1,121 research outputs found

    Acid-Base Disorders in Patients with Chronic Obstructive Pulmonary Disease: A Pathophysiological Review

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    The authors describe the pathophysiological mechanisms leading to development of acidosis in patients with chronic obstructive pulmonary disease and its deleterious effects on outcome and mortality rate. Renal compensatory adjustments consequent to acidosis are also described in detail with emphasis on differences between acute and chronic respiratory acidosis. Mixed acid-base disturbances due to comorbidity and side effects of some drugs in these patients are also examined, and practical considerations for a correct diagnosis are provided

    Antioxidant Efficacy of Olive By-Product Extracts in Human Colon HCT8 Cells

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    The production of olive oil is accompanied by the generation of a huge amount of waste and by-products including olive leaves, pomace, and wastewater. The latter represents a relevant environmental issue because they contain certain phytotoxic compounds that may need specific treatments before the expensive disposal. Therefore, reducing waste biomass and valorizing by-products would make olive oil production more sustainable. Here, we explore the biological actions of extracts deriving from olive by-products including olive pomace (OP), olive wastewater (OWW), and olive leaf (OLs) in human colorectal carcinoma HCT8 cells. Interestingly, with the same phenolic concentration, the extract obtained from the OWW showed higher antioxidant ability compared with the extracts derived from OP and OLs. These biological effects may be related to the differential phenolic composition of the extracts, as OWW extract contains the highest amount of hydroxytyrosol and tyrosol that are potent antioxidant compounds. Furthermore, OP extract that contains a higher level of vanillic acid than the other extracts displayed a cytotoxic action at the highest concentration. Together these findings revealed that phenols in the by-product extracts may interfere with signaling molecules that cross-link several intracellular pathways, raising the possibility to use them for beneficial health effects

    The structure behind the Galactic bar traced by red clump stars in the VVV survey★

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    Red clump stars are commonly used to map the reddening and morphology of the inner regions of the Milky Way. We use the new photometric catalogues of the VISTA Variables in the V´ıa La´ctea survey to achieve twice the spatial resolution of previous reddening maps for Galactic longitudes − 10◦ < l < 10◦ and latitudes −1.5◦ < b < 1.5◦. We use these de- reddened catalogues to construct the Ks luminosity function around the red clump in the Galactic plane. We show that the secondary peak (fainter than the red clump) detected in these regions does not correspond to the bulge red-giant branch bump alone, as previously interpreted. Instead, this fainter clump corresponds largely to the over-density of red clump stars tracing the spiral arm structure behind the Galactic bar. This result suggests that studies aiming to characterize the bulge red-giant branch bump should avoid low galactic latitudes (|b| < 2◦), where the background red clump population contributes significant contamination. It furthermore highlights the need to include this structural component in future modelling of the Galactic bar

    New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

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    © 2017 The American Astronomical Society. All rights reserved.It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color-magnitude diagrams. We provide their coordinates as well as their near-IR color-magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color-magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A Ks < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color-magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.Peer reviewedFinal Accepted Versio

    Can the Multidimensional Prognostic Index (MPI) be a predictive instrument for mortality in older adult liver transplant candidates?

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    PurposeThe most recent guidelines recommend that selection of liver transplant recipient patients be guided by a multidimensional approach that includes frailty assessment. Different scales have been developed to identify frail patients and determine their prognosis, but the data on older adult candidates are still inconclusive. The aim of this study was to compare the accuracy of the Liver Frailty Index (LFI) and the Multidimensional Prognostic Index (MPI) as predictors of mortality in a cohort of older people patients being evaluated for liver transplantation.MethodsThis retrospective study was conducted on 68 patients > 70 years being followed at the University Hospital of Padua in 2018. Clinical information on each patient, Model For End-Stage Liver Disease (MELD), Body Mass Index (BMI), Activities of Daily Living (ADL), Mini Nutritional Assessment (MNA), LFI, MPI, and date-of-death, were recorded. The observational period was 3 years.ResultsWe studied 68 individuals (25 women), with a mean age 72.21 & PLUSMN; 1.64 years. Twenty-five (36.2%) patients died during the observational period. ROC curve analysis showed both MPI and LFI to be good predictors of mortality (AUC 0.7, p = 0.007, and AUC 0.689, p = 0.015, respectively). MELD (HR 1.99, p = 0.001), BMI (HR 2.34, p = 0.001), and poor ADL (HR 3.34, p = 0.04) were risk factors for mortality in these patients, while male sex (HR 0.1, p = 0.01) and high MNA scores (HR 0.57, p = 0.01) were protective factors.ConclusionOur study confirmed the prognostic value of MPI in older adult patients awaiting liver transplantation. In this cohort, good nutritional status and male sex were protective factors, while high MELD and BMI scores and poor functional status were risk factors.Key summary pointsAimThe aim of this study was to compare the accuracy of the Liver Frailty Index (LFI) and the Multidimensional Prognostic Index (MPI) as predictors of mortality in a cohort of older adult patients being evaluated for liver transplantationFindingsOn the 68 patients studied, ROC curve analysis showed that MPI was similar or slightly better than LFI as predictor of mortality (AUC 0.7, p=0.007, and AUC 0.689, p=0.015, respectively).MessageIn older people patients listed for liver transplantation, MPI is as good a prognostic tool as LFI for predicting mortality

    Activation of group III metabotropic glutamate receptors inhibits the production of RANTES in glial cell cultures

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    The chemokine RANTES is critically involved in neuroinflammation and has been implicated in the pathophysiology of multiple sclerosis. We examined the possibility that activation of G-protein-coupled metabotropic glutamate (mGlu) receptors regulates the formation of RANTES in glial cells. A 15 hr exposure of cultured astrocytes to tumor necrosis factor-alpha and interferon-gamma induced a substantial increase in both RANTES mRNA and extracellular RANTES levels. These increases were markedly reduced when astrocytes were coincubated with l-2-amino-4-phosphonobutanoate (l-AP-4), 4-phosphonophenylglycine, or l-serine-O-phosphate, which selectively activate group III mGlu receptor subtypes (i.e., mGlu4, -6, -7, and -8 receptors). Agonists of mGlu1/5 or mGlu2/3 receptors were virtually inactive. Inhibition of RANTES release produced by l-AP-4 was attenuated by the selective group III mGlu receptor antagonist (R,S)-alpha-methylserine-O-phosphate or by pretreatment of the cultures with pertussis toxin. Cultured astrocytes expressed mGlu4 receptors, and the ability of l-AP-4 to inhibit RANTES release was markedly reduced in cultures prepared from mGlu4 knock-out mice. This suggests that activation of mGlu4 receptors negatively modulates the production of RANTES in glial cells. We also examined the effect of l-AP-4 on the development of experimental allergic encephalomyelitis (EAE) in Lewis rats. l-AP-4 was subcutaneously infused for 28 d by an osmotic minipump that released 250 nl/hr of a solution of 250 mm of the drug. Detectable levels of l-AP-4 ( approximately 100 nm) were found in the brain dialysate of EAE rats. Infusion of l-AP-4 did not affect the time at onset and the severity of neurological symptoms but significantly increased the rate of recovery from EAE. In addition, lower levels of RANTES mRNA were found in the cerebellum and spinal cord of EAE rats infused with l-AP-4. These results suggest that pharmacological activation of group III mGlu receptors may be useful in the experimental treatment of neuroinflammatory CNS disorders

    Nitrate derived from beetroot juice lowers blood pressure in patients with arterial hypertension: A systematic review and meta-analysis

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    Background: Although there are a considerable number of clinical studies on nitrate (NO3) rich beetroot juice (BRJ) and hypertension, it is difficult to indicate the real effects of NO3 from BRJ on the BP of hypertensive patients because there are still no estimates of the effects of NO3 derived from BRJ on the BP of hypertension patients. Objective: To clarify these effects, we developed a systematic literature review with a meta-analysis of randomized clinical trials (RCTs). Design: The searches were accomplished through EMBASE, Cochrane Library, MEDLINE, CINAHL, Web of Science, and LILACS databases. The study included single or double-blinded RCTs and participants older than 18 years with hypertension [systolic BP (SBP) > 130 mmHg and diastolic BP (DBP) > 80 mmHg]. NO3 BRJ was required to be consumed in a format that possibly blinded participants/researchers. These studies should also report the SBP and DBP values (mmHg) measured before and after the treatment. Risk of Bias tools and GRADE were enforced. Results: Seven studies were included (218 participants). BRJ intervention time ranged from 3 to 60 days with daily dosages of 70–250 mL of BRJ. After the intervention with NO3 from BRJ, SBP underwent significant changes (p < 0.001) of −4.95 (95% CI: −8.88; −1.01) (GRADE: ⊕⊕⊕○ Moderate), but not for DBP (p = 0.06) −0.90 mmHg (95% CI: −3.16; 1.36) (GRADE: ⊕⊕⊕○ Moderate), compared to the control group. Conclusions: The NO3 derived from BRJ reduces SBP, but not DBP in patients with arterial hypertension

    Characterization of the sub-mesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of high-resolution MCS data

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    Part of the kinetic energy that maintains ocean circulation cascades down to small scales until it is dissipated through mixing. While most steps of this downward energy cascade are well understood, an observational gap exists at horizontal scales of 103-101 m that prevents characterizing a key step in the chain: the transition from anisotropic internal wave motions to isotropic turbulence. Here we show that this observational gap can be covered using high-resolution multichannel seismic (HR-MCS) data. Spectral analysis of acoustic reflectors imaged in the Alboran Sea thermocline shows that this transition is likely caused by shear instabilities. In particular, we show that the averaged horizontal wavenumber spectra of the reflectors vertical displacements display three subranges that reproduce theoretical spectral slopes of internal waves [λx > 100 m], Kelvin-Helmholtz-type shear instabilities [100 m > λx > 33 m], and turbulence [λx < 33 m], indicating that the whole chain of events is occurring continuously and simultaneously in the surveyed area
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