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91.
Acetylcholinesterase Adaptation to Voluntary Wheel Running is Proportional to the Volume of Activity in Fast, but not Slow, Rat Hindlimb Muscles 总被引:4,自引:0,他引:4
Victor Gisiger Manon Bélisle Phillip F. Gardiner 《The European journal of neuroscience》1994,6(5):673-680
Chronic enhancement of neuromuscular activity by forced exercise training programmes results in selective adaptation of the G4 acetylcholinesterase (AChE) molecular form in hindlimb fast muscles of the rat, with only minor and non-selective AChE changes in the soleus. In order to shed further light on the physiological significance of this G4 adaptation to training, we turned to a voluntary exercise model. The impact of 5 days and 4 weeks of voluntary wheel cage running on AChE molecular forms was examined in four hindlimb fast muscles and the slow-twitch soleus from two rat strains. Inbred Fisher and Sprague– Dawley rats, placed in live-in wheel cages, exercised spontaneously for distances which progressively increased up to an average of ∼3 and 18 km/day, respectively, by the end of week 4. Fast muscles responded to this voluntary activity by massive G4 increases (up to 420%) with almost no changes in A12 , so that by week 4 the tetramer became the main AChE component of these muscles. The additional G4 was composed primarily of amphiphilic molecules, suggesting a membrane-bound state. The G4 content of fast muscles was highly correlated with the distance covered by the rats during the 5 days before they were killed ( r = 0.850-0.879, P < 0.001 in three muscles). The soleus muscle, in turn, responded to wheel cage activity by a marked selective reduction of its asymmetric forms—up to 45% for A12 . This A12 decline, already maximal by day 5 of wheel cage running, showed no relationship with the distance covered. The present results constitute strong new evidence suggesting that the role of AChE in neuromuscular transmission is not limited solely to the rapid inactivation of just-released acetylcholine. 相似文献
92.
An experimental model for canine visceral leishmaniasis 总被引:6,自引:1,他引:5
PEDRO ABRANCHES GABRIELA SANTOS-GOMES NURIT RACHAMIM† LENEA CAMPINO LIONEL F. SCHNUR‡ CHARLES L. JAFFE† 《Parasite immunology》1991,13(5):537-550
Seven mixed-breed dogs were challenged with either promastigotes or amastigotes of Leishmania donovani infantum strains recently isolated from naturally infected dogs. Different routes and numbers of parasites were utilized and each dog was monitored for at least 1 year post-infection. Anti-parasite specific antibody levels were measured by enzyme-linked immunosorbence, immunofluorescence, crossed-immune electrophoresis and Western blotting on crude antigen. Western blotting on two pure parasite proteins, dp72 and gp70-2, was also done. Mitogenic and antigen-specific stimulation of peripheral blood lymphocytes was monitored; and the haematological, clinical and parasitological parameters measured. Dogs challenged with amastigotes exhibited a more pronounced humoral response to leishmanial antigens. Only in one case was strong antigen-specific proliferation detected. Clinical signs of disease, including hypergammaglobulinaemia, enlarged lymph nodes and the presence of parasites, were also more apparent in the dogs challenged with amastigotes. None of the seven dogs died. Serum antibodies to leishmanial antigens were apparent between 1.5 to 3 months following challenge and correlated with the appearance of enlarged lymph nodes, hypergammaglobulinaemia and the presence of parasites in tissue biopsies. Serum antibodies remained chronically high in these dogs throughout the period of the study. Only one dog (1/3) challenged intravenously with promastigotes and the dog challenged intradermally with amastigotes produced transient antibody responses to leishmanial antigen. 相似文献
93.
本文运用模糊数学原理,对东台市1993年7月份市面上的全脂乳粉抽查监测结果进行卫生质量综合评价,结果令人满意,从而为乳粉卫生质量评比建立了客观有效的评价模型。 相似文献
94.
由头皮上电极所记录下的EEG信号是大脑中各种电活动,尤其是神经元电活动,互相耦合而产生的电位变化的整体反映。有一种看法认为,表面看来随机、无规则的EEG信号,实际上它的变化只是由少量几个动力学参量控制着的非线性过程。根据这个假定,我们提出使用多复指数(MCE)模型来描述EEG信号的想法。文中首先简要地介绍了用来估计时序信号MCE模型参数的非调和Fourier展开算法(NHFE)的基本思想。然后,对一个叠加有白噪声、具有4个频率成分的模拟信号,用NHFE算法估计出其MCE模型参数,并把所得的结果与用经典的周期图谱分析方法、AR模型谱分析方法所得到的信号频谱作了比较。结果表明,在SNR高的条件下,NHFE算法所估计出的模型参数能更客观地反映信号的固有特性。基于目前的有关EEG形成的假设,应用MCE模型来描述EEG将更能反映出其特征。因此,我们对MCE模型及其参数在EEG数据分析中的几种可能应用作了初步尝试。这些应用包括:EEG信号段(或一段诱发电位,或一段事件关联电位)的特征参数的提取,这些特征参数包括优势频率值、独立的频率成分个数、幅度值、正负衰减指数的个数、频带宽度与幅度乘积(能量);EEG的频率调制特性的粗略描述等。从而看到了用通常信号分析方法所看不到的EEG信号中所反映的大脑活动的变化。由于用MCE模型及其参数来描述EEG的方法更符合目前关于大脑非线性动力学行为的假设,所以这一方法将是表示EEG信号的有效途径之一。另外,MCE模型方法在EEG信号的模拟研究与数据压缩等方面也将是有用的。文中还讨论了NHFE算法应用中的一些问题。 相似文献
95.
Camilla Nyboe Jonas A. Funder Morten H. Smerup Hans Nygaard J. Michael Hasenkam 《European journal of cardio-thoracic surgery》2006,29(6):1008-1013
Objective: Mechanical heart valves can cause thromboembolic complications, possibly due to abnormal flow patterns that produce turbulence downstream of the valve. The objective of this study was to investigate whether three different bileaflet valve designs would exhibit clinically relevant differences in downstream turbulent stresses. Methods: Three bileaflet mechanical heart valves (Medtronic Advantage®, CarboMedics© Orbis™ Universal and St. Jude Medical® Standard) were implanted into 19 female 90 kg pigs. Blood velocity was measured during open chest conditions in the cross sectional area downstream of the valves with 10 MHz ultrasonic probes connected to a modified Alfred® Pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at three different cardiac output ranges (3–4, 4.5–5.5, 6–7 L/min). Results: Data from 12 animals were obtained. RNS correlated with increasing cardiac outputs. The highest instantaneous RNS observed in these experiments was 47 N/m2, and the mean RNS taken spatially over the cross sectional area of the aorta during systole was between 3 N/m2 and 15 N/m2. In none of the cardiac output ranges RNS values exceeded the lower critical limit for erythrocyte or thrombocyte damage for any of the valve designs. Conclusions: Reynolds normal stress values were below 100 N/m2 for all three valve designs and the difference in design was not reflected in generation of turbulence. Hence, it is unlikely that any of the valve designs causes flow induced damage to platelets or erythrocytes. 相似文献
96.
To evaluate changes in matrix molecules of the joint capsule, the right knees of 24 skeletally mature female NZW rabbits were immobilized while the contralateral limb served as an unoperated control. The immobilization was discontinued at 8 weeks and the rabbits were divided among four groups (n = 6) based on the number of weeks the right knees were remobilized: 0, 8, 16, or 32. Three rabbits (six knees) that did not have operations provided normal control joint capsules. The mRNA levels for collagen types I, II, and III, and MMP-1 and -13 were significantly increased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. In contrast, the mRNA levels for TIMP-1, -2, and -3 were decreased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. The mRNA levels for lumican and decorin were increased in the joint capsules of the contracture knees in all groups when compared to normal capsules. Many of the changes observed in this animal model are similar to those observed in human joint capsules from posttraumatic elbow contractures, supporting the value of this rabbit model. 相似文献
97.
目的:综合评价学生体质健康状况。方法:利用现代计算机技术提供的手段用AHP模型以人一机对话的方式对我国各省市学生体质与健康水平和学生体质状况进行了综合评估。结果:得到了学生体质健康排序权值。结论:这种方法具有定性分析与定量分析相结合的特点,能够充分考虑到人在体质与健康综合评估中的主观能动作用,是一种十分有效的评价方法。 相似文献
98.
由于操作简便、节省人力物力,大鼠体外循环模型的应用愈加广泛。大鼠在小型呼吸机辅助下,应用颈静脉插管入右心房引流血液至贮血瓶,在蠕动移液泵作用下,经膜式氧合器氧合、变温器变温,通过股动脉或尾动脉插管注入动脉系统,建立体外循环回路。有血预充、减少总预充量和维持足够的转流流量是建立大鼠体外循环模型的关键。 相似文献
99.
Anne M Landau Edouard Kouassi Rosmarie Siegrist-Johnstone Julie Desbarats 《Movement disorders》2007,22(3):403-407
Defects in the ubiquitin-proteasome system have been implicated in Parkinson's Disease (PD). Recently, a rat model of PD was developed using a synthetic proteasome inhibitor (PSI), (Z-lle-Glu(OtBu)-Ala-Leu-al). We attempted to transfer this model to mouse studies, where genetics can be more readily investigated due to the availability of genetically modified mice. We treated C57BL/6 (B6) mice with six intraperitoneal injections of 6 mg/kg PSI in 50 mul of 70% ethanol over a 2-week-period. We found significant decreases in nigrostriatal dopamine in PSI-treated mice compared with saline-treated mice. However, we observed similar decreases in the ethanol-treated vehicle control group. Administration of ethanol alone led to significant long-term alterations in dopamine levels. Ethanol significantly eclipses the effects of PSI in the dopamine system, and therefore is a confounding vehicle for this model. 相似文献
100.
青少年精神分裂症患者家庭因素的研究 总被引:2,自引:0,他引:2
目的:探讨青少年精神分裂症患者的发病和家庭因素的相关性.方法:采用父母养育方式评价量表(EMBU)及家庭环境量表中文版(FES-CV)对60名青少年精神分裂症患者进行测评并与60名健康青少年进行对照及相关分析.结果:青少年精神分裂症患者父母养育方式与正常组对照显示:其父亲惩罚严厉、拒绝否认因子分显著高于对照组,情感温暖、理解因子分显著低于对照组(P<0.05或P<0.01);其母亲过分干涉过度保护、偏爱被试因子分显著高于对照组;母亲的情感温暖理解、过度保护、偏爱被试因子分高于父亲(P<0.05或P<0.01).家庭环境的亲密度、情感表达、文化性、娱乐性的因子分低于对照组,矛盾性和控制性均高于对照组(P<0.05或P<0.01).相关分析显示:父亲过度保护与母亲拒绝否认,及母亲过度保护与父亲拒绝否认因子之间呈负相关(r≥0.8);父亲与母亲EMBU相同因子得分具有相关关系(r≥0.6).结论:不良的家庭环境和父母养育方式对青少年精神分裂症的发病起一定作用,具有相关性. 相似文献