LRRC15 expression indicates high level of stemness regulated by TWIST1 in mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are used as a major source for cell therapy, and its application is expanding in various diseases. On the other hand, reliable method to evaluate quality and therapeutic properties of MSC is limited. In this study, we focused on TWIST1 that is a transcription factor regulating stemness of MSCs and found that the transmembrane protein LRRC15 tightly correlated with the expression of TWIST1 and useful to expect TWIST1-regulated stemness of MSCs. The LRRC15-positive MSC populations in human and mouse bone marrow tissues highly expressed stemness-associated transcription factors and therapeutic cytokines, and showed better therapeutic effect in bleomycin-induced pulmonary fibrosis model mice. This study provides evidence for the important role of TWIST1 in the MSC stemness, and for the utility of the LRRC15 protein as a marker to estimate stem cell quality in MSCs before cell transplantation.

Dropped head syndrome: a treatment strategy and surgical intervention.

PURPOSE: The pathology of dropped head syndrome (DHS) is diverse, and reports of surgery for DHS are scarce. We aimed to describe surgery for DHS and to investigate the surgical outcomes thereof. METHODS: We enrolled 40 consecutive patients (six males and 34 females; average age at surgery, 72.0 years) with DHS who underwent correction surgeries at a single institute. Short fusion (SF), with the extent of fixation mainly at the cervical region, was performed for 27 patients; long fusion (LF), involving the cervical and thoracic spine, for 13. Clinical and radiological outcomes were investigated, and factors analyzed using the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). RESULTS: All patients were able to gaze horizontally at the follow-up. Instances of five transient C5 palsy results, and five distal junctional kyphosis results were found, but no revisions were reported due to recurrence. Patients whose T1 slope-20° was smaller than the C2-7 angle postoperatively exhibited better clinical outcomes in the three domains of the JOACMEQ, regardless of the extent of fixation. CONCLUSION: For cases where the T1 slope is relatively small, and approximately 10° of cervical lordosis is predicted to be obtained postoperatively, SF is appropriate. Alternatively, for cases with higher T1 slope, obtaining a cervical lordosis over 20° has a risk of postoperative complications. For such cases, it is an option to perform an LF involving the cervical and thoracic spine.

Comprehensive treatment outcomes of giant cell tumor of the spine: A retrospective study.

There is no consensus on a treatment strategy for spinal giant cell tumor of bone (GCTB) because of the difficulty in their treatment. Treatment options often include the use of the controversial denosumab, an antibody therapy aimed at tumor shrinkage, different curettage techniques, resection, or a combination of these therapies. The current study aimed to identify treatment methods associated with favorable outcomes in patients with spinal GCTB. We retrospectively reviewed 5 patients with spinal GCTB, including patients with tumors of the sacrum, treated at our hospital between September 2011 and November 2020. Two men and 3 women were included in the study. The median follow-up period was 74 months (range: 14-108 months). We surveyed the tumor site, treatment method, denosumab use, and outcomes. The median age was 17 years (range: 17-42 years). There were 2 cases of sacral GCTB and 1 case each of lumbar, cervical, and thoracic vertebral GCTB. The comorbidities observed included hepatitis, malignant lymphoma, atopic dermatitis, and asthma. The treatment method included zoledronic acid after embolization and denosumab, denosumab only, curettage and posterior fusion, and curettage resection after embolization and anterior and posterior fusion. Denosumab was used in all cases. Three patients were continuously disease-free, 1 patient with no evidence of disease, and 1 patient alive with disease. Aggressive treatment, especially surgical treatment, may lead to good results in spinal GCTB.