第七届新西兰达尼丁——中国上海初中数学友谊通讯赛

从1992年开始举办的“新西兰达尼丁——中国上海数学友谊通讯赛”是新西兰和中国的两个城市间关于数学教育的一项国际交流活动,至今已进行了七届。该项竞赛由达尼丁、上海的数学会轮流主持,试题是联合命题,由主持方定卷。参赛学校各以10名初三学生组成校代表队,赛后双方各评出一个”最佳学校”;评出前三名,给予金、银、铜奖。对获奖的学校和个人双方都颁发证书。同时,还组织两国学校和学生间文化交流。

地氯雷他定联合雷尼替丁治疗慢性特发性荨麻疹临床疗效观察

目的:观察地氯雷他定联合雷尼替丁治疗慢性特发性荨麻疹的临床疗效。方法:慢性特发性荨麻疹患者随机分配进入治疗组和对照组,治疗组口服地氯雷他定和雷尼替丁,对照组单用地氯雷他定,疗程均为14 d,疗程结束时评价疗效。结果:治疗组与对照组的有效率分别为92.64%和75.80%,两组比较差异有显著性(P<0.05)。药物不良反应轻微。结论:地氯雷他定联合雷尼替丁治疗慢性特发性荨麻疹具有良好的疗效,而且疗效随着治疗时间的延长而明显提高。

尼札替丁

尼札替丁(nizatidine)(商品名:Axid,Lilly公司)是一种与西米替丁(Cimetidine)、雷尼替丁(Ranitidine)和法莫替丁(Famotidine)相似的新H_2—受体对抗剂,美国FDA已批准用于治疗活动性十二指肠溃疡和愈后维持治疗。西米替丁、雷尼替丁和法莫替丁也被批准用于治疗因分泌亢进所致的疾病,如Zollinger—Ellison氏综合征;西米替丁另外还被批准治疗胃溃疡。药物动力学:

戒烟药物现状简评及Zyban简介

“吸烟有害健康”已得到科学论证并为社会所共识。令人忧虑的是中国已成为全球最大的香烟消费国之一。本文介绍戒烟药的现状与进展 ,重点介绍了最近出现的戒烟新药——盐酸安非他酮缓释片的研究开发情况 。

Effects of galvanic interaction between galena and pyrite on their flotation in the presence of butyl xanthate

The effects of galvanic interaction between galena and pyrite on their flotation and electrochemical characters were studied by electrochemical,adsorption,flotation and FTIR techniques,respectively.Electrochemical tests indicate that galena is electrochemically more active than pyrite and serves as an anode in galvanic combination with pyrite.The galvanic current density from a mixture of galena and pyrite is 4 times as high as the self corrosion current density of galena,which indicates that the corrosion rate of galena is accelerated.Adsorption tests show that the adsorption of butyl xanthate on galena surface is enhanced,and affected by a combination of pyrite-galena mixtures and conditioning time.Compared with individual mineral particles,galvanic interaction reduces the floatability difference between galena and pyrite.The flotation recovery of galena decreases while that of pyrite increases when two minerals are mixed together due to the influence of galvanic interaction on the formation of hydrophilic/hydrophobic product.The FTIR results show that the formation of dixanthogen on pyrite surface is depressed due to the galvanic interaction.

新西兰纪行

我们可以发现世界上不少国家的国旗上,都画有星星,但较少有人知道大洋洲的岛国新西兰的国旗上也画有星星,至于新西兰的国旗那深蓝底色上的四颗亮星是代表着什么,那就更少有人知道了。由两颗一等星、一颗二等星和一颗三等星组成的这个星座,上下、左右互相对着构成了稍许竖长的菱形,如果给这四颗星划上了对角线,就会浮现出漂亮的十字架。

First-line eradication of H pylori infection in Europe:A metaanalysis based on congress abstracts,1997-2004

AIM： To meta-analyse the European abstracts presented between 1997-2004 at the European Hpylori Study Group, United European Gastroenterology Week meetings and World Congresses of Gastroenterology. METHODS： The abstracts of randomized/controlled prospective studies were classified into groups based on first-line eradication schedules. The quality of the abstracts was checked by a validated score system. The pooled eradication rates （PER） and combined odds ratios （OR） were calculated and compared with the published meta-analyses. RESULTS： The PER of proton pump inhibitor-based （PPI） one week triple therapies was 81.4% （confidence interval, 95% CI： 78.5-84.5）. Ranitidine bismuth citratebased （RBC） triple regimens have an efficiency rate of 78.5% （95% CI： 70.5%-84.3%） （P = 0.28 vs PPI）. The OR for PPI effect vs RBC regimens was 1.1 （95% CI： 0.92-1.30）. H2 receptor antagonist-based triple therapies achieved 64.1% （95% CI： 52.6-75.6） （P = 0.02 〈 0.05 vs PPI）, the OR vs PPI regimens was 1.55 （95% CI： 0.72-3.78）. PPI-based double combinations were less efficient than triple regimens （PER： 55.0%, OR： 4.90, 95% CI： 2.36-9.70）. Quadruple regimens were successful in 82.6% （95% CI： 76.0-89.7）, the OR vs triple therapies was 0.80 （0.62-1.03）. Clarithromycin ＋ amoxicillin or nitroimidazole combinations were efficient in 80.5% （95% CI： 77.2-84.2） and 83.8% （95% CI： 81.7-85.9）, respectively. Amoxicillin ＋ nitromidazole therapies eradicated the infection in 73.5% （66.6-78.5） （P = 0.01 〈 0.05 vs clarithromycin-based regimens）. CONCLUSION： PPI/RBC-based triple therapies achieved comparable results with the meta-analyses. H2-receptor antagonists and PPI-based double combinations were less efficient. Triple and quadruple regimens were equally effective. Clarithmmycin ＋ either amoxicillin or nitroimidazole containing regimens were more effective than amoxicillin ＋ nitroimidazole combinations. High quality congress abstracts constitutes a valuable pool of data which is suitable for meta-analytical workup.

Enhanced proliferation,invasion,and epithelial-mesenchymal transition of nicotine-promoted gastric cancer by periostin

AIM:To investigate the contribution of periostin in nicotine-promoted gastric cancer cell proliferation,survival,invasion,drug resistance,and epithelial-mesenchymal transition(EMT).METHODS:Gastric cancer cells were treated with nicotine and periostin protein expression was determined by immunoblotting.Periostin mRNA in gastric cancer cells was silenced using small interfering RNA(siRNA) techniques and periostin gene expression was evaluated by quantitative reverse transcription-polymerase chain reaction.Gastric cancer cells transfected with control or periostin siRNA plasmid were compared in terms of cell proliferation using the methylthiazolyldiphenyl-tetrazolium bromide assay.Cell apoptosis was compared using annexin V-fluoresceine isothiocyanate and propidium iodine double staining.Tumor invasion was determined using the Boyden chamber invasion assay,and the EMT marker Snail expression was evaluated by immunoblotting.RESULTS:Nicotine upregulated periostin in gastric cancer cells through a COX-2 dependent pathway,which was blocked by the COX-2-specific inhibitor NS398.Periostin mRNA expression was decreased by ～87.2% by siRNA in gastric cancer cells,and stable periostinsilenced cells were obtained by G418 screening.Periostin-silenced gastric cancer cells exhibited reduced cell proliferation,elevated sensitivity to chemotherapy with 5-fluorouracil,and decreased cell invasion and Snail expression(P < 0.05).CONCLUSION:Periostin is a nicotine target gene in gastric cancer and plays a role in gastric cancer cell growth,invasion,drug resistance,and EMT facilitated by nicotine.

Ulcerative colitis in smokers,non-smokers and ex-smokers

Smoking is a major environmental factor that interferes in the establishment and clinical course of ulcerative colitis (UC). Firstly, the risk of smoking status impact in the development of UC is reviewed, showing that current smoking has a protective association with UC. Similarly, being a former smoker is associated with an increased risk of UC. The concept that smoking could have a role in determining the inflammatory bowel disease phenotype is also discussed. Gender may also be considered, as current smoking delays disease onset in men but not in women. No clear conclusions can be driven from the studies trying to clarify whether childhood passive smoking or prenatal smoke exposure have an influence on the development of UC, mainly due to methodology flaws. The influence of smoking on disease course is the second aspect analysed. Some studies show a disease course more benign in smokers that in non-smokers, with lower hospitalizations rates, less flare-ups, lower use of oral steroids and even less risk of proximal extension. This is not verified by some other studies. Similarly, the rate of colectomy does not seem to be determined by the smoking status of the patient. The third issue reviewed is the use of nicotine as a therapeutic agent. The place of nicotine in the treatment of UC is unclear, although it could be useful in selected cases, particularly in recent ex-smokers with moderate but refractory attacks of UC. Finally, the effect of smoking cessation in UC patients is summarised. Given that smoking represents a major worldwide cause of death, for inpatients with UC the risks of smoking far outweigh any possible benefit. Thus, physicians should advise, encourage and assist UC patients who smoke to quit.

Pharmacokinetics and bioequivalence of ranitidine and bismuth derived from two compound preparations

AIM： To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations. METHODS： The bioavailability was measured in 20 healthy male Chinese volunteers following a single oral dose （equivalent to 200 mg of ranitidine and 220 mg of bismuth） of the test or reference products in the fasting state. Then blood samples were collected for 24 h. Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry （ICPMS）, respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC（0-t） and AUC（0-∞） were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon＇s test. RESULTS： Various pharmacokinetic parameters of ranitidine derived from the two compound preparations, including Cmax, AUC（0-t）, AUC（0-∞）, Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows： Cmax（0.67 ± 0.21 vs 0.68 ± 0.22 mg/L）, AUC（0-t）（3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour）, AUC（0-∞）（3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour）, Tmax （2.3 ± 0.9 VS 2.1 ± 0.9 h） and T1/2 （2.8 ± 0.3 vs 3.1 ± 0.4 h）. In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers. For bismuth, those parameters derived from test and reference drug were as follows： Cmax （11.80 ± 7.36 vs 11.40 ± 6.55 μg/L）, AUC（0-t） （46.65 ± 16.97 vs 47.03 ± 21.49 μg/L per hour）, Tmax （0.50 ± 0.20 vs 0.50 ± 0.20 h） and T1/2 （10.2 ± 2.3 vs 13.0 ± 6.9 h）. Ninety percent of confidence intervals for the test/reference ratio of Cmax, AUC（0-t） and AUC（0-∞） derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth. CONCLUSION： The two compound preparations are bioequivalent and may be prescribed interchangeably.

The genetics of nicotine dependence:Relationship to Pancreatic cancer

Smoking of tobacco products continues to be a major cause of worldwide health problems. Epidemiological studies have shown that tobacco smoking is the greatest risk factor for the development of pancreatic cancer. Smokers who are able to quit smoking can reduce their risk of pancreatic cancer by nearly 50% within two years, however, their risk of developing pancreatic cancer remains higher than that of non-smokers for 10 years. Nicotine is the major psychoactive substance in tobacco, and is responsible for tobacco dependence and addiction. Recent evidence suggests that individuals have genetically based differences in their ability to metabolize nicotine, as well as genetic differences in the psychological reward pathways that may influence individual response to smoking initiation, dependence, addiction and cessation. Numerous associations have been reported between smoking behavior and genetic polymorphisms in genes that are responsible for nicotine metabolism. In addition, polymorphisms in genes that encode neurotransmitters and transporters that function in psychological reward pathways have been implicated in differences in smoking behavior. However, there is a large degree of between-study variability that demonstrates the need for larger, well-controlled casecontrol studies to identify target genes and deduce mechanisms that account for the genetic basis of interindividual differences in smoking behavior. Understanding the genetic factors that increase susceptibility to tobacco addiction may result in more effective tobacco cessation programs which will, in turn, reduce the incidence of tobacco related disease, including pancreatic cancer.

A randomized open-label trial of on-demand rabeprazole vs ranitidine for patients with non-erosive reflux disease

AIM： To compare the efficacy of the proton-pump inhibitor, rabeprazole, with that of the H2-receptor antagonist, ranitidine, as on-demand therapy for relieving symptoms associated with non-erosive reflux disease （NEED）.METHODS： This is a single center, prospective, randomized, open-label trial of on-demand therapy with rabeprazole （group A） vs ranitidine （group B） for 4 wk. Eighty-three patients who presented to the American University of Beirut Medical Center with persistent gas- troesophageal reflux disease （GERD） symptoms and a normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A （n = 44） were al-lowed a maximum rabeprazole dose of 20 mg twice daily, while those in group B （n = 39） were allowed a maximum ranitidine dose of 300 mg twice daily. Ef- ficacy was assessed by patient evaluation of global symptom relief, scores of the SF-36 quality of life （QoL） questionnaires, total number of pills used, and number of medication-free days.RESULTS： Among the 83 patients who were enrolled in the study, 76 patients （40 in the rabeprazole group and 36 in the ranitidine group） completed the 4-wk trial. Baseline characteristics were comparable between both groups. After 4 wk, there was no significant difference in the subjective global symptom relief between the rabeprazole and the ranitidine groups （71.4% vs 65.4%, respectively; P = 0.9）. There were no statistically significant differences between mean cumulative scores of the SF-36 QoL questionnaire for the two study groups （rabeprazole 22.40±27.53 vs ranitidine 17.28 ± 37.06; P = 0.582）. There was no significant difference in the mean number of pills used （rabeprazole 35.70±29.75 vs ranitidine 32.86±26.98; P = 0.66）. There was also no statistically significant difference in the mean number of medication-free days between both groups.CONCLUSION： Rabeprazole has a comparable efficacy compared to ranitidine when given on-demand for the treatment of NERD. Both medications were associated with improved quality of life.

Nicotine enhances migration and invasion of human esophageal squamous carcinoma cells which is inhibited by nimesulide

AIM： To study the effect of nicotine on the migration and invasion of human esophageal squamous carcinoma cells and to investigate whether nimesulide can inhibit the effect of nicotine.METHODS： The esophageal squamous carcinoma cell line （TE-13） was treated with different concentrations of nicotine （100 μg/mL and 200 μg/mL） or 200 μg/mL nicotine plus 100 μmol/L nimesulide. Cell migration and invasion were measured using migration and invasion chamber systems. COX-2 expression was determined by Western blotting. Matrix metalloproteinase-2 （MMP-2） was analyzed by zymography and ELISA.RESULTS： Nicotine （100 μg/mL, 200 μg/mL） enhanced TE-13 cells migration and invasion, and increased the protein expression of COX-2 and the activity of MMP-2. Nicotine （200 μ/mL） stimulated TE-13 cells migration and invasion which were partly blocked by nimesulide. This was associated with decreased protein expression of COX-2 and decreased activity and protein expression of MMP-2. CONCLUSION： Nicotine enhances the migration and invasion of the esophageal squamous carcinoma cell line, and nimesulide partly blocks the effect ofnicotine-enhanced esophageal squamous carcinoma cell migration and invasion.

Effects of ranitidine for exercise induced gastric mucosal changes and bleeding

AIM： To evaluate the effect of ranitidine on gastric mucosal changes and on GI bleeding in long distance runhers. METHODS： Twenty-four long distance runners （M： 16, F： 8, age： 18.2＋ 1.5 years） participated in this study. A symptom questionnaire, stool hemoccult test, and upper gastrointestinal （GI） endoscopy were performed on the subjects prior to the study. The subjects took oral ranitidine （150 mg, b.i.d.） for two weeks. The upper GI endoscopy and stool Hemoccult tests were repeated after the treatment. RESULTS： Twenty-two of the 24 runners had at least one upper G1 mucosal lesion before the medication. The Endoscopic improvements were seen in eleven of the 14 cases of erosive gastritis and four of the 5 cases of esophagitis. Six subjects were Heine occult positive prior to the study, but only one was positive after the medication. CONCLUSION： Gastric mucosal lesions and GI bleeding in long distance runners seem to be associated to acidrelated factors mediated by the high level of regular running. Ranitidine seems to be and effective prophylaxis to prevent gastric mucosal lesions and GI bleeding.

A Method and a Surface Treatment Agent for Preventing Biofouling on Surfaces under Water

This paper presents an environm centally friendly method of inhibiting biofouling especially acorn barnacles on surfaces under water by using nicotine and selenium in the form of Se（0）, or such a substance which can be converted into them. Both of the substances are necessary to oxygen dependent organisms and will be used after conversion, but are toxic in high doses. By adding the substances to paint or other surface treatment agent which marine surfaces are treated with, organisms which are trying to establish themselves on the surfaces will be exposed to so high doses, the reactions which the settling is based on are disturbed. When the substances leak out into the seas, they will act as environment protectors, as they promote the development of organisms. Nicotine is transformed to nicotine amid which is the reactive part in NADH and one of the most important substances for the transference of hydrogen. Selenite is reduced to Se（0）, also involved in the transport chain of hydrogen to reducible oxygen. However, large quantities Se（0） may disturb the reactions of sulphur b＇./binding to it and impairing the formation of S-S-bridges.

Application of Y2O3 nanoparticles on reducing the content of tar in cigarettes

Y2O3 nanoparticles prepared in microemulsion, which were sprayed on cut tobacco, can reduce tar in cigarettes effectively. Reducing the content of tar in many brands of cigarettes was studied. The results show that Y2O3 nanoparticles can reduce tar in cigarettes effectively and have no influence on nicotine when the addition of Y2O3 nanoparticles is 0,5-1.2%. The smaller the grain size of Y2O3 nanoparticles is,the more effective tar reduction is. The principle of reducing tar in cigarettes is studied preliminarily.

Rapid Analysis of Nicotine in Mushrooms Using QuEChERS Extraction and Liquid Chromatography Tandem Mass Spectrometry

A procedure based on the QuEChERS methodology and Liquid Chromatography Tandem Mass Spectrometry （LC/MS/MS） is described, for the determination of Nicotine in mushrooms. QuEChERS methodology was used to determine Nicotine in dried and fresh mushrooms under basic conditions with primary secondary amino sorbent （PSA） clean up. The chromatography was performed on C 18 reversed phase column using a gradient of acetonitrile and ammonium formiate lmM pH = 3.4 as mobile phase at a flow rate of 0.3 mL min^-1. Nicotine was determined by using Nicotine-d3 as internal standard. Limit of quantification （LOQ） was 0.01 mg kg^-1 for both fresh and dried mushrooms. Calibration curve was linear over the concentration range of 0.01-2.3 mg mL^-1, with r2 〉 0.99. As for recoveries in dried mushrooms, spiking levels of 0.32 mg kg^-1 and 2 mg kg^-1 were considered whereas for the fresh mushrooms the recoveries were determined at 0.036 mg kg^-1 and 0.36 mg kg^-1. Satisfactory results were obtained for both matrices and the recoveries proved to range from 105% to 135%, with a standard deviation in the range 17-20. The method was applied to the analysis of Nicotine to assess the levels of nicotine in fresh and dried mushrooms.