Exposure to polycyclic aromatic hydrocarbons and assessment of potential risks in preschool children

As children represent one of the most vulnerable groups in society, more information concerning their exposure to health hazardous air pollutants in school environments is necessary. Polycyclic aromatic hydrocarbons (PAHs) have been identified as priority air pollutants due to their mutagenic and carcinogenic properties that strongly affect human health. Thus, this work aims to characterize levels of 18 selected PAHs in preschool environment, and to estimate exposure and assess the respective risks for 3–5-year-old children (in comparison with adults). Gaseous PAHs (mean of 44.5 ± 12.3 ng m−3) accounted for 87 % of the total concentration (ΣPAHs) with 3–ringed compounds being the most abundant (66 % of gaseous ΣPAHs). PAHs with 5 rings were the most abundant ones in the particulate phase (PM; mean of 6.89 ± 2.85 ng m−3) being predominantly found in PM1 (78 % particulate ΣPAHs). Overall child exposures to PAHs were not significantly different between older children (4–5 years old) and younger ones (3 years old). Total carcinogenic risks due to particulate-bound PAHs indoors were higher than outdoor ones. The estimated cancer risks of both preschool children and the staff were lower than the United States Environmental Protection Agency (USEPA) threshold of 10−6 but slightly higher than WHO-based guideline.

Phenolic compounds from olive mill wastes: Health effects, analytical approach and application as food antioxidants

Background Over the years, food industry wastes have been the focus of a growing interest due to their content in high added-value compounds. A good example are the olive oil by-products (OOBP), which retain a great amount of phenolic compounds during olive oil production. Their structure and biological properties justify their potential use as antioxidants in other food products. The efficient recovery of phenolic compounds has been extensively studied and optimized in order to maximize their reintroduction in the food chain and contribute to a higher valorization and better management of wastes from olive oil industry. Scope and approach This paper reviews the most representative phenolic compounds described in OOBP and their biological properties. New extraction procedures to efficiently recover these compounds and the most advanced chromatographic techniques that have been used for a better understanding of the phenolic profile of these complex matrices are also referred. Finally, this paper reports the main applications of OOBP, with emphasis on their phenolic content as natural antioxidants for food applications. Key findings and conclusions Besides their antioxidant activity, phenolic compounds from OOBP have also shown antimicrobial and antitumoral properties. Their application as food antioxidants requires new extraction techniques, including the use of non-toxic solvents and, in a pilot scale, the use of filters and adsorbent resins. The inclusion of phenolic compounds from OOBP in some food matrices have improved not only their antioxidant capacity but also their sensory attributes.

Potential Therapeutic Effects of Physical Exercise for Bipolar Disorder

Cognitive deficits are observed in a variety of domains in patients with bipolar disorder (BD). These deficits are attributed to neurobiological, functional and structural brain factors, particularly in prefrontal cortex. Furthermore, cortical alterations in each phase (mania/hypomania, euthymia and depression) are also present. A growing basis of evidence supports aerobic exercise as an alternative treatment method for BD symptoms. Its benefits for physical health in healthy subjects and some psychiatric disorders are fairly established; however evidence directly addressed to BD is scant. Lack of methodological consistency, mainly related to exercise, makes it difficult accuracy and extrapolation of the results. Nevertheless, mechanisms related to BD physiopathology, such as hormonal and neurotransmitters alterations and mainly related to brain-derived neurotrophic factors (BDNF) can be explored. BDNF, specially, have a large influence on brain ability and its gene expression is highly responsive to aerobic exercise. Moreover, aerobic exercise trough BDNF may induce chronic stress suppression, commonly observed in patients with BD, and reduce deleterious effects caused by allostatic loads. Therefore, it is prudent to propose that aerobic exercise plays an important role in BD physiopathological mechanisms and it is a new way for the treatment for this and others psychiatric disorders.

Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an egyptian locality

The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.

Candida glabrata susceptibility to antifungals and phagocytosis is modulated by acetate

Candida glabrata is considered a major opportunistic fungal pathogen of humans. The capacity of this yeast species to cause infections is dependent on the ability to grow within the human host environment and to assimilate the carbon sources available. Previous studies have suggested that C. albicans can encounter glucose-poor microenvironments during infection and that the ability to use alternative non-fermentable carbon sources, such as carboxylic acids, contributes to the virulence of this fungus. Transcriptional studies on C. glabrata cells identified a similar response, upon nutrient deprivation. In this work, we aimed at analyzing biofilm formation, antifungal drug resistance, and phagocytosis of C. glabrata cells grown in the presence of acetic acid as an alternative carbon source. C. glabrata planktonic cells grown in media containing acetic acid were more susceptible to fluconazole and were better phagocytosed and killed by macrophages than when compared to media lacking acetic acid. Growth in acetic acid also affected the ability of C. glabrata to form biofilms. The genes ADY2a, ADY2b, FPS1, FPS2, and ATO3, encoding putative carboxylate transporters, were upregulated in C. glabrata planktonic and biofilm cells in the presence of acetic acid. Phagocytosis assays with fps1 and ady2a mutant strains suggested a potential role of FPS1 and ADY2a in the phagocytosis process. These results highlight how acidic pH niches, associated with the presence of acetic acid, can impact in the treatment of C. glabrata infections, in particular in vaginal candidiasis.

Preliminary investigation of Culicidae species in South Pantanal, Brazil and their potential importance in arbovirus transmission

In view of the high circulation of migratory birds and the environmental and climatic conditions which favor the proliferation of arthropods, the Brazilian Pantanal is susceptible to circulation of arboviruses. However, the amount of data concerning arbovirus vectors in this area is scarce; therefore the aim of this study was to conduct a preliminary investigation of Culicidae species in the Nhecolândia Sub-region of South Pantanal, Brazil and their potential importance in the arbovirus transmission. A total of 3684 specimens of mosquitoes were captured, 1689 of which caught in the rainy season of 2007, were divided into 78 pools and submitted to viral isolation, Semi-Nested RT-PCR and Nested RT-PCR, with a view to identifying the most important arboviruses in Brazil. Simultaneously, 70 specimens of ticks found blood-feeding on horses were also submitted to the same virological assays. No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, a total of 22 Culicidae species were identified, ten of which had previously been reported as vectors of important arboviruses. The diversity of species found blood-feeding on human and horse hosts together with the arboviruses circulation previously reported suggest that the Nhecolândia Sub-region of South Pantanal is an important area for arbovirus surveillance in Brazil.

Estudo eletroquímico do dano oxidativo promovido por RNS e PAH e o efeito protetor de antioxidantes no ADN

No dia-a-dia, os organismos vivos estão sujeitos a vários tipos de agressões de origem endógena e exógena. A produção endógena exagerada de contaminantes que ocorre nos processos metabólicos dos seres vivos está intimamente associada ao aparecimento e desenvolvimento de várias patologias. Por outro lado, e devido às atividades antropogénicas, muitos contaminantes de origem ambiental e alimentar entram por via exógena no organismo dos seres vivos provocando igualmente danos a nível celular. De modo a protegerem-se dos efeitos pejorativos provocados por estes compostos, os organismos vivos desenvolveram mecanismos complexos de defesa antioxidante. Este trabalho consistiu no estudo eletroquímico do dano oxidativo induzido por contaminantes (PAH (hidrocarbonetos aromáticos policíclicos), H2O2, NO• e HClO) e do efeito protetor, ao dano oxidativo, promovido por antioxidantes no material baseado no ADN recorrendo à utilização de um biossensor de bases púricas, adenina-EPC (elétrodo pasta de carbono) e dA20-EPC, utilizando a voltametria de onda quadrada (VOQ) como técnica de deteção. A aplicação da eletroquímica apresenta várias vantagens para a quantificação da capacidade antioxidante total (CAT) pois, permite a redução da quantidade de reagentes e amostra em análise, elimina a etapa de remoção de cor (a cor é um interferente nos métodos óticos) e não requer equipamentos dispendiosos. Foram seguidas diferentes abordagens para a construção dos biossensores. A primeira consistiu na construção de um adenina-EPC em três etapas: i) condicionamento do EPC, ii) eletrodeposição da adenina no EPC e iii) leitura do sinal eletroquímico. Assim, foram otimizados diversos parâmetros: concentração de adenina (150,0 mg/L), potencial de condicionamento (Ec) (+ 1,80 V), potencial de deposição (Ed) (+ 0,40 V), tempo de condicionamento (tc) (180 s) e tempo de deposição (td) (240 s). Foi aplicado o adenina-EPC no estudo do dano oxidativo provocado por PAH (benzo (g,h,i) perileno) e constatou-se que era necessário transformar o benzo (g,h,i) perileno num radical para se possível observar danos oxidativos induzidos no biossensor. A nova estratégia consistiu na construção de um dA20-EPC, através da adsorção física de uma gota de dA20 na superfície do EPC, com posterior secagem e leitura do sinal eletroquímico. Neste procedimento foi otimizada a concentração de dA20 (100,0 mg/L). O dano oxidativo provocado pelo H2O2, NO• e HClO foi estudado sobre o dA20-EPC e verificou-se que os três contaminantes induziam dano oxidativo no dA20-EPC. Confirmou-se a capacidade do ácido ascórbico (AA) em proteger o dA20-EPC do dano oxidativo induzido por H2O2 e NO•. O biossensor desenvolvido (dA20-EPC) foi aplicado na avaliação da CAT de diferentes amostras reais (café, sumo de laranja e água aromatizada de laranja) usando-se como contaminantes o H2O2 e NO•. Todas as amostras analisadas apresentaram ter capacidade antioxidante. Quando se usou o dA20-EPC na presença de H2O2, verificou-se que as amostras de café apresentam valores mais elevados de CAT (1130-1488 mg AAE/L) do que as amostras de bebidas (110 mg AAE/L em água aromatizada e 775 mg AAE/L em sumo). Os valores de CAT obtidos para amostras de sumo e água aromatizada na presença de NO• indicam que a amostra de sumo possui maior teor de CAT (526 mg AAE/L) conforme era esperado, do que a amostra de água aromatizada (172 mg AAE/L).

Projeto de Sistema Fotovoltaico Para as Naves Industriais da Zona Econômica Especial de Luanda-Bengo

Com os preços do barril de petróleo a atingir níveis nunca antes atingidos, cada vez mais há uma maior sensibilização para a importância das fontes renováveis de energia, não só pelo seu baixo custo de exploração, mas também pela ausência de poluição ambiental. A integração de sistemas fotovoltaicos nas edificações, começa a ter uma expressão significativa especialmente por ser uma forma de produção renovável. Pelo seu carácter renovável, vai ao encontro de objetivos ambientais, e é também desejável pelo seu carácter distribuído, produção próxima do consumo, evitando perdas de transporte e utilizando o recurso disponível no consumidor. No presente projeto é feita uma breve descrição do atual sistema elétrico angolano, nomeadamente o seu potencial, capacidade instalada, e perspetivas futuras de desenvolvimento do mesmo. Com uma perspetiva introdutória são abordadas as energias renováveis especialmente a energia fotovoltaica, terminando com as diferentes formas de produção e tecnologias existentes. São apresentados diferentes equipamentos, que, com as inúmeras combinações poderão vir a constituir um sistema técnico e financeiramente viável. Devido aos vários cenários possíveis (combinações entre equipamentos), foram usadas como instrumentos de apoio ferramentas informáticas que permitem o dimensionamento de sistemas fotovoltaicos, análise de compatibilidades, e simulação do seu funcionamento. Foram dimensionadas quatro opções de sistemas fotovoltaicos, a instalar nas naves industriais da Zona Económica Especial Luanda-Bengo, para uma mesma área de cobertura, seguido de um estudo económico, onde é feito uma comparação custo/benefício dos vários sistemas.

Potential immunological markers for diagnosis and therapeutic assessment of toxocariasis

In human toxocariasis, there are few approaches using immunological markers for diagnosis and therapeutic assessment. An immunoblot (IB) assay using excretory-secretory Toxocara canis antigen was standardized for monitoring IgG, IgE and IgA antibodies in 27 children with toxocariasis (23 visceral, three mixed visceral and ocular, and one ocular form) for 22-116 months after chemotherapy. IB sensitivity was 100% for IgG antibodies to bands of molecular weight 29-38, 48-54, 95-116, 121-162, >205 kDa, 80.8% for IgE to 29-38, 48-54, 95-121, > 205 kDa, and 65.4% for IgA to 29-38, 48-54, 81-93 kDa. Candidates for diagnostic markers should be IgG antibodies to bands of low molecular weight (29-38 and 48-54 kDa). One group of patients presented the same antibody reactivity to all bands throughout the follow-up study; in the other group, antibodies decayed partially or completely to some or all bands, but these changes were not correlated with time after chemotherapy. Candidates for monitoring patients after chemotherapy may be IgG antibodies to > 205 kDa fractions, IgA to 29-38, 48-54, 81-93 kDa and IgE to 95-121 kDa. Further identification of antigen epitopes related to these markers will allow the development of sensitive and specific immunoassays for the diagnosis and therapeutic assessment of toxocariasis.

Potential utility of hyperbaric oxygen therapy and propolis in enhancing the leishmanicidal activity of glucantime

In this study we investigated the efficacy of hyperbaric oxygen (HBO) therapy, alone or combined with the pentavalent antimonial glucantime on Leishmania amazonensis infection. In parallel, the effect of Brazilian red propolis gel (propain) alone or combined with glucantime on L. amazonensis infection was evaluated. The inhibition of the infection in macrophages treated with glucantime in combination with HBO exposition was greater than that of macrophages treated with glucantime alone or HBO alone. The susceptible mouse strain BALB/c infected in the shaved rump with L. amazonensis treated with glucantime and exposed to HBO showed: time points in the course of the disease in which lesions were smaller than those of mice treated with glucantime alone and revascularization of the skin in the lesion site; interferon-gamma (IFN-g) levels were not elevated in lymph node cells from these animals. Propain alone was not efficient against lesions, although less exudative lesions were observed in animals treated with propain alone or combined with glucantime. These results reveal the potential value of HBO and red propolis in combination with glucantime for treating cutaneous leishmaniasis and encourage further studies on the effect of more aggressive HBO, propolis and glucantime therapies on different mouse models of leishmaniasis.

Genetic Control of Mosquitoes: population suppression strategies

Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods.

Evaluation of different natural ingredients as satiety inductors

Dissertation to obtain a Master’s Degree in Chemical and Biochemical Engineering

THE SCHISTOSOMULA TEGUMENT ANTIGEN AS A POTENTIAL CANDIDATE FOR THE EARLY SEROLOGICAL DIAGNOSIS OF SCHISTOSOMIASIS MANSONI

If Schistosoma mansoni infection could be detected in its early stages, especially before the egg deposition in the host tissues, the development of severe pathologic lesions could be efficiently prevented. We therefore developed an indirect enzyme-linked immunosorbent assay based on the detection of specific IgG against schistosomula antigens (ELISA-SmTeg). The assay was applied in sera samples from non-infected and infected mice collected seven and 15 days post-infection. The results were compared to the number of adult worms obtained by perfusion of the murine hepatic system 50 days post-infection. The sensitivity and specificity of the ELISA-SmTeg were 100% (p = 0.0032 and 0.0048 respectively for seven and 15 days of infection) with a cutoff value of 0.15 (p = 0.0002). Our findings show a novel low-cost serological assay using antigens which are easy to obtain, which was able to detect all the infected mice as early as seven days post-infection.