延髓腹外侧区在降压反射中的作用(摘要)

在各种心血管反射中,降压反射通常被认为是最重要的。来自动脉压力感受器的信号通过降压反射调控心脏和血管的活动,从而维持血压的相对稳定。传统认为调节心脏和血管活动的基本中枢在延髓,延髓背外侧为“加压区”,腹内侧为“减压区”。新的资料表明,原来认为延髓背外侧的所谓“加压区”不是真正的心血管神经元所在地,电刺激背外侧区所产生的升压效应实际上是刺激了路过此地的延髓腹外侧头端心血管神经元的轴突。由于对延髓心血管中枢的重新认识,使心血管中枢的经典概念受到挑战和否定。目前认为延髓腹外侧区在降压反射中起重要作用,至少有4…     

神经降压素在家兔压力感受性反射中的作用

采用电刺激减压神经及牵拉颈动脉窦的方法兴奋压力感受器,观察在产生减压效应时,血浆及某些脑区内神经降压素含量的改变,以探讨其在家兔压力感受性反射中的作用.结果表明,电刺激减压神经及牵拉颈动脉窦产生明显的减压效应时,家兔延髓、垂体、下丘脑及血浆内神经降压素含量明显增高.提示内源性神经降压素可能参与家兔压力感受性反射的调节过程.     

动脉压力感受器的离子通道机制

动脉压力感受器反射在维持血压稳定和调节心血管活动中发挥着重要作用.自1924年Hering首次阐述颈动脉压力感受器反射功能以来,有关动脉压力感受器的生理学研究已有大量报道.动脉压力感受器是位于颈动脉窦和主动脉弓部位的慢适应性机械感受器.它们在动脉壁受跨壁压牵张时兴奋,诱发动脉压力感受器反射.     

咳嗽

1 基础。定义：咳嗽是各种潜在疾病的一种症状，它是由一种复杂的反射现象引起的，这种反射由咳嗽感受器引发并受脑干咳嗽中枢的调节。这些感受器位于整个与媒质大面积接触的呼吸道(不包括下呼吸道)、咽部、鼻旁窦、外耳道和胃，并且可被热的、化学的、机械的或炎性的刺激所兴奋，随之而来的快速呼气(快速呼气可排出呼吸道分泌物)。一般来说，咳嗽是反射性的，但有时可被随意地启动或压抑。     

针刺对伤害性感受器的传出抑制作用及其与交感神经的关系

在35只用箭毒麻痹的大鼠,用钾离子透入刺激尾部皮肤,引导其诱发的背根冲动作为伤害性感受器的兴奋指标。观察到电针“足三里”可使背根冲动平均减少到对照值的23％,后效应维持十多分钟。电针后肢“环跳”等部位也有类似抑制效应,但是电针前肢或头部一些部位却没有明显抑制效应。切断支配尾部的腰骶部交感干可使电针“足三里”抑制效应显著减弱,而切断支配尾部的脊髓背根与腹根,或者切除两侧肾上腺对抑制效应没有明显影响。短时间阻断尾部血流可使尾温大幅度降低,对背根冲动的影响却不明显;电针“足三里”对尾温的影响很小,对背根冲动的抑制效应却远远超过阻断血流的效果。 实验结果说明,电针“足三里”可以通过交感神经抑制伤害性感受器,这一抑制效应与脊髓节段有密切的关系,但是其对感受器的抑制并非外周血管收缩所致。设想体内存在一个外周感觉传入——中枢——交感神经传出——控制伤害性感受器的反馈环路。针刺镇痛的机制之一可能是激活或加强了这一环路,致使外周痛觉传入冲动减少。     

电刺激中缝苍白核对肺扩张反射的影响

目的:观察中缝苍白核(RP)对肺扩张反射的影响。方法:选择性电刺激成年家兔迷走神经(Aα～βfiber)中枢端模拟肺牵张感受器,诱导肺扩张反射出现,以膈神经放电为指标观察其对呼吸的影响。电刺激RP后,再刺激迷走神经中枢端,观察和比较膈神经放电幅度及频率的变化。结果:①电刺激迷走神经中枢端可触发肺的扩张反射,引起膈神经吸气相放电幅度降低、呼气相延长、呼吸频率减慢;②电刺激RP可兴奋呼吸,呼吸频率明显加快;③与单独电刺激迷走神经相比,电刺激RP后,再长串或短串刺激迷走神经均导致膈神经吸气相放电幅度相对增高、呼吸频率加快、呼气相缩短。结论:RP可削弱肺扩张反射抑制吸气延长呼气的效应。RP参与了肺扩张反射的调节过程,在呼吸节律调整中发挥重要作用。     

延髓腹面尾端加压区对应激性高血压大鼠动脉压力感受反射的影响

目的研究延髓腹面尾端加压区（ｃＶＭＰ）对应激性高血压大鼠动脉压力感受反射的影响。方法在应激性高血压动物模型上，以递增频率电方波刺激主动脉神经，观察动脉压力感受有髓和无髓传入反射衰减的表现，并在延髓腹面尾端加压区（ｃＶＭＰ）微量注射谷氨酸钠（Ｌ－ｇｌｕ），观察其对被衰减的动脉压力感受反射的影响。结果（１）主动脉神经１０Ｈｚ以上刺激的反射性降压效应随刺激频率的增高呈明显的衰减（Ｐ＜０．０１～Ｐ＜０．００１），而２～５Ｈｚ刺激的反射性降压效应无明显变化。（２）ｃＶＭＰ在Ｌ－ｇｌｕ兴奋作用下，易化被衰减和压力感受反射效应，其易化程度也随主动脉神经刺激频率增高而增大。结论应激性高血压早期动脉压力感受反射的衰减，主要是由于有髓纤维传入中枢机能的变化。ｃＶＭＰ的兴奋活动可以改善高血压早期动脉压力感受反射中枢性机能变化。     

加压素在家兔压力感受性反射中的作用

采用电刺激神经及牵拉颈动脉窦的方法兴奋压力感受器,观察了压力感受器兴奋时家兔某些脑区内及血浆中加压素含量的改变,以探讨其在压力感受性反射中的作用。结果表明:①电刺激减压神经产生明显减压效应时,家兔下丘脑、孤束核、垂体及血浆中加压素含量明显减少;②牵拉颈动脉窦时,家兔下丘脑、孤束核、垂体、脊髓及血浆中加压素含量明显减少,而延脑加压素含量显著增加。提示内源性加压素可能参与压力感受性反射调节过程。     

延髓腹外侧区在调节呼吸和心血管系统中的作用

现已知延髓腹外侧区在呼吸调节和心血管调节中起着重要作用．延髓腹外侧区有两个重要的血管运动中枢，称为头侧和尾侧血管运动中枢．参与呼吸调节的中枢化学感受器位于延髓腹外侧区浅表部位；延髓腹外侧区还参与中枢和外周化学感受器的传入冲动的整合．文章对一些最重要的有争论的观点作一综述     

针刺“人中”加压效应的神经原理的实验研究

1.“人中”加压效应是哺乳动物比较普遍存在的一个生理现象。就兔、猫、大白鼠、狗四种动物来说,无论血压正常的或是失血性低血压的,都能对针刺“人中”发生血压上升的反应。应用筒箭毒处理,排除了麻醉和躯体挣扎等因素的干扰而又保持动物于苏醒状态,这时“人中”的加压效应就更加显著。说明在正常情况下,“人中”是一个比较敏感的加压感受野。这一感受野不仅能在针刺和按压等机械刺激的作用下而发生兴奋,对于电刺激和乙酰胆硷也同样非常敏感。这一感受野的部位不限于鼻唇沟的某一点,而是包括鼻唇沟区域和鼻端部分,但也不超出这一范围。2.“人中”加压效应是通过神经反射来实现的。切断支配鼻唇沟区域的三叉神经眶下支后,“人中”加压效应即不再出现。刺激“人中”时,在延髓的闩外侧3.3mm处记录出的诱发电位最大,这一最大诱发电位区是位于三叉神经脊束核及其邻近的网状结构中;直接刺激这一部位,可引起血压升高;局部毁坏这一部位,使“人中”加压效应显著减弱;如同时也毁坏位于延髓下凹上部的“加压区”,则“人中”加压效应完全丧失。说明这两个部位是这一反射的延髓中枢的所在。3.“人中”加压效应的延髓中枢与脑高级部位的机能是密切联系的。轻度的药物麻醉已经明显地减弱了这一加压效应,药物麻醉加深时,加压效应更为减弱。大脑皮层在K~+作用下,“人中”加压效应也受到明显的抑制。摘除两测皮层,尤其是从中脑部位切断了脑干(去大脑),都严重地减弱了这一加压效应。4.针刺家兔“人中”时,观察到心率发生减慢的变化,特别是肾脏和后肢的体积表现明显的缩小。这后一事实可以说明家兔“人中”加压效应主要是由于腹腔内脏和肢体血管收缩的加强。切断两侧肾神经后,肾体积反应消失,可说明“人中”刺激引起内脏血管收缩主要是通过交感神经传出冲动来实现的。     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.     

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas： report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.