855 research outputs found
Sensibilizar para a entrega de medicamentos usados na farmácia: Qual a importância para o ambiente e fauna selvagem?
Actualmente, é cada vez mais importante tratar devidamente os resÃduos perigosos para diminuir o
seu impacto nos ecossistemas. Neste grupo destacam-se os produtos farmacêuticos que não são
considerados resÃduos perigosos pelos cidadãos comuns, sendo por isso geralmente depositados
no lixo comum. Este facto constui um problema ambiental grave já que vários trabalhos de
investigação indicam que a contaminação por fármacos têm efeitos nocivos na fauna e nos
ecossistemas
Theranostic Fibers for Simultaneous Imaging and Drug Delivery
New methods for creating theranostic systems with simultaneous encapsulation of therapeutic, diagnostic, and targeting agents are much sought after. This work reports for the first time the use of coaxial electrospinning to prepare such systems in the form of core–shell fibers. Eudragit S100 was used to form the shell of the fibers, while the core comprised poly(ethylene oxide) loaded with the magnetic resonance contrast agent Gd(DTPA) (Gd(III) diethylenetriaminepentaacetate hydrate) and indomethacin as a model therapeutic agent. The fibers had linear cylindrical morphologies with clear core–shell structures, as demonstrated by electron microscopy. X-ray diffraction and differential scanning calorimetry proved that both indomethacin and Gd(DTPA) were present in the fibers in the amorphous physical form. This is thought to be a result of intermolecular interactions between the different components, the presence of which was suggested by infrared spectroscopy. In vitro dissolution tests indicated that the fibers could provide targeted release of the active ingredients through a combined mechanism of erosion and diffusion. The proton relaxivities for Gd(DTPA) released from the fibers into tris buffer increased (r1 = 4.79–9.75 s–1 mM–1; r2 = 7.98–14.22 s–1 mM–1) compared with fresh Gd(DTPA) (r1 = 4.13 s–1 mM–1 and r2 = 4.40 s–1 mM–1), which proved that electrospinning has not diminished the contrast properties of the complex. The new systems reported herein thus offer a new platform for delivering therapeutic and imaging agents simultaneously to the colon
Trace elements and Pb isotope variations in galena from the onça gold deposit, Mato Grosso, Brazil: fluid mixing from hydrothermal and crustal sources
This study deals with the petrography of sulfÃdes and quartz veins, Pb isotopes, major and trace elements in galena, microthermometry and Raman spectrometry of fluid inclusions, with the objective of delineating temporal and spatial aspects of the fluid circulation patterns during the origin of the Onça gold deposit, Mato Grosso State, Brazil. The Pb isotope and mineral chemistry data indicate variable sources for the Pb isotopes, major (S and Pb) and trace elements (Sb, Ag, Zn and Se), with increases or decreases of the contents during the growth of the galena crystals. The results suggest that the variation may be due to the contamination of the hydrothermal solution by mixing with components derived from supracrustal host rocks of Pontes e Lacerda metavolcanic-sedimentary sequence. The mineral chemistry and fluids inclusion studies suggest two possible sources for the hydrothermal solutions: (1) deep solutions that originated during the regional metamorphism represented by the Aguapeà metamorphic event where the solutions present aqueous-carbonic composition and Iow salinity. Geologic control of the mineralization is in agreement with this hypothesis because the ore bodies are syntectonic with foliation formed during the Aguapeà event; (2) high contents of base metais indicates a plutonic influence in the origin of the fluids. Geologic controls also are in agreement with this hypothesis because pegmatitic intrusion was synchronous with the mineralizations. The Pb isotope and fluid inclusion relations allows the conclusions that the compositions of the hydrothermal solutes were variable during the emplacement of the quartz veins and the growth of galena crystals. The earlier solutes had hydrocarbons and were more radiogenic, whereas the later solutes had base metais and were less radiogenic. The Onça deposit originated during a metamorphic event by the effect of hydrothermal solutions related to plutonism, and with an important contribution from the host rocks as recorded by the influence of isotope, major and trace element compositions on the growth of ore-forming minerais.Este estudo compreende petrografia de sulfetos e veios de quartzo, elementos traços, maiores e isótopos de Pb em galena, microtermometria e espectrometria Raman em inclusões fluidas com o objetivo de delinear aspectos temporais e espaciais da circulação de fluÃdos durante a origem do depósito aurÃfero do Onça, Estado do Mato Grosso. Os resultados de isótopos de Pb e a quÃmica mineral indicam uma fonte variável para os isótopos de Pb e para elementos maiores (S e Pb) e elementos traços (Sb, Ag, Zn e Se) com aumentos e diminuições nos seus conteúdos durante o crescimento dos cristais de galena de forma que esta variação pode ser resultado da contaminação da solução hidrotermal pelas rochas supracrustais encaixantes da Seqüência Metavulcano-sedimentar Pontes e Lacerda. A quÃmica mineral e o estudo das inclusões fluÃdas sugerem dois tipos de fontes para as soluções hidrotermais: (1) soluções originadas em profundidade durante o metamorfismo regional representado pelo evento AguapeÃ, com soluções aquocarbônicas e de baixa salinidade, hipótese corroborada pela concordância dos corpos de minério com a foliação regional gerada por este evento; (2) altos valores de metais básicos indicam uma influência plutônica na origem dos fluÃdos. Os isótopos de Pb e os estudos de inclusões fluÃdas analisadas conjuntamente permitem concluir que a composição das soluções hidrotermais foram variáveis durante o emplacement dos veios de quartzo e o crescimento dos cristais de galena. As soluções iniciais apresentam CR, na sua composição e são mais radiogênicas. As soluções finais apresentam metais básicos em sua composição e são menos radiogênicos. Como conclusão é possÃvel sugerir que o depósito do Onça foi originado durante um evento metamórfico por soluções hidrotermais com influência de plutonismo, com uma importante contribuição das rochas encaixantes na composição isotópica do Pb, nos elementos maiores e traços durante o crescimento dos minerais de minério
Diagnostic value of oral challenge tests with food additives or nickel sulphate
Objectivo: O uso crescente de aditivos na indústria alimentar e farmacêutica tem dificultado o diagnóstico das reacções adversas a estes produtos. O grande desafio é, actualmente, determinar em cada doente a substância a testar. Constituiu objectivo deste trabalho a avaliação do valor diagnóstico das provas de provocação, utilizando cápsulas de aditivos alimentares ou de nÃquel, em doentes com suspeita, respectivamente, de intolerância alimentar ou de hipersensibilidade ao nÃquel.
Métodos: IncluÃram-se num estudo prospectivo doentes observados consecutivamente, numa consulta de alergia alimentar, num perÃodo de dois anos, com suspeita de intolerância alimentar ou de dermatite sistémica ao nÃquel. Após exclusão de um mecanismo de hipersensibilidade mediado por IgE e revisão dos diários de dieta, os doentes foram submetidos, durante seis semanas, a dieta restritiva em aditivos alimentares ou alimentos com alto teor em nÃquel. Durante o perÃodo de estudo procedeu-se ao registo das reacções adversas e medicamentos consumidos. Nos doentes com lesões de eczema efectuaram-se testes epicutâneos. Os doentes que beneficiaram da dieta restritiva foram submetidos, em regime de internamento, a provas de provocação oral (PPO), controladas por placebo, utilizando cápsulas de aditivos alimentares ou de nÃquel. Os aditivos foram seleccionados de acordo com a história clÃnica.
Resultados: Dos 27 doentes submetidos a dieta restritiva, 19 (17 do sexo feminino) apresentaram melhoria clÃnica, pelo que foram submetidos a PPO. A ocorrência de urticária e/ou angioedema após ingestão de aditivos alimentares foi referida por 15 doentes (seis referiam sintomas também com medicamentos). Em três doentes observaram-se lesões de eczema generalizadas que foram, gradualmente, desaparecendo com a dieta restritiva em nÃquel. Em cinco doentes registaram-se testes epicutâneos positivos (em quatro ao sulfato de nÃquel e dicromato de potássio e numa doente a mistura de fragrâncias, timerosal e resina de butilfenol formaldeÃdo). Das 25 PPO efectuadas, 14 foram positivas (metabissulfito de sódio-5, benzoato de sódio-3, sulfato de nÃquel-3, lactose-1, soja-1, amido de trigo-1). Numa mesma doente obtivemos 2 PPO positivas: ao benzoato de sódio e à lactose. Com a evicção especÃfica dos aditivos ou de alimentos com alto teor em nÃquel, observou-se uma evolução favorável. Conclusões: As PPO permitiram o diagnóstico de dermatite de contacto sistémica, induzida pela ingestão de nÃquel em três doentes e de intolerância alimentar em dez, possibilitando o seguimento de dietas menos restritivas
An annotated checklist of freshwater copepoda (crustacea, hexanauplia) from continental Ecuador and the Galapagos archipelago
An annotated checklist of the free-living freshwater Copepoda recorded in different regions in Ecuador (including the Amazon, the Andes, the coastal region, and the Galapagos Islands) is here provided. We revised all published records, critically evaluated the validity of each taxon and provided short taxonomic and biogeographical remarks for each one. A total of 27 taxa have been reported, including species and records at the generic level only. The species and taxa identified only up to the generic level belong to five families and 14 genera. The Cyclopoida is the most diverse group with 16 records belonging to species (or identified to the generic level only) and eight genera, followed by the Harpacticoida with six species, one identification to the generic level only, and four genera, and Calanoida with four species belonging to two genera. A total of 18 taxa are recorded for the Andes. Six have been recorded in the Amazon, two are recorded for the coastal region, and six for the Galapagos. One species is shared between the Amazon and the Andes. One species is shared between the coastal region and the Amazon. Seventeen are only reported from the Andes and four are only reported from the Amazon. At the current status of the knowledge, any attempt to analyze and generalize distributional patterns of copepods in Ecuador is premature due to the scarcity of available information, and evidently there is an urgent need for more extensive field collections. A few working hypothesis for future studies are identified
High spin Fe(III)-doped nanostructures as T1 MR imaging probes
Magnetic Resonance Imaging (MRI) T1 contrast agents based on Fe(III) as an alternative to Gd-based compounds have been under intense scrutiny in the last 6-8 years and a number of nanostructures have been designed and proposed for in vivo diagnostic and theranostic applications. Excluding the large family of superparamagnetic iron oxides widely used as T2 -MR imaging agents that will not be covered by this review, a considerable number and type of nanoparticles (NPs) have been employed, ranging from amphiphilic polymer-based NPs, NPs containing polyphenolic binding units such as melanin-like or polycatechols, mixed metals such as Fe/Gd or Fe/Au NPs and perfluorocarbon nanoemulsions. Iron(III) exhibits several favorable magnetic properties, high biocompatibility and improved toxicity profile that place it as the paramagnetic ion of choice for the next generation of nanosized MRI and theranostic contrast agents. An analysis of the examples reported in the last decade will show the opportunities for relaxivity and MR-contrast enhancement optimization that could bring Fe(III)-doped NPs to really compete with Gd(III)-based nanosystems. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Peri-operative anaphylaxis in Coimbra: the experience of our drug allergy clinic
Background: The incidence of peri-operative anaphylactic reactions ranges from 1:10,000 to 1:20,000. It is crucial to identify the risk factors, the trigger agent and to fi nd adequate alternatives. Aims: To characterise patients with peri-operative anaphylactic reactions. Methods: We performed a retrospective study of patients with suspected adverse peri-operative reactions to anaesthetic drugs, observed in a Drug Allergy Outpatients Clinic from 1994 to 2005. Anaphylaxis was diagnosed based on the clinical history and skin tests to latex, neuromuscular blocking agents (NMBA), hypnotics, opioids and antibiotics. Specifi c IgE to latex was performed in patients with positive skin-prick-tests. Results: We evaluated the clinical charts of 45 patients with adverse peri-operative reactions, 39 of whom were female. Anaphylaxis was diagnosed in 16 patients (35.6%), 15 females, mean age 36.3 years. The remaining patients had non-anaphylactic (28.8%) or not well-characterised reactions (35.6%). In terms of severity, 50% presented grade III and 50% grade IV anaphylaxis. Skin-prick-tests were positive to latex in three patients and negative to all anaesthetic drugs. Intradermal skin tests were positive in 10 out of 16 patients with anaphylactic reactions: 10 to NMBA [atracurium (n = 8), vecuronium (n = 4), suxamethonium (n = 4) and pancuronium (n = 2)], one to fentanyl, one to thiopental and one to cefuroxime. In three cases, the culprit agent was not identifi ed. In four patients, at least one alternative NMBA, with no skin test reactivity, was found. Of these four patients, two underwent further surgical procedures without adverse reactions. Five patients had previously had two or more anaesthetic procedures and four had presented adverse reactions in prior surgeries. Conclusions: In our study the most common causes of anaphylaxis were NMBAs (62.5%) and latex (18.7%), in line with that described in the literature. In 81% of patients with anaphylactic reactions, skin tests were positive to at least one anaesthetic drug or to latex. A high incidence of severe anaphylaxis was found, probably because cases with less severe clinical signs were not referred to our clinic. The results emphasise the need for systematic evaluation of anaphylactic reactions during anaesthesia. This can be achieved by the creation of a specialised Allergo-Anaesthesia Clinic, as has been the case in our Department
Rash, fever and proteinuria after amoxicillin in a SLE patient
We report a case of severe type IV hypersensitivity reaction to amoxicillin, which occurred in a person with a 12-year history of SLE. The present case illustrates the wide differential diagnosis in a SLE patient who presents with an allergic drug reaction. The attribution of the presenting symptoms to the underlying SLE and/or to the drugs used to treat SLE and coexisting conditions is a major challenge
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