239 research outputs found

    Ganzheitliche Untersuchungsmethoden zur Erfassung und Prüfung der Qualität ökologischer Lebensmittel: Stand der Entwicklung und Validierung

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    In dem wachsenden Markt ökologischer Lebensmittel werden Methoden zur produktorientierten Qualitätserfassung gefordert. Dabei geht es u.a. um die Unterscheidung von Produkten aus unterschiedlichen Anbauverfahren. Die Ziele des Projektes waren daher: 1. ausgewählte ganzheitliche Methoden gemäß ISO 17025 zu validieren, d.h. Laborprozesse festzulegen, sowie Einflussgrößen und Verfahrensmerkmale zu bestimmen, 2. zu testen, ob diese Verfahren eine Differenzierung von definierten Proben statistisch abgesichert zeigen können. . Diese Ziele konnten erreicht werden. Es wurde bestätigt, dass einige der Methoden auf Grundlage dokumentierter Prozeduren Lebensmittel aus definierten Anbauversuchen (u.a. aus dem DOK-Versuch am FIBL/CH) reproduzierbar unterscheiden können. Die Koordination und die Validierung der Kupferchlorid-Kristallisation sowie die Messung der Polyphenole lag bei der Universität Kassel, FG Ökologische Lebensmittelqualität und Ernährungskultur. Die KWALIS GmbH, Dipperz, validierte die Fluoreszenz-Anregungsspektroskopie und die Bestimmung des Physiologischen Aminosäurestatus, die EQC GmbH, Weidenbach die elektrochemischen Messungen. Dr. Kromidas, Saarbrücken übernahm die Beratung der Validierungsprozeduren. . An Blindproben wurde untersucht, ob die Verfahren für Weizen- und Möhrenproben aus definierten Anbau- und Sortenversuchen geeignet sind (Fragestellung der Validierung). Die Proben wurden von unabhängiger Stelle (OEL-FAL, Trenthorst) codiert. Die Proben wurden gleichzeitig an alle Partner versandt; dadurch konnten die Methoden auch untereinander verglichen werden. Die Methoden Kupferchlorid-Kristallisation, Fluoreszenz-Anregungsspektroskopie und Physiologischer Aminosäurestatus sind für die Fragestellung geeignet. Mit allen drei Methoden konnten die Proben differenziert und gruppiert werden. Darüber hinaus konnten mit der Fluoreszenz-Anregungsspektroskopie und über den physiologischen Aminosäurestatus die Proben auch den Anbauweisen richtig zugeordnet werden. Allerdings ist damit noch keine Aussage über die Fähigkeit dieser Verfahren möglich, generell Proben aus ökologischer und konventioneller Herkunft zu unterscheiden. Dafür sind weitere Untersuchungen sowohl an Proben definierter Herkunft als auch an Marktproben notwendig

    Foodways in transition: food plants, diet and local perceptions of change in a Costa Rican Ngäbe community

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    Background Indigenous populations are undergoing rapid ethnobiological, nutritional and socioeconomic transitions while being increasingly integrated into modernizing societies. To better understand the dynamics of these transitions, this article aims to characterize the cultural domain of food plants and analyze its relation with current day diets, and the local perceptions of changes given amongst the Ngäbe people of Southern Conte-Burica, Costa Rica, as production of food plants by its residents is hypothesized to be drastically in recession with an decreased local production in the area and new conservation and development paradigms being implemented. Methods Extensive freelisting, interviews and workshops were used to collect the data from 72 participants on their knowledge of food plants, their current dietary practices and their perceptions of change in local foodways, while cultural domain analysis, descriptive statistical analyses and development of fundamental explanatory themes were employed to analyze the data. Results Results show a food plants domain composed of 140 species, of which 85 % grow in the area, with a medium level of cultural consensus, and some age-based variation. Although many plants still grow in the area, in many key species a decrease on local production–even abandonment–was found, with much reduced cultivation areas. Yet, the domain appears to be largely theoretical, with little evidence of use; and the diet today is predominantly dependent on foods bought from the store (more than 50 % of basic ingredients), many of which were not salient or not even recognized as ‘food plants’ in freelists exercises. While changes in the importance of food plants were largely deemed a result of changes in cultural preferences for store bought processed food stuffs and changing values associated with farming and being food self-sufficient, Ngäbe were also aware of how changing household livelihood activities, and the subsequent loss of knowledge and use of food plants, were in fact being driven by changes in social and political policies, despite increases in forest cover and biodiversity. Conclusions Ngäbe foodways are changing in different and somewhat disconnected ways: knowledge of food plants is varied, reflecting most relevant changes in dietary practices such as lower cultivation areas and greater dependence on food from stores by all families. We attribute dietary shifts to socioeconomic and political changes in recent decades, in particular to a reduction of local production of food, new economic structures and agents related to the State and globalization

    Fibrocytes are associated with vascular and parenchymal remodelling in patients with obliterative bronchiolitis

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    <p>Abstract</p> <p>Background</p> <p>The aim of the present study was to explore the occurrence of fibrocytes in tissue and to investigate whether the appearance of fibrocytes may be linked to structural changes of the parenchyme and vasculature in the lungs of patients with obliterative bronchiolitis (OB) following lung or bone marrow transplantation.</p> <p>Methods</p> <p>Identification of parenchyme, vasculature, and fibrocytes was done by histological methods in lung tissue from bone marrow or lung-transplanted patients with obliterative bronchiolitis, and from controls.</p> <p>Results</p> <p>The transplanted patients had significantly higher amounts of tissue in the alveolar parenchyme (46.5 ± 17.6%) than the controls (21.7 ± 7.6%) (p < 0.05). The patients also had significantly increased numbers of fibrocytes identified by CXCR4/prolyl4-hydroxylase, CD45R0/prolyl4-hydroxylase, and CD34/prolyl4-hydroxylase compared to the controls (p < 0.01). There was a correlation between the number of fibrocytes and the area of alveolar parenchyma; CXCR4/prolyl 4-hydroxylase (p < 0.01), CD45R0/prolyl 4-hydroxylase (p < 0.05) and CD34/prolyl 4-hydroxylase (p < 0.05). In the pulmonary vessels, there was an increase in the endothelial layer in patients (0.31 ± 0.13%) relative to the controls (0.037 ± 0.02%) (p < 0.01). There was a significant correlation between the number of fibrocytes and the total area of the endothelial layer CXCR4/prolyl 4-hydroxylase (p < 0.001), CD45R0/prolyl 4-hydroxylase (p < 0.001) and CD34/prolyl 4-hydroxylase (p < 0.01). The percent areas of the lumen of the vessels were significant (p < 0.001) enlarged in the patient with OB compared to the controls. There was also a correlation between total area of the lumen and number of fibrocytes, CXCR4/prolyl 4-hydroxylase (p < 0.01), CD45R0/prolyl 4-hydroxylase (p < 0.001) and CD34/prolyl 4-hydroxylase (p < 0.01).</p> <p>Conclusion</p> <p>Our results indicate that fibrocytes are associated with pathological remodelling processes in patients with OB and that tissue fibrocytes might be a useful biomarker in these processes.</p

    Dental microwear texture analysis of Homo sapiens sapiens: foragers, farmers, and pastoralists

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    Objectives. The current study seeks to determine if a sample of foragers, farmers, and pastoralists can be distinguished by their dental microwear texture signatures. Materials and Methods. The study included a sample of 719 individuals from 51 archaeological sites (450 farmers, 192 foragers, 77 pastoralists). All were over age 12 and sexes were pooled. Using a Sensofar® white-light confocal profiler we collected dental microwear texture analysis (DMTA) data from a single first or second molar from each individual. We leveled and cleaned data clouds following standard procedures and analyzed the data with Sfrax® and Toothfrax® software. The DMTA variables were complexity and anisotropy. Statistics included ANOVA with partial eta squared and Hedges's g. We also performed a follow-up K-means cluster analysis. Results. We found significant differences between foragers and farmers and pastoralists for complexity and anisotropy, with foragers having greater complexity than either the farmers or the pastoralists. The farmers and pastoralists had greater anisotropy than the foragers. The Old World foragers had significantly higher anisotropy values than New World foragers. Old and New World farmers did not differ. Among the Old World farmers, those dating from the Neolithic through the Late Bronze Age had higher complexity values than those from the Iron Age through the medieval period. The cluster analysis discerned foragers and farmers but also indicated similarity between hard food foragers and hard food farmers. Discussion. Our findings reaffirm that DMTA is capable of distinguishing human diets. We found that foragers and farmers, in particular, differ in their microwear signatures across the globe. There are some exceptions, but nothing that would be unexpected given the range of human diets and food preparation techniques. This study indicates that in general DMTA is an efficacious means of paleodietary reconstruction in humans

    Miz1 Is a Critical Repressor of cdkn1a during Skin Tumorigenesis

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    The transcription factor Miz1 forms repressive DNA-binding complexes with the Myc, Gfi-1 and Bcl-6 oncoproteins. Known target genes of these complexes encode the cyclin-dependent kinase inhibitors (CKIs) cdkn2b (p15Ink4), cdkn1a (p21Cip1), and cdkn1c (p57Kip2). Whether Miz1-mediated repression is important for control of cell proliferation in vivo and for tumor formation is unknown. Here we show that deletion of the Miz1 POZ domain, which is critical for Miz1 function, restrains the development of skin tumors in a model of chemically-induced, Ras-dependent tumorigenesis. While the stem cell compartment appears unaffected, interfollicular keratinocytes lacking functional Miz1 exhibit a reduced proliferation and an accelerated differentiation of the epidermis in response to the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Tumorigenesis, proliferation and normal differentiation are restored in animals lacking cdkn1a, but not in those lacking cdkn2b. Our data demonstrate that Miz1-mediated attenuation of cell cycle arrest pathways via repression of cdkn1a has a critical role during tumorigenesis in the skin

    Methylphenidate Normalizes Fronto-Striatal Underactivation During Interference Inhibition in Medication-Naïve Boys with Attention-Deficit Hyperactivity Disorder

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    Youth with attention deficit hyperactivity disorder (ADHD) have deficits in interference inhibition, which can be improved with the indirect catecholamine agonist methylphenidate (MPH). Functional magnetic resonance imaging was used to investigate the effects of a single dose of MPH on brain activation during interference inhibition in medication-naïve ADHD boys. Medication-naïve boys with ADHD were scanned twice, in a randomized, double-blind design, under either a single clinical dose of MPH or placebo, while performing a Simon task that measures interference inhibition and controls for the oddball effect of low-frequency appearance of incongruent trials. Brain activation was compared within patients under either drug condition. To test for potential normalization effects of MPH, brain activation in ADHD patients under either drug condition was compared with that of healthy age-matched comparison boys. During incongruent trials compared with congruent–oddball trials, boys with ADHD under placebo relative to controls showed reduced brain activation in typical areas of interference inhibition, including right inferior prefrontal cortex, left striatum and thalamus, mid-cingulate/supplementary motor area, and left superior temporal lobe. MPH relative to placebo upregulated brain activation in right inferior prefrontal and premotor cortices. Under the MPH condition, patients relative to controls no longer showed the reduced activation in right inferior prefrontal and striato-thalamic regions. Effect size comparison, furthermore, showed that these normalization effects were significant. MPH significantly normalized the fronto-striatal underfunctioning in ADHD patients relative to controls during interference inhibition, but did not affect medial frontal or temporal dysfunction. MPH therefore appears to have a region-specific upregulation effect on fronto-striatal activation

    Short-Term Exposure of Multipotent Stromal Cells to Low Oxygen Increases Their Expression of CX3CR1 and CXCR4 and Their Engraftment In Vivo

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    The ability of stem/progenitor cells to migrate and engraft into host tissues is key to their potential use in gene and cell therapy. Among the cells of interest are the adherent cells from bone marrow, referred to as mesenchymal stem cells or multipotent stromal cells (MSC). Since the bone marrow environment is hypoxic, with oxygen tensions ranging from 1% to 7%, we decided to test whether hypoxia can upregulate chemokine receptors and enhance the ability of human MSCs to engraft in vivo. Short-term exposure of MSCs to 1% oxygen increased expression of the chemokine receptors CX3CR1and CXCR4, both as mRNA and as protein. After 1-day exposure to low oxygen, MSCs increased in vitro migration in response to the fractalkine and SDF-1α in a dose dependent manner. Blocking antibodies for the chemokine receptors significantly decreased the migration. Xenotypic grafting into early chick embryos demonstrated cells from hypoxic cultures engrafted more efficiently than cells from normoxic cultures and generated a variety of cell types in host tissues. The results suggest that short-term culture of MSCs under hypoxic conditions may provide a general method of enhancing their engraftment in vivo into a variety of tissues

    CXCR4 expression on circulating pan-cytokeratin positive cells is associated with survival in patients with advanced non-small cell lung cancer

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    <p>Abstract</p> <p>Background</p> <p>The CXC chemokine, CXCL12, and its receptor, CXCR4 promote metastases of a variety of solid tumors, including non-small cell lung cancer (NSCLC). The expression of CXCR4 on tumor cells may represent a critical biomarker for their propensity to metastasize. This study was performed to evaluate the hypothesis that co-expression of pan-cytokeratin and CXCR4 may be a prognostic marker for patients with advanced NSCLC.</p> <p>Methods</p> <p>We evaluated CXCR4 levels on circulating pan-cytokeratin positive cells from patients with NSCLC. NSCLC tumor and metastases were also assessed for the presence of CXCR4.</p> <p>Results</p> <p>Pan-cytokeratin positive cells were increased in the circulation of patients with NSCLC, as compared to normal control subjects. Patients with pan-cytokeratin +/CXCR4+ = 2,500 cells/ml had a significant improvement in median survival when compared with patients with pan-cytokeratin +/CXCR4+ >2,500 cells/ml (not achieved versus 14 weeks). CXCR4 expression was found on NSCLC tumors and at sites of tumor metastasis.</p> <p>Conclusion</p> <p>This study suggests that CXCR4 may be a prognostic marker in NSCLC, and provides hypothesis-generating results, which may be important in determining metastatic potential. In future studies, we will prospectively evaluate the prognostic significance of pan-cytokeratin/CXCR4+ cells, and determine the mechanisms involved in the regulation of CXCR4 expression on tumor cells in a larger patient population.</p

    Diversidade de resultados no estudo do transtorno de déficit de atenção e hiperatividade

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    Com este artigo pretende-se abordar a problemática da diversidade de dados na investigação do Transtorno de Déficit de Atenção e Hiperatividade (TDAH). Apresenta-se uma revisão da literatura centrada na heterogeneidade de conclusões relativas à caracterização do transtorno, à distinção dos subtipos, aos contextos de informação, às diferenças de gênero e à comorbidade. Na tentativa de compreender a disparidade de conclusões, salientam-se potenciais fatores explicativos, nomeadamente a heterogeneidade das amostras, a diversidade de metodologias e de procedimentos de investigação, entre outros.With this paper we aimed at addressing the problem of data diversity in Attention-Deficit Hyperactivity Disorder (ADHD) research. We present a literature review based on the heterogeneity of findings about the characterization of the disorder, subtypes differentiation, sources of information, sex differences and comorbidities. In an effort to understand the variety of findings, we underline potential explanations, such as the sample’s heterogeneity or the multiplicity of methods and procedures, among others.(undefined
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