The toxicity of angiotensin converting enzyme inhibitors to larvae of the disease vectors Aedes aegypti and Anopheles gambiae

The control of mosquitoes is threatened by the appearance of insecticide resistance and therefore new control chemicals are urgently required. Here we show that inhibitors of mosquito peptidyl dipeptidase, a peptidase related to mammalian angiotensin-converting enzyme (ACE), are insecticidal to larvae of the mosquitoes, Aedes aegypti and Anopheles gambiae. ACE inhibitors (captopril, fosinopril and fosinoprilat) and two peptides (trypsin-modulating oostatic factor/TMOF and a bradykinin-potentiating peptide, BPP-12b) were all inhibitors of the larval ACE activity of both mosquitoes. Two inhibitors, captopril and fosinopril (a pro-drug ester of fosinoprilat), were tested for larvicidal activity. Within 24 h captopril had killed >90% of the early instars of both species with 3rd instars showing greater resistance. Mortality was also high within 24 h of exposure of 1st, 2nd and 3rd instars of An. gambiae to fosinopril. Fosinopril was also toxic to Ae. aegypti larvae, although the 1st instars appeared to be less susceptible to this pro-drug even after 72 h exposure. Homology models of the larval An. gambiae ACE proteins (AnoACE2 and AnoACE3) reveal structural differences compared to human ACE, suggesting that structure-based drug design offers a fruitful approach to the development of selective inhibitors of mosquito ACE enzymes as novel larvicides

Social representations of needlestick injuries

OBJECTIVES: understand the Social Representations about needlestick injuries elaborated by Nursing Technicians and analyze how these representations influence their conducts. METHOD: the data, obtained by interviews, were processed using ALCESTE software and their analysis was based on Serge Moscovici's Social Representations Theory. RESULTS: it was evidenced that, after the accident, these professionals take care of the affected area. Then, they report the accident, motivated by the fear of catching HIV and hepatitis. The different feelings experienced are due to this fear and the way they were forwarded by the institution, reflecting in the cause they attribute to their accident. CONCLUSIONS: it was verified that knowledge about the accident as a whole is very incipient in this professional group, demanding continuing education and greater emphasis on this subject in professional training. It is expected that this study draws public authorities and health institutions' attention to the problem and that it modifies Nursing Technicians' Social Representations about percutaneous exposure.OBJETIVOS: Comprender las Representaciones Sociales de los accidentes con materiales corto-punzantes, elaboradas por Técnicos de Enfermería, así como analizar de que modo esas representaciones influencian las conductas de eses profesionales. MÉTODO: Los datos, logrados por medio de entrevistas, fueron procesados por el software ALCESTE y el análisis de los mismos fue basado en la Teoría de las Representaciones Sociales de Serge Moscovici. RESULTADOS: se evidenció que, después de accidentarse, los Técnicos de Enfermería cuidan del área afectada. Enseguida, notifican el accidente, motivados por el miedo de que contraigan HIV y hepatitis. Los diversos sentimientos vividos son consecuentes de ese miedo y de la manera como fueron encaminados por la institución, reflejando en la causa que ellos atribuyen a su accidente. CONCLUSIONES: se constató que hay un conocimiento bastante incipiente por parte de esa clase profesional sobre el accidente como un todo, habiendo necesidad de una educación continuada y mayor énfasis en cuanto a ese asunto durante la formación profesional. Se espera que ese estudio llame la atención de los órganos gubernamentales e instituciones de salud sobre el problema y modifique las Representaciones Sociales de la exposición percutánea de los Técnicos de Enfermería.OBJETIVOS: compreender as representações sociais dos acidentes com materiais perfurocortantes, elaboradas por técnicos de enfermagem, bem como analisar de que modo essas representações influenciam as condutas desses profissionais. MÉTODO: os dados, obtidos por meio de entrevistas, foram processados pelo software Alceste e a análise dos mesmos foi baseada na Teoria das Representações Sociais de Serge Moscovici. RESULTADOS: evidenciou-se que, após se acidentarem, os técnicos de enfermagem cuidam da área afetada. Em seguida, notificam o acidente, motivados pelo medo de contraírem HIV e hepatite. Os diversos sentimentos vivenciados são decorrentes desse medo e da forma como foram encaminhados pela instituição, refletindo na causa que eles atribuem ao seu acidente. CONCLUSÕES: constatou-se que há conhecimento bastante incipiente por parte dessa classe profissional sobre o acidente, como um todo, havendo necessidade de educação continuada e maior ênfase quanto a esse assunto, durante a formação profissional. Espera-se que este estudo chame a atenção dos órgãos governamentais e instituições de saúde sobre o problema e modifique as representações sociais da exposição percutânea dos técnicos de enfermagem

Rapid responses of root traits and productivity to phosphorus and cation additions in a tropical lowland forest in Amazonia

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordSoil nutrient availability can strongly affect root traits. In tropical forests, phosphorus (P) is often considered the main limiting nutrient for plants. However, support for the P paradigm is limited, and N and cations might also control tropical forests functioning. We used a large-scale experiment to determine how the factorial addition of nitrogen (N), P and cations affected root productivity and traits related to nutrient acquisition strategies (morphological traits, phosphatase activity, arbuscular mycorrhizal colonisation and nutrient contents) in a primary rainforest growing on low-fertility soils in Central Amazonia after one year of fertilisation. Multiple root traits and productivity were affected. Phosphorus additions increased annual root productivity and root diameter, but decreased root phosphatase activity. Cation additions increased root productivity at certain times of year, also increasing root diameter and mycorrhizal colonisation. P and cation additions increased their element concentrations in root tissues. No responses were detected with N addition. Here we show that rock-derived nutrients determine root functioning in low-fertility Amazonian soils, demonstrating not only the hypothesised importance of P, but also highlighting the role of cations. The changes in fine root traits and productivity indicate that even slow-growing tropical rainforests can respond rapidly to changes in resource availability.Brazilian National Council for Scientific and 551 Technological Development (CNPq)Natural Environment Research Council (NERC)Australian Research Council (ARC)European Research Council (ERC

Does soil pyrogenic carbon determine plant functional traits in Amazon Basin forests?

Amazon forests are fire-sensitive ecosystems and consequently fires affect forest structure and composition. For instance, the legacy of past fire regimes may persist through some species and traits that are found due to past fires. In this study, we tested for relationships between functional traits that are classically presented as the main components of plant ecological strategies and environmental filters related to climate and historical fires among permanent mature forest plots across the range of local and regional environmental gradients that occur in Amazonia. We used percentage surface soil pyrogenic carbon (PyC), a recalcitrant form of carbon that can persist for millennia in soils, as a novel indicator of historical fire in old-growth forests. Five out of the nine functional traits evaluated across all 378 species were correlated with some environmental variables. Although there is more PyC in Amazonian soils than previously reported, the percentage soil PyC indicated no detectable legacy effect of past fires on contemporary functional composition. More species with dry diaspores were found in drier and hotter environments. We also found higher wood density in trees from higher temperature sites. If Amazon forest past burnings were local and without distinguishable attributes of a widespread fire regime, then impacts on biodiversity would have been small and heterogeneous. Alternatively, sufficient time may have passed since the last fire to allow for species replacement. Regardless, as we failed to detect any impact of past fire on present forest functional composition, if our plots are representative then it suggests that mature Amazon forests lack a compositional legacy of past fire

Cross examination of the conformational spaces of a set of peptide chains: Study of oligopeptidase action

A conformational search was carried out for five opioid peptide homologues and for angiotensin II. Density of states versus energy plots were obtained for each peptide, and the occurrence of common main-chain conformations was investigated by searching homologies between strings of four, five, and six contiguous main-chain amino acid residues rotamers. the results were compared to rates of hydrolysis by endooligopeptidase (EOP) 24.15, known for its specificity for substrate conformations. A catalytic assay of the hydrolysis of angiotensin II was also performed. the two best substrates of EOP 24.15 were found to share unique main-chain conformations and the two worst substrates of EOP 24.15 were found to be nonstructurally homologous to each other and the remaining peptide chains. the conformational search is compared to previous experimental and theoretical results. (C) 1996 John Wiley & Sons, Inc.INST BUTANTAN, LAB BIOQUIM & BIOFIS, BR-05503900 São Paulo, BRAZILUniversidade Federal de São Paulo, DEPT BIOFIS, São Paulo, BRAZILUniversidade Federal de São Paulo, DEPT BIOFIS, São Paulo, BRAZILWeb of Scienc

A highly selective assay for neutral endopeptidase based on the cleavage of a fluorogenic substrate related to Leu-enkephalin

An intramolecularly quenched fluorogenic peptide structurally related to Leu-enkephalin, containing o-aminobenzoyl (Abz) and ethylenediamine 2,4-dinitrophenyl (EDDnp) groups at amino- and carboxyl-terminal amino acid residues, Abz-Gly-Gly-D-Phe-Leu-Arg-Arg-Val-EDDnp (Abz-GGDFLRRV-EDDnp), was selectively hydrolyzed at the Arg-Val bond by neutral endopeptidase (NEP, enkephalinase, neprilysin, EC 3.4.24.11) with kinetic parameters (K-m = 3 mu M, k(cat) = 127 min(-1) and K-cat/K-m = 42 min(-1) mu M(-1)) similar to those of the Leu-enkephalin. the specificity of the NEP assay was demonstrated by incubating Abz-GGDFLRRV-EDDnp with a kidney homogenate or with crude membrane preparations of brain and lung: more than 95% of all products released were the complementary fragments Abz-GGDFLRR and V-EDDnp which were totally inhibited by 1 mu M thiorphan, a highly specific NEP inhibitor. the blocked amino- and carboxyl-terminal amino acids protected this substrate against the action of aminopeptidases as well as of carboxypeptidases. Furthermore, D-Phe amino acid also ensured a very good protection of Abz-GGDFLRRV-EDDnp against the action of other tissue endopeptidases distinct from NEP. A continuous fluorometric assay for only 5 min was sufficient to quantify the NEP activity with a minimum sensitivity of 5 ng of purified enzyme or the equivalent enzymatic activity in crude tissue preparations, Therefore, amounts as little as 0.5 ng of enzyme could be quantified employing longer times of incubation. (C) 1996 Academic Press, Inc.UNIV MONTREAL,FAC MED,DEPT BIOCHIM,MONTREAL,PQ H3C 3J7,CANADAINST BUTANTA,BR-05503900 São Paulo,BRAZILESCOLA PAULISTA MED,DEPT BIOFIS,BR-04044 São Paulo,BRAZILESCOLA PAULISTA MED,DEPT BIOFIS,BR-04044 São Paulo,BRAZILWeb of Scienc