Consideration of multiple load cases is critical in modelling orthotropic bone adaptation in the femur

Functional adaptation of the femur has been investigated in several studies by embedding bone remodelling algorithms in finite element (FE) models, with simpli- fications often made to the representation of bone’s material symmetry and mechanical environment. An orthotropic strain-driven adaptation algorithm is proposed in order to predict the femur’s volumetric material property distribution and directionality of its internal structures within a continuum. The algorithm was applied to a FE model of the femur, with muscles, ligaments and joints included explicitly. Multiple load cases representing distinct frames of two activities of daily living (walking and stair climbing) were considered. It is hypothesised that low shear moduli occur in areas of bone that are simply loaded and high shear moduli in areas subjected to complex loading conditions. In addition, it is investigated whether material properties of different femoral regions are stimulated by different activities. The loading and boundary conditions were considered to provide a physiological mechanical environment. The resulting volumetric material property distribution and directionalities agreed with ex vivo imaging data for the whole femur. Regions where non-orthogonal trabecular crossing has been documented coincided with higher values of predicted shear moduli. The topological influence of the different activities modelled was analysed. The influence of stair climbing on the properties of the femoral neck region is highlighted. It is recommended that multiple load cases should be considered when modelling bone adaptation. The orthotropic model of the complete femur is released with this study

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 sulfídes 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 Aguapeí 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 Aguapeí 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 fluídos durante a origem do depósito aurífero do Onça, Estado do Mato Grosso. Os resultados de isótopos de Pb e a química 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 química mineral e o estudo das inclusões fluídas sugerem dois tipos de fontes para as soluções hidrotermais: (1) soluções originadas em profundidade durante o metamorfismo regional representado pelo evento Aguapeí, 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 fluídos. Os isótopos de Pb e os estudos de inclusões fluídas 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 possível 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

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

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

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 níquel, em doentes com suspeita, respectivamente, de intolerância alimentar ou de hipersensibilidade ao níquel. Métodos: Incluíram-se num estudo prospectivo doentes observados consecutivamente, numa consulta de alergia alimentar, num período de dois anos, com suspeita de intolerância alimentar ou de dermatite sistémica ao níquel. 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 níquel. Durante o período 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 níquel. Os aditivos foram seleccionados de acordo com a história clínica. Resultados: Dos 27 doentes submetidos a dieta restritiva, 19 (17 do sexo feminino) apresentaram melhoria clínica, 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 níquel. Em cinco doentes registaram-se testes epicutâneos positivos (em quatro ao sulfato de níquel e dicromato de potássio e numa doente a mistura de fragrâncias, timerosal e resina de butilfenol formaldeído). Das 25 PPO efectuadas, 14 foram positivas (metabissulfito de sódio-5, benzoato de sódio-3, sulfato de níquel-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 específica dos aditivos ou de alimentos com alto teor em níquel, observou-se uma evolução favorável. Conclusões: As PPO permitiram o diagnóstico de dermatite de contacto sistémica, induzida pela ingestão de níquel em três doentes e de intolerância alimentar em dez, possibilitando o seguimento de dietas menos restritivas

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