[Effect of CT Value and CT Value Difference on the Pulmonary Arteriovenous Automatic Extraction Function of the Medical Workstation].

This study aimed to evaluate the effect of pulmonary arteriovenous computed tomography (CT) value and CT value difference on the pulmonary arteriovenous automatic extraction ability of a medical workstation. We classified patients who previously underwent contrast-enhanced CT as those with a pulmonary arteriovenous CT value difference of <50 Hounsfield unit (HU) and ≥100 HU. The groups were further divided into four subgroups each, with a total of eight groups, based on low pulmonary arteriovenous CT values of 200 or more and <250 HU, 250 or more and <300 HU, 300 or more and <350 HU, and 350 HU or more. A radiographer conducted a visual evaluation, and we judged whether it could extract pulmonary arteries A1-A10 and pulmonary veins V1-V10 without errors. When the CT value difference was <50 HU, the low pulmonary arteriovenous CT value of 200 or more and <250 HU significantly decreased the extraction ability compared with the ≥350 HU group (p<0.05), but when the CT value difference was ≥100 HU, no difference in the CT value was found. The pulmonary arteriovenous CT value and CT value difference affect the pulmonary arteriovenous automatic extraction ability of the medical workstation, but revision by the creator is necessary because misrecognition is included even if a CT value and CT value difference is high.

Harnessing diversity towards the reconstructing of large scale gene regulatory networks.

Elucidating gene regulatory network (GRN) from large scale experimental data remains a central challenge in systems biology. Recently, numerous techniques, particularly consensus driven approaches combining different algorithms, have become a potentially promising strategy to infer accurate GRNs. Here, we develop a novel consensus inference algorithm, TopkNet that can integrate multiple algorithms to infer GRNs. Comprehensive performance benchmarking on a cloud computing framework demonstrated that (i) a simple strategy to combine many algorithms does not always lead to performance improvement compared to the cost of consensus and (ii) TopkNet integrating only high-performance algorithms provide significant performance improvement compared to the best individual algorithms and community prediction. These results suggest that a priori determination of high-performance algorithms is a key to reconstruct an unknown regulatory network. Similarity among gene-expression datasets can be useful to determine potential optimal algorithms for reconstruction of unknown regulatory networks, i.e., if expression-data associated with known regulatory network is similar to that with unknown regulatory network, optimal algorithms determined for the known regulatory network can be repurposed to infer the unknown regulatory network. Based on this observation, we developed a quantitative measure of similarity among gene-expression datasets and demonstrated that, if similarity between the two expression datasets is high, TopkNet integrating algorithms that are optimal for known dataset perform well on the unknown dataset. The consensus framework, TopkNet, together with the similarity measure proposed in this study provides a powerful strategy towards harnessing the wisdom of the crowds in reconstruction of unknown regulatory networks.

[Improvement of the Contrast Effects of Blood Vessels by Taking Internally Effervescent Agents in Abdominal Contrast-enhanced Computed Tomography].

PURPOSE: In preoperative contrast-enhanced computed tomography (CT) of the stomach, an effervescent agent is taken internally to stretch the wall of the stomach to allow evaluation of tumor depth. However, there are no reports on the effects of the effervescent agent on the contrast effects of arteries, veins, portal veins, and hepatic veins. The purpose of this study was to clarify the effects of an effervescent agent on the contrast effects of blood vessels in abdominal contrast-enhanced CT. METHODS: The subjects were 60 preoperative gastric or pancreatic CT patients who underwent contrast-enhanced CT either with or without the effervescent agent. CT attenuations of the vessels were measured. RESULTS: CT attenuations of the left gastric artery, left gastroepiploic artery, right gastroepiploic artery, left gastric vein, left gastroepiploic vein, right gastroepiploic vein, portal vein, and hepatic vein were significantly higher (p<0.01) when the effervescent agent was taken. CONCLUSION: In abdominal contrast-enhancement CT, CT attenuations of the left gastric artery, left gastroepiploic artery, right gastroepiploic artery, left gastric vein, left gastroepiploic vein, right gastroepiploic vein, portal vein, and hepatic vein were found to be higher when the patient was administered the effervescent agent.

Fluorescent supramolecular mechanophores based on charge-transfer interactions.

Supramolecular mechanofluorophores based on charge-transfer (CT) interactions between fluorescent pyrene and naphthalene diimide(s) with a tandem structure are newly developed and incorporated into the mid-chain of poly(ε-caprolactone)s. The fluorescence (FL) is quenched by the intramolecular CT interactions even at low concentrations both in solution and in the polymer matrix, and turn-on FL is induced upon application of mechanical forces.

Histone modification alteration coordinated with acquisition of promoter DNA methylation during Epstein-Barr virus infection.

Aberrant DNA hypermethylation is a major epigenetic mechanism to inactivate tumor suppressor genes in cancer. Epstein-Barr virus positive gastric cancer is the most frequently hypermethylated tumor among human malignancies. Herein, we performed comprehensive analysis of epigenomic alteration during EBV infection, by Infinium HumanMethylation 450K BeadChip for DNA methylation and ChIP-sequencing for histone modification alteration during EBV infection into gastric cancer cell line MKN7. Among 7,775 genes with increased DNA methylation in promoter regions, roughly half were "DNA methylation-sensitive" genes, which acquired DNA methylation in the whole promoter regions and thus were repressed. These included anti-oncogenic genes, e.g. CDKN2A. The other half were "DNA methylation-resistant" genes, where DNA methylation is acquired in the surrounding of promoter regions, but unmethylated status is protected in the vicinity of transcription start site. These genes thereby retained gene expression, and included DNA repair genes. Histone modification was altered dynamically and coordinately with DNA methylation alteration. DNA methylation-sensitive genes significantly correlated with loss of H3K27me3 pre-marks or decrease of active histone marks, H3K4me3 and H3K27ac. Apoptosis-related genes were significantly enriched in these epigenetically repressed genes. Gain of active histone marks significantly correlated with DNA methylation-resistant genes. Genes related to mitotic cell cycle and DNA repair were significantly enriched in these epigenetically activated genes. Our data show that orchestrated epigenetic alterations are important in gene regulation during EBV infection, and histone modification status in promoter regions significantly associated with acquisition of de novo DNA methylation or protection of unmethylated status at transcription start site.

Epigenomic Regulation of Smad1 Signaling During Cellular Senescence Induced by Ras Activation.

Epigenomic modification plays important roles in regulating gene expression during development, differentiation, and cellular senescence. When oncogenes are activated, cells fall into stable growth arrest to block cellular proliferation, which is called oncogene-induced senescence. We recently identified through genome-wide analyses that Bmp2-Smad1 signal and its regulation by harmonized epigenomic alteration play an important role in Ras-induced senescence of mouse embryonic fibroblasts. We describe in this chapter the methods for analyses of epigenomic alteration and Smad1 targets on genome-wide scale.

PRC2 overexpression and PRC2-target gene repression relating to poorer prognosis in small cell lung cancer.

Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. Expression array analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq for H3K27me3 suggested that genes with H3K27me3(+) in SCLC were extended not only to PRC2-target genes in ES cells but also to other target genes such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were repressed significantly, and introduction of the most repressed gene JUB into SCLC cell line lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of JUB alone, or a set of four genes including H3K27me3(+) genes. Treatment with EZH2 inhibitors, DZNep and GSK126, resulted in growth repression of SCLC cell lines. High PRC2 expression was suggested to contribute to gene repression in SCLC, and may play a role in genesis of SCLC.