2,291 research outputs found
Using risk-ranking of metals to identify which poses the greatest threat to freshwater organisms in the UK
Freshwater aquatic organisms face the challenge of being exposed to a multitude of chemicals discharged by the human population. The objective of this study was to rank metals according to the threat they pose to aquatic organisms. This will contribute to a wider Chemical Strategy for freshwater which will risk rank all chemicals based on their potential risk to wildlife in a UK setting. The method involved comparing information on ecotoxicological thresholds with measured concentrations in rivers. The bioconcentration factor was also considered as a ranking method. The metals; Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn, were analysed using this approach. Triclosan and lindane were used as comparative organic pollutants. Using a range of ranking techniques, Cu, Al and Zn came top of the list of concern, with Cu coming first
Hand Posture Effects on Handedness Recognition as Revealed by the Simon Effect
We investigated the influence of hand posture in handedness recognition, while varying the spatial correspondence between stimulus and response in a modified Simon task. Drawings of the left and right hands were displayed either in a back or palm view while participants discriminated stimulus handedness by pressing either a left or right key with their hands resting either in a prone or supine posture. As a control, subjects performed a regular Simon task using simple geometric shapes as stimuli. Results showed that when hands were in a prone posture, the spatially corresponding trials (i.e., stimulus and response located on the same side) were faster than the non-corresponding trials (i.e., stimulus and response on opposite sides). In contrast, for the supine posture, there was no difference between corresponding and non-corresponding trials. Control experiments with the regular Simon task showed that the posture of the responding hand had no influence on performance. When the stimulus is the drawing of a hand, however, the posture of the responding hand affects the spatial correspondence effect because response location is coded based on multiple reference points, including the body of the hand
Early Cardiac Mitochondrial Molecular and Functional Responses to Acute Anthracycline Treatment in Wistar Rats
Doxorubicin (DOX) is an anticancer drug widely used to treat human and nonhuman tumors but the late and persistent cardio-toxicity reduces the therapeutic utility of the drug. The full mechanism(s) of DOX-induced acute, subchronic and delayed toxicity, which has a preponderant mitochondrial component, remains unclear; therefore, it is clinically relevant to identify early markers to identify patients who are predisposed to DOX-related cardiovascular toxicity. To address this, Wistar rats (16 weeks old) were treated with a single DOX dose (20 mg/kg, i.p.); then, mRNA, protein levels and functional analysis of mitochondrial endpoints were assessed 24 h later in the heart, liver, and kidney. Using an exploratory data analysis, we observed cardiac-specific alterations after DOX treatment for mitochondrial complexes III, IV, and preferentially for complex I. Conversely, the same analysis revealed complex II alterations are associated with DOX response in the liver and kidney. Interestingly, H2O2 production by the mitochondrial respiratory chain as well as loss of calcium-loading capacity, markers of subchronic toxicity, were not reliable indicators of acute DOX cardiotoxicity in this animal model. By using sequential principal component analysis and feature correlation analysis, we demonstrated for the first time alterations in sets of transcripts and proteins, but not functional measurements, that might serve as potential early acute markers of cardiac-specific mitochondrial toxicity, contributing to explain the trajectory of DOX cardiac toxicity and to develop novel interventions to minimize DOX cardiac liabilities
Electromyographic analyses of muscle pre-activation induced by single joint exercise
Objetivo: Verificar se a execução de um exercício monoarticular de baixa intensidade para os extensores do joelho é uma estratégia eficaz para aumentar o número de unidades motoras recrutadas no músculo vasto lateral durante a realização de um exercício multiarticular subsequente. Métodos: Nove sujeitos saudáveis do sexo masculino (23,33±3,46 anos) foram submetidos a rotinas de treinamento nas quais os exercícios cadeira extensora e leg press 45° eram realizados em sequência. Na rotina de baixa intensidade (R30), foram realizadas 15 extensões unilaterais de joelho, seguidas de 15 repetições de leg press 45° com cargas de 30% e 60% de uma repetição máxima (1-RM), respectivamente. Na rotina de alta intensidade (R60), a mesma sequência foi executada, porém a carga dos dois movimentos foi de 60% de 1-RM. Uma série simples de 15 repetições leg press 45° com carga de 60% de 1-RM foi utilizada como exercício controle (RC). A eletromiografia de superfície foi registrada no músculo vasto lateral por meio de um arranjo linear de eletrodos. O valor RMS foi calculado para cada repetição do leg press 45° e, a partir desses resultados, foram calculadas regressões lineares. As inclinações das retas obtidas foram então normalizadas pelos coeficientes lineares das equações de regressão e comparadas por meio da ANOVA de um fator para medidas repetidas. Resultados: As inclinações observadas na rotina RC foram significativamente inferiores às de R30 e às de R60 (p<0,05). Conclusões: Os resultados indicaram um recrutamento mais efetivo de unidades motoras nas rotinas de exercício multiarticular precedidas de exercício monoarticular.Objective: To investigate whether performing a low-intensity, single-joint exercises for knee extensors was an efficient strategy for increasing the number of motor units recruited in the vastus lateralis muscle during a subsequent multi-joint exercises. Methods: Nine healthy male participants (23.33±3.46 yrs) underwent bouts of exercise in which knee extension and 45°, and leg press exercises were performed in sequence. In the low-intensity bout (R30), 15 unilateral knee extensions were performed, followed by 15 repetitions of the leg presses at 30% and 60% of one maximum repetition load (1-MR), respectively. In the high-intensity bout (R60), the same sequence was performed, but the applied load was 60% of 1-MR for both exercises. A single set of 15 repetitions of the leg press at 60% of 1-MR was performed as a control exercise (CR). The surface electromyographic signals of the vastus lateralis muscle were recorded by means of a linear electrode array. The root mean square (RMS) values were determined for each repetition of the leg press, and linear regressions were calculated from these results. The slopes of the straight lines obtained were then normalized using the linear coefficients of the regression equations and compared using one-way ANOVAs for repeated measures. Results: The slopes observed in the CR were significantly lower than those in the R30 and R60 (p<0.05). Conclusions: The results indicated that the recruitment of motor units was more effective when a single-joint exercise preceded the multi-joint exercise
Benthic foraminiferal response to variations in temperature, salinity, dissolved oxygen and organic carbon, in the Guanabara Bay, Rio de Janeiro, Brazil
Recent benthic foraminiferal distribution patterns in Guanabara Bay are investigated in relation to temperature, salinity, dissolved oxygen and organic carbon content. Patterns of foraminiferal fauna differ between the entrance of the bay and inner parts. The primary result of the present study is that the distribution of Cassidulina subglobosa and Discorbis williamsoni appear to be governed by lower temperature and higher salinities being found in the entrance of the bay. According to dissolved oxygen content it was observed that Quinqueloculina seminulum occurs when values are higher than 2 mg/l, being intolerant to low oxygen bottom water conditions. By the other hand, Buliminella elegantissima, Bolivina striatula and Bulimmina elongata flourishes under low oxygen waters and in sediment where the organic matter accumulation is high, being found mainly in the central parts of the bay.Padrões de distribuição de foraminíferos bentônicos recentes são investigados com relação a temperatura, salinidade, oxigênio dissolvido e conteúdo de carbono orgânico. A distribuição de foraminíferos é diferente na entrada da baía se comparada às partes internas. Os primeiros resultados mostram que Cassidulina subglobosa e Discorbis williamsoni são encontradas em ambientes com baixa temperatura e altas salinidades na entrada da baía. De acordo com o teor de oxigênio dissolvido foi observado que Quinqueloculina seminulum ocorre quando os valores são mais altos que 2mg/l, sendo intolerante às condições. Por outro lado, Buliminella elegantissima, Bolivina striatula e Bulimmina elongata aparecem nas partes centrais da baía, que são locais com baixa oxigenação e sedimentos onde a acumulação de matéria orgânica é alta
Scratching increases epidermal neuronal branching and alters psychophysical testing responses in atopic dermatitis and brachioradial pruritus
BackgroundChronic scratching imposes a major stress on the skin and can lead to itch intensity worsening, and consequently, patients may enter an itch–scratch cycle. This repetitive mechanical stress can result in lichenification, worsening of epidermal barrier function, and enhanced cutaneous inflammation. Furthermore, a reduction of intraepidermal nerve fibers was previously described in lichenification.AimThe aim of this study was to investigate the influence of chronic scratching on the epidermal neuroanatomy and on sensory changes, in particular the prevalence of hyperknesis and alloknesis in patients after mechanical, chemical, and electrical stimuli.MethodsAnalyses were performed on pruritic lichenified (chronically scratched), pruritic non-lichenified (not chronically scratched), and non-pruritic non-lesional (unaffected) skin areas of patients with inflammatory pruritus, i.e., atopic dermatitis (n = 35), and neuropathic pruritus, i.e., brachioradial pruritus (n = 34) vs. healthy matched controls (n = 64). Our fine-grained spatial skin characterization enabled specifically studying the differential effects of chronic scratching in inflammatory and neuropathic itch.ResultsAnalysis of intraepidermal nerve fiber density showed rarefaction of fibers in all three skin areas of patients compared with healthy controls in both diagnoses. Even more, the two pruritic areas had significantly less nerve fibers than the unaffected skin, whereas electrically induced itch was massively increased. Epidermal branching of the remaining nerve fibers in lichenified/chronically scratched skin was increased, particularly in patients with brachioradial pruritus, which may contribute to the pronounced local neuronal sensitivity. Hyperknesis and alloknesis were found to increase independently of lichenification.ConclusionOur results indicate that chronic scratching may not affect intraepidermal nerve fiber density but leads to a stronger branching pattern of intraepidermal nerve fibers, which may contribute to local hypersensitivity. The increased sensitivity in the pruritic areas suggests mechanisms of peripheral sensitization, whereas the increased sensation of electrically and chemically induced itch in unaffected skin indicates central sensitization for itch
Transcriptional activity, chromosomal distribution and expression effects of transposable elements in Coffea genomes
Plant genomes are massively invaded by transposable elements (TEs), many of which are located near host genes and can thus impact gene expression. In flowering plants, TE expression can be activated (de-repressed) under certain stressful conditions, both biotic and abiotic, as well as by genome stress caused by hybridization. In this study, we examined the effects of these stress agents on TE expression in two diploid species of coffee, Coffea canephora and C. eugenioides, and their allotetraploid hybrid C. arabica. We also explored the relationship of TE repression mechanisms to host gene regulation via the effects of exonized TE sequences. Similar to what has been seen for other plants, overall TE expression levels are low in Coffea plant cultivars, consistent with the existence of effective TE repression mechanisms. TE expression patterns are highly dynamic across the species and conditions assayed here are unrelated to their classification at the level of TE class or family. In contrast to previous results, cell culture conditions per se do not lead to the de-repression of TE expression in C. arabica. Results obtained here indicate that differing plant drought stress levels relate strongly to TE repression mechanisms. TEs tend to be expressed at significantly higher levels in non-irrigated samples for the drought tolerant cultivars but in drought sensitive cultivars the opposite pattern was shown with irrigated samples showing significantly higher TE expression. Thus, TE genome repression mechanisms may be finely tuned to the ideal growth and/or regulatory conditions of the specific plant cultivars in which they are active. Analysis of TE expression levels in cell culture conditions underscored the importance of nonsense-mediated mRNA decay (NMD) pathways in the repression of Coffea TEs. These same NMD mechanisms can also regulate plant host gene expression via the repression of genes that bear exonized TE sequences. (Résumé d'auteur
SAE-INFO MOBILE PARA A SISTEMATIZAÇÃO DA ASSISTÊNCIA DE ENFERMAGEM NO HOSPITAL CLÉRISTON ANDRADE
Para atender um paciente e posteriormente aplicar cuidados ao mesmo, formas rudimentares ainda são utilizadas, especialmente manuais
Synthetic organotelluride compounds induce the reversal of Pdr5p mediated fluconazole resistance in Saccharomyces cerevisiae
Background: Resistance to fluconazole, a commonly used azole antifungal, is a challenge for the treatment of fungal infections. Resistance can be mediated by overexpression of ABC transporters, which promote drug efflux that requires ATP hydrolysis. the Pdr5p ABC transporter of Saccharomyces cerevisiae is a well-known model used to study this mechanism of antifungal resistance. the present study investigated the effects of 13 synthetic compounds on Pdr5p.Results: Among the tested compounds, four contained a tellurium-butane group and shared structural similarities that were absent in the other tested compounds: a lateral hydrocarbon chain and an amide group. These four compounds were capable of inhibiting Pdr5p ATPase activity by more than 90%, they demonstrated IC50 values less than 2 M and had an uncompetitive pattern of Pdr5p ATPase activity inhibition. These organotellurides did not demonstrate cytotoxicity against human erythrocytes or S. cerevisiae mutant strains (a strain that overexpress Pdr5p and a null mutant strain) even in concentrations above 100 mu M. When tested at 100 mu M, they could reverse the fluconazole resistance expressed by both the S. cerevisiae mutant strain that overexpress Pdr5p and a clinical isolate of Candida albicans.Conclusions: We have identified four organotellurides that are promising candidates for the reversal of drug resistance mediated by drug efflux pumps. These molecules will act as scaffolds for the development of more efficient and effective efflux pump inhibitors that can be used in combination therapy with available antifungals.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)University of São Paulo through the NAP-CatSinQ (Research Core in Catalysis and Chemical Synthesis)Univ Fed Rio de Janeiro, CCS, Inst Microbiol Paulo Goes, Dept Microbiol Geral,Lab Bioquim Microbiana, Rio de Janeiro, RJ, BrazilUniv São Paulo, Inst Quim, Dept Quim Fundamental, São Paulo, BrazilInst Fed Educ Ciencia & Tecnol Rio de Janeiro IFR, Rio de Janeiro, RJ, BrazilUniversidade Federal de São Paulo UNIFESP, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Inst Ciencias Ambientais Quim & Farmaceut, São Paulo, BrazilFAPERJ: E-26/111.338/2013FAPESP: 2005/59572-7FAPESP: 2008/55401-1FAPESP: 2010/17228-6FAPESP: 2011/03244-2FAPESP: 2011/11613-8FAPESP: 2012/17093-9CNPq: 470360/2012-7Web of Scienc
Borrelia valaisiana resist complement-mediated killing independently of the recruitment of immune regulators and inactivation of complement components
Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B. valaisiana, a genospecies with the potential to cause Lyme disease in Europe as well as in Asia. Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum. Analyzing complement activation, complement components C3, C4 and C6 were deposited on the surface of isolates VS116 and Bv9, and similarly the membrane attack complex was formed on their surface. In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3. While further investigating the protective role of bound complement regulators in mediating complement resistance, we discovered that none of the B. valaisiana isolates analyzed bound complement regulators Factor H, Factor H-like protein 1, C4b binding protein or C1 esterase inhibitor. In addition, B. valaisiana also lacked intrinsic proteolytic activity to degrade complement components C3, C3b, C4, C4b, and C5. Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum. The molecular mechanism utilized by B. valaisiana to inhibit bacteriolysis appears not to involve binding of the key host complement regulators of the alternative, classical, and lectin pathways as already known for serum-resistant Lyme disease or relapsing fever borreliae
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