BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely used on clinic; however, there are still few reports addressing rhBMP-2-induced osteogenesis in intervertebral disc.OBJECTIVE: To verify the effect of rhBMP-2 to induce interbody fusion in rabbits.DESIGN, TIME AND SETTING: Randomized controlled animal study and multi-level evaluation, which was performed in Affiliated Hospital of Medical College of Qingdao University from February to July 2007.MATERIALS: 24 adult New-Zealand rabbits weighing 3.5-4.5 kg were used to expose L4-5 and L5-6 intervertebral disc; rhBMP-2 (1 mg/ampoule, purity≥95%) was provided by Beijing Bailingke Biological Products Co., Ltd.METHODS: 24 rabbits were randomly divided into experimental group and control group with 12 rabbits for each. In the experimental group, saline (20 μL, containing 200 μg rhBMP-2) was injected into nucleus pulposus of L4-5 intervertebral disc; equivalent saline was inserted into nucleus pulposus of L5-6 intervertebral disc as controls. Rabbits in the control group were injected with saline (20 μL) into nucleus pulposus of L4-5 intervertebral disc.MAIN OUTCOME MEASURES: Morphological changes of injected segments were observed by hand-feeling check together with histological and imaging tests at 10, 30, 60, and 90 days postoperatively.RESULTS: 24 rabbits were included in the final analysis. ①In the experimental group, the motion range of L4-5 segment was not limited at 10 days postoperatively, and lightly limited at 30 days, but severely limited at 60 days postoperatively; L4-5 segment was fixed tightly at 90 days postoperatively. Moreover, motion range of L5-6,segment and articular motion range in the control group were not changed remarkably. ② L4-5 interbedy space was narrowed at 10 days or even disappeared at 90 days postoperatively, and then osteogenesis fusion was formed. Transmittance of intervertebral space in the L5-6 segment and in the control group was not changed obviously. ③ Nucleus pulposus was gradually shrunk at 10 days postoperatively; partial cartilage endplate transformed into mature woven bone, and collagen fiber structure of annulus fibrosus gradually disappeared at 90 days postoperatively. A lot of mesenchymal cells were aggregated surrounding annulus fibrosus at 10 and 30 days postoperatively. Moreover, mature woven bone was formed in annulus fibrosus near to cartilage endplate at 90 days postoperatively. However, histological and morphological changes were not found in the control group at those four time points.CONCLUSION: rhBMP-2 can induce intervertebral disc osteogenesis so as to achieve interbody fusion.

Objective:To explore the clinical features and genetic etiology for a child with developmental delay, impaired growth, facial dysmorphism, and axonal neuropathy (DIGFAN).Methods:A child who was admitted to the Second Affiliated Hospital of Guangxi Medical University on March 22, 2021 was selected the study subject. Clinical data of the child was collected. Following extraction of genomic DNA, the child and his parents were subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing and bioinformatic analysis.Results:The child, a 10-year-and-9-month-old boy, had manifested with short stature, intellectual disability, delayed speech, motor and language development, and facial dysmorphism. WES and Sanger sequencing revealed that he has harbored a novel de novo c. 800T>C (p.Leu267Pro) variant of the MORC2 gene. The Leucine at position 267, which is highly conserved among various species, is located in the S5 domain of ribosome protein in the ATPase binding region of MORC2. And the Leu267Pro may affect the function of MORC2 by altering the spatial conformation and activity of ATPase. Based on the guidelines from the American College of Medical Genetics and Genomics, the c. 800T>C variant was classified as likely pathogenic (PS2+ PM2_Supporting+ PP2+ PP3). Conclusion:The MORC2: c. 800T>C (p.Leu267Pro) variant probably underlay the pathogenesis of DIGFAN syndrome in this child.

Background Previous research indicated that isomers and alternatives of per- and polyfluoroalkyl substances (PFAS) probably disturb glucose metabolism; however, current epidemiological evidence on the associations of PFAS with fasting blood glucose is inconsistent. Besides, studies on the joint association of multiple components of PFAS and fasting blood glucose as well as the key component are scarce. Objective To evaluate the associations of PFAS isomers and alternatives with fasting blood glucose and their joint effects, as well as identify the key component among population without glucose metabolism problems. Methods We selected 923 adults without glucose metabolism problems or missing data from the Isomers of C8 Health Project in China (2015—2016). Serum PFAS isomers and alternatives and fasting blood glucose were measured using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) and automatic biochemical analyzer. We applied multiple linear regression to explore the associations of 16 pollutants which were detected among over 80% participants with fasting blood glucose. Meanwhile, we utilized qgcomp and Bayesian kernel machine regression (BKMR) models to explore the joint effects of PFAS isomers and alternatives mixture on target outcome indicators and identify the key component. Results The average age among the 923 participants in this study was (62.4±13.8) years old, including 472 men (51.1%) and 451 women (48.9%). Among selected PFAS isomers and alternatives, the highest serum concentration was ∑3+4+5m-PFOS (perfluoro-3/4/5-methylheptanesulfonate) with a median concentration of 10.20 ng·mL⁻¹. The concentrations of linear perfluorooctane sulfonate (n-PFOS, 9.61 ng·mL⁻¹), perfluorooctanoic acid (PFOA, 4.55 ng·mL⁻¹), linear perfluorohexane sulfonic acid (n-PFHxS, 2.48 ng·mL⁻¹), 6:2 chlorinated polyfluorinated ethersulfonic acid (6:2 Cl-PFESA, 1.90 ng·mL⁻¹), perfluoro-6-methylheptanesulfonate (iso-PFOS, 1.85 ng·mL⁻¹), perfluorobutanoic acid (PFBA, 1.81 ng·mL⁻¹), perfluorinated n-nonanoic acid (PFNA, 1.39 ng·mL⁻¹), and perfluoro-1-methylheptanesulfonate (1m-PFOS, 1.27 ng·mL⁻¹) were higher than 1.00 ng·mL⁻¹. After being adjusted for selected confounders, PFAS isomers and alternatives were positively associated with fasting blood glucose. With 1 ln unit concentration increment of 6:2 Cl-PFESA and PFNA, the estimated changes of fasting blood glucose were 0.18 (95%CI: 0.13, 0.23) mmol·L⁻¹ and 0.24 (95%CI: 0.18, 0.30) mmol·L⁻¹, respectively. The multi-pollutant models indicated a joint association of PFAS isomers and alternatives mixture with fasting blood glucose. The BKMR models reveals that as the quantiles of mixture elevated from the 50^th to the 75^th percentile, the values of fasting blood glucose increased 0.25 (95%CI: 0.21, 0.30) mmol·L⁻¹, and the posterior inclusion probability of PFNA was 0.92, implying that PFNA was the key component. Conclusion PFAS isomers and alternatives are positively associated with fasting blood glucose. PFNA is the key component of the joint association.