Administration of corticosteroids for acute spinal cord injury: the current practice of trauma medical directors and emergency medical system physician advisors

Effects of albiflorin on oxidative stress and inflammatory responses in rats with acute spinal cord injury

INTRODUCTION

Oxidative stress and inflammatory responses are often the predominant detrimental factors associated with spinal cord injury (SCI). This study investigates the potential therapeutic effects of albiflorin (AF) on alleviating inflammation and oxidative stress in the rat model with SCI.

METHODS

Initially, the behavior of SCI-induced rats is examined by Basso-Beattie-Bresnahan score and the inclined plane examination. Then, the immunohistochemical staining of inflammasome-related protein (for instance, NACHT, LRR, and PYD domains-containing protein 3, NLRP3) is performed in combination with enzyme-linked immunosorbent assay (ELISA) of corresponding proinflammatory factors to assess the immunomodulatory effects of AF. Further, the markers involved in oxidative stress are examined by ELISA and western blot analysis analyses.

RESULTS

These findings indicated that AF could alleviate motor dysfunction and the loss of neuron cells in SCI-induced rats. Mechanistically, AF could attenuate the inflammatory responses by reducing oxidative stress and activating nuclear erythroid-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in SCI rats. Depleting the antioxidant capacity by inhibiting glutathione biosynthesis could counteract the anti-inflammatory activity of AF in SCI rats.

CONCLUSIONS

Together, our data suggested that AF could serve as a potential therapeutic agent against the aggravation of SCI in rats.

Sesamol-loaded stearic acid-chitosan nanomicelles mitigate the oxidative stress-stimulated apoptosis and induction of pro-inflammatory cytokines in motor neuronal of the spinal cord through NF-ĸB signaling pathway

As natural potential antioxidants suffer from low cellular uptake, the development of drug-loaded nanoplatforms may provide useful information about the treatment of spinal cord injury (SCI). In the present study, sesamol (SM)-loaded stearic acid (SA) -chitosan (CS) nanomicelles were fabricated and well-characterized. Afterwards, the neuroprotective effects of SM@SA-CS nanomicelles against lipopolysaccharide (LPS)-induced oxidative stress in NSC-34 cells was assessed by different cellular and molecular pathways. It was deduced that the size of synthesized SM@SA-CS was in the range of 10-20 nm and the hydrodynamic radii of SA-CA and SM@SA-CA nanomicelles were 53.12 ± 6.21 nm and 59.12 ± 7.31 nm, respectively. Furthermore, SM@SA-CS nanomicelles displayed a sustained drug release at physiological pH, potential dissolution rate and stability even up to 15 days. Cellular assay showed that SM@SA-CS nanomicelles co-incubation with LPS for 24 h in comparison with free drug remarkably regulated cell survival, membrane leakage, generation of ROS, activity of non-enzymatic and enzymatic antioxidant systems, and apoptotic and inflammatory signaling pathway through NF-ĸB signaling pathway. These data indicated that SM@SA-CS nanomicelles can be developed as a promising platform for the mitigation of oxidative stress-mediated apoptosis in neural cells.

A rabbit model of lumbar distraction spinal cord injury

BACKGROUND CONTEXT

Excessive spinal distraction is a major cause of distraction spinal cord injury (SCI) during spinal deformity correction surgery. However, the lack of animal models of gradable and replicable distraction SCI has hampered research about how it occurs and how it can be prevented. The rabbit is a suitable choice for a model because it is more similar to humans than the rat, the most often used for studies of distraction SCI. The rabbit is readily acquired and reasonably affordable to maintain.

PURPOSE

The study aims to develop a gradable and replicable animal model of human lumbar distraction SCI.

STUDY DESIGN

This is an animal laboratory study.

METHODS

We built a spine distractor designed to vary the percentage of spine distraction by changing the movement between the bony landmarks of the spine. Anesthetized rabbits underwent surgery to expose the vertebral segments from T12 through L4. The distractor was mounted onto the T12 and L4 vertebral segments, and distraction was effected by turning the distractor's central screw to 0% (control), 10%, 20%, or 30% of the length from the L1 to the L4 vertebral segments, with eight rabbits in each group. Cortical somatosensory evoked potentials were recorded, and neurologic function was evaluated before the distractor was mounted and after the distractor was dismounted. The rabbits were killed, and spinal cord samples were taken for biochemical, histopathologic, and stereologic studies.

RESULTS

With increasing percentage distraction, the extent of distraction SCI increased as measured by recordings of cortical somatosensory evoked potentials, neurologic function, and biochemical, histopathologic, and stereologic studies.

CONCLUSIONS

Our model can be widely applied to studies of the causes of and treatment for distraction SCI.

Safety and efficacy of corticosteroid use in neurologic trauma

Neurologic trauma, which consists of acute spinal cord injury and traumatic brain injury, is a leading cause of death and disability. In recent years, there have been improvements in the early recognition and prompt resuscitation of patients with neurologic trauma. However, there remain few pharmacologic treatments to reduce its secondary complications. Corticosteroids have been used in patients with neurologic trauma for more than 5 decades. Traditionally, their use has been to improve motor and sensory recovery. However, recently their utility to prevent and manage trauma-related pneumonia has been investigated. Given these new investigations, the purpose of this review article is to provide a comprehensive overview of the history and available scientific evidence surrounding the use of corticosteroids in neurologic trauma and caution against the use of these agents to prevent hospital-acquired pneumonia in this patient population.

Effects of combining methylprednisolone with rolipram on functional recovery in adult rats following spinal cord injury

Methylprednisolone (MP) has been widely used as a standard therapeutic agent for the treatment of spinal cord injury (SCI). Because of its controversial beneficial effects, the combination of MP and other pharmacological agents aimed at enhancing functional recovery is desirable. The phosphodiesterase 4 (PDE4) inhibitor rolipram has been implicated in promotion of regeneration due to elevating cAMP. In the present study, we sought to determine the effects of MP and rolipram, administered in combination, after spinal cord injury (SCI) in adult rats. Here we show that in vitro administration of rolipram and MP significantly increased neuron survival and promoted neurite outgrowth of neurons on the inhibitory substrate CSPGs by upregulation of MMP-2 expression; in vivo administration of rolipram and MP inhibited CSPG expression and increase CSPG digestion after rat SCI. Rolipram and MP combining treatment promoted significant neuroprotection through reduced motoneuron death, minimized lesion cavity, and increased regeneration of lesioned corticospinal tract (CST) axons beyond the lesion site after SCI. Enhanced functional recovery was also observed. Overall, our study strongly suggested that the combination treatment of MP and rolipram may represent a promising strategy for clinically applicable pharmacological therapy for rapid initiation of neuroprotection after SCI.

A review: the role of high dose methylprednisolone in spinal cord trauma in children

BACKGROUND

The use of steroids in traumatic spinal cord injury (SCI) in children is controversial. There is a paucity of literature on its usage. To help clarify recommendations on steroid use in children, we reviewed the current literature on the administration of high dose methylprednisolone (MP) use in traumatic spinal cord injuries with an emphasis in pediatric spinal cord trauma.

METHODS

A retrospective review of the current literature on traumatic spinal cord injuries was conducted. Outcomes were critically reviewed from the National Acute Spinal Cord Injury Studies (NASCIS) II and III and Cochrane review; as well as, other randomized and retrospective studies. Papers describing objective neurological outcomes were only included.

RESULTS

The outcomes of neurological improvement following steroid infusion have not been reproducible outside of the NASCIS and one single Japanese trial. High dose steroids significantly increase the risk of infections leading to prolonged hospital stay and ventilator dependence.

CONCLUSION

Data from adult studies remains controversial with insufficient data to support administration of MP for treatment of traumatic spinal cord injuries. Randomized controlled trials are needed in the pediatric population to assess the advantages of steroid use after SCI in children. On the basis of the current evidence, the use of steroids in patients is associated with increased infectious risks and no neurological improvements.

Body cooling ameliorating spinal cord injury may be neurogenesis-, anti-inflammation- and angiogenesis-associated in rats

BACKGROUND

Body cooling (BC) or mild hypothermia therapy (about 33°C) is reportedly effective for spinal cord injury (SCI). However, the mechanisms underlying the beneficial effects of BC remain unclear, so does BC ameliorating SCI via promoting neurogenesis, anti-inflammation, and angiogenesis.

METHODS

The standard rat compression SCI model was tested hypothetically in two groups: one receiving BC (33°C) and the other, normothermia (37°C). Afterward, the effects of BC therapy on the hind limb locomotion, spinal cord infarction and apoptosis, angiogenesis, neurogenesis, and inflammation in these two groups of SCI were assessed. The other group of sham SCI was used as controls.

RESULTS

Apoptosis (evidenced by higher numbers of terminal deoxynucleotidyl- transferase-mediated and duDP-biotin nick end-labeling-positive cells), infarct, activated inflammation (evidenced by higher levels of tumor necrosis factor-α, interleukin-1β, and myeloperoxidase), and hind limb locomotor dysfunction were inspected in the untreated (37°C) SCI rats 4 days after SCI. When compared with those of untreated SCI rats, SCI rats receiving BC (33°C) displayed lower levels of apoptosis, infarct volume, activated inflammation, and hind limb locomotor dysfunction. In addition, that BC promoted both angiogenesis (evidenced by increased numbers of both vascular endothelial growth factors and bromodeoxyuridine-positive endothelial cells) and neurogenesis (evidenced by increased numbers of both glial cell line-derived neurotrophic growth factors and bromodeoxyuridine-neuronal-specific nuclear protein double positive cells) in the injured spinal cord was evaluated 4 days after SCI.

CONCLUSION

BC (33°C) improved SCI outcomes by promoting angiogenesis, neurogenesis, and anti-inflammation in a rat SCI model.

Low dose estrogen prevents neuronal degeneration and microglial reactivity in an acute model of spinal cord injury: effect of dosing, route of administration, and therapy delay

Spinal cord injury (SCI), depending on the severity of injury, leads to neurological dysfunction and paralysis. Methylprednisolone, the only currently available therapy renders limited protection in SCI. Therefore, other therapeutic agents must be tested to maximize neuroprotection and functional recovery. Previous data from our laboratory indicate that estrogen (17β-estradiol) at a high dose may attenuate multiple damaging pathways involved in SCI and improve locomotor outcome. Since use of high dose estrogen may have detrimental side effects and therefore may never be used in the clinic, the current study investigated the efficacy of this steroid hormone at very low doses in SCI. In particular, we tested the impact of dosing (1-10 μg/kg), mode of delivery (intravenous vs. osmotic pump), and delay in estrogen application (15 min-4 h post-SCI) on microgliosis and neuronal death in acute SCI in rats. Treatment with 17β-estradiol (1-10 μg/kg) significantly reduced microglial activation and also attenuated apoptosis of neurons compared to untreated SCI animals. The attenuation of cell death and inflammation by estrogen was observed regardless of mode and time of delivery following injury. These findings suggest estrogen as a potential agent for the treatment of individuals with SCI.

Safety issues and concerns for the neurological patient in the emergency department

INTRODUCTION

Patient safety in our medical system has been an increasing national concern. Neurological patient safety in the emergency department (ED) has not been studied. The purpose of this article is thus to describe the issues relevant to neurological patient safety in the ED, review the current status of the literature, identify specific patient populations at risk, and suggest applicable solutions.

METHODS

Medline and PubMed literature review of key words associated with patient safety, neurological diseases, and EDs.

RESULTS

Little data can be found on overall neurological patient safety in the ED, however data for specific neurological emergencies including subarachnoid hemorrhage, stroke, status epilepticus, and head and spine trauma does exist and is reviewed.

CONCLUSIONS

Limitations in ED education and access to neurological expertise may place some patients at risk. Recommendations for improving neurological patient safety in the EDs are suggested and include a discussion on barriers to implementation.

Anti-Apoptotic Effect of Insulin in the Control of Cell Death and Neurologic Deficit after Acute Spinal Cord Injury in Rats

Recent studies confirmed that the new cell survival signal pathway of Insulin-PI3K-Akt exerted cyto-protective actions involving anti-apoptosis. This study was undertaken to investigate the potential neuroprotective effects of insulin in the pathogenesis of spinal cord injury (SCI) and evaluate its therapeutic effects in adult rats. SCI was produced by extradural compression using modified Allen's stall with damage energy of 40 g-cm force. One group of rats was subjected to SCI in combination with the administration of recombinant human insulin dissolved in 50% glucose solution at the dose of 1 IU/kg day, for 7 days. At the same time, another group of rats was subjected to SCI in combination with the administration of an equal volume of sterile saline solution. Functional recovery was evaluated using open-field walking, inclined plane tests, and motor evoked potentials (MEPs) during the first 14 days post-trauma. Levels of protein for B-cell lymphoma/leukemia-2 gene (Bcl-2), Caspase-3, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified in the injured spinal cord by Western blot analysis. Neuronal apoptosis was detected by TUNEL, and spinal cord blood flow (SCBF) was measured by laser-Doppler flowmetry (LDF). Ultimately, the data established the effectiveness of insulin treatment in improving neurologic recovery, increasing the expression of anti-apoptotic bcl-2 proteins, inhibiting caspase-3 expression decreasing neuronal apoptosis, reducing the expression of proinflammatory cytokines iNOS and COX-2, and ameliorating microcirculation of injured spinal cord after moderate contusive SCI in rats. In sum, this study reported the beneficial effects of insulin in the treatment of SCI, with the suggestion that insulin should be considered as a potential therapeutic agent.

Continuous infusion of methylprednisolone via paediatric parenteral nutrition: A pharmacokinetic animal study

BACKGROUND & AIMS

The aim of our study consisted to measure the pharmacokinetic parameters of methylprednisolone administered in a continuous infusion of a paediatric parenteral nutrition mixture for 24h in the rabbit.

METHODS

Fourteen rabbits were split into two groups and assigned a different administration vehicle (all-in-one or two-in-one nutrition mixture). We used USC PACK* pharmacokinetics software to compare the influence of the composition of the paediatric parenteral nutritional solutions on the values of the pharmacokinetic parameters of methylprednisolone.

RESULTS

Neither the steady-state plasma concentrations of methylprednisolone hemisuccinate nor the values of the pharmacokinetic parameters of methylprednisolone differed significantly when administered in two-in-one or all-in-one nutrition mixtures.

CONCLUSIONS

The composition of the nutritional medium had no discernable effect on the bioavailability of methylprednisolone. Neither the speed at which the steady-state plasma concentration was reached, nor the values of the pharmacokinetic parameters of methylprednisolone were significantly modified.

Signal transduction pathways of GM-CSF in neural cell lines

GM-CSF is recently being suggested to play important role(s) in the nervous system. Present study was intended to understand signal transduction pathways of GM-CSF in human neuroblastoma (SK-N-(BE)2) and glioblastoma (A172) cell lines. The expression of GM-CSF receptors on the surface of these cells was confirmed by immunocytochemistry, Western blot analysis and RT-PCR. When treated for 10min, GM-CSF activated the signal transducer and activator of transcription 5 (STAT5) and extracellular signal regulated kinase (ERK) in both cell lines. However, Janus kinase 2 (JAK2) was activated only in A172 cells but not in SK-N-(BE)2 cells by GM-CSF. The GM-CSF-activated cellular signal pathways were specifically inhibited by the pretreatment of GM-CSF receptor alpha antibody, suggesting the specificity of the signal activation. The experiment using specific inhibitors (AG490) to the JAK/STAT pathway showed that JAK2/STAT5 cascade was well preserved and activated by GM-CSF in A172 cells, while STAT5 was activated by GM-CSF without JAK2 activation in SK-N-(EB)2 cells. The ERK pathway was activated by GM-CSF independently of JAK2 in both cell lines. Finally, GM-CSF showed cytoprotective effect on these cell lines by inhibiting cytotoxicity of saturosporine. The results revealed the signal transduction pathways activated by GM-CSF in neural cells and suggested that GM-CSF might affect the neural functions via these signal pathways.

GM-CSF inhibits apoptosis of neural cells via regulating the expression of apoptosis-related proteins

Recently, we reported that GM-CSF showed therapeutic effects on the spinal cord injury (SCI) in rat model possibly via its anti-apoptotic activity in the nervous system. This study investigated the molecular mechanism of its anti-apoptotic and neuroprotective effects in N2a neuroblastoma cells and in rat SCI model. GM-CSF inhibited staurosporine-induced cytotoxicity and apoptosis of N2a cells. Single administration of GM-CSF either intraperitoneally or locally using a gelfoam, clearly reduced the apoptotic events in the surrounding region of the injury site in rat SCI model. Immunohistochemical analysis showed that apoptosis of cells occurred mainly in the neurons, but not significantly in the astrocytes in the surrounding regions. In both N2a cells and in rat SCI model, GM-CSF actually reduced the expression of pro-apoptotic proteins (p53, p21(WAF1/CIP1) and Bax), while further induced that of an anti-apoptotic protein (Bcl-2). In the Basso-Beattie-Bresnahan (BBB) locomotor test, the single GM-CSF administration showed better behavioral recovery than the untreated control only at early times within 1 week after injury. Overall, GM-CSF was shown to exert its neuroprotective effect on the neural injury by regulating the expression of apoptosis related genes, providing the molecular basis on its anti-apoptotic activity. Longer administration of GM-CSF appeared to be necessary for the sustained functional recovery from SCI.

Methylprednisolone treatment in acute spinal cord injury: the myth challenged through a structured analysis of published literature

BACKGROUND CONTEXT

Methylprednisolone has evolved during the 1990s, through the results obtained from the National Acute Spinal Cord Injury Studies NASCIS II and III, as a standard treatment in acute spinal injury.

PURPOSE

To evaluate the scientific basic for the use of methylprednisolone in acute spinal cord injury.

STUDY DESIGN

Systematic review of the accumulated literature.

METHODS

Critical evaluation of the data obtained in the NASCIS II and III studies plus other accumulated literature.

RESULTS

Analyses have been made on subgroups of the study populations, and the results were based on statistical artefacts. Furthermore, improved functional recovery shown by these studies was not clinically significant.

CONCLUSION

There is insufficient evidence to support the use of methylprednisolone as a standard treatment in acute spinal cord injury.