165 research outputs found
Effect of dietary vitamin A on Senegalese sole (Solea senegalensis) skeletogenesis and larval quality
16 páginas, 12 figuras, 4 tablas.The effects of different levels of vitamin A (VA) in Senegalese sole larval performance and development were evaluated by means of a dietary dose–response experiment using enriched Artemia metanauplii as a carrier of this micronutrient. Larvae were fed from 6 to 27 days post hatch (dph) with enriched Artemia containing graded levels of total VA (1.3, 2.1, 4.5 and 12.9 µg VA mg− 1 DW). The content of VA in live prey directly affected its accumulation in larvae and early juveniles. Retinyl palmitate accumulated during larval ontogeny, whereas retinol showed the opposite trend, decreasing from hatching until 41 dph and then remaining constant until the end of the study.
In metamorphic larvae (10 and 15 dph), VA did not affect the number of thyroid follicles or the intensity of the immunoreactive staining of T3 and T4. However, at older stages of development (post-metamorphic larvae: 20, 30, 41 and 48 dph), VA decreased the number of thyroid follicles but increased their mean size and enhanced T3 and T4 immunoreactive staining. A dietary excess of VA did not affect either larval performance in terms of growth and survival or the maturation of the digestive system. However, the most remarkable impact of this morphogenetic nutrient was detected during skeletal morphogenesis. Dietary VA accelerated the intramembranous ossification of vertebral centrums, which led to the formation of a supranumerary haemal vertebra and a high incidence of fused and compressed vertebrae in fish fed 2.1, 4.5 and 12.9 mg VA mg− 1 DW. In addition, VA also affected those structures from vertebrae and caudal fin formed by chondral ossification, leading to defects in their shape and fusions with adjacent skeletal elements. In particular, the caudal fin was the region most affected by the dietary treatments. In order of importance, the bones with more developmental anomalies were the modified neural and haemal spines, epural, hypurals and parahypural. The impact of systemic factors such as thyroidal hormones in skeletogenesis should not be neglected since present results revealed that an excess of dietary VA affected the levels of T3 and T4, which might have affected bone formation and remodelling, leading to skeletal deformities.This work was funded by the Ministry of Education and Culture (MEC) of the Spanish Government (project AGL2005-02478).Peer reviewe
Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean
Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm) significantly decreased metabolic rates (up to 27.4 %) of flatfish larvae, Solea senegalensis, at both present (18 °C) and warmer temperatures (+4 °C). Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT) and glutathione S-transferase (GST), mainly in post-metamorphic larvae (30 dph). The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph) seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase) and intestinal enzymes (up to 36.1 % for alkaline phosphatase) in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels) were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems.info:eu-repo/semantics/publishedVersio
Impacts of acute hypoxia on the short-snouted seahorse metabolism and behaviour
The authors would also like to express their gratitude to Oceanário de Lisboa and Aquário Vasco da Gama, and to Filipa Faleiro, António Gomes and José Pereira for the availability to support this work.
project grant to M.S.P. (PTCD/BIA-BMA/28647/2017, LISBOA-01-0145-FEDER-028647)-
Publisher Copyright:
© 2023Seahorses are one of the most unique and enigmatic animals, recognized as flagship species for several conservation issues. Unfortunately, seahorses' populations have been declining and their unique lifestyle may constrain the ability of these animals to evolve in the future climate scenarios. They inhabit shallow coastal waters that display daily or seasonal environmental fluctuations. Yet, few studies have scrutinized the impacts of climate changes on these iconic species. Within this context, the objective of this work was to test the effects of an extreme hypoxia exposure (~27 % dissolved oxygen for approximately 7 h) on the metabolism, behaviour and food intake of the temperate seahorse Hippocampus hippocampus. Regarding metabolism, hypoxia exposure led to a significant reduction in metabolic rates and an increase in ventilation rates. Seahorses showed signs of movement lethargy under oxygen depletion. The results show that a small but extreme exposure to hypoxia is tolerable by seahorses despite inducing metabolic and behavioural changes, that may jeopardize the future development and survival of these iconic organisms.publishersversionpublishe
A non-genetic model of vascular shunts informs on the cellular mechanisms of formation and resolution of arteriovenous malformations
Arteriovenous malformations (AVMs), a disorder characterized by direct shunts between arteries and veins, are associated with genetic mutations. However, the mechanisms leading to the transformation of a capillary into a shunt remain unclear and how shunts can be reverted into capillaries is poorly understood. Here, we report that oxygen-induced retinopathy (OIR) protocol leads to the consistent and stereotypical formation of AV shunts in non-genetically altered mice. OIR-induced AV shunts show all the canonical markers of AVMs. Genetic and pharmacological interventions demonstrated that changes in endothelial cell (EC) volume of venous origin (hypertrophic venous cells) are the initiating step promoting AV shunt formation, whilst EC proliferation or migration played minor roles. Inhibition of mTOR pathway prevents pathological increases in EC volume and significantly reduces the formation of AV shunts. Importantly, we demonstrate that ALK1 signaling cell-autonomously regulates EC volume, demonstrating that our discoveries link with hereditary hemorrhagic telangiectasia (HHT)-related AVMs. Finally, we demonstrate that a combination of EC volume control and EC migration is associated with the regression of AV shunts. We demonstrate that an increase in the EC volume is the key mechanism driving the initial stages of AV shunt formation, leading to asymmetric capillary diameters. Based on our results, we propose a coherent and unifying timeline leading to the fast conversion of a capillary vessel into an AV shunt. Our data advocates for further investigation into the mechanisms regulating EC volume in health and disease as a way to identify therapeutic approaches to prevent and revert AVMs.info:eu-repo/semantics/publishedVersio
Small pelagics in a changing ocean : Biological responses of sardine early stages to warming
Small pelagic fishes are known to respond rapidly to changes in ocean climate. In this study, we evaluate the effects of future environmental warming (+2°C) during the early ontogeny of the European sardine, Sardina pilchardus. Warming reduced the survival of 30-day-old larvae by half. Length at hatching increased with temperature as expected, but no significant effect was observed on the length and growth at 30 days post-hatching. Warming did not significantly affect the thermal tolerance of sardine larvae, even though the mean lethal temperature increased by 1°C. In the warm conditions, sardine larvae showed signs of thermal stress, indicated by a pronounced increase in larval metabolism (Q 10 = 7.9) and a 45% increase in the heat shock response. Lipid peroxidation was not significantly affected by the higher temperature, even though the mean value doubled. Warming did not affect the time larvae spent swimming, but decreased by 36% the frequency of prey attacks. Given the key role of these small pelagics in the trophic dynamics off the Western Iberian upwelling ecosystem, the negative effects of warming on the early stages may have important implications for fish recruitment and ecosystem structure.Fundação para a Ciência e a Tecnologia (FCT
low-cost portable NGS platform for HIV-1 surveillance in Africa
Funding Information: Foundation for Science and Technology (FCT) funded the MARVEL project (PTDC/SAU-PUB/4018/2021), GHTM (GHTM-UID/04413/2020), LA-REAL-LA/P/0117/2020 supporting the costs related to project implementation in Cape Verde, Mozambique and Sao Tome & Principe. Calouste Gulbenkian Foundation (FCG), under the ENVOLVE Ci\u00EAncia PALOP program, funded the HITOLA project (Number 250466), which is supporting the costs related to the project implementation in Angola. The funders have no role in the conceptualization, design, data collection, analysis, decision to publish, or preparation of the manuscript. Publisher Copyright: © The Author(s) 2024.Background: HIV-1 infections remain a global public health concern. Scaled-up antiretroviral treatment (ART) is crucial for reducing morbidity and mortality related to HIV/AIDS. The emergence of drug-resistance mutations (DRMs) compromises viral suppression and contributes to the continued HIV-1 transmission. Several reports indicate a recent increase in acquired (ADR) and transmitted (TDR) drug resistance in Africa, probably linked to the lack of implementation of HIV drug resistance (HIVDR) testing and suboptimal treatment adherence. Herein, we will develop a low-cost protocol using third-generation sequencing (Oxford Nanopore Technology) for HIV-1 surveillance in Portuguese-speaking African Countries - PALOP [Angola (AO), Cape Verde (CV), Mozambique (MZ), and Sao Tome & Principe (STP)]. Methods: This is a multicentric cross-sectional study that includes around 600 adult patients newly diagnosed with HIV-1 in the PALOP. An epidemiological questionnaire previously validated by our research team will be used to collect sociodemographic and clinical data. Also, whole blood samples will be collected and the plasma samples will be subjected to drug resistance testing using an in-house low-cost NGS protocol. Data analysis will involve bioinformatics, biostatistics and machine learning techniques to generate accurate and up-to-date information about HIV-1 genetic diversity, ADR and TDR. Discussion: The implementation of this low-cost NGS platform for HIV-1 surveillance in the PALOP will allow: (i) to increase DRM surveillance capacity in resource-limited settings; (ii) to understand the pattern and determinants of dissemination of resistant HIV-1 strains; and (iii) to promote the development of technical and scientific skills of African researchers for genomic surveillance of viral pathogens and bioinformatics analysis. These objectives will contribute to reinforcing the capacity to combat HIV infection in Africa by optimizing the selection of ART regimens, improving viral suppression, and reducing ADR or TDR prevalence in PALOPs, with relevant implications for public health.publishersversionpublishe
HIV-1 diversity and pre-treatment drug resistance in the era of integrase inhibitor among newly diagnosed ART-naïve adult patients in Luanda, Angola
This research was funded by the Fundação Calouste Gulbenkian (FCG), under the ENVOLVE Ciência PALOP
program that funded the HITOLA project (Number 250466), AREF (AREF-312-CRUZ-F-C0931), Science
and Technology Development Project (PDCT) within the scope of the MUTHIVAO project (Number 36
MESCTI/PDCT/2022), FCT MARVEL (PTDC/SAU-PUB/4018/2021), FCT GHTM-UID/04413/2020 and
LA-REAL-LA/P/0117/2020.The surveillance of drug resistance in the HIV-1 naïve population remains critical to optimizing the effectiveness of antiretroviral therapy (ART), mainly in the era of integrase strand transfer inhibitor (INSTI) regimens. Currently, there is no data regarding resistance to INSTI in Angola since Dolutegravir-DTG was included in the first-line ART regimen. Herein, we investigated the HIV-1 genetic diversity and pretreatment drug resistance (PDR) profile against nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and INSTIs, using a next-generation sequencing (NGS) approach with MinION, established to track and survey DRMs in Angola. This was a cross-sectional study comprising 48 newly HIV-diagnosed patients from Luanda, Angola, screened between March 2022 and May 2023. PR, RT, and IN fragments were sequenced for drug resistance and molecular transmission cluster analysis. A total of 45 out of the 48 plasma samples were successfully sequenced. Of these, 10/45 (22.2%) presented PDR to PIs/NRTIs/NNRTIs. Major mutations for NRTIs (2.2%), NNRTIs (20%), PIs (2.2%), and accessory mutations against INSTIs (13.3%) were detected. No major mutations against INSTIs were detected. M41L (2%) and I85V (2%) mutations were detected for NRTI and PI, respectively. K103N (7%), Y181C (7%), and K101E (7%) mutations were frequently observed in NNRTI. The L74M (9%) accessory mutation was frequently observed in the INSTI class. HIV-1 pure subtypes C (33%), F1 (17%), G (15%), A1 (10%), H (6%), and D (4%), CRF01_AG (4%) were observed, while about 10% were recombinant strains. About 31% of detected HIV-1C sequences were in clusters, suggesting small-scale local transmission chains. No major mutations against integrase inhibitors were detected, supporting the continued use of INSTI in the country. Further studies assessing the HIV-1 epidemiology in the era of INSTI-based ART regimens are needed in Angola.info:eu-repo/semantics/publishedVersio
Reproduction and respiration of a climate change indicator species: effect of temperature and variable food in the copepod Centropages chierchiae
The abundance of the calanoid copepod Centropages chierchiae has increased at the northern limits of its distribution in recent decades, mainly due to oceanic climate forcing, suggesting this as a key species in monitoring climate change. Laboratory experiments were conducted to study the combined effect of temperature, food type and concentration on the egg production rate (EPR) and hatching success (HS) of C. chierchiae. Females were fed on two monoalgal diets (Gymnodinium sp. and Phaeodactylum tricornutum) at two food concentrations and at three different temperatures (13, 19, 24C). Respiration rates of both genders were measured at four different temperatures (8, 13, 19, 24C). EPR was significantly different between temperatures and food concentrations, the maximum EPR being attained when the copepods were exposed to high food levels and at 19C. Prey type significantly influenced EPR; feeding on P. tricornutum resulted in higher egg production than Gymnodinium sp. HS was significantly lower at 13C than at 19 and 24C and higher with Gymnodinium sp. Respiration rates were sex independent and increased exponentially with temperature. To maintain basal metabolism, the minimum food intake of P. tricornutum ranged between 0.4 and 1.8 g C and for Gymnodinium sp. between 0.03 and 0.13 g C. Food intake was always higher than the metabolic demands, except for the highest temperature tested (24C). The present results confirm the sensitivity of C. chierchiae to temperature variations and may help in understanding the successful expansion of its distribution towards northern latitudes.Portuguese Science and Technology Foundation (FCT) [PTDC/MAR/098643/2008, PTDC/MAR/111304/2009, PTDC/MAR/0908066/2008]; FCT [SFRH/BD/28198/2006]; [SFRH/BPD/38332/2007
Determinants of HIV-1 Late Presentation in Patients Followed in Europe
To control the Human Immunodeficiency Virus (HIV) pandemic, the World Health Organization (WHO) set the 90-90-90 target to be reached by 2020. One major threat to those goals is late
presentation, which is defined as an individual presenting a TCD4+ count lower than 350 cells/mm3
or an AIDS-defining event. The present study aims to identify determinants of late presentation in
Europe based on the EuResist database with HIV-1 infected patients followed-up between 1981 and
2019. Our study includes clinical and socio-demographic information from 89,851 HIV-1 infected
patients. Statistical analysis was performed using RStudio and SPSS and a Bayesian network was
constructed with the WEKA software to analyze the association between all variables. Among 89851
HIV-1 infected patients included in the analysis, the median age was 33 (IQR: 27.0–41.0) years and
74.4% were males. Of those, 28,889 patients (50.4%) were late presenters. Older patients (>56),
heterosexuals, patients originated from Africa and patients presenting with log VL >4.1 had a higher
probability of being late presenters (p < 0.001). Bayesian networks indicated VL, mode of transmission, age and recentness of infection as variables that were directly associated with LP. This study
highlights the major determinants associated with late presentation in Europe. This study helps to
direct prevention measures for this population
Applying Next-Generation Sequencing to Track HIV-1 Drug Resistance Mutations Circulating in Portugal
Funding Information: This research was funded by FCT in the Scopus of INTEGRIV project (PTDC/SAU-INF/31990/2017), FCT MARVEL (PTDC/SAU-PUB/4018/2021), Calouste Gulbenkian Foundation (FCG), under the ENVOLVE Ci\u00EAncia PALOP program that funded the HITOLA project (N\u00BA.250466), Africa Research Excellence Fund (AREF) (AREF-312-CRUZ-F-C0931), Science and Technology Development Project (PDCT) within the scope of the MUTHIVAO project (N\u00BA.36 MESCTI/PDCT/2022), and by funds from FCT to GHTM-UID/04413/2020 and LA-REAL-LA/P/0117/2020. SGS was funded by FCT, Portugal, through a program contract (CEECINST/00102/2018/CP1567/CT0040). CiiEM has provided support through Project 10.54499/UIDB/04585/2020, funded by FCT. Publisher Copyright: © 2024 by the authors.Background: The global scale-up of antiretroviral treatment (ART) offers significant health benefits by suppressing HIV-1 replication and increasing CD4 cell counts. However, incomplete viral suppression poses a potential threat for the emergence of drug resistance mutations (DRMs), limiting ART options, and increasing HIV transmission. Objective: We investigated the patterns of transmitted drug resistance (TDR) and acquired drug resistance (ADR) among HIV-1 patients in Portugal. Methods: Data were obtained from 1050 HIV-1 patient samples submitted for HIV drug resistance (HIVDR) testing from January 2022 to June 2023. Evaluation of DRM affecting viral susceptibility to nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs) was performed using an NGS technology, the Vela Diagnostics Sentosa SQ HIV-1 Genotyping Assay. Results: About 71% of patients were ART naïve and 29% were experienced. Overall, 20% presented with any DRM. The prevalence of TDR and ADR was 12.6% and 41.1%, respectively. M184V, T215S, and M41L mutations for NRTI, K103N for NNRTI, and M46I/L for PIs were frequent in naïve and treated patients. E138K and R263K mutations against INSTIs were more frequent in naïve than treated patients. TDR and ADR to INSTIs were 0.3% and 7%, respectively. Patients aged 50 or over (OR: 1.81, p = 0.015), originating from Portuguese-speaking African countries (PALOPs) (OR: 1.55, p = 0.050), HIV-1 subtype G (OR: 1.78, p = 0.010), and with CD4 < 200 cells/mm3 (OR: 1.70, p = 0.043) were more likely to present with DRMs, while the males (OR: 0.63, p = 0.003) with a viral load between 4.1 to 5.0 Log10 (OR: 0.55, p = 0.003) or greater than 5.0 Log10 (OR: 0.52, p < 0.001), had lower chances of presenting with DRMs. Conclusions: We present the first evidence on TDR and ADR to INSTI regimens in followed up patients presenting for healthcare in Portugal. We observed low levels of TDR to INSTIs among ART-naïve and moderate levels in ART-exposed patients. Regimens containing PIs could be an alternative second line in patients with intermediate or high-level drug resistance, especially against second-generation INSTIs (dolutegravir, bictegravir, and cabotegravir).publishersversionpublishe
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