Development of a novel tumor microenvironment-related radiogenomics model for prognosis prediction in hepatocellular carcinoma.

Background: The tumour microenvironment (TME) has occupied a potent position in the tumorigenesis and tumor progression of hepatocellular carcinoma (HCC). Radiogenomics is an emerging field that integrates imaging and genetic information, thus offering a novel class of non-invasive biomarkers with diagnostic, prognostic, and treatment response. However, optimal evaluation methodologies for radiogenomics in patients with HCC have not been well established. Therefore, this study aims to develop a radiogenomics models, associating contrast-enhanced computed tomography (CECT) based radiomics features and transcriptomics data with TME, to increase predictive precision for overall survival (OS) in patients with HCC. Methods: Transcriptome profiles of 365 patients with HCC from The Cancer Genome Atlas (TCGA)-HCC cohort were used to obtain TME-related genes by differential expression analysis. TME-related radiomics features of 53 patients with HCC from The Cancer Imaging Archive (TCIA)-HCC cohort matched with the TCGA-HCC cohort were screened via correlation analysis. Furthermore, a radiogenomics score-based prognostic model was constructed using the least absolute shrinkage and selection operator (LASSO) Cox regression analysis in the TCIA-HCC cohort. Finally, the ability to predict prognosis and the value of the model in identifying the abundance of immune cell infiltration were investigated. Results: A radiogenomics prognostic model was developed, which incorporated 1 radiomics feature [original_gray-level co-occurrence matrix (glcm)_inverse difference normalized (Idn)] and 3 genes [spen paralogue and orthologue C­terminal domain containing 1 (SPOCD1); killer cell lectin like receptor B1 (KLRB1); G protein-coupled receptor 182 (GPR182)]. The model performed satisfactorily in the training and test sets [1-year, 2-year, 3-year area under the curve (AUC) of 0.81, 0.85 and 0.87 in the training set, respectively; and 0.73, 0.83, and 0.84 in the test set, respectively]. Moreover, the model showed that higher radiogenomics scores were associated with worse OS and lower levels of immune infiltration. Conclusions: The novel CECT-based radiogenomics model may provide valuable insights for prognostic stratification and TME assessment of patients with HCC.

Covering functionals of cones and double cones.

The least positive number γ such that a convex body K can be covered by m translates of γK is called the covering functional of K (with respect to m), and it is denoted by Γm(K) . Estimating covering functionals of convex bodies is an important part of Chuanming Zong's quantitative program for attacking Hadwiger's covering conjecture. Estimations of covering functionals of cones and double cones, which are best possible for certain pairs of m and K, are presented.

Inactivation of the fliY gene encoding a flagellar motor switch protein attenuates mobility and virulence of Leptospira interrogans strain Lai.

BACKGROUND: Pathogenic Leptospira species cause leptospirosis, a zoonotic disease of global importance. The spirochete displays active rotative mobility which may contribute to invasion and diffusion of the pathogen in hosts. FliY is a flagellar motor switch protein that controls flagellar motor direction in other microbes, but its role in Leptospira, and paricularly in pathogenicity remains unknown. RESULTS: A suicide plasmid for the fliY gene of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai that was disrupted by inserting the ampicillin resistance gene (bla) was constructed, and the inactivation of fliY gene in a mutant (fliY-) was confirmed by PCR and Western Blot analysis. The inactivation resulted in the mRNA absence of fliP and fliQ genes which are located downstream of the fliY gene in the same operon. The mutant displayed visibly weakened rotative motion in liquid medium and its migration on semisolid medium was also markedly attenuated compared to the wild-type strain. Compared to the wild-type strain, the mutant showed much lower levels of adhesion to murine macrophages and apoptosis-inducing ability, and its lethality to guinea pigs was also significantly decreased. CONCLUSION: Inactivation of fliY, by the method used in this paper, clearly had polar effects on downstream genes. The phentotypes observed, including lower pathogenicity, could be a consequence of fliY inactivation, but also a consequence of the polar effects.

[The relationship between the potential years of life lost of lung cancer and air pollution in Wuhan].

OBJECTIVE: To study the present situations of lung cancer in Wuhan and to explore the relationship between the potential years of life lost of lung cancer and air pollution, especially vehicle emissions. METHODS: Data gathered between 1986 and 1995 in Wuhan city, including air pollution and tobacco production and data on lung cancer between 1991 and 2000 were collected extensively. Simple Correlation and Grey Relational Analysis were used to analyze the relationship of them. RESULTS: There was a ascending tendency in variance of oxides of nitrogen (NOx). The degree of grey incidence (DGI) between the concentration of air pollutants and the male's or female's potential years of life lost of lung cancer (PYLL) were calculated respectively. In males, the values of DGI were 0.6702, 0.7071, 0.6199 on sulfur dioxide (SO2), NOx, total suspensions (TSP) respectively. In females,the values of DGI were 0.6188, 0.8555, 0.5842 according to the same order as listed above. Significant positive correlation was found between the concentration of NOx and with lung cancer in both males and females by spearman correlation test (rmale = 0.63523, P = 0.0484; rfemale = 0.76396, P = 0.0101). CONCLUSION: With the fast growing speed of the quantity of vehicles, pollution of vehicle emission-caused air pollution posed an important risk factor for lung cancer, despite the fact that tobacco smoking still played the leading role.