1,198 research outputs found

    Development of Endoscopy

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    Success and failure factors in agricultural cooperatives

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    The paper presents an integrated framework of success and failure factors of agricultural cooperatives and its applicability based on a review of recent literature and an illustrative case study. We identify six categories of success and failure factors: the societal environment, quality of management, strategy, member base, commitment, and product aspects. Contrary to expectations that failure factors mirror success factors, the framework shows that the two represent distinctive features in at least some of the distinguished categories. The analysis of an agricultural cooperative in Peru, selected and presented as an illustrative case study, shows the applicability of the framework for the analysis of success and failure factors of cooperatives

    Efficient Computation of Three-Dimensional Flow in Helically Corrugated Hoses Including Swirl

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    In this article we propose an efficient method to compute the friction factor of helically corrugated hoses carrying flow at high Reynolds numbers. A comparison between computations of several turbulence models is made with experimental results for corrugation sizes that fall outside the range of validity of the Moody diagram. To do this efficiently we implement quasi-periodicity. Using the appropriate boundary conditions and matching body force, we only need to simulate a single period of the corrugation to find the friction factor for fully developed flow. A second technique is introduced by the construction of an appropriately twisted wedge, which allows us to furthermore reduce the problem by a further dimension while accounting for the Beltrami symmetry that is present in the full three-dimensional problem. We make a detailed analysis of the accuracy and time-saving that this novelty introduces. We show that the swirl inside the flow, which is introduced by the helical boundary, has a positive effect on the friction factor. Furthermore, we give a prediction for which corrugation angles the assumption of axisymmetry is no longer valid. It then has to make place for Beltrami-symmetry if accurate results are required

    The monoaminergic footprint of depression and psychosis in dementia with Lewy bodies compared to Alzheimer's disease

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    Introduction: Depression and psychosis are two of the most severe neuropsychiatric symptoms (NPS) in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Both NPS have negative effects on cognitive performance and life expectancy. The current study aimed to investigate and compare monoaminergic etiologies between both neurodegenerative conditions, given the lack of an efficient pharmacological treatment until present.Methods: Eleven behaviorally relevant brain regions of the left frozen hemisphere of 10 neuropathologically confirmed AD patients with/without depression (AD + D/-D; 5 were psychotic within AD + D), 10 confirmed DLB patients, all of whom were depressed (DLB + D; 5 psychotic patients), and, finally, 10 confirmed control subjects were regionally dissected. All patients were retrospectively assessed before death using the Behavioral Pathology in Alzheimer's Disease Rating Scale (Behave-AD) and Cornell Scale for Depression in Dementia amongst others. The concentrations of dopamine (DA), serotonin (5-HT), (nor) adrenaline and respective metabolites, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), 5-hydroxy-3-indoleacetic acid (5-HIAA), and, 3-methoxy-4-hydroxyphenylglycol (MHPG), were determined using reversed-phase high-performance liquid chromatography with electrochemical detection.Results: DLB subjects had the overall lowest monoamine and metabolite concentrations regarding 33 out of 41 significant monoaminergic group alterations. Moreover, MHPG levels were significantly decreased in almost 8 out of 11 brain regions of DLB-compared to AD patients. We also observed the lowest 5-HT and 5-HIAA levels, and 5-HIAA/5-HT turnover ratios in DLB + D compared to AD + D subjects. Additionally, a 4- and 7-fold increase of DOPAC/DA and HVA/DA turnover ratios, and, a 10-fold decrease of thalamic DA levels in DLB + D compared to AD + D patients and control subjects was noticed. Regarding psychosis, hippocampal DA levels in the overall DLB group significantly correlated with Behave-AD AB scores. In the total AD group, DA levels and HVA/DA ratios in the amygdala significantly correlated with Behave-AD AB scores instead.Conclusions: Monoaminergic neurotransmitter alterations contribute differently to the pathophysiology of depression and psychosis in DLB as opposed to AD, with a severely decreased serotonergic neurotransmission as the main monoaminergic etiology of depression in DLB. Similarly, psychosis in DLB might, in part, be etiologically explained by dopaminergic alterations in the hippocampus, whereas in AD, the amygdala might be involved.</p

    ZIC1 gene expression is controlled by DNA and histone methylation in mesenchymal proliferations

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    AbstractRNA and protein analysis revealed the consistent upregulation of the neural transcription factors ZIC1 and ZIC4 in desmoid tumors and other fibroproliferative disorders. The 5′ flanking region of the ZIC1 promoter was unmethylated in desmoid tumor fibroblasts, while a hypermethylated ZIC1 promoter was found in human and mouse cell lines not expressing the gene. In addition, expressing cells showed a H3K4me2 at the ZIC1 promoter, whereas non-expressing cells showed higher levels of H3K9me2 in the same region. To our knowledge, this is the first report describing ZIC1 expression in mesenchymal proliferations and a role for DNA methylation in the control of ZIC1 expression

    The Same IκBα Mutation in Two Related Individuals Leads to Completely Different Clinical Syndromes

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    Both innate and adaptive immune responses are dependent on activation of nuclear factor κB (NF-κB), induced upon binding of pathogen-associated molecular patterns to Toll-like receptors (TLRs). In murine models, defects in NF-κB pathway are often lethal and viable knockout mice have severe immune defects. Similarly, defects in the human NF-κB pathway described to date lead to severe clinical disease. Here, we describe a patient with a hyper immunoglobulin M–like immunodeficiency syndrome and ectodermal dysplasia. Monocytes did not produce interleukin 12p40 upon stimulation with various TLR stimuli and nuclear translocation of NF-κB was impaired. T cell receptor–mediated proliferation was also impaired. A heterozygous mutation was found at serine 32 in IκBα. Interestingly, his father has the same mutation but displays complex mosaicism. He does not display features of ectodermal dysplasia and did not suffer from serious infections with the exception of a relapsing Salmonella typhimurium infection. His monocyte function was impaired, whereas T cell function was relatively normal. Consistent with this, his T cells almost exclusively displayed the wild-type allele, whereas both alleles were present in his monocytes. We propose that the T and B cell compartment of the mosaic father arose as a result of selection of wild-type cells and that this underlies the widely different clinical phenotype

    Rectal Optical Markers for In-vivo Risk Stratification of Premalignant Colorectal Lesions.

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    Purpose: Colorectal cancer remains the second leading cause of cancer deaths in the U.S. despite being eminently preventable by colonoscopy via removal of premalignant adenomas. In order to more effectively reduce colorectal cancer mortality, improved screening paradigms are needed. Our group pioneered the use of low coherence enhanced backscattering (LEBS) spectroscopy to detect the presence of adenomas throughout the colon via optical interrogation of the rectal mucosa. In a previous ex-vivo biopsy study of 219 patients, LEBS demonstrated excellent diagnostic potential with 89.5% accuracy for advanced adenomas. The objective of the current cross-sectional study is to assess the viability of rectal LEBS in-vivo. Experimental Design: Measurements from 619 patients were taken using a minimally invasive 3.4 mm diameter LEBS probe introduced into the rectum via anoscope or direct insertion, requiring ~1 minute from probe insertion to withdrawal. The diagnostic LEBS marker was formed as a logistic regression of the optical reduced scattering coefficient μs∗ and mass density distribution factor D. Results: The rectal LEBS marker was significantly altered in patients harboring advanced adenomas and multiple non-advanced adenomas throughout the colon. Blinded and cross-validated test performance characteristics showed 88% sensitivity to advanced adenomas, 71% sensitivity to multiple non-advanced adenomas, and 72% specificity in the validation set. Conclusions: We demonstrate the viability of in-vivo LEBS measurement of histologically normal rectal mucosa to predict the presence of clinically relevant adenomas throughout the colon. The current work represents the next step in the development of rectal LEBS as a tool for colorectal cancer risk stratification

    Monoaminergic impairment in Down syndrome with Alzheimer's disease compared to early-onset Alzheimer's disease

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    Introduction: People with Down syndrome (DS) are at high risk for Alzheimer's disease (AD). Defects in monoamine neurotransmitter systems are implicated in DS and AD but have not been comprehensively studied in DS. Methods: Noradrenaline, adrenaline, and their metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG); dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid; and serotonin and its metabolite 5-hydroxyindoleacetic acid were quantified in 15 brain regions of DS without AD (DS, n = 4), DS with AD (DS+AD, n = 17), early-onset AD (EOAD, n = 11) patients, and healthy non-DS controls (n = 10) in the general population. Moreover, monoaminergic concentrations were determined in cerebrospinal fluid (CSF)/plasma samples of DS (n = 37/149), DS with prodromal AD (DS+pAD, n = 13/36), and DS+AD (n = 18/40). Results: In brain, noradrenergic and serotonergic compounds were overall reduced in DS+AD versus EOAD, while the dopaminergic system showed a bidirectional change. For DS versus non-DS controls, significantly decreased MHPG levels were noted in various brain regions, though to a lesser extent than for DS+AD versus EOAD. Apart from DOPAC, CSF/plasma concentrations were not altered between groups. Discussion: Monoamine neurotransmitters and metabolites were evidently impacted in DS, DS+AD, and EOAD. DS and DS+AD presented a remarkably similar monoaminergic profile, possibly related to early deposition of amyloid pathology in DS. To confirm whether monoaminergic alterations are indeed due to early amyloid β accumulation, future avenues include positron emission tomography studies of monoaminergic neurotransmission in relation to amyloid deposition, as well as relating monoaminergic concentrations to CSF/plasma levels of amyloid β and tau within individuals

    USP16 is an ISG15 cross-reactive deubiquitinase targeting a subset of metabolic pathway-related proteins

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    The ubiquitin-like modifier ISG15 can modulate host and viral proteins to restrict viral and microbial infections, and act as a cytokine. Its expression and conjugation are strongly up-regulated by type I interferons. Here we identify the deubiquitinating enzyme USP16 as an ISG15 cross-reactive protease. Ubiquitin-specific protease 16 (USP16) was found to react with an ISG15 activity-based probe in pull-down experiments using chronic myeloid leukaemia-derived human cells (HAP1). Supporting this finding, recombinant USP16 cleaved pro-ISG15 and ISG15 iso-peptide linked model substrates in vitro, as well as ISGylated substrates present in cell lysates. Moreover, the interferon-induced stimulation of ISGylation in human HAP1 cells was increased by knockdown or knockout of USP16. Depletion of USP16 did not affect interferon signaling, and interferon treatment did not affect USP16 expression or enzymatic activity either. A USP16-dependent ISG15 interactome was established by anti-ISG15 immunoprecipitation mass spectrometry (IP-MS), which indicated that the deISGylating function of USP16 may regulate metabolic pathways involving GOT1, ALDOA, SOD1 and MDH1, all of which were further confirmed to be deISGylated by USP16 in HEK293T cells. Together, our results indicate that USP16 may contribute to regulating the ISGylation status of a subset of proteins related to metabolism during type I interferon responses

    USP16 is an ISG15 cross-reactive deubiquitinase that targets pro-ISG15 and ISGylated proteins involved in metabolism

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    Interferon-induced ubiquitin (Ub)-like modifier ISG15 covalently modifies host and viral proteins to restrict viral infections. Its function is counteracted by the canonical deISGylase USP18 or Ub-specific protease 18. Notwithstanding indications for the existence of other ISG15 cross-reactive proteases, these remain to be identified. Here, we identify deubiquitinase USP16 as an ISG15 cross-reactive protease by means of ISG15 activity-based profiling. Recombinant USP16 cleaved pro-ISG15 and ISG15 isopeptide-linked model substrates in vitro, as well as ISGylated substrates from cell lysates. Moreover, interferon-induced stimulation of ISGylation was increased by depletion of USP16. The USP16-dependent ISG15 interactome indicated that the deISGylating function of USP16 may regulate metabolic pathways. Targeted enzymes include malate dehydrogenase, cytoplasmic superoxide dismutase 1, fructose-bisphosphate aldolase A, and cytoplasmic glutamic-oxaloacetic transaminase 1. USP16 may thus contribute to the regulation of a subset of metabolism-related proteins during type-I interferon responses
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