36 research outputs found

    Ultra-weak photon emission from the seed coat in response to temperature and humidity - a potential mechanism for environmental signal transduction in the soil seed bank

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    Seeds beneath the soil sense the changing environment to time germination and seedling emergence with the optimum time of year for survival. Environmental signals first impact with the seed at the seed coat. To investigate whether the seed coat has a role in environmental sensing we investigated their ultra-weak photon emission (UPE) under the variable temperature, relative humidity and oxygen conditions they could experience in the soil seed bank. Using a custom built luminometer we measured UPE intensity and spectra (300-700 nm) from Phaseolus vulgaris seeds, seed coats and cotyledons. UPE was greatest from the internal surface of the seed coat. Seed coat UPE increased concomitantly with both increasing temperature and decreasing relative humidity. Emission was oxygen dependent and it was abolished by treatment with dinitrophenylhydrazine demonstrating the key role of seed coat carbonyls in the phenomenon. We hypothesize that beneath the soil surface the attenuation of light (virtual darkness: low background noise) enables seeds to exploit UPE for transducing key environmental variables in the soil (temperature, humidity and oxygen) to inform them of seasonal and local temperature patterns. Overall, seed coats were found to have potential as effective transducers of key fluctuating environmental variables in the soil

    Content, mineral allocation and leaching behavior of heavy metals in urban PM2.5

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    This work provides a novel perspective in the field of urban airborne particle investigation that is not currently found in the literature. Four sampling campaigns were performed in the urban area of Rome (Central Italy) during the winter and summer seasons (February and July 2013 and 2014, respectively). The measured concentrations of the regulated 34 elements of As, Cd, Ni and Pb were consistent with those reported by the local Environmental Agency (ARPA Lazio), but non-regulated heavy metals, including Fe, Cu, Cr and Zn, were also found in PM2.5 and analyzed in detail. As an novelty, heavy metals were associated with the host-identified mineral phases, primarily oxides and alloys, and to a lesser extent, other minerals, such as sulfates, carbonates and silicates. Leaching tests of the collected samples were conducted in a buffered solution mimicking the bodily physiological environment. Despite the highest concentration of heavy metals found during the winter sampling period, all of the elements showed a leaching trend leading to major mobility during the summer period. To explain this result, an interesting comparative analysis between the leaching test behavior and innovative mineral allocation was conducted. Both the heavy metal content and mineral allocation in PM2.5 might contribute to the bioavailability of toxic elements in the pulmonary environment. Hence, for regulatory purposes, the non-linear dependency of heavy metal bioavailability on the total metal content should be taken into account

    Coenzyme Q Metabolism Is Disturbed in High Fat Diet-Induced Non Alcoholic Fatty Liver Disease in Rats

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    Oxidative stress is believed to be a major contributory factor in the development of non alcoholic fatty liver disease (NAFLD), the most common liver disorder worldwide. In this study, the effects of high fat diet-induced NAFLD on Coenzyme Q (CoQ) metabolism and plasma oxidative stress markers in rats were investigated. Rats were fed a standard low fat diet (control) or a high fat diet (57% metabolizable energy as fat) for 18 weeks. The concentrations of total (reduced + oxidized) CoQ9 were increased by >2 fold in the plasma of animals fed the high fat diet, while those of total CoQ10 were unchanged. Reduced CoQ levels were raised, but oxidized CoQ levels were not, thus the proportion in the reduced form was increased by about 75%. A higher percentage of plasma CoQ9 as compared to CoQ10 was in the reduced form in both control and high fat fed rats. Plasma protein thiol (SH) levels were decreased in the high fat-fed rats as compared to the control group, but concentrations of lipid hydroperoxides and low density lipoprotein (LDL) conjugated dienes were unchanged. These results indicate that high fat diet-induced NAFLD in rats is associated with altered CoQ metabolism and increased protein, but not lipid, oxidative stress

    Young transgenic hMTH1 mice are protected against dietary fat-induced metabolic stress—implications for enhanced longevity

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    hMTH1 protects against mutation during oxidative stress. It degrades 8-oxodGTP to exclude potentially mutagenic oxidized guanine from DNA. hMTH1 expression is linked to ageing. Its downregulation in cultured cells accelerates RAS-induced senescence, and its overexpression in hMTH1-Tg mice extends lifespan. In this study, we analysed the effects of a brief (5 weeks) high-fat diet challenge (HFD) in young (2 months old) and adult (7 months old) wild-type (WT) and hMTH1-Tg mice. We report that at 2 months, hMTH1 overexpression ameliorated HFD-induced weight gain, changes in liver metabolism related to mitochondrial dysfunction and oxidative stress. It prevented DNA damage as quantified by a comet assay. At 7 months old, these HFD-induced effects were less severe and hMTH1-Tg and WT mice responded similarly. hMTH1 overexpression conferred lifelong protection against micronucleus induction, however. Since the canonical activity of hMTH1 is mutation prevention, we conclude that hMTH1 protects young mice against HFD by reducing genome instability during the early period of rapid growth and maximal gene expression. hMTH1 protection is redundant in the largely non-growing, differentiated tissues of adult mice. In hMTH1-Tg mice, expression of a less heavily mutated genome throughout life provides a plausible explanation for their extended longevity

    Methodology used in studies reporting chronic kidney disease prevalence: a systematic literature review

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    Background Many publications report the prevalence of chronic kidney disease (CKD) in the general population. Comparisons across studies are hampered as CKD prevalence estimations are influenced by study population characteristics and laboratory methods. Methods For this systematic review, two researchers independently searched PubMed, MEDLINE and EMBASE to identify all original research articles that were published between 1 January 2003 and 1 November 2014 reporting the prevalence of CKD in the European adult general population. Data on study methodology and reporting of CKD prevalence results were independently extracted by two researchers. Results We identified 82 eligible publications and included 48 publications of individual studies for the data extraction. There was considerable variation in population sample selection. The majority of studies did not report the sampling frame used, and the response ranged from 10 to 87%. With regard to the assessment of kidney function, 67% used a Jaffe assay, whereas 13% used the enzymatic assay for creatinine determination. Isotope dilution mass spectrometry calibration was used in 29%. The CKD-EPI (52%) and MDRD (75%) equations were most often used to estimate glomerular filtration rate (GFR). CKD was defined as estimated GFR (eGFR) <60 mL/min/1.73 m2 in 92% of studies. Urinary markers of CKD were assessed in 60% of the studies. CKD prevalence was reported by sex and age strata in 54 and 50% of the studies, respectively. In publications with a primary objective of reporting CKD prevalence, 39% reported a 95% confidence interval. Conclusions The findings from this systematic review showed considerable variation in methods for sampling the general population and assessment of kidney function across studies reporting CKD prevalence. These results are utilized to provide recommendations to help optimize both the design and the reporting of future CKD prevalence studies, which will enhance comparability of study result

    Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

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    The partial head decondensation test is a new, quick method to assess acrosome status in human spermatozoa

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    Objective: To develop a fast method for assessing acrosome status in human spermatozoa. Design: Development of a new in vitro test to assess acrosome reaction in human spermatozoa. Setting: Academic medical institution. Patient(s): Normozoosperinic subjects. Intervention(s): Spermatozoa were isolated from fresh semen samples, capacitated, and stimulated or not with P or ionomycin. Acrosome reactions were evaluated by phase-contrast microscopy after a brief sperm incubation in a decondensing solution. The results were compared with those obtained by scanning electron microscopy and fluoresceinated lectin staining. Main Outcome Measure(s): Percentage of intact acrosomes. Result(s): The new procedure allowed intact acrosomes to be easily identified and quantified by phase-contrast microscopy. In unstimulated and ionomycin-treated spermatozoa, a very good agreement was found among the new test, scanning electron microscopy, and fluoresceinated lectin staining. In P-treated spermatozoa, the proposed method allowed a significantly higher percentage of reacted acrosomes to be resolved, likely due to its ability to detect the very initial stages of the acrosome reaction. Conclusion(s): The new test allows acrosome-intact and acrosome-reacted spermatozoa to be unambiguously singled out and quantified. The method is rapid, reliable, sensitive, and easy to perform, which makes it of profitable use in both basic research and diagnostic practice. (C) 2004 by American Society for Reproductive Medicine

    A selective paper artwork cleaning process using modified Gellan hydrogel

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    Paper manuscripts are among the most valuable historical artifacts, but they are also very fragile. Furthermore, they were often strengthened by gluing external materials (like wooden or cardboard lining paper) to the original piece and the used glue underwent to structural transformations that accelerates the degradation processes of the artwork itself. Wet cleaning is one of the most important and critical steps in a paper artwork restoration process, and in the last years innovative cleaning methodologies have been proposed based on application of suitable hydrogels. Unfortunately often, to remove contaminants from paper artworks like glues or hydrophobic material components, additional specific procedures are required. In this work we present innovative multi-component materials able to remove in a single, simple and not invasive treatment, specific contaminants from paper artworks. The materials are based on rigid Gellan hydrogel; after investigating the cleaning ability of the Gellan gel “per se”, indeed, we also evaluated the possibility of using Gellan gel as a carrier of tuned cleaning agent. More in detail, Gellan hydrogel carrying alpha-amylase or proteinase K enzymes has been applied on several paper samples to remove starch paste or animal glues respectively. In this system, the enzyme works as selective cleaning agent, hydrolyzing not easily removable glues into smaller fragments soluble into the gel, which, in turn, plays the role of support and removal matrix for the enzymatic products. Finally, Gellan gel could be a not suitable agent to remove hydrophobic contaminants, due to its hydrophilic nature; to this end, we performed preliminary experiments by preparing a “mixed Gellan gel” carrying opportune polimeric surfactants.To assess the effectiveness and safety of the proposed cleaning method on the several samples under examination, we have employed a multitechnique approach, using high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and pH measurements

    Surface remodeling associated with vasopressin-induced membrane traffic in L6 myogenic cells

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    The plasma membrane is dynamically remodeled as a function of the cell cycle, motility and membrane traffic. We have previously shown that arg 8-vasopressin (AVP) stimulation of L6 myoblasts induces the activation of phosholipase D during the first minutes of stimulation, and the differentiation of L6 myoblasts as a long term effect. We now report that AVP also induces two types of morphological responses in L6 cells within a few minutes of stimulation: exocytosis, apparent as uncoated pits, and the generation of membrane projections and reffles. Thus, such an experimental model is suitable for the study of hormone-induced morphological surface modifications and their regulatory mechanisms. In L6 cells, AVP-induced projection generation depends on the integrity of microfilaments, intermediate filaments, and microtubules. Moreover, projection generation and exocytosis appear to be independently regulated phenomena: in fact, inhibition of the de novo synthesis of phosphatidylcholine inhibits membrane traffic but fails to block projection appearance. Conversely, the latter phenomenon, unlike exocytosis, is mediated by PI3-kinase signaling. Thus, AVP induces two early, independently regulated morphological modifications in L6 cells: exocytosis, involved in plasma membrane phospholipid turnover, and membrane projections, likely involved in cell migration
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