Characterization of the antitumoral activity of portuguese propolis

Dissertação de Mestrado em Ciências da SaúdeOver the years, interest in natural products has increased because they are a promising source of new pharmaceutical agents. Propolis is a natural resinous product, collected from several plants by honeybees, which is composed by beeswax, resin and volatile compounds. Propolis has several biological properties that have been widely investigated. In the last years, a number of studies have demonstrated the antitumoral activity of many propolis samples; however, studies with Portuguese propolis are scarce, especially regarding this activity. Taking that into account, we aimed to characterize the chemical composition and the antitumoral activity of a Portuguese propolis sample that was harvested in 2010 in the district of Guarda. The chemical profiling of an ethanol extract of Pereiro propolis (P10.EE) was done by HPLCMS and it allowed confirming that the composition of the studied sample is generally similar to other poplar propolis type. Relatively to the antitumoral activity, we first observed that P10.EE affects the cell viability of different tumor cell lines: breast, prostate and brain, being the MDAMB- 231 (breast) and DU145 (prostate) two of the most sensitive ones after 48 hours of treatment (IC50 = 0.015 and 0.007 mg/ml respectively). The effect of P10.EE on cancer cell proliferation, cell cycle, cell death, migration, metabolism and angiogenesis was assessed on these two sensitive cell lines. A drug combinatory study with paclitaxel was also performed. Cell proliferation and migration of both cell lines decreased significantly after 24 and 48 hours, with alterations in the cell cycle and increase in cell death in both cell lines. We also observed a significant increase of glucose consumption and lactate production, which is explained, in the MDA-MB-231 cells, by the increased expression of hypoxia inducible factor-1α (HIF-1α), pyruvate dehydrogenase kinase (PDK), glucose transporter 1 (GLUT1), lactate dehydrogenase (LDH) and carbonic anhydrase (CAIX). Regarding the antiangiogenic activity, P10.EE induced a decrease in total biomass and proliferation of HBMEC cells and appears to affect the natural occurring neovascularization from existing vessels in chicken chorioallantoic membrane (CAM). The drug combinatory study allowed to uncover the conditions of treatment and concentrations of P10.EE that potentiate the effect of paclitaxel in MDA-MB-231 and DU145 cell viability. In conclusion, apart from the increase in glycolytic metabolism, P10.EE appears to be a good candidate for cancer drug development since it decreases important characteristics that dictate tumorigenesis, such as cell proliferation, migration and angiogenesis and also increases cell death.Ao longo dos anos, o interesse em produtos naturais tem aumentado uma vez que são uma fonte promissora de novos fármacos. O própolis é um produto natural resinoso, obtido pelas abelhas a partir das plantas, que é composto por cera das abelhas, resinas e compostos voláteis, e possui diversas propriedades biológicas que têm sido investigadas. Nos últimos anos, vários estudos têm demonstrado a atividade antitumoral de diferentes amostras de propolis, no entanto, estudos com amostras Portuguesas são escassos, sobretudo em relação a esta atividade. Assim, este estudo teve como objetivo caraterizar a composição química e a atividade antitumoral de uma amostra de própolis Português, obtida em 2010 no distrito de Guarda. A caraterização química de um extrato etanólico do própolis do Pereiro (P10.EE) realizada por HPLC-MS permitiu confirmar que, em geral a nossa amostra é semelhante a amostras de propolis denominadas “poplar propolis type”. Quanto à atividade antitumoral, observou-se pela primeira vez que P10.EE afeta a viabilidade celular de diferentes linhas tumorais de mama, próstata e cérebro, sendo que as linhas MDA-MB-231 (mama) e DU145 (próstata) são das mais sensíveis após 48 horas de tratamento (IC50 = 0,015 e 0,007 mg/ml, respetivamente). Neste estudo, foi avaliado o efeito do P10.EE sobre a proliferação, ciclo celular, morte, migração, metabolismo e angiogénese nestas duas linhas celulares. Foi também realizado um estudo de combinação de fármacos. Após 24 e 48 horas, P10.EE diminuiu a proliferação e a migração em ambas as linhas celulares, provocou alterações no ciclo celular e aumento da morte. Quanto ao metabolismo, foi observado um aumento significativo do consumo de glucose e produção de lactato. Isto é explicado na linha celular MDA-MB-231 com o aumento da expressão do “hypoxia inducible factor-1α” (HIF-1α), piruvato desidrogenase quinase (PDK), transportador de glucose 1 (GLUT1), lactato desidrogenase (LDH) e anidrase carbónica IX (CAIX). Observamos ainda que P10.EE induz uma diminuição da viabilidade e proliferação da linha endotelial HBMEC e parece afetar a neovascularização natural que ocorre a partir de vasos existentes na “chicken chorioallantoic membrane” (CAM). A combinação de fármacos permitiu revelar as condições de tratamento e as concentrações de paclitaxel e P10.EE que potenciam a redução da viabilidade em ambas as linhas celulares. Em conclusão, apesar do aumento do metabolismo glicolítico, P10.EE parece ser um bom candidato para o desenvolvimento de agentes anticancerígenos, visto que diminui caraterísticas importantes que determinam a tumorigénese, como sejam a proliferação celular, migração e angiogénese e aumento da morte celular

Materiais estruturados para a educação matemática pré-escolar

Neste artigo, apresentam-se alguns métodos de utilização de materiais estruturados na educação matemática pré-escolar. A análise apresentada incide sobre os dons de Fröebel, as barras cuisenaire, o tangram e os blocos lógicos. Estes materiais, podendo também ser utilizados noutros níveis de ensino, revelam-se muito adequados para a faixa etária dos 3-5 anos.info:eu-repo/semantics/publishedVersio

Hyaluronic acid-amphotericin B nanocomplexesa: a promising anti-leishmanial targeted drug delivery system

Leishmaniasis has been classified as one of the most neglected tropical diseases, causing 50 thousand deaths and 1.5 to 2 million new cases every year, according to the World Health Organization. This disease, promoted by protozoan parasites of the genus Leishmania, has a high incidence affecting 89 countries worldwide. Nowadays, current treatment strategies still rely on the antifungal agent amphotericin B (AmB) but are rather inadequate due to the high prevalence of the disease within low-income population of sub-developed regions, the intracellular location of the parasite and the emergence of parasite resistance. Thus, other strategies have been pursued to improve the therapeutic efficacy and to reduce the toxicity of AmB such as the use of biocompatible polysaccharides as carriers. In this work, a simple and inexpensive production process using hyaluronic acid (HA, 50 kDa) was used in order to develop water-soluble hyaluronic acid-amphotericin B nanocomplex (HA-AmB). HA is the main ligand of CD44 receptor, thus being favorably internalized by macrophages that overexpress this receptor upon infection. Therefore, HA arises as a suitable polysaccharide to target the AmB delivery to the leishmania-infected macrophages. The nanocomplex, obtained by simply processing the mixture of the polysaccharide with the drug in a nanospray dryer (HA-AmB SD), was characterized in terms of size/zeta potential (DLS) and morphology (SEM and Cryo-SEM). Furthermore, an HPLC-MS detection method was optimized and used to determine the AmB content in the nanocomplex. Also, to ascertain the interaction between AmB and the HA, FTIR, DSC and PXRD analysis were performed. Cytotoxic and hemolytic effects were assessed on different cell lines through the resazurin test and in dogs blood, respectively. Anti-leishmanial activity was assessed in vitro in axenic cultures of Leishmania by resazurin and in infected bone marrow-derived macrophages (BMM) stained with different fluorescent probes using high-content microscopy. Our results shown that the produced material has a spherical morphology in aqueous solution with a mean hydrodynamic diameter of 318.4 ± 34.7 nm and low polydispersity (0.239 ± 0.02). Moreover, this material that presents an AmB content of 13.56 ± 3.49 %, has a good colloidal stability due to the highly negative surface charge (-39.45 ± 1.12 mV). DSC and PXRD analysis strongly suggested the formation of an amorphous inclusion complex between AmB and the complex polysaccharide chain networks, explaining the high solubility of the drug in water. The in vitro assays showed that compared to free-AmB, the nanocomplex had significantly less cytotoxicity against BMM and HEK293T cell lines, significant less hemolytic effect and inhibited the infection in the Leishmania-infected BMM. Exploratory in vivo assays are being conducted in mice. In conclusion, this work has shown that the hyaluronic acid-AmB nanocomplex is a promising system for the treatment of Leishmaniasis, possessing similar effects to the free-AmB against Leishmania-infected macrophages and Leishmania axenic cultures, with reduced cytotoxicity. Given the affordability, simplicity, low-toxicity and facile scale up of the developed formulation, the hyaluronic acid-AmB nanocomplex may represent an alternative to the expensive nanoformulations available.The authors would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for supporting this study under the scope of the strategic funding of UID/BIO/04469 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01- 0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ricardo Silva-Carvalho also acknowledges FCT for the PhD scholarship SFRH/BD/118880/2016.info:eu-repo/semantics/publishedVersio

Development of dextrin-amphotericin B formulations for the treatment of Leishmaniasis

The most effective medicines available for the treatment of leishmaniasis, a life-threatening disease, exhibit serious toxicological issues. To achieve better therapeutic efficiency while decreasing toxicity associated with amphotericin B (AmB), water-soluble dextrin-AmB (Dex-AmB) formulations were developed. Self-assembled nanocomplexes were formed by dissolving Dex and AmB in alkaline borate buffer, followed by dialysis and either freeze-drying (FD) or nano spray-drying (SD), yielding water dispersible particles with a diameter of 214nm and 347nm, respectively. The very simple production process allowed the formation of amorphous inclusion complexes containing 14% of AmB in the form of monomers and water-soluble aggregates. Nanocomplexes were effective against parasites in axenic culture (IC50 of 0.056 and 0.096M for L. amazonensis and 0.030 and 0.044M for L. infantum, respectively for Dex-AmB FD and Dex-AmB SD) and in decreasing the intramacrophagic infection with L. infantum (IC50 of 0.017 and 0.023M, respectively for Dex-AmB FD and Dex-AmB SD). Also, the formulations were able to significantly reduce the cytotoxicity of AmB. Overall, this study demonstrates the suitability of dextrin as an AmB carrier and the facile and inexpensive development of a delivery system for the treatment of leishmaniasis.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2019 and BioTecNorte operation (NORTE-01-0145-FEDER000004 - Underpinning Biotechnology to foster the north of Portugal bioeconomy and NORTE-01-0145-FEDER-000012 - Structured program on bioengineered therapies for Infectious diseases and tissue regeneration) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ricardo Silva-Carvalho gratefully acknowledge FCT for the granted scholarship (SFRH/BD/118880/2016). Karoline Rachel Melo and Moacir Fernandes Queiroz gratefully acknowledge Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil for the granted scholarship.info:eu-repo/semantics/publishedVersio

Advanced polymeric membranes as biomaterials based on marine sources envisaging the regeneration of human tissues

The self-repair capacity of human tissue is limited, motivating the arising of tissue engineering (TE) in building temporary scaffolds that envisage the regeneration of human tissues, including articular cartilage. However, despite the large number of preclinical data available, current therapies are not yet capable of fully restoring the entire healthy structure and function on this tissue when significantly damaged. For this reason, new biomaterial approaches are needed, and the present work proposes the development and characterization of innovative polymeric membranes formed by blending marine origin polymers, in a chemical free cross-linking approach, as biomaterials for tissue regeneration. The results confirmed the production of polyelectrolyte complexes molded as membranes, with structural stability resulting from natural intermolecular interactions between the marine biopolymers collagen, chitosan and fucoidan. Furthermore, the polymeric membranes presented adequate swelling ability without compromising cohesiveness (between 300 and 600%), appropriate surface properties, revealing mechanical properties similar to native articular cartilage. From the different formulations studied, the ones performing better were the ones produced with 3 % shark collagen, 3% chitosan and 10% fucoidan, as well as with 5% jellyfish collagen, 3% shark collagen, 3% chitosan and 10% fucoidan. Overall, the novel marine polymeric membranes demonstrated to have promising chemical, and physical properties for tissue engineering approaches, namely as thin biomaterial that can be applied over the damaged articular cartilage aiming its regeneration.The authors would like to acknowledge the Portuguese Foundation of Science and Technology (FCT) for Ph.D. fellowship (D. N. Carvalho, under the scope of doctoral program TERM&SC, ref. PD/BD/143044/2018), post-doctoral fellowship (L.C. Rodrigues, ref. SFRH/BPD/93697/2013) and research project with ref. PTDC/CTM-CTM/29813/2017-(POCI-01-0145-FEDER-029813). The authors also thank Jellagen Ltd. (UK) for the provision of purified jellyfish collagen and Julio Maroto (Fundación CETMAR, Vigo, Spain) for the kind offer of the squid pens for chitosan production.This work has been partially funded by ERDF under the scope of the Atlantic Area Program through project EAPA_151/2016 (BLUEHUMAN)

Portuguese propolis: a source of valuable bioactivities

To FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER-006958 and FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Updated cardiovascular prevention guideline of the Brazilian Society of Cardiology: 2019

Sem informação113478788

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants.

BACKGROUND: Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. METHODS: We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. FINDINGS: The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. INTERPRETATION: Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings. FUNDING: WHO