利尿剂和镇静剂对慢性呼吸衰竭患者带3蛋白阴离子转运功能的影响

为探讨药物对带３蛋白阴离子交换功能的影响及其临床意义，为临床正确治疗提供依据。对临床呼吸系疾病常用药物进行了筛选实验。结果表明，速尿、双氢克尿塞、安定可快速、可逆地抑制带３蛋白阴离子转运功能，其作用机制是通过药物与带３蛋白阴离子转运系统的两个位点相互结合完成。临床上使用利尿剂、镇静剂为肺性脑病的常见诱因，可能与这些药物抑制阴离子交换，减少ＣＯ＿２排出有关。因此肺功能不全，特别是肺心病Ⅱ型呼吸衰竭患者，应慎用此类药物。     

离子色谱法同时测定附子理中丸中9种无机阴离子含量

目的：建立同时测定附子理中丸中9种无机阴离子（氟离子、甲酸根离子、氯离子、亚硝酸根离子、溴离子、硝酸根离子、硫酸根离子、草酸根离子和磷酸根离子）含量的离子色谱法。方法：采用Ion Pac AS11-HC阴离子交换分析色谱柱,ASRS 300 （4 mm）阴离子抑制型电导检测器检测,7-40mmol/L氢氧化钾溶液梯度淋洗20 min,平衡5min,流速为1.0 mL/min,柱温为35℃,进样量为20μL。结果：9种无机阴离子达到良好分离,0.1-10mg/L的线性关系良好,相关系数为0.9990-0.9998,精密度的RSD为0.5%-1.7%,重复性的RSD为0.8%-2.7%,稳定性的RSD为1.1%-2.9%,平均加样回收率为89.18%-106.81%间,RSD为0.51%-2.73%（n=6）,检测限为0.004-0.023 mg/L,定量限为0.015-0.018 mg/L。结论：本方法快速简单,选择性好,灵敏度高,适用于附子理中丸中9种无机阴离子的含量测定。     

Organic anion permeation at the proximal tubule of Necturus

This study deals with the electrical responses of the peritubular membrane of the Necturus proximal tubule to 8 organic anions, in NaHCO₃-free (trismaleate-buffered) and NaHCO₃-containing solutions. The anions glutamate and gluconate brought about a small depolarization, but only in NaHCO₃-free media. Benzene sulfonate did not alter significantly membrane p.d. The 5 other test-anions produced hyperpolarization. The magnitude of membrane depolarization elicited by high-K media was proportionally larger in the presence of the test-anions propionate, lactate, pyruvate, acetate and formate than with chloride: it is inferred that these anions increasedT _K. The same 5 anions shifted in the negative direction the p.d. achieved at peak K-depolarization; according to a previous analysis (Anagnostopoulos, 1977), this observation suggests that their permeabilities (P _A) are greater thanP _Cl, at least during the substitution. The association ofP _A>P _Cl with an increase ofT _K, upon exposure of the kidney to test-anions, is at best accounted for by a decrease ofP _Cl. The pattern of voltage attenuation along the epithelial cable during anionic substitutions is also consistent with an increase ofT _K via a decrease ofP _Cl. In conclusion, the apparent sequence of relative anionic permeabilities, as obtained from the responses of the tissue to a single anion, irrespective of buffering procedures, is:P _acet,P _lact,P _pyruv,P _prop,P _form>P _ClP _gluc,P _glut. The test-anions propionate, lactate, pyruvate, acetate and formate tend to increaseT _K, mainly by reducingP _Cl. The effect of glutamate and gluconate on physiologic ion permeabilities is too small to be specified with accuracy: it depends to some extent on the buffer used in the solutions.     

氨基胍对糖尿病大鼠心肌损伤的拮抗作用

目的：研究氨基胍（AG）对糖尿病大鼠心肌保护作用的机制。 方法：用透射电镜观察AG对链脲佐菌素诱导的糖尿病大鼠心肌形态学改变的影响，并测定心肌组织内超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)、诱导型一氧化氮合酶(iNOS)的活性及丙二醛(MDA)含量，采用Western blotting法检测ONOO-标志物-硝基酪氨酸(NT)蛋白质在心肌组织中的含量。 结果：电镜下可见模型组大鼠心肌细胞核周围水肿，部分肌节断裂消失，Z线模糊或消失，心肌细胞线粒体部分嵴部分膜断裂或消失；SOD含量变化无统计学差异，NOS、iNOS活性，MDA和NT蛋白质含量大于对照组。AG组心肌组织形态学病变较轻，心肌细胞线粒体嵴部分消失，肌纤维排列较整齐，仅见少量脂滴沉着；AG治疗组NOS、iNOS活性及MDA含量低于模型组；NT含量低于模型组。 结论：AG可能通过抗脂质过氧化作用和降低ONOO^-水平而对糖尿病心肌产生保护作用。     

Ionic effects on human recombinant P2X7 receptor function

The actions of monovalent and divalent ions on the P2X₇ receptor have been assessed by measuring their effect on responses to the P2 receptor agonist, 2’- and 3’-O-(4-benzoyl-benzoyl)-ATP (DbATP), in HEK293 cells expressing the human recombinant P2X₇ receptor. In these cells, DbATP increased the cellular accumulation of the DNA binding, fluorescent dye, YO-PRO-1. The potency of DbATP to elicit this effect was decreased by both calcium and magnesium ions. In addition, when the pH was increased above 8 or reduced below 6.5, the potency of DbATP was less than obtained at pH 7.5. Monovalent ions also affected the P2X₇ receptor such that the potency of DbATP was 19-fold higher in NaCl-free buffer containing 280 mM sucrose (pEC₅₀=6.48) than in 140 mM NaCl containing buffer (pEC₅₀=5.19). Monovalent cations differentially affected the potency of DbATP. Thus, when the chloride concentration was maintained at 140 mM, pEC₅₀ values for DbATP were 6.14, 5.87 and 5.19 when the counter cation was 140 mM choline, potassium or sodium, respectively. Monovalent anions also differentially affected the potency of DbATP and in the presence of 140 mM sodium ions, pEC₅₀ values for DbATP were 6.14, 6.07, 5.19 and 4.53, respectively, when the counter anion was 140 mM aspartate, glutamate, chloride or iodide. The inhibitory effect of monovalent anions on P2X₇ receptor function was also observed in electrophysiological studies. Thus in sodium glutamate containing buffer the potency of DbATP (pEC₅₀=5.55) was approximately 22-fold higher than in NaCl containing buffer (pEC₅₀=4.20). This study has demonstrated that P2X₇ receptor function can be markedly affected by a wide range of ions and that physiological concentrations of sodium and chloride ions, as well as divalent cations, contribute to the low potency of ATP as an agonist at this receptor. Received: 27 July 1998 / Accepted: 18 November 1998     

超氧化物阴离子自由基对菌斑牙面氧化还原电位的影响

目的：验证牙菌斑中超氧化物阴离子自由基与菌斑氧化还原电位的关系。方法：①测试菌斑氧化还原电位。②利用ＳＯＤ作为干扰因素观察氧化还原电位的变化。结果：菌斑电位低于非菌斑牙面电位,为负电位。菌斑加ＳＯＤ后使菌斑电位升高。结论：菌斑负电位与超氧化物阴离子自由基有关,自由基可能是菌斑负电位形成的主要因素。     

离子色谱法同时测定饮用水中七种阴离子的含量

目的:建立同时测定饮用水中7种无机阴离子含量的测定方法。方法:样品用0.2μm滤膜过滤后直接进样,离子色谱法同时测定氟化物、氯化物、亚硝酸盐氮、溴化物、硝酸盐、硫酸盐和磷酸盐。色谱柱为:IonPac AS19型阴离子交换色谱柱(4 mm×250 mm i.d)和IonPac AG19保护柱;检测方式为:抑制型电导检测器。结果:本法相关性好(r>0.9993),精密度高(RSD%<3.0),样品加标回收率为95.0%～103.7%,检出限分别为:F-:0.0015 mg/L;Cl-:0.0010 mg/L;NO2--N:0.0019 mg/L;SO42-:0.0012 mg/L;Br-:0.0018 mg/L;NO3-:0.0013 mg/L;HPO24-:0.0023 mg/L。结论:该方法操作简单、快速、准确、线性范围广,可满足大批量水样检测分析要求。     

Hydrogen/anion electrosorption at rhodized electrodes as revealed by electrochemical impedance spectroscopy

Electrosorption properties of rhodized electrodes in H₂SO₄ and HClO₄ electrolyte solutions, with and without small concentration of added chloride and (bi)sulphate anions, are investigated by use of the electrochemical impedance spectroscopy. Potentials between the threshold of the hydrogen evolution and initial stage of (oxy)hydroxide formation are applied. Kinetic contributions of hydrogen under-potential deposition (UPD) are over restricted and adsorption of chloride and (bi)sulphate anions over almost whole potential region is clearly marked by present impedance spectra. Added anions, as well as products formed by decomposition of perchlorate ions from HClO₄ electrolyte solution, influenced kinetics of the hydrogen UPD at the rhodized electrode. Adsorption of (bi)sulphate ions from H₂SO₄ electrolyte solution is not detected directly as a kinetic process, but is indicated through increased apparent double-layer capacitance values. Theoretical equation for the frequency dependence of adsorption impedance is derived on the basis of (partial) charge transfer adsorption of ions, the state variable approach, and concept of two-step adsorption. The derived equation is found to be adequate for fitting impedance spectra in the hydrogen/anion transition region. Values of impedance parameters and their potential dependences are discussed and compared to already published data on similar electrodes, including low-index rhodium and platinum single-crystal electrodes.     

稳健统计-迭代法在环境样品中四种阴离子测定不确定度评估中的应用

目的探讨稳健统计-迭代法在环境样品中四种阴离子测定不确定度评估中的应用。方法对水中氟化物、氯化物、硝酸盐、硫酸盐四种阴离子的质控样品的检测数据进行不确定度评估。结果使用稳健统计-迭代法评估的不确定度和相对标准偏差都与质控样品的结果基本一致。结论该方法适用于环境样品中四种阴离子测定不确定度的评估。     

饮用水中5种阴离子的离子色谱测定法

目的 研究电导-离子色谱法同时测定水中5种阴离子的分析方法.方法 用正交实验法L9(34)选择IC-2000型离子色谱仪的最佳实验条件,并在该条件下,将水样经0.45μm微孔滤膜过滤后直接利用离子色谱仪同时测定F-、Cl-、NO2-、SO42-、NO3-阴离子浓度.结果 最佳流速和柱温分别为1.2 ml/min和35℃,方法的RSD%均小于5.0%,各离子加标回收率为90%～106.7%,F-、Cl-、NO2-、SO42-、NO3-标准曲线回归方程的相关系数分别为0.999 7,0.999 9,0.990 5,0.999 9,0.999 9.结论 该方法具有准确、简便、快速、样品无须前处理等优点,可用于饮用水样品中5种阴离子的同时分析.