AN-132 block of cardiac sodium channels: A gate-related receptor analysis

Summary Based on the gate-related receptor hypothesis, an analysis of kinetics of AN-132, a new antiarrhythmic agent, blockade of cardiac sodium channels and the gate-related receptor which is bound by the drug was performed by computer simulation. Model-predicted apparent rates of onset of AN-132 (30 μmol/L) blocking were 0.051, 0.038, and 0.034 AF⁻¹ at stimulation frequencies of 1.0, 2.0 and 3.0 Hz, respectively. The time constant of recovery from block by AN-132 at resting potential -90 mV was 39.5 s. These findings are in agreement with those experimental data documented. The analysis of gate-related receptor shows that AN-132 binds the inactivation gate-related receptor, and the binding and unbinding are modulated by the inactivation process.     

Differential effects of the pyrethroid tetramethrin on tetrodotoxin-sensitive and tetrodotoxin-resistant single sodium channels

The differential effects of the pyrethroid tetramethrin on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) single sodium channel currents in rat dorsal root ganglion (DRG) neurons were investigated using the outside-out configuration of patch-clamp technique. Channel conductances were 10.7 and 6.3 pS for TTX-S and TTX-R sodium channels, respectively, at a room temperature of 24–26°C. The single-channel current of TTX-S sodium channels at the test potential of −30 mV was −1.27 ± 0.25 pA, and was not changed after exposure to 10 μM tetramethrin (−1.28 ± 0.23 pA). The open time histogram of TTX-S single-channel currents could be fitted by a single exponential function with a time constant of 1.27 ms. After exposure to 10 μM tetramethrin, the open time histogram could be fitted by the sum of two exponential functions with time constants of 1.36 ms (τ_fast) and 5.73 ms (τ_low). The percentage of contribution of each component to the population was 62% for the fast component representing the normal channels and 38% for the slow component representing the tetramethrin modified channels. The amplitudc of TTX-R single-channel currents was slightly changed from −0.72 ± 0.14 to −0.83 ± 0.07 pA by 10 μM tetramethrin. The open time histogram of TTX-R single-channel currents could be fitted by a single exponential function with a time constant of 1.92 ms. In the presence of 10 μM tetramethrin, the open time histogram could be fitted by the sum of two exponential functions with time constants of 2.07 ms (τ_fast) and 9.75 ms (τ_slow). The percentage of contribution of each component was 15% for the fast, unmodified component and 85% for the slow, modified component. Differential effects of tetramethrin on the open time distribution of single sodium channel currents explains the differential sensitivity of TTX-S and TTX-R sodium channels.     

各种肝病的肝纤维化标志改变的探讨

目的 :探讨各种肝病患者血清肝纤维化标志的改变 ,甘草酸二胺注射液对肝脏炎症、纤维化指标的作用。方法 :用放免法检测透明质酸 (HA)、层粘蛋白 (LN)、Ⅲ型前胶原多肽 (PCⅢ )。结果 :急性肝炎的三种肝纤指标均升高 (P <0 0 5 )。急黄肝高于急无黄肝 (P <0 0 5 )。慢性肝炎 1 1 2例 ,三项肝纤指标显著高于正常对照 (P <0 0 5 )。慢肝重度显著高于慢肝轻度 (P<0 0 0 1 )。肝硬化的三项肝纤指标又显著高于慢肝 (P <0 0 0 1 ) ,其它肝病的肝纤指标也升高。 2 5例慢肝用甘草酸二胺注射液治疗 2月 ,ALT、AST、GGT显著降低 (P <0 0 1 )。三项肝纤指标中HA降低较显著 (P =0 0 5 ) ,LN和PCⅢ虽有降低 ,但差异不明显 (P =0 4 5 9,P =0 1 92 )。结论 :各种肝病的三项肝纤维化指标均升高 ,以慢肝重度 ,肝硬化升高明显。甘草酸二胺注射液治疗有抗炎及改善肝纤维化的作用     

高危出血患者应用吉派林抗凝血液透析疗效观察

目的：观察危重型肾功能衰竭合并高危出血患者选择抗凝药物进行血液透析治疗的效果。方法：应用吉派林(低分子肝素钠)作为抗凝剂进行血液透析。结果：129例病人进行血液透析386次，均没有出血发生。结论：吉派林在高危出血患者血液透析中使用方便，安全，效果良好。     

小鼠卵细胞质内显微注入单精子受精的实验研究

为了探讨提高小鼠卵细胞质内单精子注入受精率的方法，选取鼠龄１２－１４周的健康昆明白小鼠作为精子和卵子的供体，受用ＩＣＳＩ技术，以受精后二细胞卵裂的形成率为指标，了解不同采卵时间，不同微注射针参数及不同培养液对细胞质单精子注入的影响。结果表明，ｈＣＧ注射后１８－１９ｈ采卵，用针尖内径为４－５μｍ，斜面角度为３５－４０度的微注射针进行ＩＣＳＩ操作受精后卵子置ＣＺＢ中培养可获得较多的２细胞胚，卵裂率明显     

中药蝶脉灵注射液在心肺复苏中脑保护作用的实验研究

目的 探讨中药蝶脉灵注射在心脏骤停时对脑复苏的作用。方法 用电刺激导致室颤制备家兔心脏骤停模型，在光镜和电镜下观察大剂量肾上腺素治疗时，蝶脉灵注射液对脑组织的影响。结果 蝶脉灵注射液对脑细胞有明显的保护作用。结论 蝶脉灵注射液能明显改善心脏骤停时脑缺血性损害，因而有利于脑复苏。     

Radionuclide venography vs Tc-99m-RBC equilibrium angiography: A comparative paired study

Combined direct injection venography (DIV) and equilibrium angiography (EA) were performed in 13 patients, by injecting in vitro labeled ^99mTc autologous RBC, via pedal veins, and imaging the first pass and the equilibrium phase. This paired comparative study of DIV with EA shows that DIV has advantages over EA because it provides selective information on the deep venous system from the calves to the inferior vena cava. DIV provides information on the flow dynamics and the high contrast first pass images provide better definition of non filling venous segments as well as visualization of collaterals. When using ^99mTc-MAA, lung perfusion can also be imaged. DIV is recommended as the procedure of choice for the diagnosis of DVT and EA should be employed only when pedal vein injection is not possible.