The effects of glucosamine on platelet aggregation

The effects of glucosamine on platelet aggregation induced by a variety of agents were investigated. When compared with the effects of N-acetyl glucosamine (NAG), an acetylated derivative of glucosamine (1), it became apparent that the N-acetyl group was important in stimulating $\text{Staphylococcus aureus}$ induced platelet aggregation. The absence of the N-acetyl group from NAG changes it to glucosamine which is an inhibitor rather than a stimulator of $\text{S. aureus}$ induced platelet aggregation and release. Glucosamine also inhibits collagen, epinephrine, and ADP induced platelet aggregation and release.     

Effects of short-term training on heart rate dynamics in individuals with spinal cord injury

Increased risk of cardiovascular diseases and autonomic dysregulation are common health concerns in individuals with spinal cord injury (SCI). Two therapies that may help improve cardiovascular control are body-weight supported treadmill training (BWSTT) and head-up tilt training (HUTT). The purpose of this study was to examine the effects of short-term BWSTT and HUTT on cardiac autonomic function. Seven participants (6 male, 37.1 ± 7.7 years) with SCI (C5-T10, ASIA A-C; 5.0 ± 4.4 years post-injury) completed the study protocol. In this randomized cross-over design, participants were required to complete 4 weeks of thrice-weekly BWSTT and HUTT (i.e. 12 sessions each), separated by a 4 week detraining period. Cardiac autonomic function was assessed at rest, before and after, each 4 week training period using linear and non-linear measures (sample entropy and detrended fluctuation analysis (α₁)) of heart rate dynamics. Participants completed equivalent amounts of time performing BWSTT and HUTT (453.7 ± 27.3 min vs. 471.6 ± 19.7 min, p = 0.24). There were no significant differences in linear heart rate variability following BWSTT or HUTT (p > 0.05). In contrast, there was a significant change in sample entropy following BWSTT (1.05 ± 0.14 to 1.42 ± 0.12, p < 0.05). Due to the bi-directional pattern of α₁ values, distance scores were calculated (│1 − α₁│) and demonstrated a significant reduction following BWSTT (0.54 ± 0.06 to 0.26 ± 0.05, p = 0.001). In conclusion, 4 weeks of BWSTT but not HUTT training are sufficient to increase sample entropy and reduce the fractal scaling distance score in participants with SCI.     

Effects of exercise and fetal spinal cord implants on the H-reflex in chronically spinalized adult rats

This study investigated the modulation of hindlimb reflex excitability after transection of the spinal cord in adult rats. After transection, the H-reflex exhibited decreased depression at high stimulation frequencies compared to intact animals. Groups of animals which received a spinal cord transection followed by either an exercise regimen for the hindlimbs or a fetal spinal cord implant, showed high stimulation frequency depression similar to controls. This suggests that each of these palliative strategies helped to ‘normalize’ the excitability of specific spinal reflexes.     

Proprioceptive neuropathy affects normalization of the H-reflex by exercise after spinal cord injury

The H-reflex habituates at relatively low frequency (10 Hz) stimulation in the intact spinal cord, but loss of descending inhibition resulting from spinal cord transection reduces this habituation. There is a return towards a normal pattern of low-frequency habituation in the reflex activity with cycling exercise of the affected hind limbs. This implies that repetitive passive stretching of the muscles in spinalized animals and the accompanying stimulation of large (Group I and II) proprioceptive fibers has modulatory effects on spinal cord reflexes after injury. To test this hypothesis, we induced pyridoxine neurotoxicity that preferentially affects large dorsal root ganglia neurons in intact and spinalized rats. Pyridoxine or saline injections were given twice daily (IP) for 6 weeks and half of the spinalized animals were subjected to cycling exercise during that period. After 6 weeks, the tibial nerve was stimulated electrically and recordings of M and H waves were made from interosseous muscles of the hind paw. Results show that pyridoxine treatment completely eliminated the H-reflex in spinal intact animals. In contrast, transection paired with pyridoxine treatment resulted in a reduction of the frequency-dependent habituation of the H-reflex that was not affected by exercise. These results indicate that normal Group I and II afferent input is critical to achieve exercise-based reversal of hyper-reflexia of the H-reflex after spinal cord injury.     

Melatonin and cortisol in individuals with spinal cord injury

Study objectivesThe aim of this study was to investigate circadian rhythm and sleep complaints in individuals with spinal cord injury (SCI) as determined by diurnal saliva melatonin and cortisol as well as activity measurements and subjective sleep quality.MethodsFourteen patients with cervical SCI (cSCI), six patients with thoracic SCI (tSCI) and eight able-bodied controls all underwent two consecutive weeks wearing a wrist actigraph in addition to filling out a sleep diary. During one 24-h period, cortisol and melatonin were measured at 4-h intervals. Furthermore, participants’ sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and their overall daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS).ResultsThe cSCI group demonstrated lower melatonin levels compared with the tSCI group and the controls at the 24:00 and 04:00 time points. Moreover, at one time point the tSCI group had a higher cortisol level than the cSCI group and the controls. In addition, baseline systolic blood pressure and oxygen saturation were significantly lower in the cSCI group. No differences were found in activity measurements or self-reported sleep quality.ConclusionsIndividuals with cSCI demonstrate reduced melatonin secretion compared with tSCI individuals, but not in other circadian measures. This supports an involvement of melatonergic cervical fibers associated with the cervical lesion.     

胚胎脊髓移植在恢复损伤脊髓传导功能中的作用

目的：探讨胚胎脊髓移植在恢复损伤脊髓传导功能中的作用。方法：将Ｅ１４胚胎脊髓植入成鼠损伤脊髓后３０、４５、６０天时，用单位放电记录技术观察了正常脊髓神经元和移植物神经元的自发放电活动，及其对刺激坐骨神经、红核和同时刺激的反应。结果：正常脊髓神经元的自发单位放电多是一个低频的单发脉冲活动。无论选择那种刺激方式，都可见兴奋、抑制和无反应三种反应。术后３０天时，胚胎神经元的自发单位放电以高频电脉冲活动为主，簇状放电所占比例较大，对刺激有反应的放电单位数也较少；随着动物存活时间的延长，这些单位放电的情况逐渐向着低频、单脉冲以及高反应率的方向发展。至术后６０天时，胚胎神经元单位放电的频率、形式以及对刺激的反应情况都变得和正常神经元的相似。结论：胚胎神经元移植后经历了一个逐渐发育分化过程，在这个过程中它们有可能逐渐和宿主神经元形成了功能性突触连接。     

促甲状腺释放激素类似物YM-14673对大鼠脊髓损伤后水肿的影响

目的研究促甲状腺释放激素（ＴＲＨ）类似物,ＹＭ－１４６７３大鼠脊髓损伤后水肿的影响。方法用改良Ａｌｌｅｎ氏法建立大鼠脊髓损伤模型,分设正常组、对照组和治疗组,治疗组在损伤后１５分钟注射ＹＭ－１４６７３,用称重法测量脊髓的水含量,公式：（湿重－干重）÷湿重×１００％。结果对照组示伤后２４小时脊髓水肿,治疗组显示在２４小时脊髓水肿减轻。结论早期应用ＴＲＨ类似物,ＹＭ-１４６７３可减轻脊髓损伤后的脊随水肿。     

The combined effects of clonidine and cyproheptadine with interactive training on the modulation of locomotion in spinal cord injured subjects

The combined effects of a noradrenergic agonist, clonidine, and a serotonergic antagonist, cyproheptadine, together with an interactive locomotor training program incorporating progressive body weight support and treadmill walking exercise, were investigated in two chronic spinal cord injured subjects. Both subjects had no independent locomotor ability due to severe spasticity. Kinematic, temporal distance and electromyographic (EMG) data were collected during treadmill walking. The EMG activity of the lower limb muscles, initially characterized by tonic discharge and abnormal timing, became more phasic with less clonus following medication, which was related to a change in the kinematic pattern. Further kinematic and functional improvement were gained by training. Previously wheelchair-bound, both patients became functionally ambulatory overground with the aid of Canadian crutches. Thus, a potentially effective strategy for facilitating the expression of the locomotor pattern following spinal cord injury is proposed. This preliminary study showed that such a treatment strategy could possibly lead to a recovery of locomotor function in some chronic, wheelchair-bound spinal cord injured patients who had previously been stabilized on conventional therapies.     

人参皂甙对损伤脊髓诱发电位的影响

目的　研究猫急性脊髓损伤 (SCI)后脊髓诱发电位 (SCEP)的变化规律及人参皂甙 (GS)对其的影响 ,探讨 GS对 SCI的作用 ,旨在寻求治疗 SCI的新方法。方法　采用改良 Allen氏重量打击法制作猫急性脊髓损伤模型 ,动物随机分组 ,通过电生理及病理学方法 ,研究 SCEP的变化规律及 GS对其的影响 ,脊髓形态学的改变作为进一步的佐证。结果　 (1)损伤组伤后 SCEP辐值随时间延长逐渐变小 ,潜伏期逐渐延长 ;治疗组波形则逐渐恢复 ,6 h全部恢复 ,差异显著。(2 )光镜下两组均有水肿、中心性出血 ,神经元空泡变性 ,核溶解或固缩 ,尼氏小体消失 ,部分神经纤维脱髓鞘或断裂 ,损伤组最重 ,治疗组均有不同程度的恢复。结论　 GS对 SCI有治疗作用。     

脊髓损伤早期手术及康复训练的疗效分析

目的介绍脊髓损伤早期脊髓探查和脊髓软化切开手术的术式和术后步行训练方法并分析其疗效。方法对40例完全性脊髓损伤30 d内的患者行脊柱脊髓损伤早期联合手术方式:一次性完成椎体内固定、松解硬脊膜下粘连、脊髓内外彻底清创减压,从而减轻脊髓二次损伤,保护神经细胞和残存神经纤维;术后辅以个体化脊柱固定减负背心,开展伤后早期康复训练;术后进行6个月的定期脊髓功能评价。结果术中术后未发生手术部位大出血、感染、残损加重等并发症。术后6个月,美国脊柱损伤协会(ASIA)残损分级A级17例、B级5例、C级11例、D级7例。ASIA评分:平均运动提高16.7分、针刺觉提高10.32分、轻触觉提高11.52分。结论在脊髓损伤早期行脊髓探查和脊髓软化切开手术是安全有效的,可恢复部分患者的部分脊髓功能。     

Passive exercise and fetal spinal cord transplant both help to restore motoneuronal properties after spinal cord transection in rats

Spinal cord transection influences the properties of motoneurons and muscles below the lesion, but the effects of interventions that conserve muscle mass of the paralyzed limbs on these motoneuronal changes are unknown. We examined the electrophysiological properties of rat lumbar motoneurons following spinal cord transection, and the effects of two interventions shown previously to significantly attenuate the associated hindlimb muscle atrophy. Adult rats receiving a complete thoracic spinal cord transection (T-10) were divided into three groups receiving: (1) no further treatment; (2) passive cycling exercise for 5 days/week; or (3) acute transplantation of fetal spinal cord tissue. Intracellular recording of motoneurons was carried out 4-5 weeks following transection. Transection led to a significant change in the rhythmic firing patterns of motoneurons in response to injected currents, as well as a decrease in the resting membrane potential and spike trigger level. Transplants of fetal tissue and cycling exercise each attenuated these changes, the latter having a stronger effect on maintenance of motoneuron properties, coinciding with the reported maintenance of structural and biochemical features of hindlimb muscles. The mechanisms by which these distinct treatments affect motoneuron properties remain to be uncovered, but these changes in motoneuron excitability are consistent with influences on ion conductances at or near the initial segment. The results may support a therapeutic role for passive limb manipulation and transplant of stem cells in slowing the deleterious responses of motoneurons to spinal cord injury, such that they remain more viable for subsequent alternative strategies.     

胸腰椎骨折合并脊髓神经损伤功能锻炼的临床护理

目的探讨胸腰椎骨折合并脊髓神经损伤患者功能锻炼的临床护理方法及效果。方法选取我院2011-06—2013-12 55例胸腰椎骨折合并脊髓神经损伤患者,设为研究组,给予系统功能锻炼方法护理。选取同期55例常规功能锻炼护理的胸腰椎骨折合并脊髓神经损伤患者为对照组,观察2组护理效果。结果研究组康复恢复率为80.0%,对照组康复恢复率为49.1%,研究组明显的高于对照组,差异有统计学意义(P0.05);研究组并发症发生率为3.6%,对照组为14.5%,差异有统计学意义(P0.05)。结论胸腰椎骨折合并脊髓神经损伤患者实施系统化的功能锻炼护理能够有效的促进功能恢复,降低并发症,值得临床应用。     

Effect of strenuous arm exercise on oxidized-LDL-potentiated platelet activation in individuals with spinal cord injury

This study investigates how strenuous arm exercise affects oxidized-low density lipoprotein (O(X)-LDL) mediated-platelet activation in patients with SCI. Ten patients with SCI and ten age- and sex-matched healthy subjects exercised strenuously using an arm crank ergometer. The following measurements were taken both when the subjects were at rest, and immediately after exercise: plasma lipid profile, O(X)-LDL mediated platelet aggregability and [Ca(2+)]i, urinary 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 8-iso-prostaglandin F(2alpha), (8-iso-PG F(2alpha)) contents, and plasma NO metabolite (nitrite plus nitrate) level. Based on these measurements, the major findings of this study can be summarized as follows: 1) the SCI group had higher urinary 8-iso-PGF(2alpha) and 11-dehydro-TXB2 contents, but a lower plasma nitrite plus nitrate level than the control group; 2) at rest, the SCI group had a higher platelet aggregability and [Ca(2+)]i, and O(X)-LDL-potentiated platelet activation than the control group; 3) O(X)-LDL-potentiated platelet aggregation was enhanced by strenuous arm exercise in both groups, but the effect of exercise was more pronounced in the SCI group than in the control group; 4) treating the platelet with L-arginine inhibited O(X)-LDL-potentiated platelet activation in both groups. The study concludes that individuals with SCI had more extensive resting and exercise-enhanced O(X)-LDL-potentiated platelet activation and greater amounts of preformed lipid peroxides than those without SCI. Therefore, supplementation therapy with antioxidants may be needed for patients with SCI, especially in a strenuous arm exercise period.     

Robot-assisted gait training in individuals with spinal cord injury: A systematic review for the clinical effectiveness of Lokomat

BackgroundSpinal cord injury (SCI) is a critical medical condition that causes numerous impairments leading to accompanying disability. Robotic-assisted gait training (RAGT) offers many advantages, including the capability to increase the intensity and total duration of training while maintaining a physiological gait pattern. The effects of the RAGT ‘Lokomat’ on various impairments following SCI remain unclear.ObjectivesThis review was conducted to examine the impacts of the RAGT ‘Lokomat’ on the impairments following SCI.MethodsWe searched PubMed, SCOPUS, PEDro, REHABDATA, MEDLINE, EMBASE, and web of science from inception to January 2021. Experimental studies examining the effects of the Lokomat on the impairments following incomplete SCI were selected. The methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale.ResultsSixteen studies were met the inclusion criteria. Thirteen were randomized controlled trials, two were clinical trials, and one was a pilot study. The scores on the PEDro scale ranged from two to eight, with a median score of six. The results showed evidence for the beneficial effects of the Lokomat on many motor impairments following incomplete SCI.ConclusionsThe Lokomat may improve gait speed, walking distance, strength, range of motion, and mobility after incomplete SCI. There is insufficient evidence for the effect of the Lokomat on balance, depression, cardiorespiratory fitness, and quality of life. The effects of the Lokomat on the lower extremity spasticity were limited.     

Exercise restores levels of neurotrophins and synaptic plasticity following spinal cord injury

We have conducted studies to determine the potential of exercise to benefit the injured spinal cord using neurotrophins. Adult rats were randomly assigned to one of three groups: (1) intact control (Con); (2) sedentary, hemisected at a mid-thoracic level (Sed-Hx), or (3) exercised, hemisected (Ex-Hx). One week after surgery, the Ex-Hx rats were exposed to voluntary running wheels for 3, 7, or 28 days. BDNF mRNA levels on the lesioned side of the spinal cord lumbar region of Sed-Hx rats were approximately 80% of Con values at all time points and BDNF protein levels were approximately 40% of Con at 28 days. Exercise compensated for the reductions in BDNF after hemisection, such that BDNF mRNA levels in the Ex-Hx rats were similar to Con after 3 days and higher than Con after 7 (17%) and 28 (27%) days of exercise. After 28 days of exercise, BDNF protein levels were 33% higher in Ex-Hx than Con rats and were highly correlated (r=0.86) to running distance. The levels of the downstream effectors for the action of BDNF on synaptic plasticity synapsin I and CREB were lower in Sed-Hx than Con rats at all time points. Synapsin I mRNA and protein levels were higher in Ex-Hx rats than Sed-Hx rats and similar to Con rats at 28 days. CREB mRNA values were higher in Ex-Hx than Sed-Hx rats at all time points. Hemisection had no significant effects on the levels of NT-3 mRNA or protein; however, voluntary exercise resulted in an increase in NT-3 mRNA levels after 28 days (145%). These results are consistent with the concept that synaptic pathways under the regulatory role of BDNF induced by exercise can play a role in facilitating recovery of locomotion following spinal cord injury.     

大鼠脊髓损伤后巢蛋白表达

目的探讨成年大鼠脊髓损伤后损伤区局部巢蛋白（nestin）的表达及意义。方法应用Allen＇s法建立大鼠脊髓拟伤模型，行为学评分采用BBB评分（Basso，Beattie＆Bresnahan locomotor rating scale，BBB scale），观察局部病理组织学改变及用免疫荧光组织化学方法检测局部脊髓在不同时段nestin的阳性表达变化。结果伤后1w BBB评分最低，随后增加，到4w以后达到最高并进入平台期。常规病理学检查显示拟伤模型类似于临床常见的脊髓损伤。损伤后1W，可见损伤区附近nestin表达升高，2W达高峰，4W后nestin表达明显下调。结论脊髓损伤可诱导损伤区周围短暂的nestin阳性表达，后者可能存在脊髓损伤后的再生与修复中起重要作用。     

Experimental studies on spinal cord injuries in the last fifteen years

Abstract

Experimental studies on spinal cord (SC) injuries published from 1975 to 1989 in some of the most widely circulating neurosurgical journals were reviewed. The relatively large number of animal species utilized as well as the intensely variable dynamic or static methods employed to induce SC injury represent elements of confusion more than objective necessities in this field of research. In fact, the objective of SC injury research should be to solve the problem of severe SC injuries by either preventing and/or repairing SC damage, rather than looking for modalities to provoke a large spectrum of SC injuries with the result of establishing a correlation between for example, the clinical picture and trauma magnitude. It should be time to study all variables and treatments mainly in only one experimental model. The rat with a permanent paraplegia should represent such a model; the abdominal aorta occlusion for 45 minutes, distal to the renal arteries in rabbits should be the experimental model of choice for ischaemia. If a significant result, such as reversing permanent paraplegia, were obtained in rats, it would be logical to repeat the study in higher mammals and if successful' in humans. For the last decade of this century it is necessary to further study all the mechanisms implied in secondary SC damage as well as to attempt to repair definitive SC damage by using grafts and enhancing the potential regenerative ability of the SC with known and new growth factors. Presently, methylprednisolone, dexametasone, thiopental, naloxone, and hypothermia seem to have some clinical potentials that require studies in humans.     

功能锻炼在胸腰椎骨折合并脊髓损伤患者护理工作中的应用

目的探讨功能锻炼在胸腰椎骨折合并脊髓损伤患者护理工作中的应用。方法回顾性分析我院2014-05—2015-05收治的90例胸腰椎骨折合并脊髓损伤患者的临床资料,按照就诊时间顺序分为常规护理组与功能锻炼组,每组45例,对比2组康复情况、并发症发生率、焦虑抑郁评分。结果常规护理的康复恢复率为62.22%,功能锻炼组为82.22%,功能锻炼组的康复恢复率明显高于常规护理组,差异具有统计学意义(χ2=4.79,P0.05)。常规护理组并发症发生率为22.22%,功能锻炼组为8.89%,功能锻炼组的并发症发生率明显低于常规护理组,差异具有统计学意义(χ2=4.62,P0.05)。锻炼组焦虑评分与抑郁评分相比均明显低于常规护理组,差异具有统计学意义(t=4.32,P0.05;t=4.52,P0.05)。结论于常规护理基础上加用功能锻炼护理可提高胸腰椎骨折合并脊髓损伤患者的康复效果,降低并发症发生率,降低焦虑抑郁评分,值得推广与应用。     

Effect of submaximal and incremental upper extremity exercise on platelet function and the role of blood shear stress

Introduction: Platelets are involved in the pathogenesis of atherosclerosis. Although physical exercise is recommended to prevent atherosclerosis, the effect of exercise on platelet function and the underlying mechanisms of these effects are not completely understood. Accordingly, we aimed to examine the effect of different intensities acute arm exercises on platelet function. In addition, we evaluated the effect of lipid peroxidation and fluid shear rate on platelet response. Materials and methods: Twenty four healthy sedentary male volunteers aged 18–24 years performed submaximal and incremental exercises by upper extremity ergometer. The shear rate in the right artery was measured by Power Doppler Ultrasound (US) at rest and immediately after exercise. Pre and postexercise maximum intensities of ADP and collagen-induced platelet aggregation were measured using the impedance technique. Bioluminescent detection of thrombin-induced platelet ATP release and measurement of thromboxane B₂ (TxB₂) levels (as a marker of thromboxane A₂ (TxA₂) formation) by enzyme-linked immunoassay were performed before and after exercise. Results and conclusion: Shear rate increased after both submaximal and incremental exercise. Collagen-induced platelet aggregation increased after submaximal exercise, while ADP-induced aggregation and thromboxane B₂ levels did not alter with this protocol. Incremental exercise caused increased collagen and ADP-induced platelet aggregation and thromboxane B₂ levels. Neither of the protocols altered platelet ATP release. It was shown that acute upper extremity exercise increased platelet aggregation, without an increase in platelet release. Collagen-induced signalling pathways were more sensitive than those induced by ADP. The increase in thromboxane B₂ after incremental exercise implied increase in thromboxane A₂ formation and lipid peroxidation. Despite a significant correlation between platelet aggregation and thromboxane B₂ levels at rest, we found no clear-cut relationship between thromboxane A₂ formation, blood shear rate and platelet response to exercise.     

The effect of locomotor training combined with functional electrical stimulation in chronic spinal cord injured subjects: walking and reflex studies

With the new developments in traumatology medicine, the majority of spinal cord injuries sustained are clinically incomplete and the proportion is likely to continue to rise. Thus, it is necessary to continue to develop new treatment and rehabilitation strategies and understand the factors that can enhance recovery of walking following spinal cord injury (SCI). One new development is the use of functional electrical stimulation (FES) device to assist locomotion. The objective of this review is to present findings from some recent studies on the effect of long-term locomotor training with FES in subjects with SCI. Promising results are shown in all outcome measures of walking, such as functional mobility, speed, spatio–temporal parameters, and the physiological cost of walking. Furthermore, the change in the walking behavior could be associated with plasticity in the CNS organization, as seen by the modification of the stretch reflex and changes in the corticospinal projection to muscles of the lower leg. In conclusion, recovery of walking is an increasing possibility for a large number of people with SCI. New modalities of treatment have become available for this population but most still need to be evaluated for their efficacy. This review has focused on FES assisted walking as a therapeutic modality in subjects with chronic SCI, but it is envisaged that the care and recovery of SCI in the early phase of recovery could also be improved.