长效催产素受体激动剂卡贝缩宫素的药理作用与临床应用

卡贝缩宫素是一种合成的具有激动剂性质的长效催产素九肽类似物,用于选择性硬膜外或腰麻下剖腹产术后,以预防子宫收缩乏力和产后出血。本文综述了卡贝缩宫素的化学结构、药理毒理、药动学、临床应用、最大耐受量、安全性等,供临床参考,以促进临床安全合理用药。     

羟苯磺酸钙对去甲斑蝥素致血管内皮细胞毒性拮抗作用的研究

目的 探讨羟苯磺酸钙对去甲斑蝥素致血管内皮细胞损伤的影响,并测定羟苯磺酸钙的有效拮抗作用浓度.方法 将体外培养人脐静脉内皮细胞系完全随机分为对照组、毒性组和干预组.对照组用DMEM培养基培养48 h;毒性组用含去甲斑蝥素浓度为50μmol/L的DEME培养基培养48 h;干预组分为7组,分别加入含羟苯磺酸钙5、10、20、60、80、100和200 mmoL/L的DMEM培养基中再培养46h.测定细胞存活率.结果 干预组细胞存活率随着羟苯磺酸钙剂量的增加而升高,羟苯磺酸钙剂量达80 mmol/L时,细胞存活率明显升高.四甲基偶氮唑盐微量酶反应比色法测定的干预组(5 mmol/L)细胞存活率与毒性组相近,差异无统计学意义(P＞0.05),干预组(200 mmol/L)细胞存活率高于毒性组,组间比较差异有统计学意义[(69.4±3.8)％比(49.5±1.0)％,P＜0.05].结论 去甲斑瞀素抑制内皮细胞增殖,降低细胞存活率,当羟苯磺酸钙的浓度为80 mmol/L时,对去甲斑蝥素的毒性具有明显拮抗作用,能有效保护血管内皮细胞.     

Intercepting real and simulated falling objects: What is the difference?

The use of virtual reality is nowadays common in many studies in the field of human perception and movement control, particularly in interceptive actions. However, the ecological validity of the simulation is often taken for granted without having been formally established. If participants were to perceive the real situation and its virtual equivalent in a different fashion, the generalization of the results obtained in virtual reality to real life would be highly questionable. We tested the ecological validity of virtual reality in this context by comparing the timing of interceptive actions based upon actually falling objects and their simulated counterparts. The results show very limited differences as a function of whether participants were confronted with a real ball or a simulation thereof. And when present, such differences were limited to the first trial only. This result validates the use of virtual reality when studying interceptive actions of accelerated stimuli.     

医用臭氧对大鼠体外星形胶质细胞的毒性

目的 评价医用臭氧对大鼠体外星形胶质细胞的毒性.方法 Wistar大鼠12只,日龄1～2 d,麻醉下取脑,分离、培养星形胶质细胞,接种入24孔培养板,每孔1 ml,细胞浓度7 × 105/ml,分为4组(n=7):正常对照组(C组)加入无任何干预的完全培养基400 μl;不同浓度医用臭氧组(O2-O340组、O2-O360组、O2-O380组)分别加入经40、60、80 μg/ml医用臭氧干预的完全培养基400 μl,于孵育2 h(T1)、4 h(T2)时观察细胞形态,测定星形胶质细胞超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及乳酸脱氢酶(LDH)漏出率.结果 O2-O360组与O2-O380组胞体肥大、肿胀、突起增多,胞浆内出现黑色变性颗粒及空泡样改变,核固缩细胞增多,O2-O380组更明显.与C组比较,T1时O2-O340组SOD活性和MDA含量升高,LDH漏出率降低,O2-O360组SOD活性和MDA含量升高,O2-O380组SOD活性和MDA含量升高,LDH漏出率升高,T2时O2-O340组SOD活性升高,MDA含量和LDH漏出率降低,O2-O360组SOD活性和LDH漏出率升高,O2-O380组MDA含量和LDH漏出率升高(P<0.01);O2-O340组、O2-O360组和O2-O380组T1时MDA含量和LDH漏出率依次升高,T2时SOD活性依次降低,MDA含量和LDH漏出率依次升高(P<0.01);与T1时比较,T2时O2-O340组、O2-O360组和O2-O380组SOD活性和MDA含量降低,O2-O360组和O2-O380组LDH漏出率升高(P<0.05).结论 医用臭氧对大鼠体外星形胶质细胞的毒性作用与其浓度和作用时间有关.     

Modification of planned actions

To elucidate the time course and processes underlying pre-movement modification of planned actions, participants prepared to make an action at a time of their own choosing within a specified temporal window. In some conditions, participants prepared to make a single right index finger key press, whereas in others, they prepared to make a sequence of two key presses consisting of a right index finger key press followed by a right middle finger key press. On a proportion of trials, their internal preparation was interrupted by an auditory tone, in response to which they made either: the same action as they were intending, a different action requiring an additional effector (i.e. switch from preparing a single right index finger key press to executing a right index, middle finger sequence), or a different action requiring one less effector (i.e. switch from preparing a right index, middle finger sequence to executing a right index finger key press). For unmodified actions, switching from an internally generated to an externally triggered mode of response production produced a significant reaction time cost (RT cost) for both single and sequential actions, with the cost for single actions being significantly greater than that for sequential actions. Given that the RT cost did not increase as the complexity of the actions increased it is unlikely that the source of the cost is related to motor execution processes, and it is suggested that it may arise at a higher level cognitive stage of processing. In addition, reaction times to produce modified actions were significantly greater than those to produce unmodified actions. Finally, it took significantly longer to produce modified actions requiring one less effector than to produce modified actions requiring one more effector. We suggest that two time-consuming processes are involved in switching between internally generated and externally triggered actions that are modified or unmodified: a trigger switch cost when the same action has to be produced in response to an external trigger as opposed to an internal trigger, and a switch cost reflecting changes in the pattern of executed motor commands when modification is necessary. It is suggested that such processes may be mediated by regions of the frontal lobes. An erratum to this article can be found at     

Action word understanding and overt motor behavior

Cutaneous reflexes induced in lower leg muscles by non-noxious electrical stimulation to the foot sole are strongly modified depending on the stimulated location. Little is known, however, about the functional importance of this location-specificity. We examined modulation of cutaneous reflexes in the peroneus longus muscle during co-activation of the peroneus longus (PL), soleus, and tibialis anterior muscles in ten healthy volunteers. We successfully recorded 121 intramuscular single motor units (MU) of cutaneous reflexes in PL elicited by stimulating either fore-medial, fore-lateral, or heel regions of the plantar foot while performing plantarflexion and eversion (PF + EV), dorsiflexion and eversion (DF + EV), or isolated eversion (EV). Firing probability increased following fore-lateral stimulation during the PF + EV and EV tasks, but not during the DF + EV. Fore-medial stimulation, irrespective of the task, suppressed the reflex. Heel stimulation facilitated the reflex only during the PF + EV and DF + EV tasks. In general, cutaneous reflex magnitudes were larger during the PF + EV task than during the others, irrespective of whether the effects were facilitatory or suppressive. These results suggest that the magnitude of the reflex effects on the PL motoneurons strongly depends on activation of plantarflexors and dorsiflexors.     

益气养阴消癥通络中药对早期糖尿病大鼠肾脏的保护作用及其相关机制

目的 探讨益气养阴消癥通络中药对早期糖尿病大鼠肾脏的保护作用及其可能的分子生物学作用机制.方法 将SD大鼠随机分为6组:单纯肾切组,模型组,厄贝沙坦组,中药低、中、高剂量组,按各组相应药物剂量灌胃.于给药第6周末检测各组大鼠24h尿蛋白(UPro)量及肾功能水平;光镜下观察各组大鼠肾脏的病理改变;Western blo...     

原人参二醇型皂苷活性代谢物Compound K药理活性的研究进展

人参皂苷Compound K〔20-O-β-D-葡萄糖基-20(S)-原人参二醇,CK〕是原人参二醇型人参皂苷在人体内主要吸收形式和药效实体。近年来,CK的药理活性研究又有了新进展:①CK可通过活化胱天蛋白酶8直接或通过线粒体途径间接地激活胱天蛋白酶3,诱导肿瘤细胞凋亡;下调基质金属蛋白酶9基因的表达,抑制肿瘤细胞的转移;②可通过下调多种炎症因子如白细胞介素-4(IL-4),IL-6,肿瘤坏死因子α等及环氧合酶2与一氧化氮合酶的表达而发挥抗炎、抗过敏和神经保护作用;③可阻断ATP敏感性K+离子通道,促进胰岛素分泌,增强组织胰岛素敏感性,抑制糖异生,促进糖酵解,对胰岛素依赖性糖尿病表现出良好的疗效;④可上调核苷切除修复相关蛋白基因的表达,减少紫外线引起的DNA损伤,防止皮肤老化等。本文重点对近几年有关CK的药理活性及其作用机制研究新进展进行综述。     

三聚氰胺污染饲料致大鼠肾毒性的代谢组学研究

目的探讨三聚氰胺污染饲料致大鼠尿液和肾脏组织内源性代谢产物的变化,寻找三聚氰胺污染饲料致大鼠肾毒性的差异代谢物。方法大鼠喂食三聚氰胺污染饲料20 d后,通过光学显微镜观察大鼠肾脏组织病理变化,并采用气相色谱-质谱联用(GC-MS)分析手段对正常对照组和三聚氰胺组大鼠尿液和肾脏组织的代谢物进行分析。利用代谢组学分析软件SIMCA-P+11对大鼠尿液和肾脏组织采集的GC-MS数据进行多元统计分析。结果与正常对照组相比,三聚氰胺组大鼠肾脏组织部分纤维化,有大量尿酸盐结晶,可见颗粒管形病变。正常对照组和三聚氰胺组大鼠尿液和肾脏组织样品在主成分分析(PCA)中得到了很好的分离,并通过偏最小二乘判别分析(PLS-DA)指认引起差异的特征代谢物。与正常对照组相比,三聚氰胺组大鼠肾脏组织中丙氨酸显著上升;缬氨酸和乙醇胺等明显下降;尿液中乳酸显著上升,而半胱氨酸和尿嘧啶等明显下降。结论三聚氰胺污染饲料引起大鼠明显的肾毒性,尿液中有17种物质,肾脏组织中有11种物质被判定为可能特征代谢物。     

大黄素药理作用的分子机制研究进展

大黄素是中药大黄的主要有效单体,具有多种药理作用,具有较高的临床应用价值。近年来国内外有关大黄素药理作用分子机制的研究较多,特别对其消炎、抗肿瘤的作用高度关注。这些作用主要是通过改变离子浓度及转运、抗氧化和自由基、影响炎症因子的分泌和酶活性、细胞凋亡等途径实现的。该文对此进行了总结,希望能为其实际应用提供理论依据。