An Improved Binary Differential Evolution Algorithm for Feature Selection in Molecular Signatures

The discovery of biomarkers from high-dimensional data is a very challenging task in cancer diagnoses. On the one hand, biomarker discovery is the so-called high-dimensional small-sample problem. On the other hand, these data are redundant and noisy. In recent years, biomarker discovery from high-throughput biological data has become an increasingly important emerging topic in the field of bioinformatics. In this study, we propose a binary differential evolution algorithm for feature selection. Firstly, we suggest using a two-stage approach, where three filter methods including the Fisher score, T-statistics, and Information gain are used to generate the feature pool for input to differential evolution (DE). Secondly, in order to improve the performance of differential evolution algorithm for feature selection, a new variant of binary DE called BDE is proposed. Three optimization strategies are incorporated into the BDE. The first strategy is the heuristic method in initial stage, the second one is the self-adaptive parameter control, and the third one is the minimum change value to improve the exploration behaviour thus enhance the diversity. Finally, Support vector machine (SVM) is used as the classifier in 10 fold cross-validation method. The experimental results of our proposed algorithm on some benchmark datasets demonstrate the effectiveness of our algorithm. In addition, the BDE forged in this study will be of great potential in feature selection problems.

[Copy number aberrations of genes related to extrohepatic metastasis-free survival after operation for hepatocellular carcinoma]

Objective: To investigate the molecular markers of copy number aberrations (CNAs) of genes related to extrohepatic metastasis-free survival after the operation for hepatocellular carcinoma (HCC). Methods: The CNA status of 20 candidate genes in 66 HCC samples was detected by microarray comparative genomic hybridization. The associations between gene CNAs and extrohepatic metastasis-free survival were evaluated using the Cox regression model, Log-rank test, and Kaplan-Meier survival analysis. Results: Multivariate Cox analysis revealed that the independent risk factors for metastasis-free survival were MDM4 gain (hazard ratio [HR] = 2.74, 95% confidence interval [CI] = 1.18-6.37, P < 0.05), APC loss (HR = 8.43, 95% CI = 2.48-28.66, P < 0.01), and BCL2L1 gain (HR = 3.45, 95% CI = 1.13-10.52, P < 0.05) and the independent protective factor was FBXW7 loss (HR = 0.32, 95% CI = 0.12-0.89, P < 0.05). By stepwise Cox regression analysis, three CNAs related to metastasis-free survival were screened out: MDM4 gain (HR = 2.71, 95% CI = 1.11-6.64, P < 0.05), APC loss (HR = 7.19, 95% CI = 1.88-27.60, P < 0.005), and FBXW7 loss (HR = 0.16, 95% CI = 0.05-0.46, P < 0.01). There were significant differences in metastasis-free survival rate between the HCC patients with FBXW7 loss and without MDM4 gain or APC loss, those with MDM4 gain and/or APC loss and without FBXW7 loss, and those with other CNA combinations (log-rank test, P < 0.01). Conclusion: MDM4 gain, APC loss, and FBXW7 loss are the independent prognostic factors for extrohepatic metastasis-free survival after the operation for HCC and can be used to predict the risk of extrohepatic metastasis after the operation for HCC.

Cryopreservation and transplantation of dog trachea

In order to meet the need of trachea transplantation for clinical application, it is important to research the methods of cryopreservation and transplantation of trachea. By the thermal analyses and thermal control techniques, combined with electron microscopy, the effects of cooling and warming rates with different concentrations of cryoprotective agents were studied. Also the transplantation technique was studied, eighty five percent (17/20) of the dogs were survival after the transplantation with cryopreserved tracheas.

Report of a case of sympathetic ophthalmia with special regard to ultrastructural examination

A case of sympathetic ophthalmia (SO) is reported. A long lasting stable result was obtained for this patient treated basically with traditional Chinese medicine. His exciting eye was investigated under light and transmission electron microscopes. Prominent granulomatous lesions in the choroid, Dalen-Fuchs nodules (DFNs) and disruption of outer and inner basement membrane of Bruch's membrane under DFNs are found, plasma cells are not few and melanocytes and retinal pigment epithelial cells are possibly the target cells. In various cells, nuclear bodies (NBs) are ubiquitous and sometimes multiple in an individual cell nucleus. Microtubule-like structures are present inside and outside the NBs and parallel lines composed of relatively uniform high electron dense granules as lattice-like structures can be seen. It was surmised that a virus induced autoimmune process might be involved in the pathogenesis of SO.

Pseudoxanthoma elasticum. A report of 5 cases in one family

Five cases of pseudoxanthoma elasticum (PXE) found in one family are reported. The hereditary pattern is probably of autosomal dominant type 2. In the fundi of all the 5 cases, mottlings of the retinal pigment epithelium or orange skin-like lesions in both eyes which are of significant diagnostic importance are seen. The fundus changes are more prominent when skin lesions are typical. Under electron and light microscope, the pathological changes of clinically typical and atypical lesions show similar characteristics of this disorder. Remarkable calcification of elastic fibers with abnormal contour and fragmentation, destruction of mitochondria of fibroblasts and a great number of mast cells leaning against fibroblasts are the chief findings in the histochemically stained specimens. The pathogenetic mechanism of this disorder is possibly dystrophy of elastic fibers with its inherent nature of being easily calcified. Involvement of autoimmune factors in the pathogenesis is quite possible.

A family with Fabry's disease. Ocular manifestations and transmission electron microscopic examination of a skin lesion biopsy

A family with Fabry's disease including 2 hemizygotes and 3 heterozygotes is reported. The ocular manifestations include tortuosity of conjunctival vessels, Fabry's deposits underlying the anterior capsule of the lens and the whorl-like corneal dystrophy. Foam cells or mulberry cells in the urinary sediment and varying numbers of high electron-dense inclusions in the cytoplasm of endothelial cells in skin lesions are also important in diagnosing this disease. The concentrations of lipid peroxide in the sera of 2 hemizygotes in this report were higher than normal, possibly due to the patients weak ability of anti-oxygenation and malfunction of cells whose plasma membranes are easily attacked by free oxygen radicals. The biochemical and pathological changes, diagnosis, treatment, genetics and prevention of the disease are discussed.