654-2对麻醉犬急性缺血心肌交替电活动的影响

一些实验中,心电交替现象(EA)时有发生,文献对共发生规律及机制的阐述尚欠深入。本实验目的在于探索急性缺血心肌心外膜电图(EpiEG)EA的某些发生规律及病理意义。 给10只健康成年麻醉开胸犬静脉注射654_2 10mg/kg,随即结扎左冠脉前降支(LAD)并维持10分钟(654_2加结扎)形     

丹参对急性心肌缺血时脂质过氧化的影响

本实验以结扎家兔冠脉左室支造成在体急性心肌缺血模型,以硫代巴比妥酸荧光法测定心肌组织脂质过氧化物含量,探讨心肌脂质过氧化情况及其与心电图ST段改变的关系,并以丹参注射液为心肌保护因素,观察脂质过氧化物、心电图ST段的变化,探讨丹参对心肌的保护作用。实验结果表明:结扎冠脉左室支40分钟时,缺血区心肌脂质过氧化物含量比对照组增加2.4倍(P<0.01),缺血区脂质过氧化物含量与心电图ST段抬高程度呈正相关(r=0.822,P<0.025)。预先静脉注射丹参注射液,使缺血区心肌脂质过氧化物含量较缺血组缺血区降低47.9%(P<0.02).并使冠脉左室支结扎后2至5分钟的心电图ST段抬高程度降低44.8～47.0%(P<0.05)。     

碘杂环—65抗大鼠心肌缺血/再灌注损伤的机制探讨

雄性SD大鼠30只,随机分为假手术组、缺血再灌组、缺血再灌给药组。开胸正压呼吸,结扎左冠状动脉40分钟再灌注20分钟,取左心室前壁左半部分用原子吸收光谱法测定心肌组织内钙含量,取左心室前壁右半部     

内皮素A受体拮抗剂BQ610对猫急性心肌缺血保护作用的超微结构观察

目的 观察内皮素Ａ受体拮抗剂ＢＱ６１０对急性缺血心肌超微结构的影响,以探讨内源性内皮素是否参与急性心肌缺血的病理过程。方法 结扎１２只猫左冠状动脉前降支（ＬＡＤ）造成急性心肌缺血,立即向已结扎的ＬＡＤ内直接注射ＢＱ６１０或注射生理盐水作对照,观察ＬＡＤ结扎后３０分钟缺血区及非缺血区心肌超微结构。结果 急性缺血区心肌出现肌细胞肿胀、肌原纤维排列紊乱及灶性溶解、线粒体肿胀及内皮细胞肿用 结构损伤,ＢＱ     

5-羟色胺对大鼠心肌单相动作电位及室性心律失常的影响

为探讨5-HT与缺血性室性心律失常的关系,观察了外源性5-HT对大鼠在体缺血心肌单相动作电位(MAP)及心电图的影响。结果证实(1)5-HT使心肌缺血动物DVA的VE数目增加,VT、VF持续时间延长,而不造成非心肌缺血动物的室性心律失常。(2)5-HT对缺血心脏DVA的影响不是通过MAPD的延长,而是与缺血心肌Vmax及MAPA有关。     

山莨菪碱对缺血心肌的保护作用

本文观察山莨菪碱(654-2)对大鼠缺血心肌的保护作用。发现大鼠左冠状动脉主干结扎后早期腹腔注射654-2,可使结扎后6小时及21天时的梗塞范围显著缩小,并使21天时的左室心肌收缩性恢复得更好,而结扎后3小时缺血区心肌的超微结构改变得到显著改善。654-2对冠脉结扎与非冠脉结扎大鼠的直接血液动力学作用表现为平均动脉压、心输出量和左室心肌收缩性显著降低,提示654-2可以减少心肌氧耗量,从而对缺血心肌发生有利影响。     

生脉注射液对山羊心肌缺血的作用

山羊19只,左冠状动脉分支结扎后,如对照组一样,采取以注射利多卡因为主的综合性保护措施,以防止和减少心律不齐的发生,并在结扎冠状动脉分支后0.5小时,3.5小时和20.5小时分别注射生脉液,总剂量为1毫升/公斤体重。经处理后的动物有12只存活时间超过24小时。与对照组相比,使用生脉浓的试验组利多卡因用量明显地低于对照组:第一时段内(结扎后0.5～12小时)的用量303.6±283.7毫克对862.6±498.1毫克;第二时段内(结扎后21.5～25.5小时)的用量80.0±75.5毫克对192.2±93.5毫克,这提示着生脉注射液具有抗心律不齐的作用。本文还发现,缺血后24小时心肌的坏死区重量,试验组的小于对照组(3.4±1.6对4.7±1.5克),这提示着生脉注射液有改善缺血区供血的作用。     

刺五加对大鼠离体心脏缺血再灌心律失常与细胞动作电位的作用

用Langendorff法以台氏液灌流大鼠离体心脏。结扎冠脉左前降支10min,松结再灌3min。再灌期内对照组(n=49)室颤(VF)发生率为86%,室速(VT)发生率为88%,正常窦律时间(NSRT)为68±10s。给药组(n=21)用含刺五加浸膏(1.2～2.4mg生药/ml)的台氏液灌流。再灌期内VF下降至29%(P<0.001),VT下降至66%(P<0.05),NSRT延长至134±14s(P<0.011)。     

心肌缺血再灌注β-受体改变实验研究

本研究采用~3H-DHA放射配体结合分析法观察了8只实验猫,结扎左冠状动脉前降支25分钟后再灌注缺血区和非缺血区心肌β-受体改变。β-受体测定方法:心肌组织剪碎后在20mMTris-HCl缓冲液(含0.9%NaCl、pH7.5)中匀浆,低速离心,上清高速冷冻离心2次(20,000g,10min,4℃以下),制备粗制心肌细胞膜,Lowry氏法蛋白定量,将蛋白浓度调制为3mg/ml。取膜悬液100μl,分别加至~3H-DHA(美国Dupont     

丹参制剂对家兔缺血心肌腺苷酸类代谢的影响

本文以结扎家兔冠状动脉左室支为心肌缺血模型、应用阴离子交换高效液相色谱方法(HPLC)测定了心肌缺血40分钟以及预先给丹参制剂再行缺血,心肌游离腺苷酸的含量变化。从而观察了丹参对心肌的保护作用。结果表明,缺血心肌ATP、ADP、AMP、AN(总腺苷酸量)以及ATP/ADP均明显减少。预先给予丹参制剂后再缺血40分钟,各类腺苷酸下降幅度与单纯缺血组相比明显增加。AMP及AN值近于正常。ATP、ADP及ATP/ADP值与正常心肌比虽亦下降,但与单纯缺血组比却明显上升,差异显著。说明丹参制剂对心肌具有明显的保护作用。     

Level of functioning of siblings and parents of probands of varying degrees of retardation

A further analysis of already published data supports the position that retardates of low ability level less frequently have retarded siblings, retarded parents, and parents low in occupational level than do retardates higher in ability level. The analysis supports the position that there are two types of retarded individuals, persons retarded as a result of gene or chromosomal anomalies, brain injury, etc., who more frequently occur in the lower-level retardate group, and persons whose retardation represents polygenic segregation, who more frequently occur in the higher-level group.     

Modes of Inheritance of Errors of Refraction

Eighteen families in which both parents had refractions within the range of +4·0 D to −4·0 D and axial lengths seen in emmetropia (22·3-26·0 mm) showed coefficients of correlation of the order 0·5 indicative of polygenic inheritance. Such coefficients were seen for axial length (0·407) and for the cornea (0·487), but not for the lens (which is known to be yoked to the axial length). No such coefficients were seen in 19 families in which one of the parents had axial length outside the emmetropic range (nine families with long axes and 10 with short axes).

The pattern of polygenic inheritance for emmetropia (completely correlated optical components) and errors of refraction up to 4·0 D (inadequately correlated components: correlation ametropia) follows that seen in stature and other measurable characters. In contrast the high refractive errors with their abnormal axial lengths (component ametropia) are—like the extremes in stature—pathological anomalies with monofactorial inheritance.

     

Recovery of responsiveness of cells of lateral geniculate nucleus of rat

1. Recovery of responsiveness of single cells in lateral geniculate nucleus of rat has been determined in both P and I cells. There are three types of recovery curve among P cells; (a) early recovery, (b) early partial recovery followed by depression and then complete recovery, (c) prolonged depression followed by cyclic recovery. Type (c) is by far the commonest recovery curve. In contrast to the spike in a P cell, the synaptic potential recovers to its full amplitude in about 20 msec. All I cells exhibit similar rapid recovery curves after a prolonged depression.2. Conditioning stimuli applied to visual cortex also produce a prolonged depression in most P cells but I cells can be re-excited at short intervals from cortex. Decortication does not prevent the prolonged depression of the multineuronal response produced by optic nerve stimulation.3. A neuronal model is proposed to explain these observations. It is supposed that I cells (interneurones) are innervated by axon collaterals of the P cells (principal cells, projecting to visual cortex) and that the I cells exert an inhibitory influence on the P cells.     

局部注射辛伐他汀对骨质疏松大鼠股骨髁骨小梁的改建效应

背景：局部注射具有成骨作用的辛伐他汀,可显著增加骨质疏松大鼠股骨颈及股骨髁部的骨密度及力学强度,分析局部注射辛伐他汀对股骨髁骨小梁的影响。 目的：进一步研究骨质疏松大鼠股骨内局部注射辛伐他汀对股骨髁骨小梁的影响。为将辛伐他汀应用于临床骨质疏松局部治疗提供实验基础。 方法：18只雌性SD大鼠双侧卵巢切除后3个月,制备大鼠骨质疏松模型。实验大鼠随机数字表法均分为3组,分别在实验大鼠的右侧股骨髓腔内单次注射辛伐他汀溶液5 mg、10 mg,对照组单纯注射空白载体。分别在注射后1个月处死大鼠并取材。Micro-CT扫描并定量分析骨组织形态变化。 结果与结论：给药后1个月,Micro-CT扫描结果显示,辛伐他汀治疗组的骨微结构参数如骨皮质厚度、骨小梁密度及连接率明显优于对照组。说明疏松骨骼单次注射小剂量辛伐他汀可显著促进股骨髁部骨小梁改建,改善骨骼微结构,可为强化局部、防治骨质疏松骨折的新选择进一步提供实验基础。