BACKGROUND: Previous studies have confirmed that nano-hydroxyapatite/collagen (nHAC) and mesenchymal stem cells for repair of bone defect have the ability of bone formation in vivo. OBJECTIVE: To observe the effects of vascular endothelial growth factor (VEGF) and bone marrow mesenchymal stem cells (BMSCs), nHAC composite in the repair of femoral defect in rats. METHODS: Sprague-Dawley rat models of middle part of the femur defect were established and randomly assigned to two groups. Control group was implanted with BMSCs/nHAC composite. Experimental group was implanted with VEGF/BMSCs/nHAC composite. At 2, 4 and 8 weeks postoperation, imaging and histology observation of femoral samples were performed. At 8 weeks postoperation, scanning electron microscopy was performed in new bony callus environment. RESULTS AND CONCLUSION: nHAC composite implantation in the rats did not show rejection or inflammatory reaction. Moreover, bone formed rapidly using VEGF and BMSCs, nHAC composite, which exhibited better bone regeneration capacity compared with BMSCs/nHAC composite. The way of ossification mainly was endochondral ossification. It is presumed that VEGF promoted the formation of local microvessels, differentiation and proliferation of osteoblasts, speeded up the speed of endochondral ossification, shortened bone repair time, and elevated the quality and velocity of osteanagenesis.

Objective To investigate the inter-hemispheric resting-state functional connectivity and its relation with cognitive function in patients with end-stage renal disease (ESRD) by using resting-state functional magnetic resonance imaging (rs-fMRI) based on voxel-mirrored homotopic connectivity (VMHC). Methods A total of 52 patients with ESRD (ESRD group), admitted to our hospital from July 2018 to January 2019, were enrolled; 36 age-, gender-, and education level-matched healthy controls (HCs group) were collected at the same time period. The cognitive function of all subjects was assessed by Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT)-A, TMT-B and Symbol Digit Modalities Test (SDMT). The rs-fMRI and 3D-T1WI data were acquired from all subjects; after image preprocessing, VMHC values between brain hemispheres were calculated and the regions with significantly different VMHC values were obtained. The correlations between VMHC values in significant regions and cognitive scale scores were analyzed. Results MMSE, MoCA and SDMT scores of ESRD patients were significantly lower than those of the HCs group (P<0.05), and ESRD patients took longer time to complete TMT-A and TMT-B tests than the HCs group (P<0.05). As compared with that of the HCs group, significant decrease of VMHC values of ESRD patients was found in the hippocampus, lingual gyrus, superior temporal gyrus, caudate nucleus and anterior cingulate gyrus (P<0.01, AlphaSim correction); the VMHC values of the anterior cingulate gyrus and hippocampus were positively correlated with MMSE and MoCA scores (P<0. 05). Conclusion Significant abnormal inter-hemisphere functional connectivity is found in patients with ESRD, which is associated with cognitive function.

Objective To investigate the change patterns of functional brain networks and their relations with cognitive function in patients with end-stage renal disease (ESRD).Methods Sixty-two patients with ESRD (ESRD group),admitted to our hospital from July 2018 to June 2019,and 36 age-,gender-,and education level-matched healthy controls (HC group) were enrolled.Mini-mental State Examination (MMSE),Montreal Cognitive Assessment (MoCA),Trail Making Test A (TMT-A),TMT-B and Symbol Digit Modalities Test (SDMT) were used to evaluate the cognitive function for all subjects.Resting-state functional magnetic resonance imaging data were acquired;after data preprocessing,the brain functional networks were constructed and the topological parameters were calculated.Statistical methods were used to compare the differences of cognitive function scores and topological parameters between the two groups,and to analyze the correlations between these topological parameters and cognitive function scores in the ESRD group.Results The MMSE,MoCA and SDMT scores of the ESRD group were significantly lower than those of the HC group (P＜0.05),and the ESRD group took significantly longer time to complete TMT-A and TMT-B than the HC group (P＜0.05).The ESRD group had significantly lower normalized clustering coefficient (γ),small-worldness (σ) and local efficiency (Elocal) values than the HC group (P＜0.05).Patients in the ESRD group exhibited significantly decreased nodal efficiency in the paralimbic-limbic network (including the bilateral insula,median cingulate and paracingulate gyri,hippocampus,parahippocampal gyrus,amygdala,temporal pole:superior temporal gyrus,and temporal pole:middle temporal gyrus),right heschl gyrus and left superior temporal gyrus,and exhibited significantly increased nodal efficiency in the visual network (including the right distal-shaped gyrus,bilateral wedge,and left superior and middle occipital gyrus) as compared with the HC group (P＜0.05).In the ESRD group,the area under the curve (AUC) ofγ and σ was positively correlated with MoCA scores (r=0.698,P=0.000;r=0.661,P=0.000),and the AUC of Elocal showed positive correlation with MMSE scores (r=0.407,P=0.003).Conclusion Abnormal topological organization of the functional brain networks is revealed in patients with ESRD,which affects the cognitive function of these patients.