Drenagem urbana: centro histórico de Leiria

No que concerne ao funcionamento de um sistema de drenagem urbana a maior preocupação é o encaminhamento das águas provenientes de precipitações ocorrentes em áreas urbanas para pontos de descarga no meio recetor fora das zonas urbanas, o mais rápido possível. Os centros urbanos estão munidos de diversos tipos de ocupação do solo, conduzindo ao aumento da impermeabilização do solo, que em termos de drenagem urbana não é vantajoso porque reduz a capacidade de infiltração no solo, aumentando o volume de escoamento superficial, reduzindo os tempos de concentração nas áreas de drenagem e aumento do caudal de ponta. Os sistemas públicos de drenagem devem ser implantados de acordo com o Regulamento Geral dos Sistemas Públicos e Prediais de Distribuição de Água e de Drenagem de Águas Residuais (RGSPPDADAR). A implantação de sistemas de drenagem nos pontos baixos das bacias de drenagem pode, por vezes, introduzir efeitos nefastos ao nível do desempenho global do sistema, já que dificulta o escoamento por gravidade das águas pluviais para jusante. Nesta dissertação é estudado o desempenho hidráulico do sistema público de drenagem urbana do Centro Histórico da cidade de Leiria. O conhecimento do cadastro da rede e o modo de funcionamento do sistema torna-se imperativo para uma análise mais pormenorizada da situação existente, bem como para propor as medidas mais adequadas para melhorar o seu desempenho. O desempenho da rede de drenagem foi estudado tendo por base a análise dos resultados obtidos através do software Storm Water Management Model (SWMM)

Characterization of Clostridium difficile 027 strains from an outbreak in a Portuguese hospital

C. difficile infection (CDI) is the cause of an intestinal disease mediated by two potent cytotoxins, TcdA and TcdB. Symptoms of CDI can range from asymptomatic colonization or mild diarrhea, to life-threatening inflammatory lesions such as pseudomembraneous colitis, toxic megacolon or bowel perforation. In part because of the recent emergence of so-called hypervirulent strains, especially (but not exclusively) those belonging to ribotype 027, C. difficile is now considered a main nosocomial enteric pathogen. Hypervirulent epidemic strains have been associated with more severe disease conditions, with higher relapse rates and increased mortality. Health care-associated CDI develops in hospitalized patients undergoing antibiotic treatment because C. difficile can colonize the gut if the normal intestinal microbiota is disturbed. However, C. difficile is also emerging as an important pathogen in the community, as well as in animal husbandry. The organism is an obligate anaerobe, and has the ability to form spores. Spores are extremely resilient and can accumulate and remain viable in the environment or in the host for long periods of time. Spores that remain latent in the gut are responsible for the recurrence of C. difficile-associated disease (CDAD) when antibiotic therapy is stopped. At least some of the hypervirulent epidemic strains show a greater sporulation capacity in vitro, as well as robust toxin production. The first detection of C. difficile 027 hypervirulent epidemic strains implicated in a hospital outbreak in Portugal dates from January 2012, involving 12 patients, with a crude mortality rate of 50%. Here we report on the genetic characterization of those strains as well as the antibiotic resistance profile, toxin production, and rate and efficiency of spore formation. In parallel, C. difficile 027 non-outbreak strains isolated from other Portuguese health care facilities are also investigated

Central nitrergic system regulation of neuroendocrine secretion, fluid intake and blood pressure induced by angiotensin-II

<p>Abstract</p> <p>Background</p> <p>Nitric oxide (NO) synthesis has been described in several circumventricular and hypothalamic structures in the central nervous system that are implicated in mediating central angiotensin-II (ANG-II) actions during water deprivation and hypovolemia. Neuroendocrine and cardiovascular responses, drinking behavior, and urinary excretions were examined following central angiotensinergic stimulation in awake freely-moving rats pretreated with intracerebroventricular injections of Nω-nitro-L-arginine methyl ester (L-NAME, 40 μg), an inhibitor of NO synthase, and L-arginine (20 ug), a precursor of NO.</p> <p>Results</p> <p>Injections of L-NAME or ANG-II produced an increase in plasma vasopressin (VP), oxytocin (OT) and atrial natriuretic peptide (ANP) levels, an increase in water and sodium intake, mean arterial blood pressure and sodium excretion, and a reduction of urinary volume. L-NAME pretreatment enhanced the ANG-II response, while L-arginine attenuated VP and OT release, thirst, appetite for sodium, antidiuresis, and natriuresis, as well as pressor responses induced by ANG-II.</p> <p>Discussion and conclusion</p> <p>Thus, the central nitrergic system participates in the angiotensinergic responses evoked by water deprivation and hypovolemia to refrain neurohypophysial secretion, hydromineral balance, and blood pressure homeostasis.</p

Copper Acts Synergistically With Fluconazole in Candida glabrata by Compromising Drug Efflux, Sterol Metabolism, and Zinc Homeostasis

Funding Information: This work was supported by (1) Project LISBOA-01-0145-FEDER-007660 (“Microbiologia Molecular, Estrutural e Celular”) funded by FEDER funds through COMPETE2020 – “Programa Operacional Competitividade e Internacionalização” (POCI); (2) “Fundação para a Ciência e a Tecnologia” (FCT) through programme IF (IF/00124/2015) to CP; (3) the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No. 810856; (4) COST Action CA15133, supported by COST (European Cooperation in Science and Technology); and (5) PPBI – Portuguese Platform of BioImaging (PPBI-POCI-01-0145-FEDER-022122) co-funded by national funds from OE – “Orçamento de Estado” and by FEDER. AG-C was supported by a FCT Ph.D. fellowship (SFRH/BD/118866/2016), and CA and VP by a FCT contract according to DL57/2016 (SFRH/BPD/74294/2010 and SFRH/BPD/87188/2012, respectively). Publisher Copyright: Copyright © 2022 Gaspar-Cordeiro, Amaral, Pobre, Antunes, Petronilho, Paixão, Matos and Pimentel.The synergistic combinations of drugs are promising strategies to boost the effectiveness of current antifungals and thus prevent the emergence of resistance. In this work, we show that copper and the antifungal fluconazole act synergistically against Candida glabrata, an opportunistic pathogenic yeast intrinsically tolerant to fluconazole. Analyses of the transcriptomic profile of C. glabrata after the combination of copper and fluconazole showed that the expression of the multidrug transporter gene CDR1 was decreased, suggesting that fluconazole efflux could be affected. In agreement, we observed that copper inhibits the transactivation of Pdr1, the transcription regulator of multidrug transporters and leads to the intracellular accumulation of fluconazole. Copper also decreases the transcriptional induction of ergosterol biosynthesis (ERG) genes by fluconazole, which culminates in the accumulation of toxic sterols. Co-treatment of cells with copper and fluconazole should affect the function of proteins located in the plasma membrane, as several ultrastructural alterations, including irregular cell wall and plasma membrane and loss of cell wall integrity, were observed. Finally, we show that the combination of copper and fluconazole downregulates the expression of the gene encoding the zinc-responsive transcription regulator Zap1, which possibly, together with the membrane transporters malfunction, generates zinc depletion. Supplementation with zinc reverts the toxic effect of combining copper with fluconazole, underscoring the importance of this metal in the observed synergistic effect. Overall, this work, while unveiling the molecular basis that supports the use of copper to enhance the effectiveness of fluconazole, paves the way for the development of new metal-based antifungal strategies.publishe

Diversification of a single ancestral gene into a successful toxin superfamily in highly venomous Australian funnel-web spiders

Background: Spiders have evolved pharmacologically complex venoms that serve to rapidly subdue prey and deter predators. The major toxic factors in most spider venoms are small, disulfide-rich peptides. While there is abundant evidence that snake venoms evolved by recruitment of genes encoding normal body proteins followed by extensive gene duplication accompanied by explosive structural and functional diversification, the evolutionary trajectory of spider-venom peptides is less clear. Results: Here we present evidence of a spider-toxin superfamily encoding a high degree of sequence and functional diversity that has evolved via accelerated duplication and diversification of a single ancestral gene. The peptides within this toxin superfamily are translated as prepropeptides that are posttranslationally processed to yield the mature toxin. The N-terminal signal sequence, as well as the protease recognition site at the junction of the propeptide and mature toxin are conserved, whereas the remainder of the propeptide and mature toxin sequences are variable. All toxin transcripts within this superfamily exhibit a striking cysteine codon bias. We show that different pharmacological classes of toxins within this peptide superfamily evolved under different evolutionary selection pressures. Conclusions: Overall, this study reinforces the hypothesis that spiders use a combinatorial peptide library strategy to evolve a complex cocktail of peptide toxins that target neuronal receptors and ion channels in prey and predators. We show that the ω-hexatoxins that target insect voltage-gated calcium channels evolved under the influence of positive Darwinian selection in an episodic fashion, whereas the κ-hexatoxins that target insect calcium-activated potassium channels appear to be under negative selection. A majority of the diversifying sites in the ω-hexatoxins are concentrated on the molecular surface of the toxins, thereby facilitating neofunctionalisation leading to new toxin pharmacology. © 2014 Pineda et al.; licensee BioMed Central Ltd

Insights on Host–Parasite Immunomodulation Mediated by Extracellular Vesicles of Cutaneous Leishmania shawi and Leishmania guyanensis

Funding Information: This study was supported by FCT-Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and PTDC/CVT-CVT/0228/2020 and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2023 by the authors.Leishmaniasis is a parasitic disease caused by different species of Leishmania and transmitted through the bite of sand flies vector. Macrophages (MΦ), the target cells of Leishmania parasites, are phagocytes that play a crucial role in the innate immune microbial defense and are antigen-presenting cells driving the activation of the acquired immune response. Exploring parasite–host communication may be key in restraining parasite dissemination in the host. Extracellular vesicles (EVs) constitute a group of heterogenous cell-derived membranous structures, naturally produced by all cells and with immunomodulatory potential over target cells. This study examined the immunogenic potential of EVs shed by L. shawi and L. guyanensis in MΦ activation by analyzing the dynamics of major histocompatibility complex (MHC), innate immune receptors, and cytokine generation. L. shawi and L. guyanensis EVs were incorporated by MΦ and modulated innate immune receptors, indicating that EVs cargo can be recognized by MΦ sensors. Moreover, EVs induced MΦ to generate a mix of pro- and anti-inflammatory cytokines and favored the expression of MHCI molecules, suggesting that EVs antigens can be present to T cells, activating the acquired immune response of the host. Since nano-sized vesicles can be used as vehicles of immune mediators or immunomodulatory drugs, parasitic EVs can be exploited by bioengineering approaches for the development of efficient prophylactic or therapeutic tools for leishmaniasis.publishersversionpublishe

The sealing ability of MTA apical plugs exposed to a phosphate-buffered saline

OBJECTIVE: The aim of this study was to evaluate the influence of exposure of the mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) - to phosphate-buffered saline (PBS) on the apical microleakage using a glucose leakage system. MATERIAL AND METHODS: Sixty root segments were randomly divided into 4 experimental groups (n=15). After resecting the apical segments and enlarging the canals with Gates-Glidden drills, the apical cavities were filled with MTA with or without CaCl2 and the root canals were dressed with a moistened cotton pellet or PBS, as follows: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. All root segments were introduced in floral foams moistened with PBS. After 2 months, all root segments were prepared to evaluate the glucose leakage along the apical plugs. The amount of glucose leakage was measured following an enzymatic reaction and quantified by a spectrophotometer. Four roots were used as controls. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests (p;0.05), and 3 and 4 (p>;0.05). The addition of CaCl2 to the MTA significantly decreased its sealing ability (

Hanseniase neural primaria: revisao sistematica

The authors proposed a systematic review on the current concepts of primary neural leprosy by consulting the following online databases: MEDLINE, Lilacs/SciELO, and Embase. Selected studies were classified based on the degree of recommendation and levels of scientific evidence according to the “Oxford Centre for Evidence-based Medicine”. The following aspects were reviewed: cutaneous clinical and laboratorial investigations, i.e. skin clinical exam, smears, and biopsy, and Mitsuda's reaction; neurological investigation (anamnesis, electromyography and nerve biopsy); serological investigation and molecular testing, i.e. serological testing for the detection of the phenolic glycolipid 1 (PGL-I) and the polymerase chain reaction (PCR); and treatment (classification criteria for the definition of specific treatment, steroid treatment, and cure criteria).Os autores propuseram-se a realizar uma revisão sistemática em conceitos atuais sobre a hanseníase neural primária, consultando as seguintes bases bibliográficas on-line: MEDLINE, Lilacs/SciELO e Embase. Os estudos selecionados foram classificados conforme o grau de recomendação e o nível de evidência científica de acordo com o “Oxford Centre for Evidence-based Medicine”. Os seguintes temas foram revisados: investigações clínica e laboratorial cutâneas, ou seja, exame, esfregaço e biópsia de pele e reação de Mitsuda; investigação neurológica (anamnese, eletroneuromiografia e biópsia de nervo); investigação sorológica e testes moleculares, ou seja, testes sorológicos para detecção de um glicolipídio fenólico e reação de cadeia de polimerase (PCR) e tratamento (critérios de classificação para definição de tratamento específico, tratamento com esteroides e critérios de cura).Secretaria de Estado de Saude Instituto Lauro de Souza LimaUniversidade de São Paulo (USP) School of Medicine of Ribeirao Preto Department of NeurosciencesUSP Department of Neurology and NeurosurgeryFundacao Oswaldo CruzUniversidade Federal de São Paulo (UNIFESP) Department of DermatologySecretaria de Estado de Saude Instituto de SaudeConselho Federal de Medicina Associacao Medica Brasileira Projeto DiretrizesUNIFESP, Department of DermatologySciEL