Methodological considerations for near-infrared spectroscopy to assess mitochondrial capacity after spinal cord injury

Background: Skeletal muscle mitochondrial activity is reduced by?～?50–60% after SCI, resulting in impaired energy expenditure, glucose utilization and insulin sensitivity. Near infra-red spectroscopy (NIRS) is a non-invasive tool that can be used to assess mitochondrial capacity.

Objectives: (1) Highlight methodological limitations impacting data acquisition and analysis such as subcutaneous adipose tissue (SAT) thickness, movement artifacts, inadequate muscle stimulation, light interference, and ischemic discomfort. (2) Provide technical considerations to improve data acquisition and analysis. This may serve as guidance to other researchers and clinicians using NIRS.

Study Design: cross-sectional observational design.

Settings: Clinical research medical center.

Participants: Sixteen men with 1?>?year post motor complete SCI.

Methods: NIRS signals were obtained from right vastus lateralis muscle utilizing a portable system. Signals were fit to a mono-exponential curve.

Outcome Measures: Rate constant and r ² values for the fit curve, indirectly measures mitochondrial capacity.

Results: Only four participants produced data with accepted rate constants of 0.002–0.013?s^?1 and r ² of 0.71–0.87. Applications of studentized residuals ≥2.5 resulted in sparing data from another four participants with rate constants of 0.010–0.018?s^?1and r ² values ranging from 0.86–0.99.

Conclusions: Several limitations may challenge the use of NIRS to assess mitochondrial capacity after SCI. Acknowledging these limitations and applying additional data processing techniques may overcome the discussed limitations and facilitate data sparing.     

The effects of cryotherapy on athletes’ muscle strength,flexibility, and neuromuscular control: A systematic review of the literature

PurposeThis review aimed to investigate the effects of cryotherapy on the functional capacity parameters of athletes, such as muscular strength, flexibility, neuromuscular control, and balance.MethodsA computerized search of EBSCO Host databases, Proquest, Medline, SportDiscus, CinahlPlus, Health Source Nursing/Academic Edition, Academic Search Complete, and GoogleScholar databases was performed to identify clinical trials with a focus on cryotherapy applications in sport. Thekeywords used were “cryotherapy,” “sports,”“strength,”“flexibility,” and “proprioception.”Study selectionRandomized control trials and randomized crossover studies of healthy athletes were included in this review. The methodological quality of the studies was assessed by the validation criteria given by Furlan et al (2009).ResultsA total of 50 randomized controlled trials (RCTs) and randomized crossover studies met the above criteria and were included in the final analysis. The studies available indicate that there is no strong research evidence to suggest that cryotherapy can definitely influence joint strength and neuromuscular control. The only positive effect of cryotherapy appears to be an improvement in joint flexibility.ConclusionsLimited and equivocal evidence is available to address the effect of cryotherapy on muscular function. The only evidence-based positive impact after the applications of cryotherapy is improved joint flexibility. Despite the extensive use of cryotherapy in sports, further research is needed to document the actual effects of cryotherapy applications on athletes' functional performance and rehabilitation parameters.     

腰椎间盘突出症动物模型的研究进展

近年来,腰椎间盘突出症发病率逐渐增高,由于动物模型对于阐明疾病发病机制及评估新的治疗方法具有重要作用,越来越多的学者开始研究如何建立合适的、能够更好地模拟人类腰椎间盘突出的动物模型。近期的研究多选用包括大鼠、兔、羊、猪等动物作为实验对象,通过物理或化学方式直接损伤其椎间盘或神经根,或通过限制实验动物的行为动作、改变其饲养环境以及性别年龄导致的生理因素等方式诱导其出现椎间盘退变。各种造模方法均有其特点及局限性,适用于不同情况,有必要继续完善。     

Ghrelin attenuates secondary brain injury following intracerebral hemorrhage by inhibiting NLRP3 inflammasome activation and promoting Nrf2/ARE signaling pathway in mice

Ghrelin, a brain-gut peptide, has been proven to exert neuroprotection in different kinds of neurological diseases; however, its role and the potential molecular mechanisms in secondary brain injury (SBI) after intracerebral hemorrhage (ICH) are still unknown. In this study, we investigate whether treatment with ghrelin may attenuate SBI in a murine ICH model, and if so, whether the neuroprotective effects are due to the inhibition of nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation and promotion of nuclear factor-E2-related factor 2 (Nrf2)/antioxidative response element (ARE) signaling pathway. Stereotactically intrastriatal infusion of autologous blood was performed to mimic ICH. Ghrelin was given intraperitoneally immediately following ICH and again 1 h later. Results showed that ghrelin attenuated neurobehavioral deficits, brain edema, hematoma volume, and perihematomal cell death post-ICH. Ghrelin inhibited the NLRP3 inflammasome activation and subsequently suppressed the neuroinflammatory response as evidenced by reduced microglia activation, neutrophil infiltration, and pro-inflammatory mediators release after ICH. Additionally, ghrelin alleviated ICH-induced oxidative stress according to the chemiluminescence of luminol and lucigenin, malondialdehyde (MDA) content, and total superoxide dismutase (SOD) activity assays. These changes were accompanied by upregulation of Nrf2 expression, Nrf2 nuclear accumulation, and enhanced Nrf2 DNA binding activity, as well as by increased expressions of Nrf2 downstream target antioxidative genes, including NAD(P)H quinine oxidoreductase-1 (NQO1), glutathione cysteine ligase regulatory subunit (GCLC), and glutathione cysteine ligase modulatory subunit (GCLM). Together, our data suggested that ghrelin protected against ICH-induced SBI by inhibiting NLRP3 inflammasome activation and promoting Nrf2/ARE signaling pathway.     

CSF-1R inhibition attenuates ischemia-induced renal injury and fibrosis by reducing Ly6C+ M2-like macrophage infiltration

Acute kidney injury (AKI) to chronic kidney disease (CKD) progression has become a life-threatening disease. However, an effective therapeutic strategy is still needed. The pathophysiology of AKI-to-CKD progression involves chronic inflammation and renal fibrosis driven by macrophage activation, which is physiologically dependent on colony-stimulating factor-1 receptor (CSF-1R) signaling. In this study, we modulated macrophage infiltration through oral administration of the CSF-1R inhibitor GW2580 in an ischemia–reperfusion (I/R)-induced AKI model to evaluate its therapeutic effects on preventing the progression of AKI to CKD. We found that GW2580 induced a significant reduction in the number of macrophages in I/R-injured kidneys and attenuated I/R-induced renal injury and subsequent interstitial fibrosis. By flow cytometry, we observed that the reduced macrophages were primarily Ly6C⁺ inflammatory macrophages in the GW2580-treated kidneys, while there was no significant difference in the number and percentage of Ly6C⁻CX3CR1⁺ macrophages. We further found that these reduced macrophages also demonstrated some characteristics of M2-like macrophages, which have been generally regarded as profibrotic subtypes in chronic inflammation. These results indicate the existence of phenotypic and functional crossover between Ly6C⁺ and M2-like macrophages in I/R kidneys, which induces AKI worsening to CKD. In conclusion, therapeutic GW2580 treatment alleviates acute renal injury and subsequent fibrosis by reducing Ly6C⁺ M2-like macrophage infiltration in ischemia-induced AKI.     

Community exercise programing and its potential influence on quality of life and functional reach for individuals with spinal cord injury*

Context/Objective: After an individual with a Spinal Cord Injury (SCI) participates in the initial rehabilitation process, they often experience limited access to physical therapy services and other fitness activities. The purpose of this study was to examine previously collected data for changes in quality of life (QoL) and functional reach in individuals with SCI following an 8-week community exercise program.

Design: Secondary analysis of previously collected data.

Setting: Community-based exercise program.

Participants: Twenty-two participants with an average of 9 years post-SCI, both complete and incomplete injuries, and injury levels ranging from C2 to L5.

Interventions: Participants completed an 8-week program, once per week for 4 hours that included a four-station circuit of resistance training, aerobic exercise, trunk stability, and education.

Outcome Measures: Physical function was measured using the modified Functional Reach Test (mFRT). QoL was measured with the Life Satisfaction Questionnaire-9 (LiSAT-9).

Results: The mFRT improved by 2 inches (±7.04) P?<?0.001 and QoL improved as well, P?<?0.001.

Conclusion: The findings of this study are consistent with the hypothesis that a supervised post-rehabilitation community exercise program, like Spinal Mobility, may positively impact the QoL and functional reach in individuals with SCI.     

A brief fall prevention intervention for manual wheelchair users with spinal cord injuries: A pilot study

Objective: To conduct a pilot study of an intervention to decrease fall incidence and concerns about falling among individuals living with Spinal Cord Injury who use manual wheelchairs full-time.

Design: Pre/post. After a baseline assessment, a structured intervention was implemented. The assessment protocol was repeated 12 weeks after the baseline assessment.

Setting: Research laboratory and community.

Participants: 18 individuals living with SCI who use a manual wheelchair full-time with an average age of 35.78?±?13.89 years, lived with SCI for 17.06?±?14.6 years; 61.1% were female.

Intervention: A 1:1, 45 minute, in-person intervention focused on factors associated with falls and concerns about falling: transfers skills and seated postural control.

Outcome measures: Participants reported fall incidence and completed the Spinal Cord Injury Fall Concerns Scale, Community Participation Indicators and the World Health Organization Quality of Life – short version (WHOQOL-BREF). Transfer quality was assessed with the Transfer Assessment Instrument (TAI) and seated postural control with the Function In Seating Test (FIST).

Results: Recruitment, assessment and delivery of the intervention were successfully completed. After exposure to the intervention, fall incidence significantly decreased, (P?=?0.047, d_{z ?}=?0.507) and FIST scores improved (P?=?0.035, d_z? =?0.54). Significant improvements were also found in the WHOQOL-BREF Physical (P?=?0.05, d_{z ?}=?1.566) and Psychological (P?=?0.040, d_{z ?}=?0.760) domains.

Conclusion: The feasibility of the structured intervention was established and the intervention has the potential to reduce fall incidence and improve quality of life among individuals living with SCI who use a wheelchair. Appropriately powered randomized controlled trials of the program are warranted.     

Combining robotic exoskeleton and body weight unweighing technology to promote walking activity in tetraplegia following SCI: A case study

Context: To investigate the feasibility of combining the lower-limb exoskeleton and body weight unweighing technology for assisted walking in tetraplegia following spinal cord injury (SCI).

Findings: A 66-year-old participant with a complete SCI at the C7 level, graded on the American Spinal Injury Association Impairment Scale (AIS) as AIS A, participated in nine sessions of overground walking with the assistance from exoskeleton and body weight unweighing system. The participant could tolerate the intensity and ambulate with exoskeleton assistance for a short distance with acceptable and appropriate gait kinematics after training.

Conclusion: This report showed that using technology can assist non-ambulatory individuals following SCI to stand and ambulate with assistance which may promote general physical and psychological health if used in the long term.