Roles of TNF-α gene polymorphisms in the occurrence and progress of SARS-Cov infection: A case-control study

<p>Abstract</p> <p>Background</p> <p>Host genetic factors may play a role in the occurrence and progress of SARS-Cov infection. This study was to investigate the relationship between tumor necrosis factor (TNF)-<it>α </it>gene polymorphisms with the occurrence of SARS-CoV infection and its role in prognosis of patients with lung interstitial fibrosis and femoral head osteonecrosis.</p> <p>Methods</p> <p>The association between genetic polymorphisms of <it>TNF-α </it>gene and susceptibility to severe acute respiratory syndromes (SARS) was conducted in a hospital-based case-control study including 75 SARS patients, 41 health care workers and 92 healthy controls. Relationships of TNF-α gene polymorphisms with interstitial lung fibrosis and femoral head osteonecrosis were carried out in two case-case studies in discharged SARS patients. PCR sequencing based typing (PCR-SBT) method was used to determine the polymorphisms of <it>TNF-α </it>gene in locus of the promoter region and univariate logistic analysis was conducted in analyzing the collected data.</p> <p>Results</p> <p>Compared to TT genotype, the CT genotype at the -204 locus was found associated with a protective effect on SARS with OR(95%<it>CI</it>) of 0.95(0.90–0.99). Also, TT genotype, CT and CC were found associated with a risk effect on femoral head necrosis with ORs(95%<it>CI</it>) of 5.33(1.39–20.45) and 5.67(2.74–11.71), respectively and the glucocorticoid adjusted OR of CT was 5.25(95%CI 1.18–23.46) and the combined (CT and CC) genotype OR was 6.0 (95%<it>CI </it>1.60–22.55) at -1031 site of <it>TNF-α </it>gene. At the same time, the -863 AC genotype was manifested as another risk effect associated with femoral head necrosis with OR(95%<it>CI</it>) of 6.42(1.53–26.88) and the adjusted OR was 8.40(95%CI 1.76–40.02) in cured SARS patients compared to CC genotype.</p> <p>Conclusion</p> <p>SNPs of <it>TNF-α </it>gene of promoter region may not associate with SARS-CoV infection. And these SNPs may not affect interstitial lung fibrosis in cured SARS patients. However, the -1031CT/CC and -863 AC genotypes may be risk factors of femoral head necrosis in discharged SARS patients.</p

A Triangle Mesh Standardization Method Based on Particle Swarm Optimization

<div><p>To enhance the triangle quality of a reconstructed triangle mesh, a novel triangle mesh standardization method based on particle swarm optimization (PSO) is proposed. First, each vertex of the mesh and its first order vertices are fitted to a cubic curve surface by using least square method. Additionally, based on the condition that the local fitted surface is the searching region of PSO and the best average quality of the local triangles is the goal, the vertex position of the mesh is regulated. Finally, the threshold of the normal angle between the original vertex and regulated vertex is used to determine whether the vertex needs to be adjusted to preserve the detailed features of the mesh. Compared with existing methods, experimental results show that the proposed method can effectively improve the triangle quality of the mesh while preserving the geometric features and details of the original mesh.</p></div

Triangle quality distribution of the different triangle mesh standardization methods.

<p>Triangle quality distribution of the different triangle mesh standardization methods.</p

Original data.

<p>Original data.</p

Comparison of the standardization algorithms on the cylinder head model.

<p>(A) original model; (B) standardization result by Laplace; (C) standardization result by Taubin; (D) standardization result by Vollmer; (E) standardization result by Chen; (F) standardization result by our method.</p

Parameter settings of our algorithm.

<p>Parameter settings of our algorithm.</p

Zoomed region of the cylinder head model.

<p>(A) original model; (B) standardization result by Laplace; (C) standardization result by Taubin; (D) standardization result by Vollmer; (E) standardization result by Chen; (F) standardization result by our method.</p