BACKGROUND & AIMS: :This study compared the effects of fatigue on corticospinal responsiveness in the upper- and lower-limb muscles of the same participants. Seven healthy males performed a 2-min maximal voluntary isometric contraction of the elbow flexors or knee extensors on four separate days. Electromyographic responses were elicited by nerve stimulation (maximal M-wave) in all sessions and by transcranial magnetic stimulation (motor-evoked potential; silent period) and spinal tract stimulation (cervicomedullary or thoracic motor-evoked potentials; silent period) in one session each per limb. During sustained maximal voluntary contractions, motor-evoked potential area normalised to M-waves increased from baseline in biceps brachii (155 ± 55%) and rectus femoris (151 ± 44%) (both p ≤ 0.045). At the end of maximal voluntary contractions, spinal tract motor-evoked potential area normalised to M-waves was smaller than baseline in biceps brachii (74 ± 23%; p = 0.012) but not rectus femoris (108 ± 40%; p = 0.999). The ratio of motor-evoked potential to spinal tract-evoked potential areas increased dramatically from 90 to 115 s in biceps brachii (p = 0.001) but not in rectus femoris (p = 0.999). Silent period durations increased similarly in both muscles (p ≤ 0.008) after transcranial and spinal stimulation. Sustained maximal contractions elicit different neurophysiological adjustments in upper- and lower-limb muscles. Specifically, motoneuronal excitability was reduced in biceps brachii, but not in rectus femoris, and this reduction required greater compensatory adjustments from the motor cortex. Therefore, changes in cortical and spinal excitability during sustained maximal exercise are likely specific to the muscle performing the task.

背景与目标： : 这项研究比较乏力对同一参与者上肢和下肢肌肉皮质脊髓反应性的影响。七名健康男性在四个不同的日子里对肘部屈肌或膝伸肌进行了2分钟的最大自愿等距收缩。在所有会话中通过神经刺激 (最大M波) 以及经颅磁刺激 (运动诱发电位; 静默期) 和脊髓道刺激 (颈髓或胸腔运动诱发电位; 静默期) 引起肌电图反应每个肢体。在持续最大自愿收缩期间，肱二头肌 (155   ±   55%) 和股直肌 (151   ±   44%) (均p  ≤   0.045) 的运动诱发电位区域从基线增加到M波。在最大自愿性收缩结束时，肱二头肌 (74   ±   23%; P   =   0.012) 的脊髓道运动诱发电位面积标准化为M波，小于基线，而股直肌 (108   ±   40%; P   =   0.999)。肱二头肌 (p   =   0.001) 的运动诱发电位与脊髓束诱发电位区域的比率从90到115  s急剧增加，而股直肌 (p   =   0.999) 则没有。经颅和脊柱刺激后，两种肌肉的静默期持续时间相似地增加 (p  ≤   0.008)。持续的最大收缩会引起上肢和下肢肌肉的不同神经生理调节。具体来说，肱二头肌的运动神经元兴奋性降低，但股直肌却没有，这种降低需要运动皮层进行更大的补偿性调整。因此，持续最大运动期间皮质和脊柱兴奋性的变化可能是特定于执行任务的肌肉的。

BACKGROUND & AIMS: :Radix astragali is a popular traditional herbal medicine that provides significant protection against tissue injury in various models of oxidative stress-related diseases. In this study, we aimed to investigate whether administration of Radix astragali prevented atrophy in both slow- and fast-twitch muscles following cast immobilization. Twenty-seven 12-week-old male F344 rats were divided into three experimental groups: control (CON), immobilized (IM), and immobilized with Radix astragali administration (IM+AR). Rats in the IM and IM+AR groups were subjected to immobilization of both lower extremities using casting-tape for 14 days. Rats in the IM+AR group were orally administered a decoction of Radix astragali daily for 21 days beginning 7 days before cast immobilization. As expected, rats in the IM group showed significant decreases (P < 0.05) in soleus and plantaris muscle-to-body weight ratios by 74.3% and 70.5%, respectively, compared with those in the CON group. Administration of Radix astragali significantly reversed (+35.5%) the weight reduction observed in soleus muscle, but not in the plantaris muscle, compared with that in the IM group. Furthermore, administration of Radix astragali inhibited MuRF1 mRNA expression only in the soleus muscle during cast immobilization. Our results demonstrated that administration of Radix astragali suppressed the immobilization-induced reductions in skeletal muscle mass and expression of MuRF1 mRNA in slow-twitch soleus muscles, but not in fast-twitch plantaris muscles.

背景与目标： : 黄芪是一种流行的传统草药，在各种氧化应激相关疾病模型中提供对组织损伤的显着保护。在这项研究中，我们旨在研究黄芪的给药是否可以预防石膏固定后缓慢和快速抽搐肌肉的萎缩。将27只12周龄雄性F344大鼠分为三个实验组: 对照组 (CON)，固定化 (IM) 和固定化黄芪给药 (IM AR)。IM和IM AR组的大鼠使用流延胶带固定两个下肢14天。IM AR组的大鼠在石膏固定前7天开始每天口服黄芪汤21天。正如预期的那样，与CON组相比，IM组大鼠比目鱼肌和plantaris的肌肉重量比分别显着降低了74.3% 和70.5% (P <0.05)。与IM组相比，黄芪的给药显着逆转 (35.5%) 比目鱼肌中观察到的重量减少，但在plant肌中没有。此外，黄芪的给药仅在石膏固定期间抑制比目鱼肌中的MuRF1 mRNA表达。我们的结果表明，黄芪的给药抑制了固定诱导的慢抽搐比目鱼肌骨骼肌质量的减少和MuRF1 mRNA的表达，但抑制了快抽搐的plant肌。

BACKGROUND & AIMS: :1. The influence of perinatal and pubertal gonadal androgens on acetylcholinesterase (AChE) activity was studied in the hormone-sensitive levator ani (LA) and extensor digitorum longus (EDL) muscles of adult male rats (105 days). 2. The hormone was withdrawn by gonadectomy at various ages and the effects on AChE and weight were compared with those induced by chronic denervation of both muscles from adult rats. 3. Gonadectomy of infantile (2-30 days) rats prevented LA muscle growth, and reduced total AChE activity to values similar to those found in denervated muscles (15% of control). The EDL muscles were slightly affected and only in rats castrated on the 2nd postnatal day. 4. When the rats were castrated at puberty (45 days), LA muscle weight and total AChE activity were reduced to 20% and 18% of control values, respectively. 5. Gonadectomy of adult (60 and 75 days) rats led to atrophy of the LA muscle (to 29% of control) and reduced the total AChE activity (to 40% of control). 6. AChE activity per unit weight was reduced by 30% in rats castrated from 5 to 20 days of age, and increased by 30% in both LA and EDL muscles from rats castrated in adulthood. Gonadectomy before puberty prevented total AChE in the LA from increasing above the levels detected in chronically denervated muscles. 7. Gonadectomy after puberty reduced total AChE of the LA but never to the extent caused by muscle denervation. 8. It is concluded that testosterone regulates AChE in the LA by early priming of the motoneuron and by pubertal stimulation of enzyme synthesis, the synthesis being dependent on intact innervation.

背景与目标： : 1。在成年雄性大鼠 (105天) 的激素敏感性提ani (LA) 和趾长伸肌 (EDL) 肌肉中研究了围产期和青春期性腺雄激素对乙酰胆碱酯酶 (AChE) 活性的影响。2.在不同年龄的性腺切除术中停用激素，并将其对疼痛和体重的影响与成年大鼠两种肌肉慢性去神经支配引起的影响进行比较。3.婴儿 (2-30天) 大鼠的性腺切除术可防止LA肌肉生长，并将总AChE活性降低至与失神经肌肉相似的值 (对照15%)。EDL肌肉受到轻微影响，仅在出生后第二天cast割的大鼠中。4.当大鼠在青春期 (45天) 去势时，LA肌肉重量和总AChE活性分别降低至对照值的20% 和18%。5.成年 (60和75天) 大鼠的性腺切除术导致LA肌肉萎缩 (至对照29%) 并降低总AChE活性 (至对照40%)。6.在5至20日龄的大鼠中，每单位重量的AChE活性因30% 而降低，而在成年后被阉割的大鼠的LA和EDL肌肉中，每单位重量的AChE活性因30% 而增加。青春期前的性腺切除术可防止LA的总疼痛增加到慢性失神经肌肉中检测到的水平以上。7.青春期后的性腺切除术减少了LA的总疼痛，但从未达到由肌肉神经支配引起的程度。8.结论是，睾丸激素通过运动神经元的早期启动和青春期刺激酶合成来调节LA中的AChE，该合成取决于完整的神经支配。

BACKGROUND & AIMS: :The cell adhesion molecule N-CAM is localized to the adult neuromuscular junction but is also expressed in the extrajunctional membrane of denervated muscles concurrent with extrajunctional acetylcholine receptors. Here we used N-CAM immunohistochemistry to determine whether we could detect early denervation in hindlimb muscles of the G93A transgenic mouse model of amyotrophic lateral sclerosis (ALS). In denervated wild type mouse muscles, N-CAM immunoreactivity on the sarcolemma of all fiber types and within the sarcoplasm of only type IIA fibers was detected at day 2: approximately 30% of the muscle fibers in cross-section were fully circumscribed by N-CAM immunoreactivity and approximately 25% of fibers were incompletely circumscribed. The proportion of the latter fibers remained constant over the next 8 days as the proportions of the former fibers increased exponentially. Thereafter, fully circumscribed muscle fibers increased to a maximum by 30 days with a concomitant fall in the incompletely circumscribed fibers. Hence, early muscle denervation was detected by the incomplete circumscription of fiber membranes by N-CAM immunoreactivity with full circumscription and intracellular localization indicating more long-term denervation. In the G93A transgenic mouse, rapid denervation of fast-twitch muscles was readily detected by a corresponding proportion of muscle fibers in cross-section with positive N-CAM immunoreactivity. The proportions of incompletely and completely circumscribed muscle fibers corresponded well with the rate of decline in intact motor units and reduced muscle contractile forces. Progressively more fully circumscribed muscle fibers became evident with age. We conclude that the N-CAM immunoreactivity on muscle fiber membranes in muscle cross-sections provides a sensitive means of detecting early muscle fiber denervation.

背景与目标： : 细胞粘附分子N-CAM定位于成人神经肌肉接头，但也与接头外乙酰胆碱受体同时在失神经支配肌肉的结外膜中表达。在这里，我们使用N-CAM免疫组织化学来确定是否可以检测到肌萎缩性侧索硬化症 (ALS) G93A转基因小鼠模型后肢肌肉的早期去神经支配。在失神经的野生型小鼠肌肉中，在第2天检测到对所有纤维类型的肌膜和仅IIA型纤维的肌浆内的N-CAM免疫反应性: 横截面中大约30% 的肌肉纤维被N-CAM免疫反应性完全限制，并且大约25% 的纤维不完全限制。后一种纤维的比例在接下来的8天内保持恒定，因为前一种纤维的比例呈指数增长。此后，完全外接的肌肉纤维增加到最大30天，同时不完全外接的纤维也随之下降。因此，通过N-CAM免疫反应性通过纤维膜的不完全外接检测到早期肌肉去神经，并具有完全外接和细胞内定位，表明更长期的去神经。在G93A转基因小鼠中，通过具有正N-CAM免疫反应性的横截面中相应比例的肌纤维很容易检测到快速抽动肌肉的快速去神经。不完全和完全外接的肌肉纤维的比例与完整运动单位的下降速度和肌肉收缩力的降低非常吻合。随着年龄的增长，逐渐变得更加完全限制的肌肉纤维。我们得出的结论是，肌肉横截面中肌纤维膜上的N-CAM免疫反应性提供了检测早期肌纤维去神经支配的敏感手段。

BACKGROUND & AIMS: :Paraspinal muscle fatigability during various trunk extension tests has been widely investigated by electromyography (EMG), and its task-dependency is established recently. Hip extensor muscle fatigability during the Sorensen test has been reported. The aim of the present experiments was to evaluate the task-dependency of back and hip extensor muscle fatigue during two variants of the Sorensen test. We hypothesized that the rate of muscular fatigue of the hip and back extensor muscles varies according to the test position. Twenty healthy young males with no history of low back pain volunteered to participate in this cross-sectional study. They were asked to perform two body weight-dependent isometric back extension tests (S1 = Sorensen test; S2 = modified Sorensen on a 45 degrees Roman chair). Surface EMG activity of the paraspinal muscles (T10 and L5 levels) and hip extensor muscles (gluteus maximus; biceps femoris) was recorded, and muscular fatigue was assessed through power spectral analysis of the EMG data by calculating the rate of median power frequency change. We observed hip extensor muscle fatigue simultaneously with paraspinal muscle fatigue during both Sorensen variants. However, only L5 level EMG fatigue indices showed a task-dependency effect between S1 and S2. Hip extensor muscles appear to contribute to load sharing of the upper body mass during both Sorensen variants, but to a different extent because L5 level fatigue differs between the Sorensen variants. Our findings suggest that task-dependency has to be considered when EMG variables are compared between two types of lumbar muscle-fatiguing tasks.

背景与目标： : 肌电图 (EMG) 已广泛研究了各种躯干伸展测试过程中的脊柱旁肌肉疲劳能力，并且最近建立了其任务依赖性。已经报道了Sorensen测试期间的髋伸肌易疲劳性。本实验的目的是评估Sorensen测试的两个变体中背部和髋部伸肌乏力的任务依赖性。我们假设髋部和背部伸肌的肌肉乏力率根据测试位置而变化。20名没有腰痛病史的健康年轻男性自愿参加了这项横断面研究。他们被要求进行两次体重相关的等距背部伸展测试 (S1 = Sorensen测试; S2 = 在45度罗马椅上修改后的Sorensen)。记录椎旁肌 (T10和L5水平) 和髋伸肌 (臀大肌; 股二头肌) 的表面EMG活动，并通过计算中值功率频率变化率，通过EMG数据的功率谱分析评估肌肉乏力。在两个Sorensen变体中，我们同时观察到了髋关节伸肌乏力和椎旁肌乏力。但是，只有L5级EMG乏力指数在S1和s2之间显示出任务依赖性效应。在两个Sorensen变体中，髋关节伸肌似乎都有助于上半身质量的负荷分担，但程度不同，因为Sorensen变体之间的L5水平乏力有所不同。我们的发现表明，在比较两种类型的腰肌疲劳任务之间的EMG变量时，必须考虑任务依赖性。

BACKGROUND & AIMS: BACKGROUND:The impact of vitamin D3 (VD3) on obesity has been reported in the past. Our study was aimed at investigating the possible mechanisms by which VD3 affects obesity induced by a high fat diet. METHODS:Eight-week-old C57BL/6 J male mice were fed a normal- or high-fat diet for 9 weeks and were treated with a gavage of vehicle (corn oil) or cholecalciferol (50 μg/kg, daily). Body weight, white adipose tissue weight, blood lipid and glucose levels were measured. In addition, we investigated the expression of 1,25(OH)2D3 (calcitriol)/VDR-regulated genes involved in energy and lipid metabolism, such as of uncoupling protein 3 (UCP3), by using qRT-PCR in the liver, adipose tissue, skeletal muscle and C2C12, L6, and H-EMC-SS cells. We also measured UCP3 promoter transcription in the same cell lines using a Dual Luciferase Assay. Furthermore, we analyzed the binding site consensus sequences of VDR on the UCP3 promoter. RESULTS:Mice consuming a high-fat diet treated with cholecalciferol had lower body weight and adipose tissue weight and higher expression of UCP3 compared to the other treatment groups. Changes in the expression of genes correlated with calcitriol/VDR. Luciferase activity was dose-dependently associated with calcitriol/VDR levels. We confirmed the functional VDR binding site consensus sequences at -2200, -1561, -634, and +314 bp in the UCP3 promoter region. CONCLUSION:We suggest that VD3/VDR inhibits weight gain by activating UCP3 in the muscles.

背景与目标：

BACKGROUND & AIMS: :Reactive oxygen species (ROS) are not only a cause of oxidative stress in a range of disease conditions but are also important regulators of physiological pathways in vivo. One mechanism whereby ROS can regulate cell function is by modification of proteins through the reversible oxidation of their thiol groups. An experimental challenge has been the relative lack of techniques to probe the biological significance of protein thiol oxidation in complex multicellular tissues and organs. We have developed a sensitive and quantitative fluorescence labeling technique to detect and localize protein thiol oxidation in histological tissue sections. In our technique, reduced and oxidized protein thiols are visualized and quantified on two consecutive tissue sections and the extent of protein thiol oxidation is expressed as a percentage of total protein thiols (reduced plus oxidized). We tested the application of this new technique using muscles of dystrophic (mdx) and wild-type C57Bl/10Scsn (C57) mice. In mdx myofibers, protein thiols were consistently more oxidized (19 ± 3%) compared with healthy myofibers (10 ± 1%) in C57 mice. A striking observation was the localization of intensive protein thiol oxidation (70 ± 9%) within myofibers associated with necrotic damage. Oxidative stress is an area of active investigation in many fields of research, and this technique provides a useful tool for locating and further understanding protein thiol oxidation in normal, damaged, and diseased tissues.

背景与目标： : 活性氧 (ROS) 不仅是一系列疾病条件下氧化应激的原因，而且还是体内生理途径的重要调节剂。ROS调节细胞功能的一种机制是通过蛋白质的巯基可逆氧化来修饰蛋白质。实验挑战是相对缺乏技术来探索复杂的多细胞组织和器官中蛋白质硫醇氧化的生物学意义。我们已经开发了一种灵敏且定量的荧光标记技术来检测和定位组织学组织切片中的蛋白质硫醇氧化。在我们的技术中，还原和氧化的蛋白质硫醇在两个连续的组织切片上进行可视化和定量，并且蛋白质硫醇氧化的程度表示为总蛋白质硫醇的百分比 (还原加氧化)。我们使用营养不良 (mdx) 和野生型C57Bl/10Scsn (C57) 小鼠的肌肉测试了这种新技术的应用。在mdx肌纤维中，与C57小鼠的健康肌纤维 (10 ± 1%) 相比，蛋白硫醇始终被氧化 (19 ± 3%)。一个引人注目的观察是与坏死损伤相关的肌纤维内蛋白质巯基氧化 (70 ± 9%) 的定位。氧化应激是许多研究领域中积极研究的领域，该技术为定位和进一步了解正常，受损和患病组织中的蛋白质硫醇氧化提供了有用的工具。

BACKGROUND & AIMS: :Prostaglandin E2 (PGE2) induced a dose-dependent increase in tone of the circular muscles of guinea pig ileum in vitro. These actions of PGE2 were deleted in the cold-stored preparations and blocked by tetrodotoxin. Atropine reduced the effects of PGE2 and physostigmine potentiated the PGE2-induced contractions. The release of acetylcholine (ACh) by PGE2 was responsible for initiating this contraction. The effect of PGE2 was compared with that of an electrical stimulation which also initiated a non-receptor-mediated release of ACh. Hexamethonium abolished the effect of PGE2 but did not influence the actions of the electrical stimulations. Synaptosomal fractions of the circular muscles were prepared to study the release of [14C]ACh. However, PGE2 failed to evoke a marked increase in the efflux of radioactivity, even at the maximal concentration. Damage and/or removal of the myenteric plexus may be responsible for this result because electrical stimulations that exert a powerful spasmogenic effect on longitudinal muscles also induced an insensitive response. Alloxan and ethacrynic acid, inhibitors of adenylate cyclase, reduced the activity of PGE2 at a concentration insufficient to modify either the actions of ACh or the electrical stimulations. 3-Isobutyl-1-methylxanthine (IBMX) potentiated the responses to PGE2 at a dose sufficient to block the activity of phosphodiesterase (PDE). Imidazole, a stimulator of PDE, decreased the actions of PGE2 in a dose-dependent manner. IBMX, like imidazole, failed to modify the activities of both ACh and the electrical stimulations. These results indicate that PGE2 may function as a releaser of ACh in a cyclic AMP-dependent manner in the circular muscles of guinea pig ileum.

背景与目标： : 前列腺素E2 (PGE2) 在体外诱导豚鼠回肠环形肌张力的剂量依赖性增加。PGE2的这些作用在冷藏制剂中被删除，并被河豚毒素阻断。阿托品降低了PGE2的作用，毒扁豆碱增强了PGE2-induced收缩。PGE2释放乙酰胆碱 (ACh) 是引发这种收缩的原因。将PGE2的作用与电刺激的作用进行了比较，电刺激也启动了非受体介导的ACh释放。六甲铵消除了PGE2的作用，但不影响电刺激的作用。环状肌肉的突触体部分准备研究 [14C]ACh的释放。然而，PGE2未能引起放射性外排的显着增加，即使在最大浓度下。肌间神经丛的损伤和/或去除可能是造成这一结果的原因，因为对纵向肌肉产生强大痉挛作用的电刺激也会引起不敏感的反应。四氧嘧啶和乙酸，腺苷酸环化酶的抑制剂，降低了PGE2的活性，其浓度不足以改变ACh或电刺激的作用。3-异丁基-1-甲基黄嘌呤 (IBMX) 以足以阻断磷酸二酯酶 (PDE) 活性的剂量增强了对PGE2的反应。咪唑，PDE的刺激剂，以剂量依赖的方式降低了PGE2的作用。像咪唑一样，IBMX未能改变ACh和电刺激的活性。这些结果表明PGE2可能以循环AMP依赖的方式在豚鼠回肠的环形肌肉中起到ACh的释放作用。

BACKGROUND & AIMS: The cell cycle time of satellite cells in growing rats was determined to be approximately 32 hr, with an S-phase of 14 hr. The estimated cycle time was the same for satellite cells in both oxidative soleus and glycolytic EDL muscles and is consistent with the rate at which myonuclei are produced during growth. Continuous infusion of bromodeoxyuridine (BrdU) was used to determine if all satellite cells had the same cycle time in vivo. Approximately 80% of the satellite cell population was readily labeled over the first 5 days of continuous infusion. Remaining satellite cells accumulated label at a much slower rate and were still not completely saturated after an additional 9 days of infusion. Only a small portion of the cells labeled with BrdU during the first 5 days could be labeled with a second label ([3H]thymidine) during tandem continuous infusion experiments, suggesting that they pass through a limited number of mitotic divisions prior to fusion. These results suggest that satellite cells in growing oxidative and glycolytic skeletal muscles can be subdivided into two distinct compartments. About 80% divide with a 32-hr cell cycle duration and are responsible chiefly for providing myonuclei to growing fibers. The remaining 20% of the cells divide more slowly, probably because the cells enter a G(0)-phase between mitotic divisions. These reserve cells, through asymmetric divisions, may generate the myonuclei-producing satellite cell population. Proliferative potential for regeneration and adaptive responses is likely located in this reserve population.

背景与目标： 确定生长中的大鼠中卫星细胞的细胞周期时间约为32小时，S期为14小时。氧化比目鱼肌和糖酵解EDL肌肉中的卫星细胞的估计周期时间相同，并且与生长过程中产生肌核的速率一致。连续输注溴脱氧尿苷 (BrdU) 用于确定所有卫星细胞在体内是否具有相同的循环时间。在连续输注的前5天，大约80% 的卫星细胞群容易被标记。剩余的卫星细胞以慢得多的速度积累标记，并且在输注另外9天后仍未完全饱和。在串联连续输注实验中，只有一小部分用BrdU标记的细胞可以用第二个标记 ([3H] 胸苷) 标记，表明它们在融合之前通过有限数量的有丝分裂分裂。这些结果表明，生长中的氧化和糖酵解骨骼肌中的卫星细胞可以细分为两个不同的区室。大约80% 次分裂，细胞周期持续时间为32小时，主要负责向生长中的纤维提供肌核。其余的20% 细胞分裂得更慢，可能是因为细胞进入有丝分裂分裂之间的G(0) 期。这些储备细胞通过不对称分裂，可能产生产生肌核的卫星细胞群。再生和适应性反应的增殖潜力可能位于该储备群体中。

BACKGROUND & AIMS: :The association between physical exercise and oxidative damage in the skeletal musculature has been the focus of many studies in literature, but the balance between superoxide dismutase and catalase activities and its relation to oxidative damage is not well established. Thus, the aim of the present study was to investigate the association between regular treadmill physical exercise, oxidative damage and antioxidant defenses in skeletal muscle of rats. Fifteen male Wistar rats (8-12 months) were randomly separated into two groups (trained n=9 and untrained n=6). Trained rats were treadmill-trained for 12 weeks in progressive exercise (velocity, time, and inclination). Training program consisted in a progressive exercise (10 m/min without inclination for 10 min/day). After 1 week the speed, time and inclination were gradually increased until 17 m/min at 10% for 50 min/day. After the training period animals were killed, and gastrocnemius and quadriceps were surgically removed to the determination of biochemical parameters. Lipid peroxidation, protein oxidative damage, catalase, superoxide dismutase and citrate synthase activities, and muscular glycogen content were measured in the isolated muscles. We demonstrated that there is a different modulation of CAT and SOD in skeletal muscle in trained rats when compared to untrained rats (increased SOD/CAT ratio). TBARS levels were significantly decreased and, in contrast, a significant increase in protein carbonylation was observed. These results suggest a non-described adaptation of skeletal muscle against exercise-induced oxidative stress.

背景与目标： : 体育锻炼与骨骼肌肉组织氧化损伤之间的关系一直是许多文献研究的重点，但超氧化物歧化酶和过氧化氢酶活性之间的平衡及其与氧化损伤的关系尚未得到很好的确立。因此，本研究的目的是研究常规跑步机体育锻炼，氧化损伤和大鼠骨骼肌抗氧化防御之间的关系。将15只雄性Wistar大鼠 (8-12个月) 随机分为两组 (训练n = 9和未训练n = 6)。训练的大鼠在进行性运动 (速度，时间和倾斜度) 中进行跑步机训练12周。培训计划包括渐进式锻炼 (10 m/min，无倾斜度，每天10分钟)。1周后，速度，时间和倾斜度逐渐增加，直到10% 为17 m/min，持续50 min/天。训练期结束后，将动物杀死，并通过手术切除腓肠肌和股四头肌以确定生化参数。在分离的肌肉中测量脂质过氧化，蛋白质氧化损伤，过氧化氢酶，超氧化物歧化酶和柠檬酸合酶活性以及肌肉糖原含量。我们证明，与未经训练的大鼠相比，训练有素的大鼠骨骼肌中CAT和SOD的调节不同 (SOD/CAT比增加)。TBARS水平显着降低，相反，观察到蛋白质羰基化显着增加。这些结果表明，骨骼肌对运动引起的氧化应激的适应性未描述。

BACKGROUND & AIMS: :Forelimb alpha-motoneurones were intracellularly recorded in anaesthetized cats and iontophoretically filled with horseradish peroxidase (HRP). All motoneurones to the elbow flexors, elbow extensor and to the extensor carpi radialis muscles displayed in parallel homonymous recurrent inhibitory postsynaptic potentials (RIPSPs) and axon collaterals. Homonymous RIPSPs and axon collaterals were missing in the nuclei to the long digit extensor muscles. Two populations of motoneurones, with and without recurrent axon collaterals, seem to be present in the extensor carpi ulnaris motor nucleus. These results are consistent with the hypothesis that the motoneurones to the extrinsic digit extensors lack a recurrent axonal system. This indicates that the contribution of the recurrent Renshaw systems to motor control may be more complex than hitherto assumed.

背景与目标： : 在麻醉的猫中，前肢 α-运动神经元在细胞内记录，并在离子电渗中充满辣根过氧化物酶 (HRP)。肘部屈肌，肘部伸肌和腕侧伸肌的所有运动神经元均以平行的同名复发性抑制性突触后电位 (RIPSPs) 和轴突侧支显示。长指伸肌的核中缺少同名的ripsp和轴突侧支。尺骨伸肌运动核中似乎存在两个运动神经元群体，有或没有复发性轴突侧支。这些结果与以下假设一致: 外在手指伸肌的运动神经元缺乏复发性轴突系统。这表明recurrent Renshaw系统对运动控制的贡献可能比迄今为止所假设的更为复杂。

BACKGROUND & AIMS: :Electrical activity and soreness in the quadriceps muscles were examined during a 48-h period after eccentric (EC) and concentric contraction (CC) to study the amplitude and frequency characteristics of the electrical signal after exercise and to study the relationship between the electrical signal and muscle soreness. The exercise protocol included a step test performed for 15 min using a 46-cm step in which one quadriceps contracted eccentrically and one contracted concentrically. Electrical activity was quantified by computing both root mean square electromyograph (rmsEMG) and mean power frequency of the myoelectrical signal during low-level contractions of the muscles. Recordings of muscle activity were made before exercise, immediately after exercise, 1, 12, 24 and 48 h after exercise in 12 volunteer subjects (mean age 28.5 yr). Recordings were made with the subject seated, holding the leg being tested slightly off the ground. Subjects were given a subjective pain rating scale. The before exercise values for rmsEMG (EC = 13.3 microV; CC = 13 microV) and mean power frequency (EC = 55.3 Hz; CC = 54.4 Hz) were within the range that would be expected for surface electrodes. The mean rating of soreness for the eccentrically exercised muscles ranged from slightly uncomfortable at 12 h after exercise to sore during the period 24-48 h after exercise. Subjects reported the concentrically exercised muscles as normal to slightly uncomfortable during the whole recording period. Analysis of variance revealed a significant (P less than 0.05) difference between EC and CC rmsEMG value at 1 h after exercise (EC = 17.2 +/- 7.6; CC = 12.3 +/- 5.5) and at 12 h after exercise (EC = 15.0 +/- 5.0; CC = 12.3 +/- 4.2). The results suggest that an increase in the electrical activity of muscles is needed to produce the same pre-exercise contraction after performing eccentric exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

背景与目标： : 在偏心 (EC) 和同心收缩 (CC) 后的48小时内检查股四头肌的电活动和酸痛，以研究运动后电信号的幅度和频率特征，并研究电信号之间的关系和肌肉酸痛。运动方案包括使用46厘米步长进行15分钟的步长测试，其中股四头肌偏心收缩，股四头肌同心收缩。通过计算肌肉低水平收缩期间的均方根肌电图 (rmsEMG) 和肌电信号的平均功率频率来量化电活动。在运动前，运动后立即，运动后1、12、24和48小时对12名志愿者受试者 (平均年龄28.5岁) 进行肌肉活动记录。录音时，对象就座，将被测试的腿略微离地。对受试者进行了主观疼痛评定量表。rmsEMG的前运动值 (EC = 13.3 microV; CC = 13 microV) 和平均功率频率 (EC = 55.3Hz; CC = 54.4Hz) 在表面电极预期的范围内。偏心运动肌肉的酸痛平均评分范围从运动后12小时的轻微不适到运动后24-48小时的酸痛。受试者报告说，在整个记录期间，同心运动的肌肉正常至轻微不舒服。方差分析显示，运动后1小时 (EC = 17.2 +/- 7.6; CC = 12.3 +/- 5.5) 和运动后12小时 (EC = 15.0 +/- 5.0) EC和CC rmsEMG值之间存在显着差异 (P <0.05); CC = 12.3 +/- 4.2)。结果表明，在进行偏心运动后，需要增加肌肉的电活动才能产生相同的运动前收缩。(摘要截断为250字)

BACKGROUND & AIMS: INTRODUCTION:Sit-to-stand (SitTS) and stand-to-sit (StandTS) are very important functional tasks that become compromised in stroke patients. As in other voluntary movements, they require an adequate postural control (PC) involving the generation of anticipatory postural adjustments (APAs). In order to give clues for more efficient and directed rehabilitation programs, a deeper knowledge about APAs during challenging and daily life movements is essential. PURPOSE:To analyze the activation timing of tibialis anterior (TA) and soleus (SOL) muscles during SitTS and StandTS in healthy subjects and in post-stroke patients. METHODS:Two groups participated in this study: one composed of ten healthy subjects and the other by ten subjects with a history of stroke and increased H-reflex. Electromyographic activity (EMGa) of SOL and TA was analyzed during SitTS and StandTS in the ipsilateral (IPSI) and the contralateral (CONTRA) limb to the side lesion in stroke subjects, and in one limb in healthy subjects. A force plate was used to identify the movement onset. RESULTS:In both sequences, in the stroke group SOL activation timing occurred prior to movement onset, contrary to the pattern observed in the healthy subjects. Statistically significant differences were found in SOL activation timings between each lower limb of the stroke and healthy groups, but no significant differences were found between the IPSI and the CONTRA limb. The TA activation timing seems to be delayed in the CONTRA limb when compared to the healthy subjects and showed a better organization of TA timing activation in StandTS when compared to SitTS. CONCLUSION:Compared to healthy subjects, APAs seem to be altered in both limbs of the post-stroke subjects, with the SOL activation timing being anticipated in both SitTS and StandTS.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Unstable conditions during ambulance transportation are not conducive to the performance of high-quality cardiopulmonary resuscitation by emergency medical technicians. OBJECTIVE:The present study was conducted to clarify differences in the quality of chest compression and associated muscle activity between static and ambulance transportation conditions. METHODS:Nine paramedic students performed chest compression for 5 minutes on the floor and during ambulance transportation. Compression rate and depth and success and error rates of chest compression were determined using the Resusci Anne manikin with a PC SkillReporting System (Laerdal Medical). Integrated electromyography (i-EMG) values of eight different muscles were also recorded bilaterally during the first and last 30 seconds of compression. RESULTS:There was no significant difference in compression rate per minute (p = 0.232) and depth of chest compression (p = 0.174) between the two conditions. The success rate was significantly lower under the ambulance transportation condition than under the static condition (p = 0.0161). Compared with those under the static condition, the total i-EMG values were significantly lower for the multifidus (p = 0.0072) and biceps femoris (p < 0.0001) muscles and significantly higher for the deltoid (p = 0.0032), pectoralis major (p = 0.0037), triceps brachii (p = 0.0014), vastus lateralis (p < 0.0001), and gastrocnemius (p = 0.0004) muscles under the ambulance transportation condition. CONCLUSIONS:Chest compression is performed mainly through flexion and extension of the hip joint while kneeling on the floor and through the elbow and shoulder joints while standing in a moving ambulance. Therefore, the low quality of chest compression during ambulance transportation may be attributable to an altered technique of performing the procedure.

背景与目标：

BACKGROUND & AIMS: To establish whether botulinum A toxin (BTX-A) acts on modifying reciprocal inhibition between forearm muscles in spasticity, 20 patients with post-stroke upper limb spasticity lasting for more than 1 year were studied. Clinical examination, physiotherapeutic evaluation, standardized video-tape assessment and electrophysiological testing (flexor carpi radialis muscle M and H responses with study of reciprocal inhibition) were performed at baseline and 2 weeks, 1, 2, 3, 4 months after BTX-A treatment. BTX-A induced a significant decrease of tone and an improvement of motility and functional status, with a significant decrease of the M wave and the H reflex. The reduction in both inhibitory phases of reciprocal inhibition did not change after BTX-A treatment differently from that reported in upper limb dystonia. These findings indicate that the efficacy of BTX-A in upper limb spasticity is mainly due to peripheral effects.

背景与目标： 为了确定肉毒杆菌毒素 (btx-a) 是否在改善痉挛状态下前臂肌肉之间的相互抑制作用，研究了20例中风后上肢痉挛持续超过1年的患者。在基线和btx-a治疗后2周，1、2、3、4个月进行临床检查，理疗评估，标准化录像带评估和电生理测试 (桡侧腕屈肌M和H反应，研究相互抑制)。Btx-a引起音调显着降低，运动和功能状态得到改善，M波和H反射显着降低。Btx-a治疗后，相互抑制的两个抑制阶段的减少与上肢肌张力障碍的报道不同。这些发现表明，btx-a在上肢痉挛中的功效主要是由于外周效应。