Bunichiro Izumi

MicroRNA-146a expresses in interleukin-17 producing T cells in rheumatoid arthritis patients

BackgroundInterleukin (IL)-17 is an important factor in rheumatoid arthritis (RA) pathogenesis. MicroRNA (miRNA)s are a family of non coding RNAs and associated with human diseases including RA. The purpose of this study is to identify the miRNAs in the differentiation of IL-17 producing cells, and analyze their expression pattern in the peripheral blood mononuclear cells (PBMC) and synovium from RA patients.MethodsIL-17 producing cells were expanded from CD4+T cell. MiRNA microarray was performed to identify the miRNAs in the differentiation of IL-17 producing cells. Quantitative polymerase chain reaction was performed to examine the expression patterns of the identified miRNAs in the PBMC and synovium from RA and osteoarthritis (OA) patients. Double staining combining in situ hybridization and immunohistochemistry of IL-17 was performed to analyze the expression pattern of identified miRNA in the synovium.ResultsSix miRNAs, let-7a, miR-26, miR-146a/b, miR-150, and miR-155 were significantly up regulated in the IL-17 producing T cells. The expression of miR-146a and IL-17 was higher than in PBMC in the patients with low score of Larsen grade and short disease duration. MiR-146a intensely expressed in RA synovium in comparison to OA. MiR-146a expressed intensely in the synovium with hyperplasia and high expression of IL-17 from the patients with high disease activity. Double staining revealed that miR-146a expressed in IL-17 expressing cells.ConclusionThese results indicated that miR-146a was associated with IL-17 expression in the PBMC and synovium in RA patients. There is the possibility that miR-146a participates in the IL-17 expression.

Responses of microRNAs 124a and 223 following spinal cord injury in mice.

Study design:We investigated microRNA (miRNA) expression after spinal cord injury (SCI) in mice.Objectives:The recent discovery of miRNAs suggests a novel regulatory control over gene expression during plant and animal development. MiRNAs are short noncoding RNAs that suppress the translation of target genes by binding to their mRNAs, and play a central role in gene regulation in health and disease. The purpose of this study was to examine miRNA expression after SCI.Setting:Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University.Methods:We examined the expression of miRNA (miR)-223 and miR-124a in a mouse model at 6 h, 12 h, 1 day, 3 days and 7 days after SCI using quantitative PCR. The miRNA expression was confirmed by in situ hybridization.Results:Quantitative PCR revealed two peaks of miR-223 expression at 6 and 12 h and 3 days after SCI. MiR-124a expression decreased significantly from 1 day to 7 days after SCI. In situ hybridization demonstrated the presence of miR-223 around the injured site. However, miR-124a, which was present in the normal spinal cord, was not observed at the injured site.Conclusion:Our results indicate a time-dependent expression pattern of miR-223 and miR-124a in a mouse model of SCI. In this study, the time course of miRNA-223 expression may be related to inflammatory responses after SCI, and the time course of decreased miR-124a expression may reflect cell death.

MicroRNA-223 expression in neutrophils in the early phase of secondary damage after spinal cord injury

MicroRNA (miR)s are short non-coding RNAs that suppress the translation of target genes, and play an important role in gene regulation. Despite this prominence, there are few reports that refer to the expression of miRs after spinal cord injury (SCI). Previously, we reported on miR-223 expression after SCI in mice. The purpose of this study is to reveal the distribution of miR-223 and identify the cells that express miR-223 in the injured spinal cord. Quantitative polymerase chain reaction analysis revealed high expression of miR-223 at 12h after SCI. Double staining of in situ hybridization and immunohistochemistry showed that the signals of miR-223 merged with Gr-1 positive neutrophils. Our data indicate that miR-223 might regulate neutrophils in the early phase after SCI.

Medium-term clinical results of microsurgical lumbar flavectomy that preserves facet joints in cases of lumbar degenerative spondylolisthesis: comparison of bilateral laminotomy with bilateral decompression by a unilateral approach.

Study Design: A retrospective study of medium-term results. Objective: To describe a technique for posterior decompression using microsurgical lumbar flavectomy (MLF) without facetectomy, which is based on the anatomic features of the ligamentum flavum, and to examine the clinical outcomes of patients with lumbar spinal spondylolisthesis with lower extremity symptoms rather than low back pain, who underwent this procedure by 2 different approaches. Summary of Background Data: Posterior decompression with fusion has been the optimal and standard operative treatment for lumbar degenerative spondylolisthesis. Alternatively, minimally invasive procedures have been used for the treatment of lumbar degenerative spondylolisthesis with favorable outcomes. Methods: A bilateral laminotomy (BL group) was performed on 44 consecutive patients, and bilateral decompression by a unilateral approach (BDU group) was performed on 23 consecutive patients. The mean follow-up period was 7.0 years. The Japanese Orthopaedic Association score and recovery rate were obtained, and radiographic assessment was performed using plain radiograms on the lateral view while standing in flexion, neutral, and extension postures before surgery and at the final follow-up. Results: The Japanese Orthopaedic Association score at the final follow-up was improved in the BL and BDU groups, compared with that before MLF. The mean recovery rate was 72.4% and 68.4%, respectively. The mean % slip increased at the final follow-up, compared with that before surgery in both groups, except for the % slip in the extension posture in the BDU group. However, there was no significant difference in the dynamic % slip in the flexion-extension posture between before surgery and at the final follow-up. Conclusions: Clinical and radiologic parameters were not significantly different between the 2 groups. This technique of MLF using either approach did not increase the dynamic % slip and showed favorable medium-term clinical results in cases of lumbar degenerative spondylolisthesis.

Investigation of segmental motor paralysis after cervical laminoplasty using intraoperative spinal cord monitoring with transcranial electric motor-evoked potentials.

Study Design A retrospective study of segmental motor paralysis after cervical laminoplasty for cervical myelopathy. Objective The objective of this study was to use transcranial electric motor-evoked potentials during cervical laminoplasty, to monitor and investigate the intraoperative electrophysiologic change in patients with cervical myelopathy, who subsequently develop postoperative segmental motor paralysis potentials. Summary of Background Data There have been several reports about segmental motor paralysis after cervical laminoplasty for patients with cervical myelopathy. However, the pathogenesis of segmental motor paralysis of C5 myotome, so-called C5 palsy, remains unclear. Methods The cases of 184 consecutive patients who underwent cervical laminoplasty were analyzed to clarify the incidence of postoperative segmental motor paralysis and to monitor intraoperative change. Postoperative C5 palsy was defined as development of postoperative motor palsy of the deltoid and biceps muscles in the upper extremity by at least 1 grade in the manual muscle test without sensory disturbance or impairment of the lower extremities. All patients underwent cervical laminoplasty under intraoperative spinal cord monitoring with transcranial electric motor-evoked potentials. The evoked potentials were recorded over the deltoid, biceps, and triceps muscles in the bilateral upper extremities. Results Postoperative C5 palsy developed in 6 patients (3.3%, 5 males and 1 female) but there were no abnormal changes monitored. The incidence of C5 palsy involved 4 of 124 (3.2%) cervical spondylotic myelopathy patients, 2 of 31 (6.5%) patients with cervical ossification of the posterior longitudinal ligament. No patients with cervical disc herniation or cervical spondylotic amyotrophy developed C5 palsy. Conclusions There were no abnormal findings on transcranial electric motor-evoked potential monitoring even in those patients who developed postoperative C5 palsy. These results indicate that the development of postoperative segmental motor paralysis after cervical laminoplasty occurs even if there are no abnormal findings during intraoperative monitoring.

Quantitative assessment of myelopathy patients using motor evoked potentials produced by transcranial magnetic stimulation

Motor evoked potentials (MEPs) study using transcranial magnetic stimulation (TMS) may give a functional assessment of corticospinal conduction. But there are no large studies on MEPs using TMS in myelopathy patients. The purpose of this study is to confirm the usefulness of MEPs for the assessment of the myelopathy and to investigate the use of MEPs using TMS as a screening tool for myelopathy. We measured the MEPs of 831 patients with symptoms and signs suggestive of myelopathy using TMS. The MEPs from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles were evoked by transcranial magnetic brain stimulation. Central motor conduction time (CMCT) is calculated by subtracting the peripheral conduction time from the MEP latency. Later, 349 patients had surgery for myelopathy (operative group) and 482 patients were treated conservatively (nonoperative group). CMCTs in the operative group and nonoperative group were assessed. MEPs were prolonged in 711 patients (86%) and CMCTs were prolonged in 493 patients (59%) compared with the control patients. CMCTs from the ADM and AH in the operative group were significantly more prolonged than that in the nonoperative group. All patients in the operative group showed prolongation of MEPs or CMCTs or multiphase of the MEP wave. MEP abnormalities are useful for an electrophysiological evaluation of myelopathy patients. Moreover, MEPs may be effective parameters in spinal pathology for deciding the operative treatment.

The effects of combining chondroitinase ABC and NEP1-40 on the corticospinal axon growth in organotypic co-cultures

The area surrounding the injured spinal cord is a non-permissive milieu for axonal growth due to the inhibitory factors, especially chondroitin sulfate proteoglycan (CSPG) and Nogo. Recent studies have reported that chondroitinase ABC (ChABC) or Nogo-66(1-40) antagonist peptide (NEP1-40) promote axonal growth after spinal cord injury. But no study has addressed the effects on spinal cord injury of combining ChABC and NEP1-40. Previously, we described an organotypic co-culture system using the brain cortex and spinal cord from neonatal rats. In this study, we examined whether the combination of ChABC and NEP1-40 creates an action that promotes corticospinal axon growth in organotypic co-cultures. Organotypic co-cultures of brain and spinal cord were prepared from rats, and ChABC or NEP1-40 was delivered to them. To examine the effects of this combination these two drugs were applied together. We counted the number of labeled axons with DiI and assessed the immunoreactivity of CSPG and Nogo. Axonal growth was enhanced by infusing ChABC or NEP1-40 compared with that in the control group, whereas synergistic effects of combined administration of ChABC and NEP1-40 on axonal growth were not observed. There is a possibility that ChABC and NEP1-40 affect the same intracellular pathways and have no synergistic influence on axonal growth.

Surgical treatment of high-grade dysplastic spondylolisthesis using intraoperative electrophysiological monitoring: report of two cases and review of the literature

Treatment of high-grade dysplastic spondylolisthesis in adolescents remains challenging. Surgical treatment of spondylolisthesis has been recommended in adolescents with pain refractory to conservative treatment, slippage progression, or severe slippage on presentation. Controversy exists as to the optimal surgical approach for high-grade spondylolisthesis. Moreover, some authors reported the incidence of L5 root palsy during the reduction procedure. We performed 2 cases of surgical treatment using intraoperative electrophysiological monitoring for patients with high-grade dysplastic spondylolisthesis in adolescence. Each patient received treatment consisting of decompression of nerve with surgical microscope, reduction, and circumferential fusion with transpedicular and monosegmental fixation surgery with intraoperative neurological monitoring with transcranial electric motor evoked potentials and continuous spontaneous electromyography recording. Intraoperative monitoring did not show any abnormal changes. The patients got well after surgery, and they showed no postoperative motor paralysis of the extremities. A postoperative radiogram showed reduction of the slippage, and computed tomogram showed bone union between L5 and S1 vertebral body. This report describes 2 cases of surgical treatment using intraoperative electrophysiological monitoring with transcranial electric motor evoked potentials and continuous spontaneous electromyography for patients with high-grade dysplastic spondylolisthesis in adolescence. We successfully perform the surgery without any neurological deficit using intraoperative electrophysiological monitoring.

Magnetic Field–Based Delivery of Human CD1331 Cells Promotes Functional Recovery After Rat Spinal Cord Injury

Study Design. Experimental animal study of spinal cord injury (SCI), using a cell delivery system. Objective. To investigate the therapeutic effects of transplantation of peripheral blood–derived CD133+ cells, with a magnetic delivery system in a rat SCI model. Summary of Background Data. There are no reports on intrathecal transplantation of peripheral blood–derived CD133+ cells, with a magnetic cell delivery system to treat SCI. Methods. Magnetically isolated peripheral blood–derived CD133+ cells were used as the cell source. Contusion SCI was induced by an Infinite Horizon impactor in athymic nude rats. CD133+ cells or phosphate-buffered saline was administered via a lumbar puncture immediately after SCI, and a magnetic field was applied to rats for 30 minutes. Animals were analyzed at specific times after transplantation by several methods to examine cell tracking, functional recovery, and histological angiogenesis and neurogenesis. Results. A combination of cell transplantation and application of a magnetic field at the site of injury caused significant functional recovery. Transplantation of the cells alone in the absence of the magnetic field showed no effect beyond that observed in control rats. Conclusion. The combination of intrathecal transplantation of CD133+ cells and application of a magnetic field at the site of injury is a possible therapeutic strategy to treat rat SCI and may therefore find application in clinical settings.

The Efficacy of Intraoperative Neurophysiological Monitoring Using Transcranial Electrically Stimulated Muscle-evoked Potentials (TcE-MsEPs) for Predicting Postoperative Segmental Upper Extremity Motor Paresis After Cervical Laminoplasty.

Study Design:Prospective study. Objective:To investigate the efficacy of transcranial electrically stimulated muscle-evoked potentials (TcE-MsEPs) for predicting postoperative segmental upper extremity palsy following cervical laminoplasty. Summary of Background Data:Postoperative segmental upper extremity palsy, especially in the deltoid and biceps (so-called C5 palsy), is the most common complication following cervical laminoplasty. Some papers have reported that postoperative C5 palsy cannot be predicted by TcE-MsEPs, although others have reported that it can be predicted. Methods:This study included 160 consecutive cases that underwent open-door laminoplasty, and TcE-MsEP monitoring was performed in the biceps brachii, triceps brachii, abductor digiti minimi, tibialis anterior, and abductor hallucis. A >50% decrease in the wave amplitude was defined as an alarm point. According to the monitoring alarm, interventions were performed, which include steroid administration, foraminotomies, etc. Results:Postoperative deltoid and biceps palsy occurred in 5 cases. Among the 155 cases without segmental upper extremity palsy, there were no monitoring alarms. Among the 5 deltoid and biceps palsy cases, 3 had significant wave amplitude decreases in the biceps during surgery, and palsy occurred when the patients awoke from anesthesia (acute type). In the other 2 cases in which the palsy occurred 2 days after the operation (delayed type), there were no significant wave decreases. In all of the cases, the palsy was completely resolved within 6 months. Discussion:The majority of C5 palsies have been reported to occur several days after surgery, but some of them have been reported to occur immediately after surgery. Our results demonstrated that TcE-MsEPs can predict the acute type, whereas the delayed type cannot be predicted. Conclusions:A >50% wave amplitude decrease in the biceps is useful to predict acute-type segmental upper extremity palsy. Further examination about the interventions for monitoring alarm will be essential for preventing palsy.