AIM:To study the electrophysiological effects of amiodarone on the pacemaker cells in guinea-pig left ventricular outflow tract under the conditions of hypoxia,acidosis and treatment with epinephrine.METHODS:The action potentials of the pacemaker cells in guinea-pig left ventricular outflow tract were recorded by conventional intracellular microelectrode technique.The effects of amiodarone on the spontaneous slow response potentials were investigated under the conditions of hypoxia,acidosis and treatment with epinephrine.RESULTS:(1) Amiodarone at concentration of 0.1 ?mol/L markedly decreased the rate of pacemaker firing (RPF) and maximal diastolic potential (MDP),lengthened 80% of the duration of action potential (APD80).Amiodarone at concentration of 1 ?mol/L significantly decreased the velocity of diastolic depolarization (VDD) and RPF,the maximal rate of depolarization (Vmax),MDP and amplitude of action potential (APA),lengthened 50% of the duration of action potential (APD50) and APD80.Amiodarone at concentration of 10 ?mol/L led to a significant decrease in VDD and RPF,Vmax,MDP and APA,a notable lengthening in APD50 and APD80 was also observed.(2) Under the condition of hypoxia and perfusion with deprived glucose content for 15 min,VDD,RPF,MDP,Vmax and APA decreased significantly,APD50 was shortened notably.Under the condition of hypoxia,amiodarone at concentration of 1 ?mol/L significantly decreased VDD,RPF and Vmax,increased MDP,lengthened APD50 and APD80 as compared to the cells treated with hypoxia only.(3) Perfusion with pH 6.8 solution for 10 min,VDD and RPF significantly decreased,Vmax and APA notably reduced,APD80 was markedly shortened.Under the condition of acidosis for 10 min,amiodarone significantly decreased VDD,RPF,MDP and APA,lengthened APD50 and APD80 as compared to the cells under the condition of acidosis only.(4) Perfusion of epinephrine at concentration of 10 ?mol/L for 10 min resulted in a significant increase in VDD,RPF,Vmax,MDP and APA,a notable shorting in APD50 and APD80 was also observed.Compared to 10 ?mol/L epinephrine group,1 ?mol/L amiodarone+ 10 ?mol/L epinephrine significantly reduced VDD,RPF,Vmax,MDP and APA,lengthened APD50 and APD80.CONCLUSION:Amiodarone markedly decreases the autorhythmicity of the pacemaker cells in guinea-pig left ventricular outflow tract.This electrophysiological effects were significantly influenced by hypoxia,acidosis and epinephrine.

BACKGROUND: Emblic leafflower fruit contains rich vitamin C, organic acid and mineral substance. It is indicated in modern research that emblic leaafflower fruit acts on preventing from cancer and anti-aging too. In recent years, more and more concerns have been paid to the researches on functional factor of emblic leafflower fruit and the development of the relevant functional food. It has been verified that emblic leafflower fruit acts on reducing lipid and anti-oxidation in vitro, but there are still lacks of enough basic researches to support it.OBJECTIVE: To probe into mechanism of emblid leafflower fruit on anti-oxidation and protection of vascular endothelial function in rabbits with hyperlipemia.DESIGN: Randomized controlled experimental study based on the experimental animals.SETTING: Atherosclerosis(As) experimental room in a university hospital.MATERIALS: Totally 24 normal NewZealand male rabbits, mass weighted (2.2±0.5) kg.METHODS: The experiment was performed in As Experimental Room of Beijing Anzhen Hospital from September 2001 to May 2002. Totally 24 New Zealand male rabbits were randomized into the control, the power of emblid leafflower fruit group(powder group)(4 g/kg day) and hypercholesterolemia model group (model group), 8 rabbits in each group. In both power and model groups, the rabbits were fed with hypercholesterol food. Oxidase method was applied to assay the content of serum lipid, chemical method to assay the plasma total anti-oxidation and the content of malondialdehyde (MDA), radio-immune method to assay the content of plasma endothelin-1 (ET-1), digoxin labeled probe and tissue hybridism in situ to assay the expression of endothelin mRNA of aortic tunica intima, and image analyzer to assay the area of aortic intimal atherosclerosis plaque and the ratio between the area of tunica intima and the area of tunica media.MAIN OUTCOME MEASURES: The primary outcomes included blood lipid level, serum MDA concentration and the comparison of artery plaque areas. The secondary outcomes included the changes in plasma ET-1.RESULTS: By the comparison between the powder group and model group in triglyceride(TG) and low density lipoprotein cholesterol(LDL-C) were significantly reduced [(11.70 ± 1.73), (14.32 ±2.22) mmol/L, P<0.05; (0.740 ± 0.107), (1.450 ± 0.220) mmol/L, P <0.01 successively]and thehigh density lipoprotein cholesterol(HDL-C) was increased MDA was significantly decreased [ (3.88 ± 0.51 ), (6. 29 ± 1.43 ) mmol / L,P < 0.01 ] and the total anti-oxidation significantly increased [ (10. 771der photo-microscope that the plaque area and the ratio between intima area and media area were remarkably decreased [(39.46±6.53), (50.69± 12.36)mmol/L, P < 0.05; (0. 62 ±0. 32), (1.38 ±0.38) mmol/L, Pgranules of aortic intima ET-1 gene were rem~kably decreased compared with the model group.CONCLUSION: Emblic leafflower fruit prevents from the formation of experimental atheromatous plaque in rabbits probably by regulating rabbit lipid metabolism, improving anti-oxidation to reduce lipid peroxidation and protecting endothelial function to inhibit the expression of artery intima ET-1 gene.

Objective To investigate the application of polymerase chain reaction and single strand conformation polymorphism analysis(PCR-SSCP)to the screening of gene mutation of exon 13 of the LDLR gene in familial hypercholesterolemia(FH).Methods Peripheral blood DNA of 16 clinically diagnosed FH patients was extracted and the exon 13 coding region of the LDLR gene was amplified by PCR.PCR products were separated by optimized SSCP electrophoresis and visualized by silver staining.DNA fragments with abnormal mobility were sequenced to determine the nature and position of mutations.Results The SSCP electrophoresis conditions were optimized as 8%polyaerylamide(degree of cross linking 49:1)gel without glycerin at a electrophoresis temperature of 10℃ or 8%polyacrylamide gel with 5%glycerin at room temperature,gel thickness of＜0.4 mm,and a voltage of 5 V/cm.DNA fragments were well resolved with the conditions and sequencing of the abnormal bands resuhed in detections of missense mutations of A606T,D601N,Y601D and G636V together with a synonymous mutation of 1959C→T in 4 patients and a sole synonymous mutation of 1959C→T in other 4 patients.Conclusion PCR-SSCP is an effective method for the screening of exon13 mutations of LDLR gene in FH patients.

OBJECTIVE To investigate the knowledge of Helicobacter pylori infection among outpatients,analyzing the data and providing useful information and measures for H.pylori infected and uninfected patients. METHODS Questionnaires about the knowledge of H.pylori were operated on 286 patients randomly selected from patients taking gastrointestinal endoscopy in October,2005. RESULTS Among 286 patients investigated,177 cases(61.9%) took the examination for diagnosis,while 157 cases(54.9%) had upper abdominal symptom more than 12 months.There were 60% patients investigated who knew only 2 items from total(7 items) about H.pylori in the questionnaires,while 46.7% patients wanted to obtain the knowledge of the disease and instructions on health care from medical professionals.In addition,it showed that there was no close relation between education level and knowledge of the disease. CONCLUSIONS Investigating the knowledge of special disease,which mastered by the patients,will help to identify patients blind to the disease they have,and patients who are in need of health-care instructions.

Objective:To conduct a systematic study of the immunologic response of rats to transplanted glutaraldehyde ( GA)-treated porcine blood vessels in vivo.Methods: The experiment was divided into two groups:fresh group and glutaraldehyde-treated group.Twenty cases of fresh and glutaraldehyde-treated porcine pulmonary arteries were subcutaneously embedded in rats.We compared the changes using HE staining and immunohistochemistry.Results:HE staining showed that there were stronger expression on day 12 and day 30 in the fresh group than that in the glutaraldehyde group.There were similar results in morphology in CD68,C3,IgG.The results of integral optical density ( IOD) in immunohistochemistry showed that IOD started rising from day 4 and got the peak on day 12 or day 30 and or fell on day 60.Conclusion: Innate immunity played an important role in the research on xenogenic immunological rejection mechanism.The immunogenicity of glutaraldehyde-treated xenogenic blood vessels is lower than that in fresh blood vessels.However there is still immunogenicity in glutaraldehyde-treated xenogenic blood vessels.We will explore better ways to obviously weaken the rejection.

OBJECTIVETo screen the point mutation of the low-density lipoprotein receptor (LDL-R) gene in Chinese familial hypercholesterolemia (FH) patients, characterize the relationship between the genotype and the phenotype and discuss the molecular pathological mechanism of FH.

METHODSA patient with clinical phenotype of homozygous FH and her parents were investigated for mutations in the promoter and all eighteen exons of the LDL-R gene. Screening was carried out using Touch-down PCR and direct DNA sequencing; multiple alignment analysis by DNASIS 2.5 was used to find base alteration, and the LDL-R gene mutation database was searched to identify the alteration. In addition, the apolipoprotein B gene (apo B) was screened for known mutations (R3500Q) that cause familial defective apo B100 (FDB) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTSTwo new heterozygous mutations in exons 4 and 9 of the LDL-R gene were identified in the proband (C122Y and T383I) as well as her parents. Both of the mutations have not been published in the LDL-R gene mutation database. No mutation of apo B100 (R3500Q) was observed.

CONCLUSIONTwo new mutations (C112Y and T383I) were found in the LDL-R gene, which may result in FH and may be particularly pathogenetic genotypes in Chinese people.

Adult ; Apolipoproteins B ; genetics ; Asian Continental Ancestry Group ; Child ; China ; Female ; Heterozygote ; Homozygote ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Male ; Mutation ; Receptors, LDL ; genetics