71 research outputs found

    Bone marrow chimeric mice reveal a dual role for CD36 in Plasmodium berghei ANKA infection

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    BACKGROUND: Adhesion of Plasmodium-infected red blood cells (iRBC) to different host cells, ranging from endothelial to red blood cells, is associated to malaria pathology. In vitro studies have shown the relevance of CD36 for adhesion phenotypes of Plasmodium falciparum iRBC such as sequestration, platelet mediated clumping and non-opsonic uptake of iRBC. Different adhesion phenotypes involve different host cells and are associated with different pathological outcomes of disease. Studies with different human populations with CD36 polymorphisms failed to attribute a clear role to CD36 expression in human malaria. Up to the present, no in vivo model has been available to study the relevance of different CD36 adhesion phenotypes to the pathological course of Plasmodium infection. METHODS: Using CD36-deficient mice and their control littermates, CD36 bone marrow chimeric mice, expressing CD36 exclusively in haematopoietic cells or in non-haematopoietic cells, were generated. Irradiated CD36(-/- )and wild type mice were also reconstituted with syngeneic cells to control for the effects of irradiation. The reconstituted mice were infected with Plasmodium berghei ANKA and analysed for the development of blood parasitaemia and neurological symptoms. RESULTS: All mice reconstituted with syngeneic bone marrow cells as well as chimeric mice expressing CD36 exclusively in non-haematopoietic cells died from experimental cerebral malaria between day 6 and 12 after infection. A significant proportion of chimeric mice expressing CD36 only in haematopoietic cells did not die from cerebral malaria. CONCLUSION: The analysis of bone marrow chimeric mice reveals a dual role of CD36 in P. berghei ANKA infection. Expression of CD36 in haematopoietic cells, most likely macrophages and dendritic cells, has a beneficial effect that is masked in normal mice by adverse effects of CD36 expression in non-haematopoietic cells, most likely endothelial cells

    Infection by and protective immune responses against Plasmodium berghei ANKA are not affected in macrophage scavenger receptors A deficient mice

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    BACKGROUND: Scavenger receptors (SRs) recognize endogenous molecules modified by pathological processes as well as components of diverse microorganisms. Mice deficient for both SR-AI and II are more susceptible to infections by a variety of bacterial and viral pathogens. RESULTS: Here we show that SR-A deficient mice and wild type mice are equally susceptible to malaria infection both during liver and blood stages. Moreover, like wild type mice, SR-A deficient mice are able to mount a protective immune response against radiation attenuated sporozoites. CONCLUSION: Our results do not reveal a function of SR-A I and II receptors in the Plasmodium berghei ANKA infection, both in the development of CM and parasitemia control. Moreover, these receptors appear not to be required for the establishment of a protective immune response against the malaria liver stages

    Antispasmodic activity of aqueous extracts from Mentha x piperita native from Trás-os-Montes region (Portugal)

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    The wild mint Mentha x piperita (Mentha rotundifolia Huds.), has been used by the local people in a northern region of Portugal to prepare infusions for treating digestive pain and spasms, as an appetite stimulant and for treating headache and migraine. This suggests that these aqueous extracts have analgesic; antispasmodic and stomachic properties. In the present study the antioxidant potential of aqueous extracts of Mentha x piperita is investigated since natural antioxidants can scavenge the reactive oxygen species, ROS, and thus might attenuate inflammation pathways. The antispasmodic activity was also checked. The antioxidant potential of the extract was evaluated by the DPPH* method, by the quantification of the total phenolic compounds and by characterization of the main phenolic compounds. The antispasmodic effects were investigated by performing pharmacological assays using the distal ileum of guinea pigs. The aqueous extract exhibits antioxidant properties that may be due to its phenolic content. The main phenolic compounds were quinic, caffeic, rosmarinic and chlorogenic acids. The antispasmodic affects are observed after electrical stimulation of segments of distal ileum of guinea pigs and may be attributed, at least, to a alfa1 blockage

    Biocompatibility of a self-assembled crosslinkable hyaluronic acid nanogel

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    Hyaluronic acid nanogel (HyA-AT) is a redox sensitive crosslinkable nanogel, obtained through the conjugation of a thiolated hydrophobic molecule to the hyaluronic acid chain. Engineered nanogel was studied for its biocompatibility, including immunocompatibility and hemocompatability. The nanogel did not compromise the metabolic activity or cellular membrane integrity of 3T3, microvascular endothelial cells, and RAW 264.7 cell lines, as determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase release assays. Also, we didn't observe any apoptotic effect on these cell lines through the Annexin V-FITC test. Furthermore, the nanogel cell internalization was analyzed using murine bone marrow derived macrophages, and the in vivo and ex vivo biodistribution of the Cy5.5 labeled nanogel was monitored using a non-invasive near-infrared fluorescence imaging system. The HyA-AT nanogel exhibits fairly a long half-live in the blood stream, thus showing potential for drug delivery applications.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/ BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project “BioHealth – Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124- FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The authors would like to acknowledge also the support of FCT for the PhD grant reference SFRH/BD/61516/2009. They would also like to thank Bioimaging department on Molecular Medicine Institute (IMM) in Lisbon, namely Dr José Rino and Dr António Temudo. Also thank the animal facilities in IMM (Lisbon), specially Dr. Dolores Bonaparte and Dr. Joana Marques. Finally, the authors thank Dr Africa Gonzalez and Mercedes Pelletero the performance of the studies on the activation of complement

    Medical rescuers’ occupational health during COVID-19 : contribution of coping and emotion regulation on burnout, trauma and post-traumatic growth

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    The COVID-19 pandemic places unique challenges to medical rescuers’ occupational health. Thus, it is crucial to assess its direct and indirect impacts on key psychological outcomes and adaptation strategies. This study aims to analyse the impact of this pandemic on medical rescuers’ coping and emotion regulation strategies, and their levels of work-related psychological outcomes, such as burnout, trauma and post-traumatic growth. Additionally, it aims to analyse the contribution of coping and emotion regulation strategies, employed to manage the COVID-19 pandemic, on burnout, trauma and post-traumatic growth. A sample of 111 medical rescuers answered the Brief Cope, Emotion Regulation Questionnaire, Oldenburg Burnout Inventory, Impact of Event Scale-Revised and Post-Traumatic Growth Inventory. Medical rescuers resorted moderately to coping and emotion regulation strategies, since the beginning of COVID-19. They presented moderate burnout and post-traumatic growth and low trauma. Coping presented a higher weight on burnout, trauma and post-traumatic growth, than emotion regulation. Expressive suppression and dysfunctional coping predicted burnout and trauma, and problem and emotion-focused coping predicted post-traumatic growth. Dysfunctional coping mediated and, thus, exacerbated the effect of expressive suppression on burnout and on trauma. Practitioners should pay closer attention to professionals with higher burnout and trauma. Occupational practices should focus on reducing dysfunctional coping and expressive suppression and promoting problem-focused coping.Resumo: A pandemia COVID-19 coloca desafios únicos à saúde ocupacional dos profissionais do pré-hospitalar. Assim, é fundamental avaliar o seu impacto psicológico, para sintomatologia direta ou indiretamente relacionada com a COVID-19. Pretende-se analisar o impacto desta pandemia nos outcomes psicológicos laborais, como burnout, trauma e crescimento pós-traumático, e nas estratégias de coping e regulação emocional. Pretende-se também analisar o contributo do coping e regulação emocional para estes outcomes. Uma amostra de 111 profissionais de emergência médica pré-hospitalar responderam ao Brief Cope, Emotion Regulation Questionnaire, Oldenburg Burnout Inventory, Impact of Event Scale-Revised e Post-Traumatic Growth Inventory. Os profissionais recorreram moderadamente a estratégias de coping e regulação emocional, desde o início da pandemia. Reportaram moderado burnout e crescimento pós-traumático e baixo trauma. O coping apresentou maior peso para os outcomes. A supressão emocional e o coping disfuncional contribuíram para o burnout e trauma, e coping problema e emoção contribuíram para o crescimento pós-traumático. O coping disfuncional mediou e exarcebou o efeito da supressão emocional no burnout e trauma. Assim, poderá ser dada especial atenção a profissionais com elevado burnout e trauma e as práticas poderão ser focadas na redução do coping disfuncional e supressão emocional, bem como na promoção do coping problema.info:eu-repo/semantics/publishedVersio

    Self-assembled nanoparticles made of fucan

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    Amphiphilic polymers can self-assemble in water due to hydrophilic and hydrophobic interactions, forming nanoparticles (NPs) with unique physicochemical characteristics and thermodynamic stability. A non toxic sulfated Fucan, extracted from Spatoglossum schroederi was chemically modified by the grafting of Hexadecylamine (C16) to the polymer hydrophilic backbone. The resulting modified material (Fucan-C16) formed nanosized particles which were characterized by 1H NMR to assess the substitution degree of the hydrophobic chains, fluorescence spectroscopy to determine the critical aggregation concentration (cac), cryo-field emission scanning electron microscopy (Cryo- FESEM) to evaluate the shape and size of the NPs, and dynamic light scattering (DLS) to verify the size distribution. The (cac) of Fucan-C16 NPs ranged between 0.05 and 0.03mg/mL. Cryo-FESEM revealed that Fucan-C16 formed spherical macromolecular particles with diameters between 120 and 180 nm, which were confirmed by DLS. In addition, the size of the NPs were not affected by the concentration of the polymer or by the variation of the pH.The size of nanoparticles increases with increasing its concentration in solution.CAPES, FCT and CNP

    Avaliação da assistência à saúde da mulher e da criança em localidade urbana da região Sudeste do Brasil

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    OBJECTIVE: To describe and analyze primary health care provided to mother-and-child population in Teresópolis, state of Rio de Janeiro, Brazil. METHODS: A population survey was performed at the main vaccination station on the local Vaccine National Day, to collect information about the use of health care services and preventive primary care. RESULTS: Information was collected from 329 mothers and their children. More than 90% of children had at least one pediatric visit in the past three months. Almost all had their growth chart, but in 30% of them the child's weight was not registered. There was a positive association between having a routine visit and the registration of the child's weight in the card (RP = 1.34; IC: 1.13-1.58; p = 0.0002). Around 59% of the mothers had a medical visit after giving after birth; 25% said they had never had a Pap smear test before, and 36% never had a breast examination. There was a positive association between the mother's age being over 20 years and ever having a Pap smear test (RP = 1.56; IC: 1.08-2.26; p = 0.03). Almost 70% of the mothers referred the use of any contraceptional method, and the most common used were contraceptive pills, condoms and tubal ligation. CONCLUSIONS: Despite some limitations, the results suggest a valid and useful methodology, which allows the identification of important needs in primary health care delivery to children and their mothers.OBJETIVO: Analisar e comparar os cuidados primários prestados à população materno-infantil e contribuir para a avaliação da assistência integral a esse grupo. MÉTODOS: Inquérito populacional realizado por entrevistas, no principal posto de vacinação do Município de Teresópolis, RJ, no Dia Nacional de Vacinação, que abrangeu questões sobre utilização de serviços de saúde e prestação de cuidados primários preventivos. RESULTADOS: Foram colhidas informações de 329 crianças e suas respectivas mães. Mais de 90% das crianças haviam comparecido à consulta pediátrica nos três meses anteriores e quase todas possuíam o cartão da criança, embora em 30% desses cartões não havia qualquer peso registrado no período. Observou-se associação positiva entre consulta de puericultura e registro de peso no cartão da criança (RP = 1,34; IC: 1,13-1,58; p = 0,0002). Cerca de 59% das mães compareceram à consulta de revisão de parto, mas 25% referiram nunca ter feito exame colpocitológico-oncótico e 36% nunca haviam realizado exame de mama. Observou-se associação positiva entre a idade materna acima de 20 anos e a realização de algum exame colpocitológico-oncótico durante a vida reprodutiva (RP = 1,56; IC: 1,08-2,26; p = 0,03). Quase 70% das mães relataram uso de algum método anticoncepcional, principalmente pílula, condom e laqueadura tubária. CONCLUSÕES: Apesar de algumas limitações, os resultados sugerem a viabilidade da metodologia utilizada, permitindo a identificação de deficiências importantes na prestação de cuidados primários de saúde para crianças e principalmente para mães

    Exploring the correlations between epi indicators of COVID-19 and the concentration of pharmaceutical compounds in Wastewater Treatment Plants in Northern Portugal

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    The COVID-19 pandemic caused by the SARS-CoV-2 virus led to changes in the lifestyle and human behaviour, which resulted in different consumption patterns of some classes of pharmaceuticals including curative, symptom-relieving, and psychotropic drugs. The trends in the consumption of these compounds are related to their concentrations in wastewater systems, since incompletely metabolised drugs (or their metabolites back transformed into the parental form) may be detected and quantified by analytical methods. Pharmaceuticals are highly recalcitrant compounds and conventional activated sludge processes implemented in wastewater treatment plants (WWTP) are ineffective at degrading these substances. As a results, these compounds end up in waterways or accumulate in the sludge, being a serious concern given their potential effects on ecosystems and public health. Therefore, it is crucial to evaluate the presence of pharmaceuticals in water and sludge to assist in the search for more effective processes. In this work, eight pharmaceuticals from five therapeutic classes were analysed in wastewater and sludge samples collected in two WWTP located in the Northern Portugal, during the third COVID-19 epidemic wave in Portugal. The two WWTP demonstrated a similar pattern with respect to the concentration levels in that period. However, the drugs loads reaching each WWTP were dissimilar when normalising the concentrations to the inlet flow rate. Acetaminophen (ACET) was the compound detected at highest concentrations in aqueous samples of both WWTP (98. 516 g L1 in WWTP2 and 123. 506 g L1in WWTP1), indicating that this drug is extensively used without the need of a prescription, known of general public knowledge as an antipyretic and analgesic agent to treat pain and fever. The concentrations determined in the sludge samples were below 1.65 µg g1 in both WWTP, the highest value being found for azithromycin (AZT). This result may be justified by the physico-chemical characteristics of the compound that favour its adsorption to the sludge surface through ionic interactions. It was not possible to establish a clear relationship between the incidence of COVID-19 cases in the sewer catchment and the concentration of drugs detected in the same period. However, looking at the data obtained, the high incidence of COVID-19 in January 2021 is in line with the high concentration of drugs detected in the aqueous and sludge samples but prediction of drug load from viral load data was unfeasible.This study was supported by the Competitiveness and Internationalisation Operational Programme, Lisbon Regional Operational Programme and Algarve Regional Operational Programme with the support of FEDER, through the Incentive Scheme: research and development activities and investment in testing and optimisation (upscaling) infrastructures in the context of COVID-19, through the Project “SARS CONTROL: Evaluation of the impacts of SARS-CoV-2 on the urban water cycle and the downstream effects on Public Health" (Ref. 070076). Acknowledge is also due to the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. Strategic funding from FCT to cE3c and BioISI Research Units (UIDB/00329/2020 and UIDB/04046/2020) and to the Associate Laboratory CHANGE (LA/P/0121/2020) is also gratefully acknowledged. ARS holds an FCT grant SFRH/BD/131905/2017 and COVID/BD/151951/2021.ARLR and MFRP acknowledge the financial support from LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), funded by national funds through FCT/MCTES (PIDDAC). ARLR acknowledges FCT funding under DL57/2016 Transitory Norm Programme.info:eu-repo/semantics/publishedVersio

    Evaluation of biodegradable implants based on polymer blends: development, characterization and in vitro release studies

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    Implants prepared with polymer blends [poly (e-caprolactone)-poly(lactide), PCL-PLA] at different rates were developed from microspheres. Approximately 19% of dexamethasone acetate was encapsulated into the microspheres, and it was not dependent on polymer characteristics. DSC studies suggested that there is not any signal of interaction between the polymers and the drug and also no influence of any residual solvent in the microspheres. Infrared analysis indicated the chemical stability of the drug even in the blend matrix. The developed devices present low degradation rate. 34% and 21% of dexamethasone acetate was released from PLA and PCL alone implants at 10 weeks, respectively. Intermediate amounts were released from the devices prepared at different PLA-PCL ratios in such a way that the higher the amount of PCL, the slower was the drug release. This study demonstrates that polymeric drug delivery systems allowed to a prolonged release of dexamethasone acetate in vitro.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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