199 research outputs found

    Serial optical coherence microscopy for label-free volumetric histopathology

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    The observation of histopathology using optical microscope is an essential procedure for examination of tissue biopsies or surgically excised specimens in biological and clinical laboratories. However, slide-based microscopic pathology is not suitable for visualizing the large-scale tissue and native 3D organ structure due to its sampling limitation and shallow imaging depth. Here, we demonstrate serial optical coherence microscopy (SOCM) technique that offers label-free, high-throughput, and large-volume imaging of ex vivo mouse organs. A 3D histopathology of whole mouse brain and kidney including blood vessel structure is reconstructed by deep tissue optical imaging in serial sectioning techniques. Our results demonstrate that SOCM has unique advantages as it can visualize both native 3D structures and quantitative regional volume without introduction of any contrast agents

    Excluding pulmonary embolism in primary care using the Wells-rule in combination with a point-of care D-dimer test: a scenario analysis

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    ABSTRACT: BACKGROUND: In secondary care the Wells clinical decision rule (CDR) combined with a quantitative D-dimer test can exclude pulmonary embolism (PE) safely. The introduction of point-of-care (POC) D-dimer tests facilitates a similar diagnostic strategy in primary care. We estimated failure-rate and efficiency of a diagnostic strategy using the Wells-CDR combined with a POC-D-dimer test for excluding PE in primary care. We considered ruling out PE safe if the failure rate was <2% with a maximum upper confidence limit of 2.7%. METHODS: We performed a scenario-analysis on data of 2701 outpatients suspected of PE. We used test characteristics of two qualitative POC-D-dimer tests, as derived from a meta-analysis and combined these with the Wells-CDR-score. RESULTS: In scenario 1 (SimpliRed-D-dimer sensitivity 85%, specificity 74%) PE was excluded safely in 23.8% of patients but only by lowering the cut-off value of the Wells rule to <2. (failure rate: 1.4%, 95% CI 0.6-2.6%) In scenario 2 (Simplify-D-dimer sensitivity 87%, specificity 62%) PE was excluded safely in 12.4% of patients provided that the Wells-cut-off value was set at 0. (failure rate: 0.9%, 95% CI 0.2-2.6%) CONCLUSION: Theoretically a diagnostic strategy using the Wells-CDR combined with a qualitative POC-D-dimer test can be used safely to exclude PE in primary care albeit with only moderate efficienc

    Asteroseismology and Interferometry

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    Asteroseismology provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Recent developments, including the first systematic studies of solar-like pulsators, have boosted the impact of this field of research within Astrophysics and have led to a significant increase in the size of the research community. In the present paper we start by reviewing the basic observational and theoretical properties of classical and solar-like pulsators and present results from some of the most recent and outstanding studies of these stars. We centre our review on those classes of pulsators for which interferometric studies are expected to provide a significant input. We discuss current limitations to asteroseismic studies, including difficulties in mode identification and in the accurate determination of global parameters of pulsating stars, and, after a brief review of those aspects of interferometry that are most relevant in this context, anticipate how interferometric observations may contribute to overcome these limitations. Moreover, we present results of recent pilot studies of pulsating stars involving both asteroseismic and interferometric constraints and look into the future, summarizing ongoing efforts concerning the development of future instruments and satellite missions which are expected to have an impact in this field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume 14, Issue 3-4, pp. 217-36

    To what degree does cognitive impairment in Alzheimer's disease predict dependence of patients on caregivers?

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    BACKGROUND: Patients with Alzheimer's disease experience a progressive loss of cognitive function, and the ability to independently perform activities of daily life. Sometimes a dependent stage is reached quite early in the disease, when caregivers decide that the patients can no longer be left alone safely. This is an important aspect of Alzheimer's for patients, their families, and also health care providers. Understanding the relationship between a patient's current cognitive status and their need for care may assist clinicians when recommending an appropriate management plan. In this study, we investigated the relationship of cognitive function to dependence on caregivers before the patients reach a severe stage of the disease. METHODS: Data were obtained on 1,289 patients with mild-to-moderate Alzheimer's disease studied in two randomised clinical trials of galantamine (Reminyl(®)). Cognition was assessed using the cognitive part of the Alzheimer's Disease Assessment Scale (ADAS-cog) and Mini-Mental State Examination (MMSE). Patients were considered dependent if they required >12 hours of supervision each day or had high care needs. The Disability Assessment for Dementia (DAD) scale was also used as a measure of dependence. Disability was predicted directly using MMSE and ADAS-cog and compared to predictions from converted scores. RESULTS: The odds ratio of dependence was significantly higher amongst the patients with worse cognitive impairment, adjusting for age, gender and antipsychotic medication use. For example, a 4-point difference in ADAS-cog score was associated with an increase of 17% (95% CI 11–23) in the adjusted odds for >12 hours of supervision, and of 35% (95% CI 28–43) for dependence. Disability predicted directly using actual ADAS-cog and scores converted from MMSE values had close agreement using the models developed. CONCLUSION: In patients with mild-to-moderate Alzheimer's disease, even relatively small degrees of poorer cognitive function increased the risk of losing the ability to live independently

    Dementia care initiative in primary practice – study protocol of a cluster randomized trial on dementia management in a general practice setting

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    <p>Abstract</p> <p>Background</p> <p>Current guidelines for dementia care recommend the combination of drug therapy with non-pharmaceutical measures like counselling and social support. However, the scientific evidence concerning non-pharmaceutical interventions for dementia patients and their informal caregivers remains inconclusive. Targets of modern comprehensive dementia care are to enable patients to live at home as long and as independent as possible and to reduce the burden of caregivers. The objective of the study is to compare a complex intervention including caregiver support groups and counselling against usual care in terms of time to nursing home placement. In this paper the study protocol is described.</p> <p>Methods/Design</p> <p>The IDA (Initiative Demenzversorgung in der Allgemeinmedizin) project is designed as a three armed cluster-randomized trial where dementia patients and their informal caregivers are recruited by general practitioners. Patients in the study region of Middle Franconia, Germany, are included if they have mild or moderate dementia, are at least 65 years old, and are members of the German AOK (Allgemeine Ortskrankenkasse) sickness fund. In the control group patients receive regular treatment, whereas in the two intervention groups general practitioners participate in a training course in evidence based dementia treatment, recommend support groups and offer counseling to the family caregivers either beginning at baseline or after the 1-year follow-up. The study recruitment and follow-up took place from July 2005 to January 2009. 303 general practitioners were randomized of which 129 recruited a total of 390 patients. Time to nursing home admission within the two year intervention and follow-up period is the primary endpoint. Secondary endpoints are cognitive status, activities of daily living, burden of care giving as well as healthcare costs. For an economic analysis from the societal perspective, data are collected from caregivers as well as by the use of routine data from statutory health insurance and long-term care insurance.</p> <p>Discussion</p> <p>From a public health perspective, the IDA trial is expected to lead to evidence based results on the community effectiveness of non-pharmaceutical support measures for dementia patients and their caregivers in the primary care sector. For health policy makers it is necessary to make their decisions about financing new services based on strong knowledge about the acceptance of measures in the population and their cost-effectiveness.</p> <p>Trial registration</p> <p>ISRCTN68329593</p

    SProtP: A Web Server to Recognize Those Short-Lived Proteins Based on Sequence-Derived Features in Human Cells

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    Protein turnover metabolism plays important roles in cell cycle progression, signal transduction, and differentiation. Those proteins with short half-lives are involved in various regulatory processes. To better understand the regulation of cell process, it is important to study the key sequence-derived factors affecting short-lived protein degradation. Until now, most of protein half-lives are still unknown due to the difficulties of traditional experimental methods in measuring protein half-lives in human cells. To investigate the molecular determinants that affect short-lived proteins, a computational method was proposed in this work to recognize short-lived proteins based on sequence-derived features in human cells. In this study, we have systematically analyzed many features that perhaps correlated with short-lived protein degradation. It is found that a large fraction of proteins with signal peptides and transmembrane regions in human cells are of short half-lives. We have constructed an SVM-based classifier to recognize short-lived proteins, due to the fact that short-lived proteins play pivotal roles in the control of various cellular processes. By employing the SVM model on human dataset, we achieved 80.8% average sensitivity and 79.8% average specificity, respectively, on ten testing dataset (TE1-TE10). We also obtained 89.9%, 99% and 83.9% of average accuracy on an independent validation datasets iTE1, iTE2 and iTE3 respectively. The approach proposed in this paper provides a valuable alternative for recognizing the short-lived proteins in human cells, and is more accurate than the traditional N-end rule. Furthermore, the web server SProtP (http://reprod.njmu.edu.cn/sprotp) has been developed and is freely available for users

    Timp1 interacts with beta-1 integrin and CD63 along melanoma genesis and confers anoikis resistance by activating PI3-K signaling pathway independently of Akt phosphorylation

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    Background: Anoikis resistance is one of the abilities acquired along tumor progression. This characteristic is associated with metastasis development, since tumorigenic cells must survive independently of cell-matrix interactions in this process. in our laboratory, it was developed a murine melanocyte malignant transformation model associated with a sustained stressful condition. After subjecting melan-a melanocytes to 1, 2, 3 and 4 cycles of anchorage impediment, anoikis resistant cells were established and named 1C, 2C, 3C and 4C, respectively. These cells showed altered morphology and PMA independent cell growth, but were not tumorigenic, corresponding to pre-malignant cells. After limiting dilution of 4C pre-malignant cells, melanoma cell lines with different characteristics were obtained. Previous data from our group showed that increased Timp1 expression correlated with anoikis-resistant phenotype. Timp1 was shown to confer anchorage-independent growth capability to melan-a melanocytes and render melanoma cells more aggressive when injected into mice. However, the mechanisms involved in anoikis regulation by Timp1 in tumorigenic cells are not clear yet.Methods: the beta 1-integrin and Timp1 expression were evaluated by Western blotting and CD63 protein expression by flow cytometry using specific antibodies. To analyze the interaction among Timp1, CD63 and beta 1-integrin, immunoprecipitation assays were performed, anoikis resistance capability was evaluated in the presence or not of the PI3-K inhibitors, Wortmannin and LY294002. Relative expression of TIMP1 and CD63 in human metastatic melanoma cells was analyzed by real time PCR.Results: Differential association among Timp1, CD63 and beta 1-integrins was observed in melan-a melanocytes, 4C pre-malignant melanocytes and 4C11- and 4C11+ melanoma cells. Timp1 present in conditioned medium of melanoma cells rendered melan-a melanocytes anoikis-resistant through PI3-K signaling pathway independently of Akt activation. in human melanoma cell lines, in which TIMP1 and beta-1 integrin were also found to be interacting, TIMP1 and CD63 levels together was shown to correlate significantly with colony formation capacity.Conclusions: Our results show that Timp1 is assembled in a supramolecular complex containing CD63 and beta 1-integrins along melanoma genesis and confers anoikis resistance by activating PI3-K signaling pathway, independently of Akt phosphorylation. in addition, our data point TIMP1, mainly together with CD63, as a potential biomarker of melanoma.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, Dept Pharmacol, São Paulo, BrazilUniversidade Federal de São Paulo, Microbiol Immunol & Parasitol Dept, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, São Paulo, BrazilLudwig Inst Canc Res, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pharmacol, São Paulo, BrazilUniversidade Federal de São Paulo, Microbiol Immunol & Parasitol Dept, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biochem, São Paulo, BrazilFAPESP: 2011/12306-1FAPESP: 2010/18715-8CAPES: 2867/10Web of Scienc

    Thiolutin is a zinc chelator that inhibits the Rpn11 and other JAMM metalloproteases

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    Thiolutin is a disulfide-containing antibiotic and anti-angiogenic compound produced by Streptomyces. Its biological targets are not known. We show that reduced thiolutin is a zinc chelator that inhibits the JAB1/MPN/Mov34 (JAMM) domain–containing metalloprotease Rpn11, a deubiquitinating enzyme of the 19S proteasome. Thiolutin also inhibits the JAMM metalloproteases Csn5, the deneddylase of the COP9 signalosome; AMSH, which regulates ubiquitin-dependent sorting of cell-surface receptors; and BRCC36, a K63-specific deubiquitinase of the BRCC36-containing isopeptidase complex and the BRCA1–BRCA2-containing complex. We provide evidence that other dithiolopyrrolones also function as inhibitors of JAMM metalloproteases

    Cooperative control of striated muscle mass and metabolism by MuRF1 and MuRF2

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    The muscle-specific RING finger proteins MuRF1 and MuRF2 have been proposed to regulate protein degradation and gene expression in muscle tissues. We have tested the in vivo roles of MuRF1 and MuRF2 for muscle metabolism by using knockout (KO) mouse models. Single MuRF1 and MuRF2 KO mice are healthy and have normal muscles. Double knockout (dKO) mice obtained by the inactivation of all four MuRF1 and MuRF2 alleles developed extreme cardiac and milder skeletal muscle hypertrophy. Muscle hypertrophy in dKO mice was maintained throughout the murine life span and was associated with chronically activated muscle protein synthesis. During ageing (months 4–18), skeletal muscle mass remained stable, whereas body fat content did not increase in dKO mice as compared with wild-type controls. Other catabolic factors such as MAFbox/atrogin1 were expressed at normal levels and did not respond to or prevent muscle hypertrophy in dKO mice. Thus, combined inhibition of MuRF1/MuRF2 could provide a potent strategy to stimulate striated muscles anabolically and to protect muscles from sarcopenia during ageing
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