365 research outputs found

    Energetics of genome complexity?

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    The absence of genome complexity in prokaryotes, being the evolutionary precursors to eukaryotic cells comprising all complex life (the prokaryote–eukaryote divide), is a long-standing question in evolutionary biology. A previous study hypothesized that the divide exists because prokaryotic genome size is constrained by bioenergetics (prokaryotic power per gene or genome being significantly lower than eukaryotic ones). However, this hypothesis was evaluated using a relatively small dataset due to lack of data availability at the time, and is therefore controversial. Accordingly, we constructed a larger dataset of genomes, metabolic rates, cell sizes and ploidy levels to investigate whether an energetic barrier to genome complexity exists between eukaryotes and prokaryotes while statistically controlling for the confounding effects of cell size and phylogenetic signals. Notably, we showed that the differences in bioenergetics between prokaryotes and eukaryotes were less significant than those previously reported. More importantly, we found a limited contribution of power per genome and power per gene to the prokaryote–eukaryote dichotomy. Our findings indicate that the prokaryote–eukaryote divide is hard to explain from the energetic perspective. However, our findings may not entirely discount the traditional hypothesis; in contrast, they indicate the need for more careful examination

    Adversarial attacks on voter model dynamics in complex networks

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    This paper investigates adversarial attacks conducted to distort voter model dynamics in complex networks. Specifically, a simple adversarial attack method is proposed to hold the state of opinions of an individual closer to the target state in the voter model dynamics. This indicates that even when one opinion is the majority the vote outcome can be inverted (i.e., the outcome can lean toward the other opinion) by adding extremely small (hard-to-detect) perturbations strategically generated in social networks. Adversarial attacks are relatively more effective in complex (large and dense) networks. These results indicate that opinion dynamics can be unknowingly distorted

    ホコウ カクトク チエン オ シメシタ ノウセイ マヒ ケイチョクガタ リョウマヒジ

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    There have been concerns for the child with cerebral palsy (CP) to get to walk independently among thepeople who involved the habilitation of CP. Especially physical therapist (PT) have been in charge ofgetting to walk. Although many of the children with CP have had the benefit, on the other hand, some arenot effective despite of the consumption of long time, labor and cost. Based on some reviews, the study ofthe prognosis of getting independent walking of CP by the medical doctors, physical therapists and othersis vigorous. Reviewing the studies on the prognosis of walking of CP children, there are some view points. Thesereviews are the prospective studies of the capability of future gait due to their early motor dvelopment,the critical age of getting walking and the capability of gaint due to different type of CP and others. There are many studies about CP with spastic diplegia. They said that the child with CP could get towalk when the child had acquired neck control within 9 months, rolling and crawling and sitting withsupport at 0 year, independent sitting until 24 months (at the latest 4 years) and creeping on all foursreciprocally between one and a half years and 2 and a half years. Getting independent walking washopeless when the children were older than 8 years. I have experienced the child with CP spastic diplegia walked at the age of 9 years and 3 months over 8years, the critical age of getting walking. I want to represent this case as one example who had gotindependent walking over 8 years, showing the aims and programs of PT and / or OT for him and hisprogress, and to consider the reasons why he got independent walking at that age

    ホコウ ホジョグ ノ キノウ ト ブンルイ リョウイク バメン デ シヨウサレル モノ オ チュウシンニ

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    The ultimate purpose of physical therapy (PT) in medical rehabilitation is to acquire the ability oflocomotion activity by means of walking motion. Therefore, it is very important for the patients with theimpairment of movement to improve their movemant function. But some of the patients are difficultyaquiring the standing posture and walking motion despite their efforts and PT. However if they could not stand and walk independently, we have another measure to do with it. That is,we can apply the walking apparatus. By applying those like canes or walkers, they could stand and walk.Therefore these walking apparatus are considered for the patients as the necessities and for the PT as thesymbol of our technique. In this paper, I want to represent the concept of locomotion activity, the conditions of standing andwalking, and the characteristics of the walking apparatus. I also want to show the relationship of motorability and the function of the walking apparatus

    Regulation of miR-200c and miR-141 by methylation in prostate cancer

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    BACKGROUND: In prostate cancer (PCa), abnormal expression of several microRNAs (miRNAs) has been previously reported. Increasing evidence shows that aberrant epigenetic regulation of miRNAs is a contributing factor to their altered expression in cancer. In this study, we investigate whether expression of miR‐200c and miR‐141 in PCa is related to the DNA methylation status of their promoter. METHODS: PCR analysis of miR‐200c and miR‐141, and CpG methylation analysis of their common promoter, was performed in PCa cell‐lines and in archived prostate biopsy specimens. The biological significance of miR‐200c and miR‐141 expression in prostate cancer cells was assessed by a series of in vitro bioassays and the effect on proposed targets DNMT3A and TET1/TET3 was investigated. The effect on promoter methylation status in cells treated with demethylating agents was also examined. RESULTS: miR‐200c and miR‐141 are both highly elevated in LNCaP, 22RV1, and DU145 cells, but significantly reduced in PC3 cells. This correlates inversely with the methylation status of the miR‐200c/miR‐141 promoter, which is unmethylated in LNCaP, 22RV1, and DU145 cells, but hypermethylated in PC3. In PC3 cells, miR‐200c and miR‐141 expression is subsequently elevated by treatment with the demethylating drug decitabine (5‐aza‐2′deoxycytidine) and by knockdown of DNA methyltransferase 1 (DNMT1), suggesting their expression is regulated by methylation. Expression of miR‐200c and miR‐141 in prostate biopsy tissue was inversely correlated with methylation in promoter CpG sites closest to the miR‐200c/miR‐141 loci. In vitro, over‐expression of miR‐200c in PC3 cells inhibited growth and clonogenic potential, as well as inducing apoptosis. Expression of the genes DNMT3A and TET1/TET3 were down‐regulated by miR‐200c and miR‐141 respectively. Finally, treatment with the soy isoflavone genistein caused demethylation of the promoter CpG sites closest to the miR‐200c/miR‐141 loci resulting in increased miR‐200c expression. CONCLUSIONS: Our findings provide evidence that miR‐200c and miR‐141 are under epigenetic regulation in PCa cells. We propose that profiling their expression and methylation status may have potential as a novel biomarker or focus of therapeutic intervention in the diagnosis and prognosis of PCa. Prostate 76:1146–1159, 2016. © 2016 The Authors. The Prostate published by Wiley Periodicals, Inc

    XRCC1 Arg194Trp polymorphism, risk of nonmelanoma skin cancer and extramammary Paget’s disease in a Japanese population

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    The X-ray repair cross-complementing groups 1 gene plays an important role in base excision repair. At least three common single nucleotide polymorphisms frequently occur in this gene (Arg399Gln, Arg194Trp and Arg280His). Recent studies reported that these polymorphisms were associated with not only risk of visceral malignancy but also that of skin cancer such as basal cell carcinoma and squamous cell carcinoma, whereas the results of previous study vary among races. In this case–control study, we investigated whether these single nucleotide polymorphisms were associated with the risk of skin cancer in a Japanese population. The study population was composed of 197 patients with skin cancer (27 actinic keratoses, 47 basal cell carcinomas, 27 squamous cell carcinomas, 29 Bowen’s diseases, 46 malignant melanomas and 21 extramammary Paget’s diseases) and 93 control subjects. We genotyped two single nucleotide polymorphisms (Arg194Trp and Arg399Gln) using polymerase chain reaction-restriction fragments length polymorphism analysis. We found a significantly increased risk for basal cell carcinoma, squamous cell carcinoma and extramammary Paget’s disease associated with Arg194Trp [adjusted odds ratio (AOR) = 2.347, 3.587, 3.741, 95 % confidence interval (CI) 1.02–5.39, 1.19–10.8, 1.15–12.2, respectively]. We also found a significantly decreased risk for basal cell carcinoma associated with Gln399Gln (AOR = 0.259, 95 % CI 0.07–0.96). Our data suggest that the Arg194Trp polymorphism could be associated with nonmelanoma skin cancer and extramammary Paget’s disease risk in a Japanese population

    MiR-145 directly targets p70S6K1 in cancer cells to inhibit tumor growth and angiogenesis

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    MiR-145 can regulate cell apoptosis, proliferation, neural development and stem cell differentiation. Previous studies indicate that miR-145 is downregulated in human colon cancer cells. However, the molecular mechanisms of miR-145 used to regulate colon carcinogenesis and angiogenesis remain to be clarified. Here, we show that the expression of miR-145 is downregulated in colon and ovarian cancer tissues and cell lines. MiR-145 inhibits p70S6K1 post-transcriptional expression by binding to its 3′-UTR. The angiogenic factors hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF), which are downstream molecules of p70S6K1, are decreased by miR-145 overexpression. P70S6K1 rescues miR-145-suppressed HIF-1 and VEGF levels, tumorigenesis and tumor angiogenesis. Furthermore, the miR-145 level is inversely correlated with the amount of p70S6K1 protein in colon cancer tissues. Taken together, these studies suggest that miR-145 serves as a tumor suppressor which downregulates HIF-1 and VEGF expression by targeting p70S6K1, leading to the inhibition of tumor growth and angiogenesis. The miR-145 rescue could be a rationale for therapeutic applications in colon cancer in the future

    Identification of a hypoxia-regulated miRNA signature in bladder cancer and a role for miR-145 in hypoxia-dependent apoptosis

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    Background: Hypoxia leads to the stabilisation of the hypoxia-inducible factor (HIF) transcription factor that drives the expression of target genes including microRNAs (miRNAs). MicroRNAs are known to regulate many genes involved in tumourigenesis. The aim of this study was to identify hypoxia-regulated miRNAs (HRMs) in bladder cancer and investigate their functional significance. Methods: Bladder cancer cell lines were exposed to normoxic and hypoxic conditions and interrogated for the expression of 384 miRNAs by qPCR. Functional studies were carried out using siRNA-mediated gene knockdown and chromatin immunoprecipitations. Apoptosis was quantified by annexin V staining and flow cytometry. Results: The HRM signature for NMI bladder cancer lines includes miR-210, miR-193b, miR-145, miR-125-3p, miR-708 and miR-517a. The most hypoxia-upregulated miRNA was miR-145. The miR-145 was a direct target of HIF-1a and two hypoxia response elements were identified within the promoter region of the gene. Finally, the hypoxic upregulation of miR-145 contributed to increased apoptosis in RT4 cells. Conclusions: We have demonstrated the hypoxic regulation of a number of miRNAs in bladder cancer. We have shown that miR- 145 is a novel, robust and direct HIF target gene that in turn leads to increased cell death in NMI bladder cancer cell lines
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