PRELIMINARY STUDY OF THE EXTRACT OF THE BARKS OF Licania macrophylla BENTH: PHYTOCHEMICALS AND TOXICOLOGICAL ASPECTS

O objetivo desta pesquisa foi avaliar o perfil fitoquímico, físico-químico da espécie vegetal e determinar a toxicidade do extrato bruto etanólico de L. macrophylla Benth frente às larvas de Artemia salina L. A análise fitoquímica foi realizado por meio do extrato bruto etanólico das cascas do caule e a determinação físico-química foi realizada de acordo com a Farmacopeia Brasileira. As análises fitoquímicas detectaram a presença de saponinas, ácidos orgânicos, açúcares redutores, taninos, antraquinonas, depsídios e depsidonas. Em relação aos parâmetros físico-químicos a planta apresentou pH=4,64, pela ocorrência de saponinas, ácidos orgânicos e taninos; Lipídeos= 0,55% indica que o material vegetal apresenta poucos lipídios de baixo peso molecular; Umidade= 12,09%±0,12, o que relaciona a pouca quantidade de água, fator indispensável para a não ocorrência de desenvolvimento de microrganismo ou degradação enzimática. Os resíduos por incineração (cinzas) da espécie se encontra dentro dos padrões farmacognósticos de 8,30%±0,54. O extrato bruto segundo o teste de toxicidade é atóxico com CL50=1253µg/mL, isto é, confirma-se a relação estabelecida entre a taxa de mortalidade e CL50 deve ser superior a 1000µg/mL para serem considerados atóxicos. As análises fitoquímicas confirmaram em parte a utilização da espécie para fins fitoterápicos, porém a forma de tratamento e acondicionamento pode influenciar na determinação de metabólitos secundários. Os parâmetros físico-químicos adotados mostraram que espécie encontra-se livre de agentes decompositores.Palavras-chave: Fitoquímica, L. macrophilla Benth, Toxicidade, Físico-Química.The objective of this research was to evaluate the phytochemical, physicochemical and toxicity profile of ethanol crude extract of L. macrophyllain relation to Artemiasalina L. The Phytochemical analysis of the ethanol crude extract of the barks and stem and physicochemical calculation were performed by methods found in the Brazilian Pharmacopoeia. Phytochemical analysis detected saponins, organic acids, reducing sugars, tannins, anthraquinones, and depsidedepsidone. In relation to the physicochemical parameters, it showed pH = 4.64, due to the occurrence of saponins, organic acids and tannins; lipid = 0.55% indicates that the material presents few lipids of low molecular weight; humidity = 12.09% ± 0.12, relates to a small amount of water, indispensable for non occurrence of development of microorganisms or enzymatic degradation. Waste by incineration is within the pharmacognostic standards of 8.30% ± 0.54. The crude extract is practically nontoxic with LC50 = 1253μg/mL, since the mortality rate and LC50 should be higher than 1000μg/mL to be considered nontoxic. Phytochemical analysis have confirmed, in part, the use of species for phytotherapic purposes, however, the type of treatment and packaging can influence the determination of secondary metabolites. The adopted physicochemical parameters have shown that the species is free of decomposersagents.Keywords: Herbal medicine; L. macrophilla Benth; Toxicity; Physicochemical

Comparative Transcriptomic Analysis of the Burkholderia cepacia Tyrosine Kinase bceF Mutant Reveals a Role in Tolerance to Stress, Biofilm Formation, and Virulence

The bacterial tyrosine-kinase (BY-kinase) family comprises the major group of bacterial enzymes endowed with tyrosine kinase activity. We previously showed that the BceF protein from Burkholderia cepacia IST408 belongs to this BY-kinase family and is involved in the biosynthesis of the exopolysaccharide cepacian. However, little is known about the extent of regulation of this protein kinase activity. In order to examine this regulation, we performed a comparative transcriptome profile between the bceF mutant and wild-type B. cepacia IST408. The analyses led to identification of 630 genes whose expression was significantly changed. Genes with decreased expression in the bceF mutant were related to stress response, motility, cell adhesion, and carbon and energy metabolism. Genes with increased expression were related to intracellular signaling and lipid metabolism. Mutation of bceF led to reduced survival under heat shock and UV light exposure, reduced swimming motility, and alteration in biofilm architecture when grown in vitro. Consistent with some of these phenotypes, the bceF mutant demonstrated elevated levels of cyclic-di-GMP. Furthermore, BceF contributed to the virulence of B. cepacia for larvae of the Greater wax moth, Galleria mellonella. Taken together, BceF appears to play a considerable role in many cellular processes, including biofilm formation and virulence. As homologues of BceF occur in a number of pathogenic and plant-associated Burkholderia strains, the modulation of bacterial behavior through tyrosine kinase activity is most likely a widely occurring phenomenon.FCT contract: (PTDC/BIA-MIC/66977/2006), FCT postdoctoral grant and a doctoral grant, Fundação Calouste Gulbenkian scholarship

Factors affecting post-fire crown regeneration in cork oak (Quercus suber L.) trees

Cork oak (Quercus suber) forests are acknowledged for their biodiversity and economic (mainly cork production) values. WildWres are one of the main threats contributing to cork oak decline in the Mediterranean Basin, and one major question that managers face after Wre in cork oak stands is whether the burned trees should be coppiced or not. This decision can be based on the degree of expected crown regeneration assessed immediately after Wre. In this study we carried out a post-Wre assessment of the degree of crown recovery in 858 trees being exploited for cork production in southern Portugal, 1.5 years after a wildWre. Using logistic regression, we modelled good or poor crown recovery probability as a function of tree and stand variables. The main variables inXuencing the likelihood of good or poor crown regeneration were bark thickness, charring height, aspect and tree diameter. We also developed management models, including simpler but easier to measure variables, which had a lower predictive power but can be used to help managers to identify, immediately after Wre, trees that will likely show good crown regeneration, and trees that will likely die or show poor regeneration (and thus, potential candidates for trunk coppicin

Increase in Ca2+ current by sustained cAMP levels enhances proliferation rate in GH3 cells

Aims: Ca2 + and cAMP are important intracellular modulators. In order to generate intracellular signals with various amplitudes, as well as different temporal and spatial properties, a tightly and precise control of these modulators in intracellular compartments is necessary. The aim of this study was to evaluate the effects of elevated and sustained cAMP levels on voltage-dependent Ca2 + currents and proliferation in pituitary tumor GH3 cells. Main methods: Effect of long-term exposure to forskolin and dibutyryl-cyclic AMP (dbcAMP) on Ca2 + current density and cell proliferation rate were determined by using the whole-cell patch-clamp technique and real time cell monitoring system. The cAMP levels were assayed, after exposing transfected GH3 cells with the EPAC-1 cAMP sensor to forskolin and dbcAMP, by FRET analysis. Key findings: Sustained forskolin treatment (24 and 48 h) induced a significant increase in total Ca2 + current density in GH3 cells. Accordingly, dibutyryl-cAMP incubation (dbcAMP) also elicited increase in Ca2 + current density. However, the maximum effect of dbcAMP occurred only after 72 h incubation, whereas forskolin showed maximal effect at 48 h. FRET-experiments confirmed that the time-course to elevate intracellular cAMP was distinct between forskolin and dbcAMP. Mibefradil inhibited the fast inactivating current component selectively, indicating the recruitment of T-type Ca2 + channels. A significant increase on cell proliferation rate, which could be related to the elevated and sustained intracellular levels of cAMP was observed. Significance: We conclude that maintaining high levels of intracellular cAMP will cause an increase in Ca2 + current density and this phenomenon impacts proliferation rate in GH3 cells

DNA single-strand break repair and spinocerebellar ataxia with axonal neuropathy-1

DNA single-strand breaks (SSBs) are the commonest DNA lesions arising spontaneously in cells, and if not repaired may block transcription or may be converted into potentially lethal/clastogenic DNA double-strand breaks (DSBs). Recently, evidence has emerged that defects in the rapid repair of SSBs preferentially impact the nervous system. In particular, spinocerebellar ataxia with axonal neuropathy (SCAN1) is a human disease that is associated with mutation of TDP1 (tyrosyl DNA phosphodiesterase 1) protein and with a defect in repairing certain types of SSBs. Although SCAN1 is a rare neurodegenerative disorder, understanding the molecular basis of this disease will lead to better understanding of neurodegenerative processes. Here we review recent progress in our understanding of TDP1, single-strand break repair (SSBR), and neurodegenerative disease

Merchandising social como estratégia de inclusão de grupos marginalizados em telenovelas

No escopo do presente texto, a telenovela é entendida como um dispositivo utilizado para compartilhar referências comuns sobre representações da realidade social ou inerentes ao próprio indivíduo, que atuam, ou, ao menos, tendem a atuar, para a inclusão social e a construção da cidadania. Dessa forma, observam-se as estratégias dos autores das telenovelas em retratar, em suas tramas, grupos sociais tipicamente vistos como marginalizados, através da inserção do merchandising social. Assim, este trabalho pretende contribuir para o amplo debate sobre a participação dos meios de comunicação na manutenção e na transformação das relações sociais desiguais, sobretudo no que concerne ao fomento do debate sobre a maneira como diversos grupos são retratados nas telenovelas. Tal profícuo debate encontra ótimo pretexto para ser realizado quando da análise das novelas de Manoel Carlos e Glória Perez. Avalia-se, portanto, que tais produtos podem contribuir na busca por uma sociedade mais igualitária e fazer com que grupos marginais, através da mídia de massa, saiam do submundo em que vegetam, como preconiza Luiz Beltrão

Genetic diversity and shedding profiles for Cryptosporidium parvum in adult cattle and their calves

Cryptosporidiosis is an important disease in neonatal calves, causing watery diarrhoea, loss of appetite, and production losses. Dehydration from diarrhoea often results in the calf requiring rehydration or veterinary treatment to prevent calf mortality. Transmission of Cryptosporidium to calves still has some major knowledge gaps, such as the initial source of oocysts ingested by calves and how these oocysts can persist between calving periods. Some studies have examined the role of adult cattle in the transmission of Cryptosporidium oocysts, although these have yielded inconclusive results. In this study, highly sensitive oocyst extraction from faeces and detection techniques, sensitive to 5 oocysts per gram using a 50 g sample, were used to genotype faecal samples from adult cattle and their calves to determine if adult cattle could be a source of Cryptosporidium infection for their calves. On a dairy farm, faecal samples from adult cattle were collected twice per week for 0–3 weeks before calving and from their calves three times per week until they reached 3 weeks of age followed by twice per week until they reached 6 weeks of age. On a beef farm, samples were collected from both adults and calves at a single time point. Faecal samples were examined to compare species and multilocus genotypes of Cryptosporidium parvum. Results show that C. parvum was the most prevalent species on both the dairy and beef farms. The calves within each herd appear to have one predominant single multilocus genotype, whereas adult cattle have multiple distinct genotypes. Adult cattle on the dairy farm, tested before calving, in the majority of cases had a multilocus genotype that is different from that detected in their calves. On the beef farm, where samples were taken at the same time, the majority of adult cattle matched the multilocus genotype of their calves. This study shows that adult cattle display a higher diversity of C. parvum genotypes on both farms compared to the calves. The data also represent a detailed longitudinal prevalence study of the shedding profiles and genotype of Cryptosporidium parasites detected in dairy calves from birth to 6 weeks of age