788 research outputs found
Relationship between NOX4 level and angiotensin II signaling in Gitelman's syndrome. Implications with hypertension
Recent evidence showed that endogenous nicotinamide adenine dinucleotide phosphate-oxidase 4 (NOX4) may exert a protective role on the cardiovascular system inducing vasodilation, reduction of blood pressure, and anti-proliferative actions. However, the functional significance of NOX4 in the cardiovascular system in humans remains elusive. Mononuclear cell levels of NOX4 were assessed by immunoblotting in 14 Gitelman's patients (GS), a unique human model of endogenous Ang II signaling antagonism and activation of anti-atherosclerotic and anti-remodeling defenses, and compared to 11 untreated essential hypertensive patients as well as to 11 healthy normotensive subjects. The association between NOX4 and its effector heme oxygenase (HO-1) (sandwich immunoassay) was also evaluated. NOX4 protein levels were decreased in hypertensive patients as compared to both GS and healthy subjects (1.06±0.31 AU vs. 1.76±0.54, P=0.002 and vs. 1.61±0.54, P=0.018, respectively). NOX4 protein level did not differ between GS and healthy subjects. HO-1 levels were increased in GS patients as compared to both hypertensive patients and healthy subjects (8.65±3.08 ng/ml vs 3.70±1.19, P<0.0001, and vs 5.49±1.04, P=0.008, respectively. NOX4 levels correlate with HO-1 levels only in GS (r(2)=0.63; P=0.001), (r(2)=0.088; P=ns, in hypertensive patients and r(2)=0.082; P=ns, in healthy subjects). Our findings show that NOX4 and its effector HO-1 are reduced in hypertensive patients compared to GS patients, a human model opposite to hypertension. Although the functional significance of NOX4 needs further clarification, our preliminary data in a unique human model of anti-atherosclerotic and anti-remodeling defenses activation, highlight the potentially protective role of NOX4 in the human cardiovascular system
Does p63RhoGEF, a new key mediator of angiotensin II signalling, play a role in blood pressure regulation and cardiovascular remodelling in humans?
Corresponding author: Lorenzo A Calo, Department of Clinical and Experimental Medicine, Clinica Medica 4, University of Padova, Via Giustiniani, 2 35128 Padova, Italy. Email: [email protected] Journal of the Renin-AngiotensinAldosterone System 12(4) 634 –636 © The Author(s) 2011 Reprints and permission: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1470320311407232 jra.sagepub.com Letter to the Edito
The gustin (CA6) gene polymorphism, rs2274333 (A/G), as a mechanistic link between PROP tasting and fungiform taste papilla density and maintenance
Taste sensitivity to PROP varies greatly among individuals and is associated with polymorphisms in the bitter receptor gene TAS2R38, and with differences in fungiform papilla density on the anterior tongue surface. Recently we showed that the PROP non-taster phenotype is strongly associated with the G variant of polymorphism rs2274333 (A/G) of the gene that controls the salivary trophic factor, gustin. The aims of this study were 1) to investigate the role of gustin gene polymorphism rs2274333 (A/G), in PROP sensitivity and fungiform papilla density and morphology, and 2) to investigate the effect of this gustin gene polymorphism on cell proliferation and metabolic activity. Sixty-four subjects were genotyped for both genes by PCR techniques, their PROP sensitivity was assessed by scaling and threshold methods, and their fungiform papilla density, diameter and morphology were determined. In vitro experiments examined cell proliferation and metabolic activity, following treatment with saliva of individuals with and without the gustin gene mutation, and with isolated protein, in the two iso-forms. Gustin and TAS2R38 genotypes were associated with PROP threshold (p=0.0001 and p=0.0042), but bitterness intensity was mostly determined by TAS2R38 genotypes (p<0.000001). Fungiform papillae densities were associated with both genotypes (p<0.014) (with a stronger effect for gustin; p=0.0006), but papilla morphology was a function of gustin alone (p<0.0012). Treatment of isolated cells with saliva from individuals with the AA form of gustin or direct application of the active iso-form of gustin protein increased cell proliferation and metabolic activity (p<0.0135). These novel findings suggest that the rs2274333 polymorphism of the gustin gene affects PROP sensitivity by acting on fungiform papilla development and maintenance, and could provide the first mechanistic explanation for why PROP super-tasters are more responsive to a broad range of oral stimul
Quotas regulation is necessary but not sufficient to mitigate the impact of SCUBA diving in a highly visited marine protected area
When effectively managed, Marine Protected Areas (MPAs) can produce wide ecosystem benefits that can foster, directly and indirectly, local economies. Tourism is one of the sectors mainly benefited by the effect of conservation. SCUBA diving represents an important tourism activity, especially in the context of MPAs, where it is one of the few activities often fostered rather than limited, for its capacity to integrate environmental and socio-economic sustainability. However, SCUBA diving can also produce negative impacts on the environment when tourism frequentation exceeds a sustainable threshold, these potentially generating negative effects on the sector itself. In this study, we (1) investigated the impact of SCUBA diving in one of the most frequented diving areas of the Mediterranean Sea (Cabo de Palos - Islas Hormigas marine reserve), and (2) assessed the potential benefits over time related to the adoption of a regulation change for the diving activity (i.e., formally adoption of diving quotas). Specifically, we compared demographic (density of alive and dead colonies) and morphometric (height, width and complexity) characteristics of the false coral (Myriapora truncata) between dived and fully protected (non-dived) locations over four diving seasons (one before and three after the change in diving quotas). The density of alive colonies of the false coral was, on average, six times lower in dived locations compared to controls, highlighting a clear impact of SCUBA diving (consistent over time). Colonies were also significantly smaller in dived locations. The diving quotas produced a significant reduction of the ratio dead/total colonies in the dived locations soon after their adoption, but these benefits disappeared over the following years, possibly due to a gradual decline in operators' and divers' observance and concern, rather than an increasing number of dives. This suggests that the adoption of effective regulations is crucial for the environmental sustainability of diving tourism in protected areas and can provide positive effects, but an effort is needed to ensure that compliance is consistent over time, and that low-impact diving practices are adopted by this important recreational sector
EVALUATION OF DEM DERIVED BY REPEAT-PASS X-BAND STRIPMAP MODE PAZ DATA
Abstract. This paper, presents the initial results of digital elevation model (DEM) extraction from PAZ Synthetic Aperture Radar (SAR) satellite images using repeat-pass interferometric analysis. We used a multi-temporal high-resolution strip-map mode X-band satellite image that has a single polarization. Five main classes, i.e., volcanic structures, agriculture, settlement, sand dune and plain bareland are considered depending on the structure of the region. Within the category, the coherence value and DEM value are evaluated. In the accuracy assessment analysis, a reference map produced from aerial photogrammetry is used. Additionally, global DEM TanDEM-X data is also tested in the study region. In the analysis, quality metrics, mean error (ME), root means square error (RMSE), standard deviation (STD), and the normalized median absolute deviation (NMAD) are used. The results showed that as the temporal baseline increases the coherence values and the quality of the DEM product decrease. The RMSE values range between 2.36 m to 7.09 m in different classes. The TanDEM-X data provided high accuracies over each class range from 0.88 m to 2.40 m. Since the study area is vulnerable to sinkhole formation, sinkhole-like signals were also observed in the interferograms obtained from different and sequential pairs. The high-resolution repeat-pass PAZ data pointed out its potential for interferometric products generation
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