important factors affecting the long-term survival of the patients.
10.Development and validation of a liquid chromatography-isotope dilution tandem mass spectrometry for determination of olanzapine in human plasma and its application to bioavailability study.
Meng-Qi ZHANG ; Jing-Ying JIA ; Chuan LU ; Gang-Yi LIU ; Cheng-Yin YU ; Yu-Zhou GUI ; Yun LIU ; Yan-Mei LIU ; Wei WANG ; Shui-Jun LI ; Chen YU
Acta Pharmaceutica Sinica 2010;45(6):767-771
A simple, reliable and sensitive liquid chromatography-isotope dilution mass spectrometry (LC-ID/MS) was developed and validated for quantification of olanzapine in human plasma. Plasma samples (50 microL) were extracted with tert-butyl methyl ether and isotope-labeled internal standard (olanzapine-D3) was used. The chromatographic separation was performed on XBridge Shield RP 18 (100 mm x 2.1 mm, 3.5 microm, Waters). An isocratic program was used at a flow rate of 0.4 m x min(-1) with mobile phase consisting of acetonitrile and ammonium buffer (pH 8). The protonated ions of analytes were detected in positive ionization by multiple reactions monitoring (MRM) mode. The plasma method, with a lower limit of quantification (LLOQ) of 0.1 ng x mL(-1), demonstrated good linearity over a range of 0.1 - 30 ng x mL(-1) of olanzapine. Specificity, linearity, accuracy, precision, recovery, matrix effect and stability were evaluated during method validation. The validated method was successfully applied to analyzing human plasma samples in bioavailability study.
Antipsychotic Agents
;
blood
;
pharmacokinetics
;
Benzodiazepines
;
blood
;
pharmacokinetics
;
Biological Availability
;
Chromatography, Liquid
;
methods
;
Humans
;
Indicator Dilution Techniques
;
Isotope Labeling
;
Reproducibility of Results
;
Sensitivity and Specificity
;
Tandem Mass Spectrometry
;
methods