When toxicity goes circular: Isoprostanes as markers and effectors of oxidative stress.

In normal conditions, there is a dynamic equilibrium between oxidants and antioxidants in the human body; however, when there is an unbalance in this redox state, oxidative stress occurs. In an unbalanced state, the peroxidation of polyunsaturated fatty acids originates isoprostanes (IsoPs), which can be considered as markers of oxidative stress. Since oxidative stress is associated with several non-communicable chronic diseases (NCDs), IsoPs can be used as clinical biomarkers of such diseases. Patients with congestive heart failure, cystic fibrosis and chronic renal insufficiency, for example, have higher levels of IsoPs

Acute toxicity of plant extracts towards Daphnia magna

The demand for natural based products for the cosmetics industry is increasing sharply and therefore the search for new alternatives to the traditionally used plants is growing. These alternative plants can be an important source of bioactive compounds under a circular economy approach. Within the framework of Inovep project, several plant species, some of which autochthonous from Portugal, were identified as potential sources of bioactive compounds, namely: gum rockrose (Cistus ladanifer), curry plant (Helichrysum italicum), hop (Humulus lupulus), Mediterranean thyme (Thymbra capitata) and basil (Ocimum basilicum). Considering the potential future use of these plant extracts by the industry, it is necessary to assess the risk associated with their introduction into the ecosystem. This work aims to evaluate the toxic effects of different extracts of these five species. Acute toxicity tests using the model organism Daphnia magna were performed and the immobilization after 24 and 48 hours of exposure was evaluated. The EC50 (the concentration estimated to immobilize 50 per cent of the Daphnia) varied from 201.8±3.28 x10-5 mg.L-1 at 24 hours and 199.5±5.9410x10-5 mg.L-1 at 48 hours for Cistus ladanifer extract and 11.2±0.2403 mg.L- 1 at 24 hours and 11.2±0.4095 mg.L-1 at 48 hours for Thymbra capitata essential oil. For Humulus lupulus, Helichrysum italicum, Thymbra capitata in the form of hidrolate, and Ocimum basilicum no immobilization was observed until the highest concentrations tested for various types of extracts, suggesting these extracts present low to no risk towards D. magna

Different ability of multidrug-resistant and-sensitive counterpart cells to release and capture extracellular vesicles

Cancer multidrug resistance (MDR) is one of the main challenges for cancer treatment efficacy. MDR is a phenomenon by which tumor cells become resistant to several unrelated drugs. Some studies have previously described the important role of extracellular vesicles (EVs) in the dissemination of a MDR phenotype. EVs’ cargo may include different players of MDR, such as microRNAS and drug-efflux pumps, which may be transferred from donor MDR cells to recipient drug-sensitive counterparts. The present work aimed to: (i) compare the ability of drug-sensitive and their MDR counterpart cells to release and capture EVs and (ii) study and relate those differences with possible distinct fate of the endocytic pathway in these counterpart cells. Our results showed that MDR cells released more EVs than their drug-sensitive counterparts and also that the drug-sensitive cells captured more EVs than their MDR counterparts. This difference in the release and capture of EVs may be associated with differences in the endocytic pathway between drug-sensitive and MDR cells. Importantly, manipulation of the recycling pathway influenced the response of drug-sensitive cells to doxorubicin treatment.This article is a result of the project NORTE-01-0145-FEDER-000029, supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). We thank Spanish MINECO (SAF2015-66312 to JMF) and for the REDIEX (Spanish Excellence Network in Exosomes) and the Severo Ochoa Excellence Accreditation (SEV-2016-0644). The authors thank the Portuguese Foundation for Science and Technology (FCT) for the PhD grant of DS (SFRH/BD/98054/2013). Cristina P.R. Xavier is supported by FCT and Fundo Social Europeu (FSE), through the post-doc grant SFRH/BPD/122871/2016. The authors also acknowledge the European COST Action-European Network on Microvesicles and Exosomes in Health and Disease (ME-HaD, BM1202) for short-term mission fellowship (ECOST-STSM-BM1202-150317-083396) and Grupo Español de investigacion en Vesiculas Extracelulares for GEIVEX mobility fellowship which allowed the work of DS in CICbioGUNE

IgA nephropathy in a young adult with nephrotic syndrome: Case report

IgA nephropathy has many clinical presentations, of which nephrotic syndrome is possibly the rarest. Recently, the association of IgA nephropathy with minimal change disease was better described with patients having complete response to steroid therapy and no progression to CKD. We report a similar case in a young male presenting with nephrotic syndrome.info:eu-repo/semantics/publishedVersio

Disturbance and diversity at two spatial scales

The spatial scale of disturbance is a factor potentially influencing the relationship between disturbance and diversity. There has been discussion on whether disturbances that affect local communities and create a mosaic of patches in different successional stages have the same effect on diversity as regional disturbances that affect the whole landscape. In a microcosm experiment with metacommunities of aquatic protists, we compared the effect of local and regional disturbances on the disturbance–diversity relationship. Local disturbances destroyed entire local communities of the metacommunity and required reimmigration from neighboring communities, while regional disturbances affected the whole metacommunity but left part of each local community intact. Both disturbance types led to a negative relationship between disturbance intensity and Shannon diversity. With strong local disturbance, this decrease in diversity was due to species loss, while strong regional disturbance had no effect on species richness but reduced the evenness of the community. Growth rate appeared to be the most important trait for survival after strong local disturbance and dominance after strong regional disturbance. The pattern of the disturbance–diversity relationship was similar for both local and regional diversity. Although local disturbances at least temporally increased beta diversity by creating a mosaic of differently disturbed patches, this high dissimilarity did not result in regional diversity being increased relative to local diversity. The disturbance–diversity relationship was negative for both scales of diversity. The flat competitive hierarchy and absence of a trade-off between competition and colonization ability are a likely explanation for this pattern

The Environmental History of Cetaceans in Portugal: Ten Centuries of Whale and Dolphin Records

The history between cetaceans and humans is documented throughout time not only in reports, descriptions, and tales but also in legal documents, laws and regulations, and tithes. This wealth of information comes from the easy spotting and identification of individuals due to their large size, surface breathing, and conspicuous above water behaviour. This work is based on historical sources and accounts accounting for cetacean presence for the period between the 12th and 17th centuries, as well as scientific articles, newspapers, illustrations, maps, non-published scientific reports, and other grey literature from the 18th century onwards. Information on whale use in Portugal's mainland has been found since as early as the 12th century and has continued to be created throughout time. No certainty can be given for medieval and earlier events, but both scavenging of stranded whales or use of captured ones may have happened. There is an increasing number of accounts of sighted, stranded, used, or captured cetaceans throughout centuries which is clearly associated with a growing effort towards the study of these animals. Scientific Latin species denominations only started to be registered from the 18th century onwards, as a consequence of the evolution of natural sciences in Portugal and increasing interest from zoologists. After the 19th century, a larger number of observations were recorded, and from the 20th century to the present day, regular scientific records have been collected. Research on the environmental history of cetaceans in Portugal shows a several-centuries-old exploitation of whales and dolphins, as resources mainly for human consumption, followed in later centuries by descriptions of natural history documenting strandings and at sea encounters. Most cetaceans species currently thought to be present in Portuguese mainland waters were at some point historically recorded

Whole-Community Facilitation Regulates Biodiversity on Patagonian Rocky Shores

Understanding the factors that generate and maintain biodiversity is a central goal in ecology. While positive species interactions (i.e., facilitation) have historically been underemphasized in ecological research, they are increasingly recognized as playing important roles in the evolution and maintenance of biodiversity. Dominant habitat-forming species (foundation species) buffer environmental conditions and can therefore facilitate myriad associated species. Theory predicts that facilitation will be the dominant community-structuring force under harsh environmental conditions, where organisms depend on shelter for survival and predation is diminished. Wind-swept, arid Patagonian rocky shores are one of the most desiccating intertidal rocky shores ever studied, providing an opportunity to test this theory and elucidate the context-dependency of facilitation.Surveys across 2100 km of southern Argentinean coastline and experimental manipulations both supported theoretical predictions, with 43 out of 46 species in the animal assemblage obligated to living within the matrices of mussels for protection from potentially lethal desiccation stress and predators having no detectable impact on diversity.These results provide the first experimental support of long-standing theoretical predictions and reveal that in extreme climates, maintenance of whole-community diversity can be maintained by positive interactions that ameliorate physical stress. These findings have important conservation implications and emphasize that preserving foundation species should be a priority in remediating the biodiversity consequences of global climate change