RELAXATION OF MESENTERIC ARTERY OF STROKE PRONE SPONTANEOUSLY HYPERTENSIVE RATS BY CALCIUM REMOVAL

1. The time courses of the relaxation, induced by removal of extracellular Ca2+, of K-depolarized mesenteric artery preparations from stroke prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) were compared. 2. The time course of the decline in extracellular Ca2+ was estimated from the time course of the relaxation and the concentration-response curve of K(+)-depolarized preparations to Ca2+. The time course of the decline in the intracellular free Ca2+ concentration was also estimated from the reported relation between Ca2+ concentration and the contraction of skinned vascular smooth muscle. 3. The time course of relaxation was exponential, the curve being made up of three components. The time course was slower in preparations from SHRSP, especially the first component of the relaxation curve. 4. The time courses of the decline in the intracellular and extracellular Ca2+ concentrations were also exponential, being made up of three components and were also slower in the preparation made from SHRSP. 5. The wall and muscle layer of the mesenteric arteries used in the present experiments were significantly thicker in the SHRSP preparations. 6. Calculation of the half relaxation time, based on the diffusion of Ca2+ across the blood vessel wall, suggested that the slower relaxation in preparations from SHRSP is due largely to the thicker muscle layer, although differences in Ca2+ sequestration by the smooth muscle cells may also be involved.     

DIFFERENCES IN ENDOTHELIUM-DEPENDENT RELAXATION IN VARIOUS ARTERIES FROM WATANABE HERITABLE HYPERLIPIDAEMIC RABBITS WITH INCREASING AGE

1. Endothelium-dependent relaxation in response to acetylcholine (ACh) and the calcium ionophore A 23187 was examined in aorta, coronary, basilar and renal arteries isolated from Watanabe heritable hyperlipidaemic (WHHL) rabbits of 2, 6 and 12 months of age, with normolipidaemic heterozygous WHHL rabbits as controls. 2. In the rings of WHHL rabbit aortae and coronary arteries preconstricted with vasoconstrictors, endothelium-dependent relaxation in response to ACh was attenuated with age compared to the heterozygous WHHL rabbits. A significant negative correlation was found between the total cholesterol content and the relaxation response to ACh in the aortae or coronary arteries from 6 and 12 month old WHHL rabbits. 3. In the rings of basilar arteries, endothelium-dependent relaxations to ACh were not modified with age. Similarly, in the rings of renal arteries, the relaxation response to ACh was not changed with age, but in the 6 and 12 month preparations, after the age of 6 months, a contraction following the relaxation appeared at higher concentrations of ACh (10^?7 to 10^?6 mol/L). The contraction was endothelium-dependent and inhibited by indomethacin. 4. A 23187-induced endothelium-dependent relaxations were also markedly attenuated in the aorta and significantly in the coronary artery with age. 5. Endothelium-independent relaxation to sodium nitroprusside was not changed in all arteries from WHHL rabbits of different ages. 6. These findings indicate that in the aorta and coronary artery of the WHHL rabbit, the endothelium-dependent relaxation to ACh and A 23187 becomes impaired with increasing age (i.e., with the progression of cholesterol deposition in the arterial wall) but is preserved in the basilar and renal artery.     

Neuroleptic malignant syndrome in the intensive therapy unit

A case of the neuroleptic malignant syndrome occurred in a 40-year-old male after administration of chlorpromazine while on an Intensive Therapy Unit. Treatment with dantrolene sodium was successful, and a muscle biopsy was examined in the recovery phase of the illness. The importance of this condition and the difficulties in establishing a diagnosis at an early stage in patients on an Intensive Therapy Unit are discussed, along with implications for treatment.     

Development of an animal model for neuroleptic malignant syndrome: heat-exposed rabbits with haloperidol and atropine administration exhibit increased muscle activity, hyperthermia, and high serum creatine phosphokinase level

The neuroleptic malignant syndrome (NMS) is a life-threatening complication of neuroleptic treatment. To elucidate the pathogenesis of NMS, an animal model has been developed. Experimental rabbits treated with haloperidol (1 mg/kg) by intramuscular injection, were studied for the diagnostic symptoms of increased muscle rigidity, elevated body temperature, and high serum creatine phosphokinase (CPK) level. Administration of haloperidol (1 mg/kg) and atropine (0.4 mg/kg), and exposure to high ambient temperature (35°C) induced a significant increase in electromyographic activity with muscle rigidity similar to that observed in patients with NMS. Such rabbits also showed elevated body temperature and serum CPK value. In addition to the similarity of the signs and symptoms, all parameters measured (muscle rigidity, body temperature, and serum CPK level) were normalized by dantrolene treatment. The effectiveness of dantrolene in the experimental animal partially confirms the validity of this animal model for NMS. This experimental animal model for NMS may be useful to elucidate the pathogenesis of NMS.     

Muscle growth and myosin isoform transitions during development of a small teleost fish, Poecilia reticulata (Peters) (Atheriniformes, Poeciliidae): a histochemical, immunohistochemical, ultrastructural and morphometric study

The myosin composition of lateral muscle in Poecilia reticulata from birth to adult was studied by ATPase histochemistry and immunostaining with myosin isoform-specific antibodies. At birth the muscle consists of two layers containing developmental isoforms of myosin. In deep layer fibres the developmental myosin is replaced by the adult fast-white isoform soon after birth. In the epaxial and hypaxial monolayer fibres the myosin composition present at birth (J1) is replaced within 3 days by another (J2). In some fibres, this J2 composition is retained in the adult, but in others it is slowly replaced by the adult slow-red muscle isoform. Close to the lateral line, all monolayer fibres are already in transition between the J2 myosin and the adult slow-red form at birth, and rapidly complete the transition to slow-red form. These fibres, together with others generated de novo in an underlying hyperplastic zone, form the red muscle layer of the adult. The pink muscle develops during the first month after birth, and by 31 days it consists of an outer, middle and inner layer. A few middle layer fibres are already present at birth, while the outer layer fibres first appear 3 days after birth. The thin inner layer is probably a transitional form between the middle pink and adult white types, and appears at about 31 days. A morphometric analysis showed that growth of the white muscle occurs principally by hypertrophy. Even at the magnification level of the electron microscope, no satellite cells or myoblasts which could give rise to new fibres were found in the white muscle, except in the far epaxial and hypaxial regions and only in the first 10 days. A zone of hyperplastic growth was also found lying just under the superficial monolayer close to the lateral line, and this presumably contributes fibres to the red and pink muscle layers.     

慢性应激对大鼠血管平滑肌细胞的效应及与焦虑行为的关系

目的探讨慢性精神应激对血管平滑肌细胞的影响及与焦虑行为的关系。方法将38只SD大鼠按照随机数字表随机分为精神应激组(30只)和对照组(8只)。对应激组采用限制应激和饮水冲突应激,持续2个月;分别于应激前、应激后1,2个月用空场实验和高架十字迷宫实验观察大鼠焦虑水平,计算出中央格爬行次数、外周格爬行次数、开放臂进入次数及停留时间、闭合臂进入次数及停留时间。以免疫组化方法测定主动脉血管局部增殖细胞核抗原(PCNA)表达,并用苏木素-伊红染色法观察主动脉结构变化。结果(1)与对照组比较,应激1个月后,应激组大鼠在开放臂的次数和时间、闭合臂的次数少(P<0·05),闭合臂的时间多(均P<0·01);应激2个月后,应激组大鼠在外周格爬行的个数和闭合臂时间多(P<0·01),开放臂时间少(P<0·01)。(2)应激组大鼠主动脉失去原有的正常结构,中层血管平滑肌细胞排列紊乱,数目增多。(3)应激组大鼠血管壁PCNA表达的阳性细胞数为(16485±10694)个/MM2,对照组大鼠为(4012±2256)个/MM2,T=4·359,P<0·01。(4)中度焦虑组大鼠PCNA表达与大鼠焦虑呈正相关(PEARSON相关系数为0·718,P=0·004)。结论大鼠中度焦虑时,其血管平滑肌细胞增殖率与焦虑情绪呈正相关。     

糖尿病大鼠膀胱储尿期功能改变的实验研究

目的 研究糖尿病膀胱病变(Diabetic cystopathy，DCP)储尿期尿动力学特征及膀胱感觉功能障碍，为阐明DCP的发病机制提供实验依据。方法 分别以链脲佐菌素(STZ)、蔗糖诱导制作大鼠DCP模型及利尿模型，正常大鼠作对照。采用免疫组化结合图像分析技术观察膀胱感觉神经递质CGRP及其纤维改变；制备离体全膀胱，作膀胱灌注测压观察膀胱顺应性改变；放免法测定逼尿肌舒张信号转导分子cAMP。结果 DCP8周时，膀胱壁尤其是粘膜下层的CGRP及其神经纤维明显减少；离体膀胱测压显示糖尿病膀胱顺应性升高；膀胱舒张作用明显弱于对照组和利尿组，逼尿肌cAMP含量显著低于后者。结论 ①DCP对膀胱功能的损害是多方面的：CGRP为主要递质的粘膜下层膀胱容量感觉纤维明显减少，膀胱顺应性改变是DCP的致病机制之一。②DCP早期即已发生储尿期功能障碍，并且可能是膀胱收缩功能损伤的因素。③非糖尿病性利尿状态(多尿)对膀胱功能构成一定的损害作用，但不是DCP形成的主要原因。提示临床上对糖尿病患者作必要的尿动力学检查能较早发现DCP，有助于保护膀胱功能。     

颅脑外伤后肢体痉挛状态的显微外科治疗

目的 探讨显微外科治疗颅脑外伤后肢体痉挛状态的疗效.方法 回顾分析2006年7月至2008年7月实施的21例显微外科治疗颅脑外伤后肢体痉挛状态,根据不同病例采用相应的选择性周围神经部分切断术,包括:胫神经、肌皮神经、正中神经、尺神经和腰骶段脊神经后根,共计50个肢体.结果 术后随访2～24个月,全部患者术后立即感相应肢体痉挛状态缓解,随访期间缓解率为98%(49/50).随访期间运动功能改善率为86%(18/21),生活质量提高率为95%(20/21).术后发生肢体麻木、疼痛等感觉异常26个(52%),肌力下降18个(36%),随访期间均见好转.术后痉挛状态复发1个(2%).结论 选择性周围神经部分切断术是治疗颅脑外伤后肢体痉挛状态安全有效的方法.选择适应证及手术时机和术后坚持康复训练是保证疗效的关键.     

苯胺衍生物掺杂的PMMA薄膜的二次非线性光学性能的稳定性研究

具有A-π-D电子结构的苯胺衍生物掺杂的玻璃态高聚物PMMA的有机薄膜经极化取向后显示很强的二次非线性光学性能,其取向弛豫是实用化的一个有待解决的重要问题。木文通过几种苯胺衍生物以不同百分比与PMMA掺杂,用紫外-可见吸收光谱、二次谐波强度测量、动态力学粘弹谱等方法进行了取向弛豫的机理研究,结果表明分子尺寸和形状以及偶极矩的大小对取向弛豫有显著影响。     

Rectus “wrap around” flap for salvage of an infected ascending aortic graft

An application of the rectus abdominis muscle flap to salvage an infected prosthetic graft of the ascending thoracic aorta is presented. The length of this flap along with its width and thickness allows it to be wrapped around prosthetic grafts of the ascending aorta in a spiral fashion. This rectus muscle wrap around flap method is straightforward involving the use of one muscle rather than multiple muscles. The abdominal cavity is not opened as with the use of omentum. The procedure can be accomplished in a short time which is important in the critically ill patient.