Effects of low-intensity pulsed ultrasound stimulation on porous hydroxyapatite blocks for posterolateral fusion of lumbar spine in rabbits

he effects of porous hydroxyapatite blocks（PHABs） and an adjunct low-intensity pulsed ultrasound stimulation（LIPUS） on the fusion rate in a rabbit spinal posterolateral fusion（PLF） model were evaluated.Twenty rabbits underwent PLF with autograft and PHABs were randomly assigned to two groups：treated group with 20 min LIPUS daily and untreated control group for 4 weeks until euthanasia.The fused motion segments were subjected to manual palpation,gross observation,and radiographic investigation before histomorphologic and scanning electron microscopic analyses.Statistical differences between the LIPUS group and the control group are found in the fusion rate,bone density gray scale,trabecular bone formation,osteoblast-like cells,chondrocytes and positive expression of BMP-2 and TGF-β1 in the junction zone（significance level p〈0.05）.The results suggest that LIPUS can increase fusion rates and accelerate bone in-growth into PHAB.Hence,PHAB and LIPUS may be used together to increase fusion rates in a rabbit spinal fusion model with a promising extension to human application.

Integrative transcriptome analysis identifies MYBL2 as a poor prognosis marker for osteosarcoma and a pan-cancer marker of immune infiltration

MYBL2(MYB proto-oncogene like 2)is an emerging prognostic marker for malignant tumors,and its potential role in osteosarcoma and its relationship with immune infiltration in pan-cancer is yet to be elucidated.We constructed a transcription factor activity profile of os-teosarcoma using the single-cell regulatory network inference algorithm based on single-cell RNA sequencing data obtained from the Gene Expression Omnibus.Subsequently,we calcu-lated the extent of MYBL2 activation in malignant proliferative osteoblasts.We also explored the association between MYBL2 and chemotherapy resistance in osteosarcoma.Furthermore,we systematically correlated MYBL2 with immunological signatures in the tumor microenviron-ment in pan-cancer,including immune cell infiltration,immune checkpoints,and tumor immu-notherapy prognosis.Finally,we developed and validated a risk score(MRGS),derived an osteosarcoma risk score nomogram based on MRGS,and tested its ability to predict prognosis.MYBL2 and gene enrichment analyses in osteosarcoma and pan-cancer revealed that MYBL2 was positively correlated with cell proliferation and tumor immune pathways.MYBL2 expres-sion positively correlated with SLC19A1 in pan-cancer and osteosarcoma cell lines.Pan-cancer immune infiltration analysis revealed that MYBL2 was correlated with myeloid-derived sup-pressor cells,Th2 cell infiltration,CD276,RELT gene expression,and tumor mutation burden.