2,055 research outputs found

    Resting energy expenditure and fat-free mass do not decline during aging in severely obese women

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    Background & aims: Few studies have investigated the age-related modification of resting energy expenditure (REE) and free fat mass (FFM) in severe obesity. This cross-sectional study analyzed REE and FFM in severely and moderately obese women and in lean subjects at different ages to find the possible differences between obese and lean subjects during aging. Methods: Sedentary women (n = 261) were divided into three groups with different body mass indexes (BMIs): 20.0-24.9; 30-34.9; >40 kg/m2. Each group was then divided into five subgroups: 20-29; 30-39; 40-49; 50-59; 60-69 years. REE was measured with an indirect calorimetric device. The FFM was calculated by bioelectric impedance. Results: The REE in severely obese women was higher than the REE in lean or moderately obese women. The FFM of severely obese women was lower than that of moderately obese or lean women. The aging induced reductions of the REE and FFM in lean and moderately obese subjects, but not in women with severe obesity. Conclusions: This experiment indicates that REE and FFM do not decline during aging in women with BMI > 40, suggesting that the severe obesity induces different age-related adaptations of metabolism and body composition. © 2008 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism

    Light environment and Seasonal Dynamics of Microalgae in the Annual Sea Ice at Terra Nova Bay, Ross Sea, Antarctica

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    We investigated the physical conditions of the Spring pack ice environment at Terra Nova Bay to understand their influence on the structure and physiology of sympagic microalgae. Bio-optical methods were used to study the availability and spectral quality of solar radiation, both inside and underneath the ice cover. Pack ice thickness was around 2.5 m, with a temperature between -2 and -7°C. On average, only 1.4% of surface PAR penetrated to the bottom ice and less than 0.6% below platelet ice level. Surface UV-B radiation under the bottom ice was 0.2-0.4%. Biomass concentrations up to 2400 mg Chl a m-3, dominated by two species of diatoms (Entomoneis kjellmannii and Nitschia cf. stellata), showed marked spatial and temporal patterns. Maximum values were in the platelet ice during the first half of November, and in the bottom ice two weeks later. Strong shade adaptation characteristics emerged clearly and explained the relevant abundance of microalgae within the sea ice, with specific absorption coefficients (a*) as low as 0.005 m2 (mg Chl a)-1 and the photo-acclimation index (Ek) in the range of in situ irradiance. The biomass specific production values were low, around 0.12-0.13 mg C mg Chl a-1 h-1. The hypothesis suggesting bottom ice colonization by platelet ice microalgae is supported here

    Emerging treatment options for multi-drug-resistant bacterial infections

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    Antimicrobial resistance (AMR) remains one of the top public health issues of global concern. Among the most important strategies for AMR control there is the correct and appropriate use of antibiotics, including those available for the treatment of AMR pathogens. In this article, after briefly reviewing the most important and clinically relevant multi-drug-resistant bacteria and their main resistance mechanisms, we describe the emerging antimicrobial options for both MDR Gram-positive cocci and Gram-negative bacilli, including recently marketed agents, molecules just approved or under evaluation and rediscovered older antibiotics that have regained importance due to their antimicrobial spectrum. Specifically, emerging options for Gram-positive cocci we reviewed include ceftaroline, ceftobiprole, tedizolid, dalbavancin, and fosfomycin. Emerging treatment options for Gram-negative bacilli we considered comprise ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, aztreonam-avibactam, minocycline, fosfomycin, eravacycline, plazomicin, and cefiderocol. An exciting scenario is opening today with the long awaited growing availability of novel molecules for the treatment of AMR bacteria. Knowledge of mechanisms of action and resistance patterns allows physicians to increasingly drive antimicrobial treatment towards a precision medicine approach. Strict adherence to antimicrobial stewardship practices will allow us to preserve the emerging antimicrobials for our future

    Cholesterol derivatives make large part of the lipids from epidermal molts of the desert-adapted Gila monster lizard (Heloderma suspectum)

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    In order to understand the cutaneous water loss in the desert-adapted and venomous lizard Heloderma suspectum, the microscopic structure and lipid composition of epidermal molts have been examined using microscopic, spectroscopic and chemical analysis techniques. The molt is formed by a variably thick, superficial beta-layer, an extensive mesos-region and few alpha-cells in its lowermost layers. The beta-layer contains most corneous beta proteins while the mesos-region is much richer in lipids. The proteins in the mesos-region are more unstructured than those located in the beta-layer. Most interestingly, among other lipids, high contents of cholesteryl-β-glucoside and cholesteryl sulfate were detected, molecules absent or present in traces in other species of squamates. These cholesterol derivatives may be involved in the stabilization and compaction of the mesos-region, but present a limited permeability to water movements. The modest resistance to cutaneous water-loss of this species is compensated by adopting other physiological strategies to limit thermal damage and water transpiration as previous eco-physiological studies have indicated. The increase of steroid derivatives may also be implicated in the heat shock response, influencing the relative behavior in this desert-adapted lizard

    Stable Catechol Keto Tautomers in Cytotoxic Heterodimeric Cyclic Diarylheptanoids from the Seagrass Zostera marina

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    Two diarylheptanoid heterodimers, zosterabisphenones A (1) and B (2), were isolated from the seagrass Zostera marina. They feature unprecedented catechol keto tautomers, stable because of steric constraints. Their structure elucidation was based on extensive low-temperature NMR studies and ECD and MS data, with the essential aid of DFT prediction of NMR and ECD spectra. Zosterabisphenone B (2) was selectively cytotoxic against the adenocarcinoma colon cancer cell line HCT116 with IC50 3.6 ± 1.1 μM at 48 h

    Impaired radial artery compliance in normotensive subjects with familial hypercholesterolemia

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    Hypercholesterolemia impairs arteriolar dilatation, but whether the vascular abnormalities accompanying this condition include large artery function is unknown. We addressed this issue in 13 normotensive subjects with familial hypercholesterolemia (serum cholesterol 401.6 \ub1 16.9 mg/dl, mean \ub1 S.E., FHC) and no evidence of atherosclerotic lesions, in whom radial artery (RA) diameter and blood pressure (BP) were measured beat to beat by an echotracking and a Finapres device, respectively. RA compliance (RAG) was derived from the diameter/BP relationship and expressed over the systo-diastolic BP range, both at baseline and after a 12-min brachial artery occlusion. RAC was expressed also as the area under the RAC/BP curve divided for pulse BP. Measurements included maximal forearm blood flow (plethysmography) and minimal forearm vascular resistance (FVR) which were obtained from the values following the 12-min brachial arterial occlusion. Data were collected before and after 6- and 24-month lipid lowering treatment (simvastatin 40 mg/day). Ten age-matched normotensive normocholesterolemic healthy subjects (N) served as controls. Compared to N, baseline RAC was strikingly reduced in FHC (-53.5%, P < 0.01). After ischemia RAC increased significantly and markedly in N (+38.7, P < 0.01), while only a modest and non-significant increase was observed in FHC. Minimal FVR was markedly higher in FHC than in N (3.5 \ub1 0.9 vs 1.6 \ub1 0.1 units, P < 0.01). In FHC (7 subjects) RAC remained unchanged after 6 months of lipid lowering treatment, but increased markedly (+55.2%, P < 0.05) when treatment was prolonged to 24 months. Lipid lowering treatment also reduced minimal FVR, the effect being significant bath after 6 and after 24 months. No changes in RAC and minimal FVR were seen after 6 months in controls. Thus, in subjects with a marked increase in serum cholesterol due to FHC, not only arteriolar dilatation, but also RAC and distensibility are markedly impaired. This impairment can be favourably affected by an effective lipid lowering treatment of long duration

    A case study on the application of the MSFD to Mediterranean coastal systems: the Po plume, as a transitional water system in the Northern Adriatic basin.

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    1 - In the frame of the Marine Strategy Framework Directive (MSFD) of the European Community, in order to assess the Good Environmental Status (GES) of the marine coastal and estuarine waters, the eutrophication descriptors include several aspects of the phytoplankton communities (such as composition, abundance and biomass). 2 - Two oceanographic campaigns were carried out in the area off the Po River plume, where a highly dynamic frontal zone separates an inshore and an offshore system. The coupling of size structure and diagnostic pigments of phytoplankton communities in relation to different environmental contexts are tested as an expedite and informative tool to assess water quality sensu MSFD. 3 - The Po plume creates a very dynamic frontal zone, resulting in strong trophic gradients within a relatively small area. 4 - The spatio-temporal variability of salinity in coastal waters and in transitional waters plays a pivotal role in structuring phytoplankton communities. 5 - The dynamics of forcing factors drive changes in cell-size structure, in the functional group composition as well as a shift in size within the same functional group. 6 - The combination of phytoplankton size-structure and chemotaxonomic compositions is proposed as an expedite tool for investigating, at the appropriate scales, the ecology of transitional water systems

    Quantitative and Qualitative Assessments of Retinal Structure with Variable A-Scan Rate Spectralis OCT: Insights into IPL Multilaminarity

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    The aim of this study was to evaluate the qualitative and quantitative differences between 20 and 85 kHz A-scan rate optical coherence tomography (OCT) images acquired by spectral domain OCT. The study included 60 healthy subjects analyzed with horizontal linear scans with a variable A-scan rate (SHIFT technology, Heidelberg Engineering, Heidelberg, Germany). The retinal thickness measurement of each retinal layer was performed in three different positions (subfoveal, nasal, and temporal). The qualitative assessment was performed by two independent observers who rated every image with a score ranging from 1 ("sufficient") to 3 ("excellent") on the basis of three parameters: visualization of the vitreo-retinal interface, characterization of the retinal layers, and visualization of the sclero-choroidal interface. No statistically significant differences in terms of retinal layer thickness between the two A-scan rate scans were observed (p > 0.05). The coefficient of variation of the retinal thickness values was lower in the 20 kHz group (25.8% versus 30.1% with the 85 kHz). The 20 kHz images showed a higher quality index for both observers. An inner plexiform layer (IPL) multilaminarity was detected in 78.3% of patients from the 20 kHz group and in 40% of patients from the 85 kHz group (p < 0.05)
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