Reconstruction for patient-specific bone model based on digital geometry processing technique / 中国组织工程研究

BACKGROUND:Due to anisotropic CT volume data, triangular meshes extracted from bone CT images often contain staircase surface, which wil affect the subsequent medical diagnosis. OBJECTIVE:To reconstruct patient-specific bone model based on digital geometry processing technique. METHODS:Firstly, registration was performed in image registration algorithm based on mutual information for bone CT slices, and then contours were extracted by image segmentation and a stack of contours were converted into point clouds. The normals of point clouds were estimated based on Gaussian weighted principal component analysis and the noise from point clouds was removed by trilateral filtering. Final y, bone triangular meshes were constructed by adaptive spherical cover. RESULTS AND CONCLUSION:In this paper, the proposed method could generate smoothing bone surface meshes, triangular mesh shape which was formed by the rules and adaptive distribution, for finite element analysis, computer aided manufacturing and three-dimensional printing to provide accurate three-dimensional models.

The activated pathways by hypoxia in patients with Obstructive sleep apnea hypopnea syndrome / 实用医学杂志

Objective To investigate the activation of nuclear factor-B (NF-B)and hypoxia-inducible factor-1 (HIF-1)in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods Subjects were classified into mild-to-moderate OSHAS group (n = 16), severe OSAHS group (n = 14) and the matched control group (n=30). Gene and protein expressions of NF-B and HIF-1 were measured by RT-PCR, Western blot in peripheral blood mononuclear cells (PBMC). Results NF-κB p65 mRNA and NF-κB p65 protein,HIF-1α mRNA and HIF-1α protein in PBMC were significantly higher in severe OSAHS group than those in mild–to-moderate group and control group (P<0.01). But there were no significant difference in NF-κB p65 mRNA and NF-κB p65 protein between mild-to-moderate group and control group (P=0.068, P=0.254 respectively). Only gene (P<0.05) not the protein (P=0.777) of HIF-1αwas higher in mild-to-moderate as compared with control group. Both NF-κB p65 mRNA and HIF-1αmRNA were positively correlated with AHI (r=0.493, P=0.006, r=0.508, P=0.004), while negatively correlated with nighttime lowest blood oxygen saturation (LSaO2)(r=-0.488, P=0.006, r=-0.46, P=0.011). There was a positive correlation between NF-κB p65 protein level and AHI (r=0.669, P<0.001). HIF-1αprotein level was positively correlated with AHI, ODI (r=0.628, P=0.001;r=0.480, P=0.018). There were positive correlations between NF-κBp65mRNA and HIF-1αmRNA (r=0.543, P=0.002), NF-κBp65 and HIF-1αprotein respectively (r=0.716, P<0.001). Conclusions As the gene and protein of NF-κB and HIF-1 were up-regulated in patients with OSAHS, and also positively correlated with the severity of sickness. We conclude that both NF-κB and HIF-1 were involed in the pathogenesis of OSAHS.

Activation and its influence of nuclear factor-κB in peripheral blood mononuclear cells in elderly patients with obstructive sleep apnea-hypopnea syndrome / 中华老年医学杂志

Objective To evaluate the influence of nuclear factor (NF)-κB activation in peripheral blood mononuclear cells (PBMCs) on vascular inflammation in elderly patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods The 40 elderly subjects (≥65years old) were classed into control, mild, moderate and severe groups (n = 10, respectively)according to polysomnography (PSG). After PSG, the samples of peripheral venous blood were collected, and PBMCs were isolated. Nuclear protein was extracted and NF-κB was measured by Western blotting. ELISA was applied to measure the levels of TNF-α and IL-6 in serum. Blood samples from 10 cases (moderate 5 and severe 5) were measured again after four weeks of continuous positive airway pressure (CPAP) treatment. Results The expression of NF-κB in PBMCs and the concentration of TNF-α in serum were significantly increased in severe and moderate OSAHS patients compared with controls (P＜0. 05). The NF-κB expression was positively correlated with AHI (r=0. 617, P＜ 0. 001) and TNF-α concentration (r = 0. 498, P＜ 0. 001 ), negatively correlated with LSaO2 (r= -0. 548, P＜0. 001), and not correlated with IL-6 concentration (r=0. 365, P=0. 201).The CPAP treatment could significantly inhibit NF-κB activation in PBMCs and reduce TNF-αexcretion (P＜0.05, respectively). Conclusions PBMCs may play an important role in vascular endothelial injury through NF-κB expression and TNF-α excretion in elderly OSAHS patients, which is closely associated with the severity of the syndrome and night hypoxemia. CPAP treatment can inhibit the pathophysiologic process effectively.