226 research outputs found
Atmospheric Deposition of Inorganic Elements and Organic Compounds at the Inlets of the Venice Lagoon
The Venice Lagoon is subjected to long-range transport of contaminants via aerosol from the near Po Valley. Moreover, it is an area with significant local anthropogenic emissions due to the industrial area of Porto Marghera, the urban centres, and the glass factories and with emissions by ships traffic within the Lagoon. Furthermore, since 2005, the Lagoon has also been affected by the construction of the MOSE (Modulo Sperimentale Elettromeccanico—Electromechanical Experimental Module) mobile dams, as a barrier against the high tide. This work presents and discusses the results from chemical analyses of bulk depositions, carried out in different sites of the Venice Lagoon. Fluxes of pollutants were also statistically analysed on PCA with the aim of investigating the spatial variability of depositions and their correlation with precipitations. Fluxes of inorganic pollutants depend differently on precipitations, while organic compounds show a more seasonal trend. The statistical analysis showed that the site in the northern Lagoon has lower and almost homogeneous fluxes of pollutants, while the other sites registered more variable concentrations. The study also provided important information about the annual trend of pollutants and their evolution over a period of about five years, from 2005 to 2010
PCBs and PAHs in sea-surface microlayer and sub-surfacewater samples of the Venice Lagoon (Italy)
Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are two classes of micropollutants intensively monitored
and regulated due to their toxicity, persistency and wide diffusion. Their concentrations have been investigated in sea-microlayer
(SML) and sub-surface water (SSW) samples collected at two sites of the Venice Lagoon, a fragile ecosystem highly influenced by industrial
and anthropogenic emissions. The total PPCB concentration varies from 0.45 ng/l to 2.1 ng/l in SSW while a clear enrichment is
observed in the SML, where it ranges from 1.2 ng/l to 10.5 ng/l. The total PPAH concentration shows marked differences between the
two stations and varies from 12.4 ng/l to 266.8 ng/l in SSW; in SML it is more uniform and ranges from 19.6 ng/l to 178.9 ng/l. The
enrichment factors are not larger than 1 for both pollutants in the dissolved phase, while they are most significant for the particulate
phase (PPCB: 5–9; PPAH: 4–14).
2005 Elsevier Ltd. All rights reserved
N-acetylcysteine reduces oxidative stress in sickle cell patients
Oxidative stress is of importance in the pathophysiology of sickle cell disease (SCD). In this open label randomized pilot study the effects of oral N-acetylcysteine (NAC) on phosphatidylserine (PS) expression as marker of cellular oxidative damage (primary end point), and markers of hemolysis, coagulation and endothelial activation and NAC tolerability (secondary end points) were studied. Eleven consecutive patients (ten homozygous [HbSS] sickle cell patients, one HbSβ0-thalassemia patient) were randomly assigned to treatment with either 1,200 or 2,400 mg NAC daily during 6 weeks. The data indicate an increment in whole blood glutathione levels and a decrease in erythrocyte outer membrane phosphatidylserine exposure, plasma levels of advanced glycation end-products (AGEs) and cell-free hemoglobin after 6 weeks of NAC treatment in both dose groups. One patient did not tolerate the 2,400 mg dose and continued with the 1,200 mg dose. During the study period, none of the patients experienced painful crises or other significant SCD or NAC related complications. These data indicate that N-acetylcysteine treatment of sickle cell patients may reduce SCD related oxidative stress
Sequestration and Tissue Accumulation of Human Malaria Parasites: Can We Learn Anything from Rodent Models of Malaria?
The sequestration of Plasmodium falciparum–infected red blood cells (irbcs) in the microvasculature of organs is associated with severe disease; correspondingly, the molecular basis of irbc adherence is an active area of study. In contrast to P. falciparum, much less is known about sequestration in other Plasmodium parasites, including those species that are used as models to study severe malaria. Here, we review the cytoadherence properties of irbcs of the rodent parasite Plasmodium berghei ANKA, where schizonts demonstrate a clear sequestration phenotype. Real-time in vivo imaging of transgenic P. berghei parasites in rodents has revealed a CD36-dependent sequestration in lungs and adipose tissue. In the absence of direct orthologs of the P. falciparum proteins that mediate binding to human CD36, the P. berghei proteins and/or mechanisms of rodent CD36 binding are as yet unknown. In addition to CD36-dependent schizont sequestration, irbcs accumulate during severe disease in different tissues, including the brain. The role of sequestration is discussed in the context of disease as are the general (dis)similarities of P. berghei and P. falciparum sequestration
n-Alkanes, PAHs and surfactants in the sea surface microlayer and sea water samples of the Gerlache Inlet sea (Antarctica)
Sea surface microlayer (SML) and sea water samples (SSW) collected in the Gerlache Inlet Sea (Antarctica)
were analysed for n-alkanes and polycyclic aromatic hydrocarbons (PAHs). The SML is a potential enrichment
site of hydrophobic organic compounds compared to the underlying water column. Total concentration
ranges of n-alkanes and PAHs (dissolved and particulate) in subsurface water (−0.5 m depth) were 272–
553 ng l−1 (mean: 448 ng l−1) and 5.27–9.43 ng l−1 (mean: 7.06 ng l−1), respectively. In the SML, the
concentration ranges of n-alkanes and PAHs were 353–968 ng l−1 (mean: 611 ng l−1) and 7.32–23.94 ng l−1
(mean: 13.22 ng l−1), respectively. To evaluate possible PAH contamination sources, specific PAH ratios were
calculated. The ratios reflected a predominant petrogenic input. A characterisation of surface active
substances was also performed on SML and SSW samples, both by gas bubble extraction, and by dynamic
surface tension measurements. Results showed a good correlation between n-alkanes, PAHs and refractory
organic matter
Role of mTOR in autophagic and lysosomal reactions to environmental stressors in molluscs
publisher: Elsevier articletitle: Role of mTOR in autophagic and lysosomal reactions to environmental stressors in molluscs journaltitle: Aquatic Toxicology articlelink: https://doi.org/10.1016/j.aquatox.2017.12.014 content_type: article copyright: © 2017 Elsevier B.V. All rights reserved
Nitric oxide synthetic pathway and cGMP levels are altered in red blood cells from end-stage renal disease patients
Red blood cells (RBCs) enzymatically produce nitric oxide (NO) by a functional RBC-nitric oxide synthase (RBC-NOS). NO is a vascular key regulatory molecule. In RBCs its generation is complex and influenced by several factors, including insulin, acetylcholine, and calcium. NO availability is reduced in end-stage renal disease (ESRD) and associated with endothelial dysfunction. We previously demonstrated that, through increased phosphatidylserine membrane exposure, ESRD-RBCs augmented their adhesion to human cultured endothelium, in which NO bioavailability decreased. Since RBC-NOS-dependent NO production in ESRD is unknown, this study aimed to investigate RBC-NOS levels/activation, NO production/bioavailability in RBCs from healthy control subjects (C, N = 18) and ESRD patients (N = 27). Although RBC-NOS expression was lower in ESRD-RBCs, NO, cyclic guanosine monophosphate (cGMP), RBC-NOS Serine1177 phosphorylation level and eNOS/Calmodulin (CaM)/Heat Shock Protein-90 (HSP90) interaction levels were higher in ESRD-RBCs, indicating increased enzyme activation. Conversely, following RBCs stimulation with insulin or ionomycin, NO and cGMP levels were significantly lower in ESRD- than in C-RBCs, suggesting that uremia might reduce the RBC-NOS response to further stimuli. Additionally, the activity of multidrug-resistance-associated protein-4 (MRP4; cGMP-membrane transporter) was significantly lower in ESRD-RBCs, suggesting a possible compromised efflux of cGMP across the ESRD-RBCs membrane. This study for the first time showed highest basal RBC-NOS activation in ESRD-RBCs, possibly to reduce the negative impact of decreased NOS expression. It is further conceivable that high NO production only partially affects cell function of ESRD-RBCs maybe because in vivo they are unable to respond to physiologic stimuli, such as calcium and/or insulin
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