Tomonori Morita

Intravenous infusion of mesenchymal stem cells promotes functional recovery in a model of chronic spinal cord injury.

Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat models of spinal cord injury (SCI). However, most studies have focused on the acute or subacute phase of SCI. In the present study, MSCs derived from bone marrow of rats were intravenously infused 10weeks after the induction of a severe contusive SCI. Open field locomotor function was assessed weekly until 20weeks post-SCI. Motor recovery was greater in the MSC-treated group with rapid improvement beginning in earlier post-infusion times than in the vehicle-treated group. Blood spinal cord barrier (BSCB) integrity was assessed by the intravenous infusion of Evans Blue (EvB) with spectrophotometric quantitation of its leakage into the parenchyma. In MSC-treated rats, BSCB leakage was reduced. Immunohistochemical staining for RECA-1 and PDGFR-β showed increased microvasculature/repair-neovascularization in MSC-treated rats. There was extensive remyelination around the lesion center and increased sprouting of the corticospinal tract and serotonergic fibers after MSC infusion. These results indicate that the systemic infusion of MSCs results in functional improvement that is associated with structural changes in the chronically injured spinal cord including stabilization of the BSCB, axonal sprouting/regeneration and remyelination.

Intravenous infusion of mesenchymal stem cells reduces epileptogenesis in a rat model of status epilepticus

OBJECTIVE Status epilepticus (SE) causes neuronal cell death, aberrant mossy fiber sprouting (MFS), and cognitive deteriorations. The present study tested the hypothesis that systemically infused mesenchymal stem cells (MSCs) reduce epileptogenesis by inhibiting neuronal cell death and suppressing aberrant MFS, leading to cognitive function preservation in a rat model of epilepsy. METHODS SE was induced using the lithium-pilocarpine injection model. The seizure frequency was scored using a video-monitoring system and the Morris water maze test was carried out to evaluate cognitive function. Comparisons were made between MSCs- and vehicle-infused rats. Immunohistochemical staining was performed to detect Green fluorescent protein (GFP)+ MSCs and to quantify the number of GAD67+ and NeuN+ neurons in the hippocampus. Manganese-enhanced magnetic resonance imaging (MEMRI) and Timm staining were also performed to assess the MFS. RESULTS MSC infusion inhibited epileptogenesis and preserved cognitive function after SE. The infused GFP+ MSCs were accumulated in the hippocampus and were associated with the preservation of GAD67+ and NeuN+ hippocampal neurons. Furthermore, the MSC infusion suppressed the aberrant MFS in the hippocampus as evidenced by MEMRI and Timm staining. CONCLUSIONS This study demonstrated that the intravenous infusion of MSCs mitigated epileptogenesis, thus advancing MSCs as an effective approach for epilepsy in clinical practice.

Analysis of intra and extramyocellular lipids in the multifidus muscle in patients with chronic low back pain using MR spectroscopy

OBJECTIVE To analyse the intra- (IMCL) and extramyocellular lipids (EMCL) concentration in the multifidus muscle (Mm) using MR spectroscopy (MRS) in patients with low back pain (LBP), and to evaluate the correlation between those lipid concentrations and age, obesity, atrophy of the Mm and LBP intensity. METHODS 60 LBP patients underwent routine diagnostic MRI of the lumbar spine before undergoing imaging for the study. Body mass index, as an indicator of obesity and visual analogue scale, as an indicator of LBP were also measured. Proton MRS was acquired with a single-voxel point-resolved spectroscopy sequence. Furthermore, the MRS volume of interest for measuring the IMCL and EMCL concentration at L4/5 for the right Mm was determined, and we measured the cross-sectional area of Mm as an indicator of muscle atrophy. RESULTS Age showed correlation with EMCL concentration (r = 0.314, p = 0.008). The body mass index showed correlation with EMCL concentration (r = 0.358, p = 0.005). The cross-sectional area of Mm showed correlation with EMCL concentration (r = -0.543, p < 0.001). Moreover, the LBP visual analogue scale showed correlation with IMCL concentration (r = 0.367, p = 0.004). CONCLUSION There were correlations between age, obesity, muscle atrophy, and EMCL concentration in Mm. IMCL concentration in Mm showed a correlation with LBP intensity. This may suggest that IMCL concentration could become an effective objective indicator of chronic LBP intensity. Advances in knowledge: We investigated the characteristics of fat content in Mm with LBP patients. This study was demonstrated the association of the IMCL and EMCL concentration in Mm with various patient parameters.

Magnetic resonance spectroscopic analysis of multifidus muscles lipid content and association with spinopelvic malalignment in chronic low back pain

OBJECTIVE To analyze intramyocellular lipids (IMCLs) and extramyocellular lipids (EMCLs) of the multifidus muscle (Mm) using MR spectroscopy in chronic low back pain (CLBP) and control groups and to identify correlations with spinopelvic alignment. METHODS 40 patients (16 males, 24 females; mean age, 62.9 ± 1.9 years) whose visual analogue scale scores were >30 mm for CLBP were included. Furthermore, 40 control participants matched with the CLBP group subjects by sample size, gender and age (17 males, 23 females; mean age, 65.0 ± 1.2 years) were included. We compared the body mass index, physical workload, leisure time physical activity level, spinopelvic parameters, and IMCLs and EMCLs of the Mm between the groups. We also evaluated possible correlations of spinopelvic parameters with IMCLs and EMCLs of the Mm in the groups. RESULTS There were no statistically significant differences in body mass index, physical workload, exercise intensity level, spinopelvic parameters and EMCLs between the groups. The IMCLs were significantly higher in the CLBP group than in the control group (p < 0.01). In the CLBP group, there was a significantly negative correlation between IMCLs and lumbar lordosis (r = -0.64, p < 0.01) and a significantly positive correlation between IMCLs and sagittal vertical axis (r = 0.43, p < 0.01). CONCLUSION The measurement of IMCLs might be a characteristic finding of CLBP as well as a precursor to spinal deformity. Advances in knowledge: IMCLs of the Mm may be a useful prognostic marker in rehabilitation strategies for patients with CLBP.

Quantitative Analysis Concerning Atrophy and Fat Infiltration of the Multifidus Muscle with Magnetic Resonance Spectroscopy in Chronic Low Back Pain

Introduction Magnetic resonance spectroscopy (MRS) enables detailed analysis of the composition of muscular fat tissues such as intramyocellular lipids (IMCLs) and extramyocellular lipids (EMCLs). The aim of this study was to analyze the EMCL and IMCL of the multifidus muscle (Mm) using MRS in chronic low-back pain (CLBP) patients and identify their possible correlations with age, body mass index (BMI), low-back pain (LBP) visual analog scale (VAS) score, cross-sectional area (CSA), and fat infiltration of the Mm. Methods Eighty patients (32 men and 48 women; mean age, 64.7 ± 1.3 years; range, 22-83 years) with VAS scores >30 mm for CLBP were included. We analyzed the gender difference and the possible correlations of age, BMI, LBP VAS, CSA, and fat infiltration of the Mm with the IMCL and EMCL of the Mm. The subjects were divided into five groups as per their age range: < 40s, 50s, 60s, 70s, and 80s. We also analyzed the EMCL and IMCL of the Mm as per the fat infiltration classification. Results CSA was larger in the male group, EMCL was higher in the female group, and there was no significant difference in IMCL between the female and male groups. There was a significant positive correlation of EMCL with age (r = 0.33, p < 0.01) and BMI (r = 0.42, p < 0.01) and a significant negative correlation of EMCL with CSA (r = −0.61, p < 0.01). There was a significant positive correlation between IMCL and VAS (r = 0.43, p < 0.01). The EMCL and CSA of the Mm decreased with age, whereas fat infiltration increased with age. Conclusions These results suggest that EMCL could indicate Mm degeneration associated with aging, and IMCL could be an effective objective indicator of CLBP. The EMCL and IMCL of the Mm may be useful prognostic markers in rehabilitation strategies.

The difference in gender affects the pathogenesis of ligamentum flavum hypertrophy

Introduction Gender differences may play a role in the pathogenesis of lumbar spinal stenosis. However, few reports that discuss the effects of gender differences in ligamentum flavum (LF) hypertrophy have been published, and no study has investigated the relationship between LF thickness and the quantitative value of intervertebral disc (IVD) degeneration. This study aimed to investigate the impact of gender on the pathomechanisms underlying LF hypertrophy, focusing on the relationship among LF thickness, IVD degeneration, and age. Methods The subjects include 100 patients with low back pain and leg numbness, tingling, or pain. We measured LF thickness and the T2 values of IVDs using MR imaging and analyzed the relationship among LF thickness, T2 values of IVDs, and age. The interclass correlation coefficient (ICC) was calculated as the inter-rater reliability between the LF thickness values measured by two investigators. Results ICC was calculated for the two measurements of LF thickness (r = 0.923, 95% CI: 0.907-0.936). No statistically significant difference in the T2 values of IVDs was observed between females and males from L2/3 to L5/S. There were significantly negative linear correlations between LF thickness and the T2 values of IVDs at all levels, but this correlation was not observed in females at L4/5. There were significantly negative linear correlations between age and the T2 values of IVDs from L2/3 to L5/S for all patients, females, and males (r = 0.422-0.756). In addition, there were significantly positive linear correlations between age and LF thickness from L2/3 to L4/5 for all patients (r = 0.329-0.361) and females (r = 0.411-0.481). Correlations were not observed for males at all levels or for all patients at L5/S. Conclusions The relationships identified among LF thickness, age, and IVD degeneration suggest that gender differences play a role in the pathogenesis of LF hypertrophy.

Giant cell-rich osteosarcoma of the vertebra with murine double minute chromosome 2- and cyclin-dependent kinase 4-positive and histone H3F3A mutant p.Gly34Trp-negative immunophenotypes

To the Editor: Giant cell-rich osteosarcoma (GCRO) accounts for approximately 3% of all cases of osteosarcoma, with most lesions occurring in the long bones of the appendicular skeleton. GCRO is characterized by the presence of numerous osteoclast-like giant cells distributed among sarcomatous tumor cells. The stromal cells of such tumors can have a deceptively benign appearance, and the lesion may be mistaken for a giant cell tumor of bone (GCTB). Radiologically, most GCRO has little periosteal reaction and is not associated with a soft-tissue mass. Cytological atypia can be minimal in mononuclear cells with inapparent tumor bone formation making the diagnosis of osteosarcoma difficult. Recently, a case of GCRO of the maxilla with murine double minute chromosome 2 (MDM2) and cyclindependent kinase 4 (CDK4) expression was described. GCTB is currently characterized by the presence of histone H3F3A (H3.3) driver mutations, and highly sensitive and specific immunoreactivity for the H3.3 mutant p.Gly34Trp (p.G34W) has been shown in GCTBs and their malignant counterparts. Here, we report a case of GCRO of the vertebra; immunohistochemical analysis of MDM2, CDK4, and H3.3 G34W at our institution confirmed the diagnosis of GCRO. A 73-year-old female Japanese patient visited our hospital with back pain and was found to have well-circumscribed, osteolytic lesions with cortical destruction in the 6th thoracic vertebral body, arch, and spinous process by computed tomography (CT) and magnetic resonance imaging (MRI) examination (Fig. 1a). Medical work-up did not disclose signs of bone metastasis or multiple myeloma. Incisional biopsy was performed within the spinous process. Histologically, the tumor consisted of oval or spindle mononuclear cells and intervening neoplastic bone and lace-like osteoid deposits associated with osteoclast-like giant cells (Fig. 1b,c). The stromal cells showed mild nuclear pleomorphism and infrequent mitosis, but focally, they possessed moderate to marked pleomorphism. Diagnosis of GCTB was made based on these findings, and the patient received denosumab therapy for 17 months. In May 2017, the patient developed myelopathy symptoms, including weakness and hypoesthesia of the lower limbs and dysuria, and was referred to our hospital. CT and MRI of the 6th thoracic vertebra revealed tumor lesions extending to the spinal canal and paravertebral muscles on the right side. In June 2017, surgical treatment of posterior decompression and fixation of the thoracic spine were performed and the excised posterior segments of the 6th thoracic vertebra were used for pathological examination. The tumor had a similar histological and cytological appearance as the biopsy materials, and showed more pronounced bone formation and markedly reduced osteoclastlike giant cells. Immunohistochemically, the mononuclear stromal cells of both the biopsy and excised specimens were positive for MDM2 (clone IF2, diluted 1:40; Merck, Darmstadt, Germany) and CDK4 (clone DCS-31, diluted 1:50; Invitrogen, Carlsbad, CA, USA), and negative for H3.3 G34W (clone RM263, diluted 1:1000; RevMab Biosciences, South San Francisco, CA, USA) (Fig. 1e,f) and H3.3 G34V (clone RM307, dilution 1:1000; RevMab Biosciences). We also examined MDM2 and CDK4 gene amplification by fluorescence in situ hybridization (FISH) (Kreatech FISH probes MDM2 12q15/SE12 and CDK4 12q13/SE12; Leica, Wetzlar, Germany) and confirmed their amplification. The MDM2/CEP12 and CDK4/CEP12 ratios were 8.8 and 10.0, respectively, much higher than the amplification signal cutoff value of 2.0 (Fig. 1d). We concluded that MDM2 and CDK4 expression on immunohistochemistry in the current case reflected actual amplification of these genes. Given the morphological resemblance of GCRO to GCTB, we additionally performed immunostaining for MDM2, CDK4, and H3.3 G34W in 10 GCTBs located in 2 distal femurs, 2 proximal fibulas, 2 proximal tibias, and 1 each in the distal tibia, 5th lumbar vertebra, lung (metastatic GCTB), and ilium. The case involving the ilium was a secondary osteosarcoma arising in GCTB/malignant GCTB. All 10 GCTBs showed nuclear reactivity for H3.3 G34W in the stromal cells, but were negative for MDM2 and CDK4. After the diagnosis of GCRO, the patient received radiation therapy for 2 months resulting in an improvement in the symptoms of thoracic myelopathy after surgery alone. Immunohistochemical staining for MDM2 and CDK4 is a useful diagnostic tool in low-grade osteosarcomas such as low-grade central and parosteal osteosarcomas. However, the histology of this tumor, which is immunoreactive for MDM2 and CDK4, was different from that of low-grade osteosarcoma, which typically consists of long spindle cells with bland nuclei interspersed with branching well-developed bone trabeculae. Previously, immunohistochemical staining for MDM2 and CDK4 was negative in eight cases

Differentiating spinal intradural-extramedullary schwannoma from meningioma using MRI T2 weighted images

OBJECTIVE: Prior studies advocate the subjective visual differences between meningioma and schwannoma on T2 weighted images, however objective measurement of signal intensity differences may be useful in certain cases. The aim of this study was to investigate whether an objective evaluation of SIs on T2 weighted images would be useful to differentiate spinal schwannomas from meningiomas. METHODS: The patients with spinal MRIs demonstrating path proven and subsequently treated intradural extramedullary spinal tumors were selected between April 2008 and May 2017. Regions of interest (ROIs) were measured in the tumor and subcutaneous fat on the same image, and we calculated the SI ratio between tumor and fat ROIs. RESULTS: Twenty patients each with meningioma and schwannoma were enrolled. The SI ratios of schwannomas were significantly higher than those of meningiomas (both researcher 1 and 2: p = 0.002). The areas under the curve by researchers 1 and 2 were 0.780. The cutoff value of SI ratio by both of researchers 1 and 2 to differentiate between schwannomas from meningiomas was 0.420 (sensitivity: 80.0%, specificity: 70.0-75.0%). CONCLUSION: The SI ratio, calculated from the SIs of the tumor and fat on T2 weighted images, is useful for differentiating spinal schwannomas from meningiomas to obtain an accurate diagnosis. ADVANCES IN KNOWLEDGE: Signal intensity ratio of the spinal tumor and fat on T2 weighted images is useful for differentiating schwannomas from meningiomas to obtain an accurate diagnosis.