120 research outputs found

    Asymptotic Learning Curve and Renormalizable Condition in Statistical Learning Theory

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    Bayes statistics and statistical physics have the common mathematical structure, where the log likelihood function corresponds to the random Hamiltonian. Recently, it was discovered that the asymptotic learning curves in Bayes estimation are subject to a universal law, even if the log likelihood function can not be approximated by any quadratic form. However, it is left unknown what mathematical property ensures such a universal law. In this paper, we define a renormalizable condition of the statistical estimation problem, and show that, under such a condition, the asymptotic learning curves are ensured to be subject to the universal law, even if the true distribution is unrealizable and singular for a statistical model. Also we study a nonrenormalizable case, in which the learning curves have the different asymptotic behaviors from the universal law

    A Case of Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombus Refractory to Epirubicin That Showed Marked Decrease in Tumor Markers after Transcatheter Arterial Infusion with Miriplatin

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    Miriplatin, a cisplatin derivative with a high affinity for iodized ethyl esters of fatty acids from poppy seed oil, is a novel chemotherapeutic agent designed for use in the transarterial treatment of hepatocellular carcinoma (HCC). Here, we describe transcatheter arterial infusion (TAI) using miriplatin to treat a case of advanced HCC with portal vein tumor thrombus (PVTT) refractory to TAI with epirubicin. A 66-year-old man with advanced hepatitis C virus-related HCC with PVTT in the right lobe of the liver was treated with TAI with epirubicin suspended in iodized oil; however, tumor marker levels (alpha-fetoprotein and des-gamma-carboxy protein) did not decrease. Next, he was treated twice with TAI with miriplatin suspended in iodized oil. The tumor marker levels markedly decreased to a nearly normal range and the size of the main tumor was markedly reduced according to dynamic computed tomography. No serious adverse events occurred during the course of treatment with TAI and miriplatin. Therefore, we suggest that TAI with miriplatin is a safe and effective treatment option for advanced HCCs refractory to TAI with epirubicin

    Runx3 regulates folliculogenesis and steroidogenesis in granulosa cells of immature mice

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    We previously demonstrated that female Runx3 knockout (Runx3-/-) mice were anovulatory and their uteri were atrophic and that Runx3 mRNA was expressed in granulosa cells. To clarify how Runx3 regulates folliculogenesis and ovulation, we examine the effects of Runx3 knockout on the gene expression of growth factors associated with folliculogenesis and enzymes associated with steroidogenesis. In Runx3-/- mouse ovaries, the numbers of primary and antral follicles were lower than those in wild-type (wt) mice at 3 weeks of age, indicating that the loss of Runx3 affects folliculogenesis. The expression of genes encoding activin and inhibin subunits (Inha, Inhba and Inhbb) was also decreased in ovaries from the Runx3-/- mice compared with that in wt mice. Moreover, the expression of the genes Cyp11a1 and Cyp19a1 encoding steroidogenic enzymes was also decreased. In cultured granulosa cells from 3-week-old mouse ovaries, Cyp19a1 mRNA levels were lower in Runx3-/- mice than those in wt mice. Follicle-stimulating hormone (FSH) treatment increased Cyp19a1 mRNA levels in both wt and Runx3-/- granulosa cells in culture but the mRNA level in Runx3-/- granulosa cells was lower than that in wt ones, indicating that granulosa cells could not fully function in the absence of Runx3. At 3 weeks of age, gonadotropin α subunit, FSHβ subunit and luteinizing hormone (LH) β subunit mRNA levels were decreased in Runx3-/- mice. These findings suggest that Runx3 plays a key role in female reproduction by regulating folliculogenesis and steroidogenesis in granulosa cells

    The effect of pegylated interferon-alpha2b and ribavirin combination therapy for chronic hepatitis C infection in elderly patients

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    <p>Abstract</p> <p>Background</p> <p>The clearance of hepatitis C virus infection by interferon therapy significantly reduces the incidence of hepatocellular carcinoma and death in elderly chronic hepatitis patients. However, there are few reports concerning the efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients. The aims of the present study were to examine the effect and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in 427 patients with chronic hepatitis C infection. We compared the rates of sustained virological response--defined as the absence of detectable hepatitis C virus in serum 24 weeks after the treatment ended--and the treatment discontinuation rate between 319 younger patients aged < 65 years and 108 elderly patients aged ≥ 65 years. We also examined the factors contributing to a sustained virological response.</p> <p>Results</p> <p>There was no significant difference in the sustained virological response rate between younger patients and elderly patients according to their hepatitis C virus genotype (41.5% (100/241) and 40.7% (35/86) for genotype 1; <it>P </it>= 0.899, 89.7% (70/78) and 86.4% (19/22) for genotype 2; <it>P </it>= 0.703, respectively). There was also no significant difference in the treatment discontinuation rate between the two age groups (10.3% (33/319) and 13.9% (15/108), respectively; <it>P </it>= 0.378). There were no serious adverse events requiring hospitalization. The factors contributing significantly to a sustained virological response in elderly patients were gender, hepatitis C virus genotype, platelet count, and the presence of a rapid or early virological response (undetectable hepatitis C virus in serum at weeks 4 or 12 of treatment, respectively). However, upon multivariate analysis, the presence of an early virological response was the only significant factor (odds ratio: 0.115, 95% confidence interval: 0.040- 0.330, <it>P </it>< 0.001).</p> <p>Conclusions</p> <p>The efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients are not always inferior to those in younger patients. Obtaining an early virological response may be essential to achieve a sustained virological response in elderly patients with chronic hepatitis C infection.</p

    Phosphoproteomics-Based Modeling Defines the Regulatory Mechanism Underlying Aberrant EGFR Signaling

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    BACKGROUND: Mutation of the epidermal growth factor receptor (EGFR) results in a discordant cell signaling, leading to the development of various diseases. However, the mechanism underlying the alteration of downstream signaling due to such mutation has not yet been completely understood at the system level. Here, we report a phosphoproteomics-based methodology for characterizing the regulatory mechanism underlying aberrant EGFR signaling using computational network modeling. METHODOLOGY/PRINCIPAL FINDINGS: Our phosphoproteomic analysis of the mutation at tyrosine 992 (Y992), one of the multifunctional docking sites of EGFR, revealed network-wide effects of the mutation on EGF signaling in a time-resolved manner. Computational modeling based on the temporal activation profiles enabled us to not only rediscover already-known protein interactions with Y992 and internalization property of mutated EGFR but also further gain model-driven insights into the effect of cellular content and the regulation of EGFR degradation. Our kinetic model also suggested critical reactions facilitating the reconstruction of the diverse effects of the mutation on phosphoproteome dynamics. CONCLUSIONS/SIGNIFICANCE: Our integrative approach provided a mechanistic description of the disorders of mutated EGFR signaling networks, which could facilitate the development of a systematic strategy toward controlling disease-related cell signaling
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