397 research outputs found

    Dynamin- and Rab5-Dependent Endocytosis of a Ca<sup>2+</sup>-Activated K<sup>+</sup> Channel, KCa2.3

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    Regulation of the number of ion channels at the plasma membrane is a critical component of the physiological response. We recently demonstrated that the Ca2+-activated K+ channel, KCa2.3 is rapidly endocytosed and enters a Rab35- and EPI64C-dependent recycling compartment. Herein, we addressed the early endocytic steps of KCa2.3 using a combination of fluorescence and biotinylation techniques. We demonstrate that KCa2.3 is localized to caveolin-rich domains of the plasma membrane using fluorescence co-localization, transmission electron microscopy and co-immunoprecipitation (co-IP). Further, in cells lacking caveolin-1, we observed an accumulation of KCa2.3 at the plasma membrane as well as a decreased rate of endocytosis, as assessed by biotinylation. We also demonstrate that KCa2.3 and dynamin II are co-localized following endocytosis as well as demonstrating they are associated by co-IP. Further, expression of K44A dynamin II resulted in a 2-fold increase in plasma membrane KCa2.3 as well as a 3-fold inhibition of endocytosis. Finally, we evaluated the role of Rab5 in the endocytosis of KCa2.3. We demonstrate that expression of a dominant active Rab5 (Q79L) results in the accumulation of newly endocytosed KCa2.3 on to the membrane of the Rab5-induced vacuoles. We confirmed this co-localization by co-IP; demonstrating that KCa2.3 and Rab5 are associated. As expected, if Rab5 is required for the endocytosis of KCa2.3, expression of a dominant negative Rab5 (S34N) resulted in an approximate 2-fold accumulation of KCa2.3 at the plasma membrane. This was confirmed by siRNA-mediated knockdown of Rab5. Expression of the dominant negative Rab5 also resulted in a decreased rate of KCa2.3 endocytosis. These results demonstrate that KCa2.3 is localized to a caveolin-rich domain within the plasma membrane and is endocytosed in a dynamin- and Rab5-dependent manner prior to entering the Rab35/EPI64C recycling compartment and returning to the plasma membrane. © 2012 Gao et al

    A comparison of trends in mortality from primary liver cancer and intrahepatic cholangiocarcinoma in Europe

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    Background To update and compare mortality from primary liver cancer (PLC) and intrahepatic cholangiocarcinoma (ICC) in Europe in 1990-2010. Materials and methods We used data from the World Health Organization (WHO) to compute age-standardized (world population) mortality rates, and used joinpoint analysis to identify substantial changes. Results Between 2002 and 2007, PLC rates in the European Union (EU) declined from 3.9 to 3.6/100 000 men. Around 2007, the highest male rates were in France (6.2/100 000), Spain (4.9), and Italy (4.0), while the lowest ones were in Sweden (1.1), the Netherlands (1.2), and the UK (1.8). In women, mortality was lower (0.8/100 000 in 2007 in the EU), and showed more favourable trends, with a decline of over 2% per year over the last two decades as compared with 0.4% in men, in the EU. In contrast, the EU mortality from ICC increased by around 9% in both sexes from 1990 to 2008, reaching rates of 1.1/100 000 men and 0.75/100 000 women. The highest rates were in UK, Germany, and France (1.2-1.5/100 000 men, 0.8-1.1/100 000 women). Conclusions PLC mortality has become more uniform across Europe over recent years, with an overall decline; in contrast, ICC mortality has substantially increased in most Europ

    European cancer mortality predictions for the year 2012

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    Background: Estimating current cancer mortality figures is important for defining priorities for prevention and treatment. Materials and methods: Using logarithmic Poisson count data joinpoint models on mortality and population data from the World Health Organization database, we estimated numbers of deaths and age-standardized rates in 2012 from all cancers and selected cancer sites for the whole European Union (EU) and its six more populated countries. Results: Cancer deaths in the EU in 2012 are estimated to be 1 283 101 (717 398 men and 565 703 women) corresponding to standardized overall cancer death rates of 139/100 000 men and 85/100 000 women. The fall from 2007 was 10% in men and 7% in women. In men, declines are predicted for stomach (−20%), leukemias (−11%), lung and prostate (−10%) and colorectal (−7%) cancers, and for stomach (−23%), leukemias (−12%), uterus and colorectum (−11%) and breast (−9%) in women. Almost stable rates are expected for pancreatic cancer (+2-3%) and increases for female lung cancer (+7%). Younger women show the greatest falls in breast cancer mortality rates in the EU (−17%), and declines are expected in all individual countries, except Poland. Conclusion: Apart for lung cancer in women and pancreatic cancer, continuing falls are expected in mortality from major cancers in the E

    A cryptic alien seaweed spreading in Mediterranean coastal lagoons.

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    1 - Introductions of exotic macroalgae have increased recently on European shores. Each introductioninvolves at least one vector of transfer. For macroalgae, the potential vectors are aquaculture(intentional or accidental introduction), fouling on hulls, ballast water, aquarium trading, fishingnets.2 - Coastal lagoons, including Venice and Thau Lagoon, developed into major hotspots of marinemacrophyte introductions in the Mediterranean Sea. Moreover, in shallow lagoons and estuaries,eutrophication processes have resulted in the development of macroalgal biomass.3 - The most characteristic species of these macroalgal communities include members of the ulvophyceangenus Ulva L. In foliose Ulvales, simple morphology and anatomy, rampant convergence, remarkabledegrees of phenotypic plasticity in response to environmental factors tend to confound attempts atidentification and make cryptic introduction difficult to detect.4 - During a survey of macroalgal biodiversity in Venice Lagoon, among the pool of exotic speciesfound, there was an Ulva differing from the Atlantic and Mediterranean species in both vegetativeand reproductive features. Detailed observations consented us to identify the taxon as Ulva pertusaKjellman, previously reported in the Mediterranean only for Thau Lagoon

    Identifying alien macroalgae through DNA barcoding: the case of Hypnea cornuta (Cystocloniaceae, Rhodophyta)

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    1 - Introduction of non-indigenous macroalgae has become a major topic in the last decades. Potential vectors are aquaculture, fouling on hulls, ballast water, aquarium trading, fishing nets.2 - Within a program of census of macroalgal alien species through DNA barcoding we found a population of previously unreported rhodophyte in Cape Peloro Lagoon and nearby marine coasts (north-eastern Sicily, Italy).3 - All collected individuals were identified as the alien species Hypnea cornuta based on morphological characters confirmed by the analysis of COI-5’ sequences

    Shot Noise in Linear Macroscopic Resistors

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    We report on a direct experimental evidence of shot noise in a linear macroscopic resistor. The origin of the shot noise comes from the fluctuation of the total number of charge carriers inside the resistor associated with their diffusive motion under the condition that the dielectric relaxation time becomes longer than the dynamic transit time. Present results show that neither potential barriers nor the absence of inelastic scattering are necessary to observe shot noise in electronic devices.Comment: 10 pages, 5 figure

    Noise spectra of SIU-GaAs pad detectors with guard rings

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    This paper presents current noise characterization of circular pad Schottky barrier diodes with guard rings. The diodes were fabricated from undopped semi-insulating GaAs, SIU-GaAs, at the University of Glasgow. Current noise spectra were obtained for the detectors for two pad sizes, with reverse bias applied. Three measurements were also made on one of the detectors under forward bias. The noise spectra show an excess noise component, with a low frequency corner at less than 1kHz, and a flat region at higher frequencies. The magnitude of the white noise is approximately half that expected from shot noise theory for the given leakage currents. A fall in the magnitude of the noise was observed at 20kHz which is attributed to the dielectric relaxation time of the material

    Gender Differences in COVID-19 Lockdown Impact on Mental Health of Undergraduate Students

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    open13Background: Prolonged university closures and social distancing-imposed measures due to the COVID-19 pandemic obliged students to at-home learning with online lectures and educational programs promoting potential social isolation, loneliness, hopelessness, and episodes of clinical decompensation. Methods: A web-based cross-sectional survey was carried out in a university institute in Milan, Northern Italy, to assess the COVID-19 lockdown impact on the mental health of the undergraduate students. We estimated the odds ratios (OR) and the corresponding 95% confidence intervals (CI) using adjusted logistic regression models. Results: Of the 8,177 students, 12.8% reported depressive symptoms, 25.6% anxiety, 8.7% insomnia, and 10.6% reported impulsive tracts, with higher proportions among females than males. Mental health symptoms were positively associated with caring for a person at home, a poor housing quality, and a worsening in working performance. Among males compared with females, a poor housing quality showed a stronger positive association with depressive symptoms and impulsivity, and a worsening in the working performance was positively associated with depressive and anxiety symptoms. In addition, the absence of private space was positively associated with depression and anxiety, stronger among males than females. Conclusions: To our knowledge, this is the first multidisciplinary consortium study, involving public mental health, environmental health, and architectural design. Further studies are needed to confirm or refute our findings and consequent recommendations to implement well-being interventions in pandemic conditions.openAmerio A.; Bertuccio P.; Santi F.; Bianchi D.; Brambilla A.; Morganti A.; Odone A.; Costanza A.; Signorelli C.; Aguglia A.; Serafini G.; Capolongo S.; Amore M.Amerio, A.; Bertuccio, P.; Santi, F.; Bianchi, D.; Brambilla, A.; Morganti, A.; Odone, A.; Costanza, A.; Signorelli, C.; Aguglia, A.; Serafini, G.; Capolongo, S.; Amore, M

    Plasma Membrane Insertion of KCa2.3 (SK3) is Dependent Upon the SNARE Proteins, Syntaxin-4 and SNAP23

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    This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. We previously demonstrated endocytosis of KCa2.3 is caveolin-1-, dynamin II- and Rab5-dependent. KCa2.3 then enters Rab35/EPI64C- and RME-1-containing recycling endosomes and is returned to the plasma membrane (PM). Herein, we report on the mechanism by which KCa2.3 is inserted into the PM during recycling and following exit from the Golgi. We demonstrate KCa2.3 colocalizes with SNAP-23 and Syntaxin-4 in the PM of HEK and endothelial cells by confocal immunofluorescence microscopy. We further show KCa2.3 can be co-immunoprecipitated with SNAP-23 and Syntaxin-4. Overexpression of either Syntaxin-4 or SNAP-23 increased PM expression of KCa2.3, whereas shRNA-mediated knockdown of these SNARE proteins significantly decreased PM KCa2.3 expression, as assessed by cell surface biotinylation. Whole-cell patch clamp studies confirmed knockdown of SNAP-23 significantly decreased the apamin sensitive, KCa2.3 current. Using standard biotinylation/stripping methods, we demonstrate shRNA mediated knockdown of SNAP-23 inhibits recycling of KCa2.3 following endocytosis, whereas scrambled shRNA had no effect. Finally, using biotin ligase acceptor peptide (BLAP)-tagged KCa2.3, coupled with ER-resident biotin ligase (BirA), channels could be biotinylated in the ER after which we evaluated their rate of insertion into the PM following Golgi exit. We demonstrate knockdown of SNAP-23 significantly slows the rate of Golgi to PM delivery of KCa2.3. The inhibition of both recycling and PM delivery of newly synthesized KCa2.3 channels likely accounts for the decreased PM expression observed following knockdown of these SNARE proteins. In total, our results suggest insertion of KCa2.3 into the PM depends upon the SNARE proteins, Syntaxin-4 and SNAP-23

    Older Adults’ Access to Care during the COVID-19 Pandemic: Results from the LOckdown and LifeSTyles (LOST) in Lombardia Project

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    The COVID-19 pandemic disproportionally affected older people in terms of clinical outcomes and care provision. We aimed to investigate older adults’ changes in access to care during the pandemic and their determinants. We used data from a cross-sectional study (LOST in Lombardia) conducted in autumn 2020 on a representative sample of 4400 older adults from the most populated region in Italy. Lifestyles, mental health, and access to healthcare services before and during the pandemic were collected. To identify factors associated with care delays, reduction in emergency department (ED) access, and hospitalisations, we estimated prevalence ratios (PR) and 95% confidence intervals (CI) using multivariable log-binomial regression models. During the pandemic, compared to the year before, 21.5% of the study population increased telephone contacts with the general practitioner (GP) and 9.6% increased self-pay visits, while 22.4% decreased GP visits, 12.3% decreased outpatient visits, 9.1% decreased diagnostic exams, 7.5% decreased ED access, and 6% decreased hospitalisations. The prevalence of care delays due to patient’s decision (overall 23.8%) was higher among men (PR 1.16, 95% CI 1.05–1.29), subjects aged 75 years or more (PR 1.12, 95% CI 1.00–1.25), and those with a higher economic status (p for trend &lt; 0.001). Participants with comorbidities more frequently cancelled visits and reduced ED access or hospitalisations, while individuals with worsened mental health status reported a higher prevalence of care delays and ED access reductions. Access to care decreased in selected sub-groups of older adults during the pandemic with likely negative impacts on mortality and morbidity in the short and long run
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