This paper discusses the relationship between stimulating pulse width and the threshold of electrically evoked compound action potential (ECAP). Firstly, the rheobase and chronaxy from strength-duration curve of nerve fiber was computed using the shepherd's experiment results. Secondly, based on the relationship between ECAP and the action potential of nerve fiber, a mathematical expression to describe the relationship between stimulating pulse width and ECAP threshold was proposed. Thirdly, the parameters were obtained and the feasibility was proved to the expression with the results of experiment using guinea pigs. Research result showed that with ECAP compared to the action potential of nerve fiber, their threshold function relationship with stimulating pulse width was similar, and rheobase from the former was an order smaller in the magnitude than the latter, but the chronaxy was close to each other. These findings may provide meaningful guidance to clinical ECAP measurement and studying speech processing strategies of cochlear implant.
Action Potentials ; Animals ; Auditory Threshold ; Cochlear Implantation ; Cochlear Implants ; Electricity ; Evoked Potentials ; Guinea Pigs ; Neural Conduction

According to the common standard of ethic review for clinical research , it is equal to each kind of research program whether western medicine or Traditional Chinese Medicine .It should be reviewed the ethic and scientific issues in the same time .However, on account of the two majority characteristics of Traditional Chinese Medicine , it would be concerned more evidence , such as the safety data before clinic , the syndrome differentiation and treatment of target disease , drug combination , dosage and course of treatment , the methods of outcome meas-urement, admixture of the drug, the selection of control drug including placebo and so on .

High-speed counter-current chromatography (HSCCC) was used to high performance separate and prepare lignans from Schisandrae chinensis fructus. The solvent system is composed of n-hexane-ethyl acetate-methanol-water (9 : 1 : 5 : 5) and n-hexane-ethyl acetate-methanol-water (9 : 1 : 9 : 5), speed is at 900 r.min-1, and flow rate is at 2.0 mL.min-1. Five fractions from Schisandrae chinensis fructus extract were separated and prepared with one HSCCC process. They were identified as schisandrin, gomisin J, schisandrol B, schisantherin A and deoxyschizandrin by electrospray ionization-multiple tandem mass spectrometry (ESI-MSn), respectively. Their contents were obtained in 98.74%, 94.32%, 99.53%, 94.23% and 98.68% by ultra high performance liquid chromatography (UPLC), separately. The rapid and simple method can be applied for the preparation of lignans from Schisandrae chinensis fructus.
Countercurrent Distribution ; Cyclooctanes ; chemistry ; isolation & purification ; Dioxoles ; chemistry ; isolation & purification ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Fruit ; chemistry ; Lignans ; chemistry ; isolation & purification ; Molecular Structure ; Plants, Medicinal ; chemistry ; Polycyclic Compounds ; chemistry ; isolation & purification ; Schisandra ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry

Apoptosis ; drug effects ; Cell Line, Tumor ; Drug Synergism ; Flavanones ; administration & dosage ; pharmacology ; Humans ; Multiple Myeloma ; pathology ; Thalidomide ; administration & dosage ; analogs & derivatives ; pharmacology

To study the effect of Gegen Qinlian decoction and its major effective components on five hepatic microsomal CYP450 isozymes in rats. The in vitro hepatic microsomal incubation technique was used to co-culture Gegen Qinlian decoction and its major effective components together with each probe substrate. HPLC-MS/MS was used to establish the analytical method for metabolites of the five isoform probe substrates of CYP450 isozymes, detect the linearity among micoromal protein concentration, incubation time and metabolite formation amount. And HPLC-MS/MS was applied to determine the formation rate (V) of corresponding metabolites (acetaminophen, 4-OH-chlorzoxazone, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone) specific probe substrates of the five isoform probe substrates of CYP450 isozymes (phenacetin, polbutamide, dextromethorphan, chlorzoxazone, testosterone), in order to determine the activity of each isozyme. The result showed good linearity among acetaminophen, 4-OH-tolbutamide, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone, satisfactory precision, stability and average recovery, suggesting the method was feasible. The optimized in vitro microsomal incubation conditions conformed to the requirements in the guideline of drug-drug interaction. Gegen Qinlian decoction showed different degrees of inhibitor effect on 5 CYP450 isoforms (CYP1A2, CYP2C11, CYP2D2, CYP2E1, CYP3A1/2). Its major effective component berberine could inhibit each CYP450 isoform at high concentrations (except for CYP1A2, CYP3A1/2).
Animals ; Chromatography, High Pressure Liquid ; methods ; Cytochrome P-450 Enzyme Inhibitors ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Isoenzymes ; antagonists & inhibitors ; Liver ; enzymology ; Rats ; Tandem Mass Spectrometry ; methods

Objective To investigate the expression of peroxisome proliferators-activated receptor ? (PPAR?) in trophoblast and relation between PPAR? ligands and trophoblast invasion.Methods We examined the expression of PPAR? by immunohistochemistry,immunocytochemistry and real time quantitative PCR.We next examined,using the cytotrophoblast culture model,the biological role of PPAR? ligands in vitro.Results PPAR? was mainly localized in the nuclei of villous cytotrophoblast and extravillous cytotrophoblast of cell islands and cell columns.In villous tissue and cultured trophoblast from early first trimester,the level of expression of PPAR? mRNA and protein was 36.0?5.1,13.4?3.1 and 1.35?0.08,1.13?0.11;from late first trimester it was 23.3?5.5,6.1?1.3 and 1.17?0.03,0.86 ?0.05,and the expression of PPAR? was obviously decreased (P

Objective To investigate the intelligence standard for diagnose the sub-cretin children and children with mental retardation of socio-cultural type.Methods The full intelligence quotient(IQ),verbal intelligence quotient(VIQ)and performance intelligence quotient(PIQ)was tested by Wechsler scale(C-WISC)for mild iodine deficiency disordem children,children living in abnormal socio-cultural condition and normal children aged 7～14 years old in Qinba mountain area.The test results had been compared between the groups.Results There were no significant difference between psychomotor functioning well children and children living normal sociocuhural condition in VIQ,PIQ and full IQ(89.24±18.44 vs 90.75±17.58,87.58±15.78 vs 88.95±15.56,87.42±17.84 vs 89.02±17.18,t=1.14,1.19 and 1.24,respectively,all P＞O.05).PIQ and full IQ were significantly lower in mild iodine deficiency disorders children than in children with abnormal socio-cultural background (65.81±10.22 vs 72.33±13.23,62.42±12.31 vs 68.13±14.54,t=3.26,2.55,P＜0.01 or＜0.05,respectively).But the VIQ was not significantly different between these two groups.The average difference of VIQ and PIQ among mild iodine deficiency disorders children wag-0.32 without significant difierence(t=0.28,P＞0.05),however it was-2.91 among children under abnormal socio-cultural condition with significant difierenee(t=-3.59,P＜0.01).Conclusions IQ for iodine deficiency disorders children is characterized by that VIQ is damaged in parallel with PIQ,while that in children under abnormal soeio-cuhural condition is marked by that VIQ is retarded more severely than PIQ,which ean be used as an intelligence standard for differentiating the sub-cretin children from children wjth socio-cuhural mental retardation.

Background The domestic and international researches discovered that many proteins and enzymes of the extracellular matrix (ECM) participate in the sclera remodeling by affecting the collagen typeⅠand fibronectin.Objective This study was to investigate the effect of matrixmetalloproteinase-2 (TIMP-2) on expression of collagen typeⅠand fibronectin of ECM in the posterior sclera by injecting liposomes containing tissue inhibitor of TIMP-2 gene into suprachoroidal space of the form-deprivation myopia in guinea pig.Methods Form-deprivation myopia was induced by translucent goggles in 36 clean guinea pig for 2 weeks.Then the animals were randomly assigned to TIMP-2 group,empty plasmid group,saline group and 12 for each group.Liposomes of 5μl containing TIMP-2 gene,empty plasmid and saline were suprachoroidally injected in the right eye respectively,and the left eyes without any treatment were used as self-control group.Other 12 matched guinea pigs only covered the right eyes through out the experimental duration as model control group.The guinea pigs were sacrificed and the posterior sclera tissue of the eyeballs were collected at 2,7 and 14 days after injection of drug.The expressions of collagen typeⅠmRNA and fibronectin mRNA were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).This study followed the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The expression level of collagen type Ⅰ mRNA in the posterior sclera of guinea pig was lower but that of fibronectin mRNA was higher in TIMP-2 group than self-control group,showing significant differences between them (P＜0.05).The expression level of collagen type Ⅰ mRNA in the posterior scleral tissue began to increase from the 2nd day after drug injection and was obviously elevated at the 7th day and then gradually decreased at the 14th day.However,the expression level of fibronectin mRNA in the posterior scleral tissue showed the opposite pattern.The expression levels of collagen typeⅠmRNA and fibronectin mRNA at the 7th after drug injection were significantly lower than that at the 2nd day or 14th day (P＜0.01).Conclusion Suprachoroidal injection of TIMP-2 in form-deprivation myopia could up-regulate the expression of collagen typeⅠmRNA and down-regulate the expression of fibronectin mRNA in the posterior scleral tissue.It may slow down the sclera remodeling of form-deprivation myopia in guinea pig in the early stage.

A single dose of 3H-norcantharidin solution was intragastrically given, blood, tissues, urine and feces were collected as scheduled, and radioactivity in these samples was determined by tritium tracing method to investigate the pharmacokinetics, tissue distribution and excretion of norcantharidin in Kunming mice. The pharmacokinetic characteristics of norcantharidin were evaluated by DAS version 2.0. The blood concentration reached to maximum 0. 5 h after intragastric administration. The radioactivity in tissues was high in small intestine, gallbladder, stomach, adrenal gland, kidney, heart and uterus 15 minutes after administration, descending with time, and high in gallbladder, adrenal gland and uterus 3 hours post dosing. The 24 h accumulative excretion ratio of urine and feces were 65.40% and 1.33% respectively. 3H-norcantharidin was easily absorbed after orally given to mice, the radioactivity was high and existed for a long-time in gallbladder, adrenal gland and uterus, and low but also existed for a long-time in large intestine, thymus and fat tissue. 3H-norcantharidin was declined quickly in small intestine, stomach, kidney and heart, and occurred rarely in brain. Norcantharidin was excreted mainly by urinary route and seldom in feces, which may be the cause of the urinary stimulation side effects observed. Because the radioactivity measured were the sum of 3H labeled norcantharidin and its metabolites, further studies on the disposition of norcantharidin in mammal animals, on the separation or identification of metabolites and, if any, on their activities, are fairly needed.
Administration, Oral ; Animals ; Antineoplastic Agents ; administration & dosage ; chemistry ; pharmacokinetics ; urine ; Bridged Bicyclo Compounds, Heterocyclic ; administration & dosage ; chemistry ; pharmacokinetics ; urine ; Feces ; chemistry ; Female ; Male ; Mice ; Molecular Structure ; Random Allocation ; Tissue Distribution ; Tritium

OBJECTIVE Metastasis-associated in colon cancer-1 (MACC1) is an oncogene that has been newly identified. It promotes tumor proliferation and invasion via the MET pathway. Our study investigated the effects of Saikosaponin-b(SS-b) on the proliferation and apoptosis of HepG2 cells and its regulation on MACC1/c-Met/Akt signaling pathway. METHODS HepG2 cells were treated with SS-b (10-800 g·L-1) for 48 h in vitro. The CCK-8 assay was used to assess cell proliferation, and cell apoptosis was determined by Hoechst33258 staining, AnnexinⅤ/PI staining and caspase 3 assay. RT-PCR was used to examine the expression of MACC1, c- MET and hepatocyte growth factor (HGF) mRNA. MACC1 protein was detected by Western blot and immunohistochemistry. The protein expressions of p-c-MET, c-MET, p-AKT, AKT, p-BAD, BAD were measured by Western blot. RESULTS SS-b inhibited the growth of HepG2 cells in dose-dependent way and induced cell apoptosis significantly. HepG2 cells showed karyopyknosis, fragmentation and fluorescence highlight in SS-b treatment group. FCM results showed that apoptosis rate of HepG2 cells increased with SS- b concentration. The immunofluores?cence results showed that the MACC1 expression decreased significantly in HepG2 cells treated with SS-b. The expression levels of MACC1, c-MET and HGF mRNA in HepG2 cells were significantly inhibited by SS-b. SS-b also significantly decreased the protein expressions of MACC1, p-c-MET and p-AKT while increased the expression of p-BAD and caspase 3 in HepG2 cells(P<0.05). CONCLUSION SS-b inhibited the proliferation and induced the apoptosis of HepG2 cells by targeting the MACC1/c-Met/Akt signaling pathway.