Characterization of breast lesions using diffusion kurtosis model-based imaging: An initial experience.

OBJECTIVE: To investigate the characterization of breast lesions using diffusion kurtosis model-based imaging. METHODS: This prospective study included 120 consecutive patients underwent preoperative DCE-MRI examinations and multi-b-value diffusion-weighted imaging (DWI). Among them, 88 malignant lesions and 44 benign lesions were detected, 56 normal fibroglandular breast tissue were selected as normal control. Conventional apparent diffusion coefficient (ADC), DKI-based parameters mean kurtosis (MK) and mean diffusivity (MD) were analyzed by lesions types and histological subtypes using one-way ANOVA and receiver operating characteristic (ROC) curve. RESULTS: (1) The malignant group showed significantly lower ADC and MD (1.07±0.32×10-3 mm2/s and 1.30±0.40×10-3 mm2/s, respectively) and higher MK (0.87±0.18) than those in the benign group (1.29±0.26×10-3 mm2/s, 1.62±0.31×10-3 mm2/s and 0.67±0.18) and control group (1.67±0.33×10-3 mm2/s, 2.24±0.28×10-3 mm2/s and 0.52±0.08) with all P < 0.001. (2) Areas under ROC curve (AUC) for diagnosing malignant lesions were 0.936 for MD, 0.911 for MK and 0.897 for ADC, respectively. AUC for MD was significantly higher than that for ADC (P = 0.015). The optimal cut-off value, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were as follow: ADC = 1.18×10-3mm2/s, 78.3%, 93.2%, 81.2%, 81.6%, 81.4%; MD = 1.48×10-3mm2/s, 82.2%, 98.3%, 84.4%, 87.8%, 86.2%; MK = 0.78, 91.5%, 85.3%, 89.0%, 85.8%, 87.2%. (3) Invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS) and mucinous adenocarcinoma also showed significant differences among ADC, MD and MK (with P < 0.05). CONCLUSIONS: MR-DKI parameters enable to improve breast lesion characterization and have diagnostic potential applying to different pathological subtypes of breast cancers.

Extensive diversity of Rickettsiales bacteria in two species of ticks from China and the evolution of the Rickettsiales.

BACKGROUND: Bacteria of the order Rickettsiales (Alphaproteobacteria) are obligate intracellular parasites that infect species from virtually every major eukaryotic lineage. Several rickettsial genera harbor species that are significant emerging and re-emerging pathogens of humans. As species of Rickettsiales are associated with an extremely diverse host range, a better understanding of the historical associations between these bacteria and their hosts will provide important information on their evolutionary trajectories and, particularly, their potential emergence as pathogens. RESULTS: Nine species of Rickettsiales (two in the genus Rickettsia, three in the genus Anaplasma, and four in the genus Ehrlichia) were identified in two species of hard ticks (Dermacentor nuttalli and Hyalomma asiaticum) from two geographic regions in Xinjiang through genetic analyses of 16S rRNA, gltA, and groEL gene sequences. Notably, two lineages of Ehrlichia and one lineage of Anaplasma were distinct from any known Rickettsiales, suggesting the presence of potentially novel species in ticks in Xinjiang. Our phylogenetic analyses revealed some topological differences between the phylogenies of the bacteria and their vectors, which led us to marginally reject a model of exclusive bacteria-vector co-divergence. CONCLUSIONS: Ticks are an important natural reservoir of many diverse species of Rickettsiales. In this work, we identified a single tick species that harbors multiple species of Rickettsiales, and uncovered extensive genetic diversity of these bacteria in two tick species from Xinjiang. Both bacteria-vector co-divergence and cross-species transmission appear to have played important roles in Rickettsiales evolution.

Association of a LSP1 gene rs3817198T>C polymorphism with breast cancer risk: evidence from 33,920 cases and 35,671 controls.

Published data on the association between lymphocyte-specific protein 1 (LSP1) rs3817198T>C polymorphism and breast cancer risk are inconclusive. Hence, we conducted a meta-analysis of the LSP1 gene and risk of breast cancer to obtain the most reliable estimate of the association. PubMed, Embase and Web of Science databases were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between the LSP1 rs3817198T>C polymorphism and risk of breast cancer. A total of seven eligible studies including 33,920 cases and 35,671 controls based on the search criteria were involved in this meta-analysis. The distributions of genotypes in the controls were all in agreement with Hardy-Weinberg equilibrium. We observed that the LSP1 rs3817198T>C polymorphism was significantly correlated with breast cancer risk when all studies were pooled into the meta-analysis (the allele contrast model: OR = 1.06, 95% CI = 1.04-1.08; the homozygote codominant: OR = 1.14, 95% CI = 1.01-1.28). In the stratified analysis by ethnicity, significant association was observed in Caucasians for CC versus TT homozygote codominant model (OR = 1.25; 95% CI = 1.03-1.52) and for the recessive model (OR = 1.22; 95% CI = 1.02-1.47). There was significant association observed in Africans for CC versus TT homozygote codominant model (OR = 0.45; 95% CI = 0.22-0.92) and for the recessive model (OR = 0.43; 95% CI=0.22-0.88). Also, significant association was observed in mixed ethnicities for CC versus TT homozygote codominant model (OR = 1.12; 95% CI = 1.05-1.19). When stratified by study design, statistically significantly elevated risk was found in nested case-control studies (CC vs. TT: OR = 1.12, 95% CI = 1.05-1.19). But no significant association was observed for all comparison models between LSP1 rs3817198T>C polymorphism and breast cancer risk in hospital-based and people-based studies. When stratified by BRCA1 mutation carriers status, statistically significantly elevated risk was found in this meta-analysis (the allele contrast model: OR = 1.07, 95% CI = 1.01-1.14; the dominant model: OR = 1.09, 95% CI = 1.00-1.18). And significant association was found in the BRCA2 mutation carriers in the allele contrast (OR = 1.11, 95% CI = 1.03-1.20), the homozygote codominant (OR = 1.23, 95% CI = 1.04-1.47), the heterozygote codominant (OR = 1.12, 95% CI = 1.00-1.25) and the dominant models (OR = 1.14, 95% CI = 1.03-1.27). There was significant association between LSP1 rs3817198T>C polymorphism and breast cancer risk in BRCA1 and BRCA2 positive cohort in all comparison models (the allele contrast model: OR = 1.08, 95% CI = 1.03-1.13; CC vs. TT: OR = 1.16, 95% CI = 1.05-1.29; TC vs. TT: OR = 1.09, 95% CI = 1.01-1.16; the dominant model: OR = 1.10, 95% CI = 1.03-1.17; the recessive model: OR = 1.12, 95% CI = 1.01-1.23). In conclusion, this meta-analysis suggests that the LSP1 rs3817198T>C polymorphism is a low-penetrant risk factor for developing breast cancer but may not be in Africans.

[Meta-analysis of association of tumor necrosis factor alpha-308 gene promoter polymorphism with gastric cancer].

OBJECTIVE: To assess the association between tumor necrosis factor-alpha (TNF-alpha) gene promoter region -308 gene polymorphisms and gastric cancer (GC) susceptibility. METHODS: Published work about TNF-alpha-308 and GC from PubMed, EMBASE, Cochrane library in English and from Wanfang, CBM in Chinese were searched for relevant articles published by the end of July, 2009. Thirty-nine relevant articles were selected and 26 of them met the criteria. The correlated index was extracted for aggregate analysis in RevMan 4.2. RESULTS: There were 5225 GC patients and 8473 controls for TNF-alpha-308 in 26 papers. Overall, allele contrast (G:A and AA:GG) genotype of TNF-alpha-308 polymorphisms produced significant results in worldwide populations, the OR values were 0.85 (95%CI: 0.76 - 0.96, P = 0.01) and 1.19 (95%CI: 1.01 - 1.39, P = 0.03). Subgroup analysis showed that OR values of G:A and AA:GG in west population were 0.79 (95%CI: 0.70 - 0.89, P < 0.01) and 1.26 (95%CI: 1.04 - 1.52, P = 0.02), while in east populations subgroup analysis, the OR was 0.97 (95%CI: 0.75 - 1.26, P = 0.84). No significant association was observed in non-cardia GC and Helicobacter pylori positive GC, the OR values were 0.90 (95%CI: 0.79 - 1.02, P = 0.10) and 1.08 (95%CI: 0.62 - 1.88, P = 0.79). CONCLUSION: TNF-alpha-308 A allele and AA genotype were associated with a statistically significant increased risk of gastric cancer in western people.