324 research outputs found

    Nonlinear renewal theorems for random walks with perturbations of intermediate order

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    We develop nonlinear renewal theorems for a perturbed random walk without assuming stochastic boundedness of centered perturbation terms. A second order expansion of the expected stopping time is obtained via the uniform integrability of the difference between certain linear and nonlinear stopping rules. An intermediate renewal theorem is obtained which provides expansions between the nonlinear versions of the elementary and regular renewal theorems. The expected sample size of a two-sample rank sequential probability ratio test is considered as the motivating example.Comment: Published at http://dx.doi.org/10.1214/074921706000000671 in the IMS Lecture Notes--Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    The Neutral Self-Assembling Peptide Hydrogel SPG-178 as a Topical Hemostatic Agent

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    Conventional self-assembling peptide hydrogels are effective as topical hemostatic agents. However, there is a possibility to harm living tissues due to their low pH. The aim of the present study was to demonstrate the efficacy of SPG-178, a neutral self-assembling peptide hydrogel, as a topical hemostatic agent. First, we measured the bleeding duration of incisions made on rat livers after application of SPG-178 (1.0% w/v), SPG-178 (1.5% w/v), RADA16 (1.0% w/v), and saline (n = 12/group). Second, we observed the bleeding surfaces by transmission electron microscopy immediately after hemostasis. Third, we measured the elastic and viscous responses (G′ and G″, respectively) of the hydrogels using a rheometer. Our results showed that bleeding duration was significantly shorter in the SPG-178 group than in the RADA16 group and that there were no significant differences in transmission electron microscopy findings between the groups. The greater the G′ value of a hydrogel, the shorter was the bleeding duration. We concluded that SPG-178 is more effective and has several advantages: it is non-biological, transparent, nonadherent, and neutral and can be sterilized by autoclaving

    α-Synuclein Transgenic Drosophila As a Model of Parkinson's Disease and Related Synucleinopathies

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    α-Synuclein (α-Syn) is a major component of protein inclusions known as Lewy bodies, which are hallmarks of synucleinopathies such as Parkinson's disease (PD). The α-Syn gene is one of the familial PD-causing genes and is also associated with an increased risk of sporadic PD. Numerous studies using α-Syn expressing transgenic animals have indicated that α-Syn plays a critical role in the common pathogenesis of synucleinopathies. Drosophila melanogaster has several advantages for modeling human neurodegenerative diseases and is widely used for studying their pathomechanisms and therapies. In fact, Drosophila models expressing α-Syn have already been established and proven to replicate several features of human PD. In this paper, we review the current research on synucleinopathies using α-Syn Drosophila models and, moreover, explore the possibilities of these models for comprehensive genetic analyses and large-scale drug screening towards elucidating the molecular pathogenesis and developing therapies for synucleinopathies

    Intraprostatic Botulinum Neurotoxin Type A Injection for Benign Prostatic Hyperplasia:Preliminary Results with a Newly Purified Neurotoxin

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    Several studies have demonstrated the efficacy of intraprostatic injection of botulinum neurotoxin type A (BoNT/A) against symptomatic benign prostatic hyperplasia (BPH). The most commonly used BoNT/A product, Botox®, forms large complexes and composed of neurotoxin (NTX) as well as non-toxic components. We purified NTX lacking non-toxic components. We investigated the efficacy of this newly purified NTX for men with BPH. Ten male patients (mean age, 70.0 years) with BPH received 100 units (prostate volume [PV] <30ml) or 200 units (PV ァ30ml) of NTX injected into the prostate via a minimally invasive outpatient technique. Evaluation included uroflowmetry, postvoid residual urine volume (PVR), PV, and International Prostate Symptom Score (IPSS) measured at baseline and 1, 3, 6, and 12 months post-treatment. The status of 7 of the 10 patients examined was found to have improved within 1 month of treatment. The mean IPSS decreased from 23.8±7.0 to 16.3±10.3 (p=0.0093) at 1 month, to 14.9±8.2 (p=0.0074) at 3 months, and to 16.9±7.3 (p=0.018) at 12 months. The mean PV decreased from 47.8±21.2 to 39.2±19.5ml (p=0.0076) at 3 months. The PVR improved at 3 and 6 months post-treatment. Intraprostatic NTX injection induces prostate shrinkage and is effective in men with BPH

    Positioning device for outdoor mobile robots using optical sensors and lasers

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    We propose a novel method for positioning a mobile robot in an outdoor environment using lasers and optical sensors. Position estimation via a noncontact optical method is useful because the information from the wheel odometer and the global positioning system in a mobile robot is unreliable in some situations. Contact optical sensors such as computer mouse are designed to be in contact with a surface and do not function well in strong ambient light conditions. To mitigate the challenges of an outdoor environment, we developed an optical device with a bandpass filter and a pipe to restrict solar light and to detect translation. The use of two devices enables sensing of the mobile robot’s position, including posture. Furthermore, employing a collimated laser beam allows measurements against a surface to be invariable with the distance to the surface. In this paper, we describe motion estimation, device configurations, and several tests for performance evaluation. We also present the experimental positioning results from a vehicle equipped with our optical device on an outdoor path. Finally, we discuss an improvement in postural accuracy by combining an optical device with precise gyroscopes

    Development of New Functional Feed that Utilizes Yacon (\u3cem\u3eSmallanthus sonchifolius\u3c/em\u3e) and Rush (\u3cem\u3eJuncus effuses\u3c/em\u3e L.) in Japan

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    Yacon (Smallanthus sonchifolius) is acknowledged as a food as well as a medicinal plant and its cultivation in Ja-pan has recently expanded. Rush (Juncus effuses L.) which is widely distributed in the temperate regions in the north-ern hemisphere, has historically been used as a herbal medicine for nephritis and dermal disorders. However, there is a lot of harvest residue of both plants. This research was conducted to find out the way for the effective use of these residues as functional feed resources

    Directed Differentiation of Patient-Specific Induced Pluripotent Stem Cells Identifies the Transcriptional Repression and Epigenetic Modification of NKX2-5, HAND1, and NOTCH1 in Hypoplastic Left Heart Syndrome

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    The genetic basis of hypoplastic left heart syndrome (HLHS) remains unknown, and the lack of animal models to reconstitute the cardiac maldevelopment has hampered the study of this disease. This study investigated the altered control of transcriptional and epigenetic programs that may affect the development of HLHS by using disease-specific induced pluripotent stem (iPS) cells. Cardiac progenitor cells (CPCs) were isolated from patients with congenital heart diseases to generate patient-specific iPS cells. Comparative gene expression analysis of HLHS- and biventricle (BV) heart-derived iPS cells was performed to dissect the complex genetic circuits that may promote the disease phenotype. Both HLHS- and BV heart-derived CPCs were reprogrammed to generate disease-specific iPS cells, which showed characteristic human embryonic stem cell signatures, expressed pluripotency markers, and could give rise to cardiomyocytes. However, HLHS-iPS cells exhibited lower cardiomyogenic differentiation potential than BV-iPS cells. Quantitative gene expression analysis demonstrated that HLHS-derived iPS cells showed transcriptional repression of NKX2-5, reduced levels of TBX2 and NOTCH/HEY signaling, and inhibited HAND1/2 transcripts compared with control cells. Although both HLHS-derived CPCs and iPS cells showed reduced SRE and TNNT2 transcriptional activation compared with BV-derived cells, co-transfection of NKX2-5, HAND1, and NOTCH1 into HLHS-derived cells resulted in synergistic restoration of these promoters activation. Notably, gain- and loss-of-function studies revealed that NKX2-5 had a predominant impact on NPPA transcriptional activation. Moreover, differentiated HLHS-derived iPS cells showed reduced H3K4 dimethylation as well as histone H3 acetylation but increased H3K27 trimethylation to inhibit transcriptional activation on the NKX2-5 promoter. These findings suggest that patient-specific iPS cells may provide molecular insights into complex transcriptional and epigenetic mechanisms, at least in part, through combinatorial expression of NKX2-5, HAND1, and NOTCH1 that coordinately contribute to cardiac malformations in HLHS

    ヒト膵癌におけるNectin-4発現の腫瘍増殖、血管新生に対する効果と臨床的意義

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    BACKGROUND: Nectin-4 belongs to the nectin family that has diverse physiological and pathological functions in humans. Recent studies have also suggested some roles for Nectin-4 in several human cancers. However, the precise roles and clinical relevance of Nectin-4 in tumors are largely unknown. METHODS: Nectin-4 expression was investigated in 123 patients with pancreatic cancer by immunohistochemistry. Furthermore, we investigated the association of Nectin-4 in pancreatic cancer with tumor proliferation, angiogenesis and immunity by using immunohistochemistry and siRNA interference method. RESULTS: Patients with high Nectin-4 expression had poorer postoperative prognosis than those with low expression. Importantly, multivariate analysis indicated that Nectin-4 expression had a significant independent prognostic value in pancreatic cancer (HR = 1.721, 1.085-2.730; P = 0.021). Tumor Nectin-4 expression was significantly correlated with Ki67 expression. In addition, siRNA-mediated gene silencing of Nectin-4 significantly inhibited the cell proliferation in human pancreatic cancer cells, Capan-2 and BxPC-3. Furthermore, Nectin-4 expression was also positively correlated with VEGF expression and intratumoral microvessel density. However, there were no significant correlations of tumor Nectin-4 expression with tumor-infiltrating T cells. CONCLUSION: Nectin-4 is a significant prognostic predictor, and may play a critical role in pancreatic cancer. Nectin-4 may be novel therapeutic target for pancreatic cancer.博士(医学)・乙第1400号・平成29年6月28日Copyright © Nishiwada et al.; licensee BioMed Central. 2015 : This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
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