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1.
Environ Impact Assess Rev ; 99: 107013, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36532697

RESUMO

COVID-19 lockdown measures have impacted the environment with both positive and negative effects. However, how human populations have perceived such changes in the natural environment and how they may have changed their daily habits have not been yet thoroughly evaluated. The objectives of this work were to investigate (1) the social perception of the environmental changes produced by the COVID-19 pandemic lockdown and the derived change in habits in relation to i) waste management, energy saving, and sustainable consumption, ii) mobility, iii) social inequalities, iv) generation of noise, v) utilization of natural spaces, and, vi) human population perception towards the future, and (2) the associations of these potential new habits with various socio-demographic variables. First, a SWOT analysis identified strengths (S), weaknesses (W), opportunities (O), and threats (T) generated by the pandemic lockdown measures. Second, a survey based on the aspects of the SWOT was administered among 2370 adults from 37 countries during the period from February to September 2021. We found that the short-term positive impacts on the natural environment were generally well recognized. In contrast, longer-term negative effects arise, but they were often not reported by the survey participants, such as greater production of plastic waste derived from health safety measures, and the increase in e-commerce use, which can displace small storefront businesses. We were able to capture a mismatch between perceptions and the reported data related to visits to natural areas, and generation of waste. We found that age and country of residence were major contributors in shaping the survey participants ´answers, which highlights the importance of government management strategies to address current and future environmental problems. Enhanced positive perceptions of the environment and ecosystems, combined with the understanding that livelihood sustainability, needs to be prioritized and would reinforce environmental protection policies to create greener cities. Moreover, new sustainable jobs in combination with more sustainable human habits represent an opportunity to reinforce environmental policy.

2.
Parasitology ; 146(12): 1555-1563, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31232243

RESUMO

An aurantiactinomyxon type is described from the marine naidid Tubificoides pseudogaster (Dahl, 1960), collected from the lower estuary of a Northern Portuguese River. This type constitutes the first of its collective group to be reported from Portugal, and only the fourth described from a marine oligochaete worldwide. Extensive morphological comparisons of new aurantiactinomyxon isolates to all known types without available molecular data are proposed to be unnecessary, given the artificiality of the usage of morphological criteria for actinosporean differentiation and the apparent strict host specificity of the group. Recognition of naidid oligochaetes as the hosts of choice for marine types of aurantiactinomyxon and other collective groups, suggests that the family Naididae played a preponderant role in the myxosporean colonization of estuarine communities. Molecular analyses of the type in study further infer its involvement in the life cycle of Paramyxidium giardi (Cépède, 1906) Freeman and Kristmundsson, 2018, a species that infects the kidney of European eel Anguilla anguilla (Linnaeus, 1758) and that has been reported globally, including from Portuguese waters. The low intraspecific difference registered in relation to Icelandic isolates of P. giardi (0.6%) is hypothesized to result from the emergence of genotypically different subspecies due to geographic isolation.


Assuntos
Myxozoa/isolamento & purificação , Myxozoa/fisiologia , Oligoquetos/parasitologia , Distribuição Animal , Animais , DNA Ribossômico/análise , Myxozoa/crescimento & desenvolvimento , Portugal
3.
Parasitology ; 146(4): 479-496, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30301476

RESUMO

Mullets inhabit a wide range of habitats from tropical to temperate regions and play a critical role in their ecosystems. This commercially important fish group constitutes a significant source of food in several geographic regions, and the production of some species for consumption is an increasing trend. About 64 myxosporean species have been reported in mullets, some of which are cryptic, as is the case of Myxobolus exiguus, and M. muelleri. This paper provides, for the first time, a detailed and critical revision of the data available for myxobolids reported in mullets, determining the species that have bona fide mugiliform fish hosts, in accordance with the original species descriptions, the available molecular data and the currently accepted taxonomic and phylogenetic criteria. Phylogenetic analyses using Bayesian inference and maximum-likelihood methodologies suggest that the evolutionary history of myxobolids with bona fide mugiliform fish hosts reflects that of its vertebrate hosts, while reinforcing known evolutionary factors and old systematic issues of the clade of myxobolids. A comprehensive morphological, ultrastructural and molecular redescription is also provided for the cryptic species M. exiguus, from infections in the visceral peritoneum of the thinlip-grey mullet Chelon ramada in the River Minho, Portugal.


Assuntos
Myxozoa/classificação , Filogenia , Smegmamorpha/parasitologia , Animais , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Microscopia Eletrônica de Transmissão , Myxobolus/anatomia & histologia , Myxobolus/classificação , Myxobolus/genética , Myxobolus/ultraestrutura , Myxozoa/anatomia & histologia , Myxozoa/ultraestrutura , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Portugal/epidemiologia , Prevalência
4.
Scand J Immunol ; 87(3)2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29363152

RESUMO

In the murine model, it was demonstrated that pro-inflammatory cytokines and chemokines are essential to the formation and modulation of Schistosoma-induced granulomatous inflammation. However, the relationship of these immune mediators and disease severity is hard to be established in naturally infected individuals. The current study evaluates the association between plasma concentrations of MIF, sTNF-R1, CCL3, CCL7 and CCL24 and schistosomiasis morbidity in Schistosoma mansoni-infected patients with a low parasite burden. For this propose, 97 S. mansoni-infected individuals were subjected to abdominal ultrasound analysis and clinical examination. Among them, 88 had plasma concentration of immune mediators estimated by ELISA assay. Multivariate linear regression models were used to evaluate the relationship between the plasma concentration of immune mediators and the variables investigated. Although most individuals presented low parasite burden, over 30% of them showed signs of fibrosis defined by ultrasound measurements and 2 patients had a severe form of schistosomiasis. No association between parasite burden and the plasma levels of chemokine/cytokines or disease severity was observed. There was a positive association between plasma concentration of CCL4, sTNF-R1, CCL3 and MIF with gall bladder thickness and/or with portal vein thickness that are liver fibrosis markers. In contrast, no association was found between CCL7 plasma concentrations with any of the schistosomiasis morbidity parameters evaluated. The data showed that CCL24, sTNFR1, MIF and CCL3 can be detected in plasma of S. mansoni-infected individuals and their concentration would be used as prognostic makers of Schistosoma-induced liver fibrosis, even in individuals with low parasite burden.


Assuntos
Quimiocina CCL24/sangue , Quimiocina CCL3/sangue , Quimiocina CCL7/sangue , Oxirredutases Intramoleculares/sangue , Cirrose Hepática/imunologia , Fatores Inibidores da Migração de Macrófagos/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Adolescente , Adulto , Idoso , Animais , Humanos , Fígado/irrigação sanguínea , Fígado/parasitologia , Fígado/patologia , Cirrose Hepática/parasitologia , Pessoa de Meia-Idade , Veia Porta/patologia , Esquistossomose mansoni/parasitologia , Adulto Jovem
5.
Clin Sci (Lond) ; 129(7): 533-45, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25967696

RESUMO

Mineralocorticoid receptors (MRs), which are activated by mineralocorticoids and glucocorticoids, actively participate in mechanisms that affect the structure and function of blood vessels. Although experimental and clinical evidence shows that vascular damage in diabetes is associated with structural alterations in large and small arteries, the role of MR in this process needs further studies. Thus, we tested the hypothesis that MR, through redox-sensitive mechanisms, plays a role in diabetes-associated vascular remodelling. Male, 12-14-weeks-old db/db mice, a model of type 2 diabetes and their non-diabetic counterpart controls (db/+) were treated with spironolactone (MR antagonist, 50 mg/kg/day) or vehicle for 6 weeks. Spironolactone treatment did not affect blood pressure, fasting glucose levels or weight gain, but increased serum potassium and total cholesterol in both, diabetic and control mice. In addition, spironolactone significantly reduced serum insulin levels, but not aldosterone levels in diabetic mice. Insulin sensitivity, evaluated by the HOMA (homoeostatic model assessment)-index, was improved in spironolactone-treated diabetic mice. Mesenteric resistance arteries from vehicle-treated db/db mice exhibited inward hypertrophic remodelling, increased number of smooth muscle cells and increased vascular stiffness. These structural changes, determined by morphometric analysis and with a myography for pressurized arteries, were prevented by spironolactone treatment. Arteries from vehicle-treated db/db mice also exhibited augmented collagen content, determined by Picrosirius Red staining and Western blotting, increased reactive oxygen species (ROS) generation, determined by dihydroethidium (DHE) fluorescence, as well as increased expression of NAD(P)H oxidases 1 and 4 and increased activity of mitogen-activated protein kinases (MAPKs). Spironolactone treatment prevented all these changes, indicating that MR importantly contributes to diabetes-associated vascular dysfunction by inducing oxidative stress and by increasing the activity of redox-sensitive proteins.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Antagonistas de Receptores de Mineralocorticoides/química , Receptores de Mineralocorticoides/fisiologia , Aldosterona/sangue , Animais , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Colágeno/química , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Etídio/análogos & derivados , Etídio/química , Glucocorticoides/metabolismo , Insulina/sangue , Masculino , Camundongos , Mineralocorticoides/metabolismo , Potássio/sangue , Espécies Reativas de Oxigênio/química , Espironolactona/uso terapêutico
6.
Parasitol Res ; 114(10): 3721-39, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26141433

RESUMO

Samples of anadromous Alosa alosa (Clupeidae) (n = 163) and Alosa fallax (Clupeidae) (n = 223), caught in Western Iberian Peninsula Rivers from 2008 to 2013, were examined for buccal, branchial and internal macroparasites, which were identified using morphological and molecular methods. Alosa alosa were infected with Anisakis simplex s.s., Anisakis pegreffii, Hysterothylacium aduncum, Rhadinorhynchus pristis, Mazocraes alosae, Hemiurus appendiculatus, Ceratothoa italica and an unidentified ergasilid copepod. Ceratothoa italica represents a new host record for A. alosa. Alosa fallax were infected with A. simplex s.s., A. pegreffii, H. aduncum, H. appendiculatus, Clavellisa emarginata and an unidentified cymothoid isopod. This is the first report of C. italica, C. emarginata and M. alosae in the Iberian Peninsula. The phylogenetic positions of M. alosae, H. appendiculatus and C. emarginata were assessed using 18S and 28S ribosomal RNA (rRNA); our contributions provide a better understanding of the phylogenetic relationships within their groups. Qualitative and quantitative differences in the parasite faunas of these two shad species are consistent with different feeding strategies. The results provide information about host migration behaviour and transmission pathways through diet during the marine trophic phase of the shad's life cycle and their roles as paratenic or final hosts and transporters of parasites between seawater and freshwater environments. The zoonotic parasites A. simplex s.s. and A. pegreffii pose a risk for consumers or riverine mammals (e.g. European otter). The use of parasites as biological tags for shad stocks in Western Iberian Rivers could be a useful approach in multidisciplinary studies concerning fish stock delimitation and characterization.


Assuntos
Doenças dos Peixes/parasitologia , Peixes/parasitologia , Invertebrados/genética , Doenças Parasitárias em Animais/parasitologia , Filogenia , Migração Animal , Animais , Doenças dos Peixes/epidemiologia , Humanos , Estágios do Ciclo de Vida , Doenças Parasitárias em Animais/epidemiologia , Rios , Água do Mar
7.
Parasitol Res ; 114(6): 2143-54, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25810220

RESUMO

Spawning individuals of allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), were sampled from three rivers on the Atlantic coast of the Iberian Peninsula (Ulla, Minho, Mondego) during 2008 to 2013 to assess the presence of the zoonotic marine parasite Anisakis spp. larvae. The results revealed that both shad species were infected by third-larval stage Anisakis simplex s.s. and Anisakis pegreffii. The latter is reported in mixed infections in both shad species of Western Iberian Peninsula for the first time. In A. alosa, the prevalence of Anisakis infection can reach 100%, while in A. fallax, prevalence was up to 83%. Infected individuals of the former species also often contain much higher number of parasites in theirs internal organs and flesh: from 1 to 1138 Anisakis spp. larvae as compared to 1 to 121 larvae, respectively. In general, numbers of A. pegreffii were higher than those of A. simplex s.s. Our results suggest that in the marine environment of the Western Iberian Peninsula, both anadromous shad species act as paratenic hosts for A. simplex s.s. and A. pegreffii, thus widening the distribution of the infective nematode larvae from the marine to the freshwater ecosystem. This finding is of great epidemiological relevance for wildlife managers and consumers, considering the zoonotic and gastroallergic threats posed of these parasites.


Assuntos
Anisakis/isolamento & purificação , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Animais , Ecossistema , Doenças dos Peixes/epidemiologia , Humanos , Larva , Portugal/epidemiologia , Rios , Espanha/epidemiologia , Zoonoses
8.
Br J Biomed Sci ; 72(2): 78-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26126325

RESUMO

Lung cancer has a known relationship with smoking and is one of the leading causes of cancer-related death worldwide. Although the number of studies discussing lung cancer is vast, treatment efficacy is still suboptimal due to the wide range of factors that affect patient outcome. This review aims to collect information on lung cancer treatment, specially focused on radiation therapy. It also compiles information regarding the influence of radiotherapy on the immune system and its response to tumour cells. It evaluates how immune cells react after radiation exposure and the influence of their cytokines in the tumour microenvironment. The literature analysis points out that the immune system is a very promising field of investigation regarding prognosis, mostly because the stromal microenvironment in the tumour can provide some information about what can succeed in the future concerning treatment choices and perspectives. T cells (CD4+ and CD8+), interleukin-8, vascular endothelial growth factor and transforming growth factor-ß seem to have a key role in the immune response after radiation exposure. The lack of large scale studies means there is no common consensus in the scientific community about the role of the immune system in lung cancer patients treated with radiotherapy. Clarification of the mechanism behind the immune response after radiation can lead to better treatments and better quality life for patients.


Assuntos
Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/radioterapia , Humanos , Sistema Imunitário/efeitos da radiação
9.
Allergy ; 68(6): 809-12, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23647633

RESUMO

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in Córdoba (3.9 pg Ole e 1/pollen) than in Évora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in Córdoba were 2.4 times higher than in Évora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in Évora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.


Assuntos
Alérgenos/análise , Antígenos de Plantas/análise , Exposição Ambiental/análise , Proteínas de Plantas/análise , Pólen , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Ensaio de Imunoadsorção Enzimática , Modelos Estatísticos , Portugal , Estações do Ano , Espanha , Tempo (Meteorologia)
11.
Pulmonology ; 26(5): 264-267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32482604

RESUMO

INTRODUCTION: Hospitalizations due to community-acquired pneumonia (CAP) in mainland Portugal from 2000 to 2009 accounted for 3.7% of all hospital admissions in population with 18 or more years of age. There is no direct-cost data regarding these admissions. METHODS: In this observational descriptive study all adult hospitalizations associated with CAP diagnosis were retrospectively analyzed for the period between 2000 and 2009. Patients under 18 years old, those with pneumonia as secondary diagnosis, patients with tuberculous or obstructive pneumonia, and immunocompromised patients were excluded from the study. The direct cost of hospitalization was calculated according to the diagnosis-related groups (DRG), established for the respective year of hospitalization. RESULTS: There were 294,026 hospital admissions with an average annual direct cost of 80 million Euros, which almost doubled between 2000 and 2009. The average direct hospitalization costs per admission, including wards and Intensive Care Units (ICU), amounted to €2,707, with an increasing trend. The average hospitalization cost was €2,515 for admissions resulting in live discharge, and €3,457 for the deceased. CONCLUSION: The average direct cost of adult hospitalizations associated with CAP amounted to €2,707 in mainland Portugal from 2000 to 2009, showing an increase of 37.5% in hospitalization cost of living and deceased patients. The economic impact of CAP-related hospital admissions justifies the need for better implementation of preventive measures.


Assuntos
Atenção à Saúde/economia , Hospitalização/economia , Unidades de Terapia Intensiva/economia , Pneumonia/economia , Idoso , Idoso de 80 Anos ou mais , Infecções Comunitárias Adquiridas/epidemiologia , Custos e Análise de Custo , Atenção à Saúde/organização & administração , Grupos Diagnósticos Relacionados/normas , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente/economia , Pneumonia/diagnóstico , Portugal/epidemiologia , Estudos Retrospectivos
12.
Sci Total Environ ; 659: 1071-1081, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096322

RESUMO

Estuaries are productive environments used by many fish as nursery grounds. The initial stages of fishes are highly vulnerable to (a)biotic factors, and anthropogenic pressures, influencing fish larvae assemblages along the estuary. Microplastics (MPs < 5 mm) are particularly dangerous to early life stages of fishes because their ingestion can induce gut blockage, limiting food intake or exposing organisms to contamination due to MPs capacity to absorb pollutants. Present work aimed to investigate the contamination of an urban impacted estuary (Douro estuary, NW Portugal) by MPs, and study the abundance and distribution of MPs and fish larvae in this estuary. Monthly sampling surveys were performed from December 2016 to December 2017, in nine stations along the estuary. Sub-surface planktonic horizontal trawls were performed to collect fish larvae and MPs. Planktonic samples were sorted, and fish larvae identified. MPs density was determined using a protocol optimized in our laboratory. A total of 1498 fish larvae belonging to 32 taxa were collected, with a mean density of 11.66 fish larvae 100 m-3. During the spring-summer period, it was observed the typical increase in the density and diversity of the larval assemblage. Diversity was generally low, with the high dominance of very few taxa, namely the common goby, Pomatoschistus microps. Different types of MPs were found, namely fibers, soft/hard plastic, colorful/transparent plastic, in a total of 2152 particles, with a mean density of 17.06 MPs 100 m-3. Hard MPs and fibers were the most predominant types, representing 83% of the total MPs collected. In some months the number of MPs surpassed the number of fish larvae, with an average ratio of 1.0 fish larvae:1.5 MPs. Such results are concerning, highlighting that a higher availability of MPs may facilitate their ingestion by fish and therefore increase possible impacts in these communities.


Assuntos
Monitoramento Ambiental , Estuários , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Ecossistema , Peixes/fisiologia , Larva , Plâncton , Portugal
13.
Clin Transl Allergy ; 8: 9, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29636895

RESUMO

BACKGROUND: Ambient air quality monitoring is a governmental duty that is widely carried out in order to detect non-biological ("chemical") components in ambient air, such as particles of < 10 µm (PM10, PM2.5), ozone, sulphur dioxide, and nitrogen oxides. These monitoring networks are publicly funded and air quality data are open to the public. The situation for biological particles that have detrimental effects on health, as is the case of pollen and fungal spores, is however very different. Most pollen and spore monitoring networks are not publicly funded and data are not freely available. The information regarding which biological particle is being monitored, where and by whom, is consequently often not known, even by aerobiologists themselves. This is a considerable problem, as local pollen data are an important tool for the prevention of allergic symptoms. OBJECTIVE: The aim of this study was to review pollen monitoring stations throughout the world and to create an interactive visualization of their distribution. METHODS: The method employed to collect information was based on: (a) a review of the recent and historical bibliography related to pollen and fungal spore monitoring, and (b) personal surveys of the managers of national and regional monitoring networks. The interactive application was developed using the R programming language. RESULTS: We have created an inventory of the active pollen and spore monitoring stations in the world. There are at least 879 active pollen monitoring stations in the world, most of which are in Europe (> 500). The prevalent monitoring method is based on the Hirst principle (> 600 stations). The inventory is visualised as an interactive and on-line map. It can be searched, its appearance can be adjusted to the users' needs and it is updated regularly, as new stations or changes to those that already exist can be submitted online. CONCLUSIONS: The map shows the current situation of pollen and spore monitoring and facilitates collaboration among those individuals who are interested in pollen and spore counts. It might also help to improve the monitoring of biological particles up to the current level employed for non-biological components.

14.
Pulmonology ; 24 Suppl 1: 1-21, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30473034

RESUMO

Alpha-1-antitrypsin deficiency (AATD) is a genetic autosomal codominant disorder caused by mutations in SERPINA1 gene. It is one of the most prevalent genetic disorders, although it remains underdiagnosed. Whereas at international level there are several areas of consensus on this disorder, in Portugal, inter-hospital heterogeneity in clinical practice and resources available have been adding difficulties in reaching a diagnosis and in making therapeutic decisions in this group of patients. This raised a need to draft a document expressing a national consensus for AATD. To this end, a group of experts in this field was created within the Portuguese Pulmonology Society - Study group on AATD, in order to elaborate the current manuscript. The authors reviewed the existing literature and provide here general guidance and extensive recommendations for the diagnosis and management of AATD that can be adopted by Portuguese clinicians from different areas of Medicine. This article is part of a supplement entitled "Portuguese consensus document for the management of alpha-1-antitrypsin deficiency" which is sponsored by Sociedade Portuguesa de Pneumologia.


Assuntos
Pneumopatias/diagnóstico , Pneumopatias/terapia , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/terapia , Algoritmos , Humanos , Pneumopatias/etiologia , Seleção de Pacientes , Portugal , Guias de Prática Clínica como Assunto , Deficiência de alfa 1-Antitripsina/complicações
15.
Chemosphere ; 66(7): 1249-55, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16949639

RESUMO

Zinc and mercury are common contaminants of estuaries and coastal ecosystems where they may induce adverse effects on the biota. Carcinus maenas is a key-species in several European estuaries, living in close association with the sediment where a considerable number of environmental contaminants, including zinc and mercury may accumulate. In the present study, the acute effects of zinc and mercury on C. maenas from the Minho River Estuary (NW Portugal) were investigated by using the activity of the enzymes cholinesterase (ChE), lactate dehydrogenase (LDH) and glutathione S-transferases (GST) as effects' criteria. Crabs were exposed for 96h to several concentrations of Zn(2+) (0, 1.84, 3.71, 7.39 and 14.79mg/l) or Hg(2+) (0, 0.09, 0.19, 0.37 and 0.74mg/l). The choice of Zn(2+) test concentrations was based on the LC50 value (14.86mg/l) determined in a first part of the study, while the choice of Hg(2+) concentrations was based on values from the literature. At the end of the bioassays, eye, muscle and hepatopancreas tissues were isolated and used for ChE, LDH and GST determinations, respectively. Zinc significantly inhibited ChE activity (p<0.05, EC50=14.68mg/l), caused significant alterations of GST activity (p<0.05) and induced LDH activity (p<0.05) at the exposure of 14.79mg/l. Mercury significantly inhibited ChE activity (p<0.001, LOEC=0.09mg/l, EC50=0.235mg/l) and increased both GST (p<0.05, LOEC=0.774mg/l) and LDH activities (p<0.05, LOEC=0.119mg/l). These results suggest that both metals interfere with cholinergic neurotransmission in C. maenas by inhibiting ChE activity. In addition, they also interfere with GST activity and this may reduce the capacity of detoxification of some chemicals and/or to increase the probability of oxidative stress to occur. Furthermore, both metals increase LDH activity, suggesting an interference with energy production pathways. Therefore, the presence of zinc and mercury in estuaries at concentrations in the mg/l or mug/l range, respectively, may have a negative impact on C. maenas.


Assuntos
Braquiúros/efeitos dos fármacos , Glutationa Transferase/metabolismo , L-Lactato Desidrogenase/metabolismo , Compostos de Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Compostos de Zinco/toxicidade , Animais , Biomarcadores/análise , Braquiúros/enzimologia , Monitoramento Ambiental , Portugal , Rios/química
16.
Conserv Physiol ; 4(1): cov064, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27293744

RESUMO

The sea lamprey, Petromyzon marinus, is an anadromous, semelparous species that is vulnerable to endangered in parts of its native range due in part to loss of spawning habitat because of man-made barriers. The ability of lampreys to return to the ocean or estuary and search out alternative spawning river systems would be limited by their osmoregulatory ability in seawater. A reduction in tolerance to salinity has been documented in migrants, although the underlying mechanisms have not been characterized. We examined the capacity for marine osmoregulation in upstream spawning migrants by characterizing the physiological effects of salinity challenge from a molecular perspective. Estuarine-captured migrants held in freshwater (FW) for ∼1 week (short-term acclimation) or 2 months (long-term acclimation) underwent an incremental salinity challenge until loss of equilibrium occurred and upper thresholds of 25 and 17.5, respectively, occurred. Regardless of salinity tolerance, all lamprey downregulated FW ion-uptake mechanisms [gill transcripts of Na(+):Cl(-) cotransporter (NCC/slc12a3) and epithelial Na(+) channel (ENaC/scnn1) and kidney Na(+)/K(+)-ATPase (NKA) protein and activity but not transcript]. At their respective salinity limits, lamprey displayed a clear osmoregulatory failure and were unable to regulate [Na(+)] and [Cl(-)] in plasma and intestinal fluid within physiological limits, becoming osmocompromised. A >90% drop in haematocrit indicated haemolysis, and higher plasma concentrations of the cytosolic enzymes alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase indicated damage to other tissues, including liver. However, >80% of short-term FW-acclimated fish were able to osmoregulate efficiently, with less haemolysis and tissue damage. This osmoregulatory ability was correlated with significant upregulation of the secretory form of Na(+):K(+):2Cl(-) cotransporter (NKCC1/slc12a2) transcript levels and the re-emergence of seawater-type ionocytes detected through immunohistochemical NKA immunoreactivity in the gill, the central ionoregulatory organ. This work sheds light on the molecular and physiological limits to the potential return to seawater for lampreys searching for alternative FW systems in which to spawn.

17.
Diabetes ; 49(12): 2028-38, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11118004

RESUMO

Although isolated rat islets are widely used to study in vitro insulin secretion and the underlying metabolic and ionic processes, knowledge on the properties of glucose-induced electrical activity (GIEA), a key step in glucose-response coupling, has been gathered almost exclusively from microdissected mouse islets. Using a modified intracellular recording technique, we have now compared the patterns of GIEA in collagenase-isolated rat and mouse islets. Resting membrane potentials of rat and mouse beta-cells were approximately -50 and -60 mV, respectively. Both rat and mouse beta-cells displayed prompt membrane depolarizations in response to glucose. However, whereas the latter exhibited a bursting pattern consisting of alternating hyperpolarized and depolarized active phases, rat beta-cells fired action potentials from a nonoscillating membrane potential at all glucose concentrations (8.4-22.0 mmol/l). This was mirrored by changes in the intracellular Ca2+ concentration ([Ca2+]i), which was oscillatory in mouse and nonoscillatory in rat islets. Stimulated rat beta-cells were strongly hyperpolarized by diazoxide, an activator of ATP-dependent K+ channels. Glucose evoked dose-dependent depolarizations and [Ca2+]i increases in both rat (EC50 5.9-6.9 mmol/l) and mouse islets (EC50 8.3-9.5 mmol/l), although it did not affect the burst plateau potential in the latter case. We conclude that there are important differences between beta-cells from both species with respect to early steps in the stimulus-secretion coupling cascade based on the following findings: 1) mouse beta-cells have a larger resting K+ conductance in 2 mmol/l glucose, 2) rat beta-cells lack the compensatory mechanism responsible for generating membrane potential oscillations and holding the depolarized plateau potential in mouse beta-cells, and 3) the electrical and [Ca2+]i dose-response curves in rat beta-cells are shifted toward lower glucose concentrations. Exploring the molecular basis of these differences may clarify several a priori assumptions on the electrophysiological properties of rat beta-cells, which could foster the development of new working models of pancreatic beta-cell function.


Assuntos
Cálcio/metabolismo , Glucose/farmacologia , Membranas Intracelulares/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/fisiologia , Animais , Relação Dose-Resposta a Droga , Impedância Elétrica , Eletrofisiologia , Feminino , Técnicas In Vitro , Ilhotas Pancreáticas/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Concentração Osmolar , Ratos , Ratos Wistar
18.
J Clin Epidemiol ; 48(10): 1245-50, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7561986

RESUMO

The knowledge of purulent meningitis etiology is essential in deciding the immediate therapy; in developing countries, however, the etiological agent identification does not reach 60% of the cases. A comparative study using the latex particle agglutination test (LPAT) in cerebrospinal fluid (CSF) for the diagnosis of meningitis due to Haemophilus influenzae type b, Streptococcus pneumoniae or Neisseria meningitidis A and C was carried out in Belo Horizonte MG, Brazil. CSF culture was used as a gold-standard. Two hundred and ninety-nine children, ranging from 3 months to 14 years of age, were included in the investigation. One hundred and forty-four presented a positive CSF culture for the above mentioned bacteria; the remaining presented meningitis due to other organisms (other bacteria or viral) or a normal CSF. The sensitivity and the specificity of LPAT was 95.7 and 100.0% for N. meningitidis C, 95.2 and 100.0% for H. influenzae type b and 86.5 and 100.0% for S. pneumoniae, respectively. When all three organisms were considered simultaneously, the sensitivity and the specificity was 93.0 and 100.0%, respectively. Taking into consideration a realistic estimate of disease prevalence in the community where the diagnostic test is being used, the positive predictive value and the posttest probability were estimated as 36.7 and 47.1% for children < 5 years and as 21.3 and 35.1% for children < 14 years of age, respectively. LPAT is a useful diagnostic test for meningitis due to the studied pathogens, especially in developing countries where laboratory facilities are limited.


Assuntos
Testes de Fixação do Látex/métodos , Meningite por Haemophilus/líquido cefalorraquidiano , Meningite Meningocócica/líquido cefalorraquidiano , Meningite Pneumocócica/líquido cefalorraquidiano , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Meningite por Haemophilus/microbiologia , Meningite Meningocócica/microbiologia , Meningite Pneumocócica/microbiologia , Prevalência , Sensibilidade e Especificidade
19.
Int J Epidemiol ; 18(3): 680-3, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2509388

RESUMO

The signs and symptoms classically associated with Schistosoma mansoni infection were analysed in relation to their sensitivity, specificity and positive predictive value in identifying S. mansoni patients as well as more severe forms of the disease under field conditions. Data was collected in a survey conducted in a small urban area in the south east of Brazil (14.3% infection in the studied sample with a geometrical mean excretion of 95.5 S. mansoni eggs/gram of faeces). 'Blood in the stool' and a 'palpable and hardened liver' showed the highest positive predictive value; their presence, even in relatively low prevalence areas may be used by the health field workers as an indication of the existence of more advanced clinical forms of the disease.


Assuntos
Esquistossomose mansoni/diagnóstico , Brasil , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Fígado/patologia , Masculino , Sangue Oculto , Palpação , Contagem de Ovos de Parasitas , Valor Preditivo dos Testes , Esquistossomose mansoni/patologia , Sensibilidade e Especificidade
20.
Int J Epidemiol ; 17(1): 193-7, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3384537

RESUMO

This case-control study was conducted to assess the risk, among children aged 0-12 years, of developing meningitis tuberculosis (MT) associated with a lack of intradermal BCG vaccination. Cases (45) of MT admitted for treatment at the Fundacao Benjamin Guimaraes Hospital (Belo Horizonte, MG, Brazil), from 1975 to 1981, were matched for age at hospitalization, date of hospitalization and nutritional status, with two types of controls--patients with acute diarrhoea (AD) and patients with acute non-tuberculous bacterial pneumonias (BP)--admitted to the same hospital. Vaccination status was ascertained from the patients' medical records. Results showed a risk for MT, estimated by the odds ratio, between BCG non-vaccinated and BCG vaccinated patients, of 6.7 (95% Cl 2.3-19.0) comparing cases and AD controls, of 4.0 (95% Cl 1.5-11.0) comparing cases and BP controls and 5.7 (95% Cl 2.3-14.0) comparing cases with both controls. When adjustments were made for place of residence (Metropolitan Region of Belo Horizonte and other regions of Minas Gerais State), the risks decreased to 5.2 (95% Cl 1.9-14.0) and 2.9 (95% Cl 1.2-7.3) comparing cases with AD and BP controls, respectively.


Assuntos
Vacina BCG/uso terapêutico , Tuberculose Meníngea/epidemiologia , Vacina BCG/administração & dosagem , Brasil , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Injeções Intradérmicas , Masculino , Estudos Retrospectivos , Fatores de Risco , Tuberculose Meníngea/prevenção & controle
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