Osteogenesis Imperfecta – Experience of Dona Estefânia’s Hospital Orthopedics’ Department

Introdução/Objectivos: A osteogénese imperfeita (OI) é uma doença genética caracterizada por fragilidade óssea e osteopenia. O tratamento implica uma abordagem multidisciplinar e tem como objectivo a melhoria da qualidade de vida. Os autores pretendem descrever as características de uma amostra de crianças com OI, avaliar o tratamento realizado e a evolução clínica pré e pós terapêutica. Material e Métodos: Estudo observacional, longitudinal, retrospectivo e analítico, com base nos dados obtidos da consulta dos processos de todos os doentes com OI incluídos no protocolo de tratamento com pamidronato no Hospital Dona Estefânia. As variáveis estudadas foram: sexo, idade de diagnóstico, antecedentes familiares de OI, idade de fractura, localização da fractura, número de fracturas, terapêutica médica/cirúrgica, idade de início do tratamento médico, número de ciclos de terapêutica médica, idade da terapêutica cirúrgica, complicações da terapêutica cirúrgica. Adoptou-se um nível de significância de 5%. Resultados: De 21 doentes, 61,9% eram do sexo masculino e 11 tinham registado o diagnóstico do tipo de OI (cinco do tipo I, três tipo III, três tipo IV). A idade média de diagnóstico foi de 20,6 meses, verificando-se dois picos diagnósticos: no primeiro mês – 37%, e aos 24 meses - 26%. Em média os doentes apresentaram 0,62 fracturas/doente/ano, 17,4% das quais no período perinatal e 62% antes dos três anos de idade. A maioria das fracturas ocorreu nos membros inferiores (55,6%). Todos os doentes realizaram tratamento médico, com início em média aos 4,3 anos. Na amostra com seguimento (n=14) verificou-se diminuição no número de fracturas após o início do tratamento com pamidronato (de 0,76 para 0,35 fracturas/doente/ano). Foram colocadas cavilhas endomedulares em nove doentes (64,3%). Em oito doentes foram colocadas nos fémures, quatro unilaterais e quatro bilaterais, não existindo antecedentes de fractura em três casos. Não se registaram novas fracturas nos ossos encavilhados. Conclusão: A OI é uma doença com uma ampla variabilidade clínica que depende maioritariamente do seu tipo. Apesar de não existir tratamento curativo, o tratamento médico com bifosfonatos e o tratamento cirúrgico, com colocação de cavilhas endomedulares, parece reduzir a incidência de novas fracturas

A century of limnological evolution and interactive threats in the Panama Canal: Long-term assessments from a shallow basin

Large tropical river dam projects are expected to accelerate over the forthcoming decades to satisfy growing demand for energy, irrigation and flood control. When tropical rivers are dammed the immediate impacts are relatively well studied, but the long-term (decades-centuries) consequences of impoundment remain poorly known. We combined historical records of water quality, river flow and climate with a multi-proxy (macrofossils, diatoms, biomarkers and trace elements) palaeoecological approach to reconstruct the limnological evolution of a shallow basin in Gatun Lake (Panama Canal, Panama) and assess the effects of multiple linked factors (river damming, forest flooding, deforestation, invasive species, pollution and hydro-climate) on the study area. Results show that a century after dam construction, species invasion, deforestation and salt intrusions have forced a gradual change in the study basin from a swamp-type environment towards a more saline lake-governed system of benthic–littoral production likely associated with the expansion of macrophyte stands. Hydrology still remains the most important long-term (decades) structural factor stimulating salinity intrusions, primary productivity, deposition of minerals, and reduction of water transparency during wet periods. During dry periods, physical-chemical conditions are in turn linked to clear water and aerobic conditions while nutrients shift to available forms for the aquatic biota in the detrital-rich reductive sediments. Our study suggests that to preserve the natural riverine system functioning of this area of the Panama Canal, management activities must address long-term ecosystem structural drivers such as river flow, runoff patterns and physical-chemical conditions

Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital

<p>Abstract</p> <p>Background</p> <p>To probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a children's hospital.</p> <p>Methods</p> <p>From August 2009 to March 2010, serum samples were drawn from 150 HCWs in a children's hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed.</p> <p>Results</p> <p>Among the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion.</p> <p>Conclusion</p> <p>The infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.</p

Inter-hemispheric EEG coherence analysis in Parkinson's disease : Assessing brain activity during emotion processing

Parkinson’s disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3–AF4, F7–F8, F3–F4, FC5–FC6, T7–T8, P7–P8, and O1–O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities

Entrapment ability and release profile of corticosteroids from starch-based microparticles

We previously described the synthesis of starchbased microparticles that were shown to be bioactive (when combined with Bioactive Glass 45S5) and noncytotoxic. To further assess their potential for biomedical applications such as controlled release, three corticosteroids with a similar basic structure—dexamethasone (DEX), 16-methylprednisonole (MP), and 16-methylprednisolone acetate (MPA) - were used as models for the entrapment and release of bioactive agents. DEX, MP, and MPA were entrapped into starch-based microparticles at 10% wt/wt of the starch-based polymer and the loading efficiencies, as well as the release profiles, were evaluated. Differences were found for the loading efficiencies of the three corticosteroids, with DEX and MPA being the most successfully loaded (82 and 84%, respectively), followed by MP (51%). These differences might be explained based on the differential distribution of the molecules within the matrix of the microparticles. Furthermore, a differential burst release was observed in the first 24 h for all corticosteroids with DEX and MP being more pronounced (around 25%), whereas only 12% of MPA was released during the same time period. Whereas the water uptake profile can account for this first stage burst release, the subsequent slower release stage was mainly attributed to degradation of the microparticle network. Differences in the release profiles can be explained based on the structure of the molecule, because MPA, a more bulky and hydrophobic molecule, is released at a slower rate compared with DEX and MP. In this work, it is shown that these carriers were able to sustain a controlled release of the entrapped corticosteroids over 30 days, which confirms the potential of these systems to be used as carriers for the delivery of bioactive agents

Biomimetic miniaturized platform able to sustain arrays of liquid droplets for high-throughput combinatorial tests

The development of high-throughput and combinatorial technologies is helping to speed up research that is applicable in many areas of chemistry, engineering, and biology. A new model is proposed for flat devices for the high-throughput screening of accelerated evaluations of multiplexed processes and reactions taking place in aqueous-based environments. Superhydrophobic (SH) biomimetic surfaces based on the so-called lotus effect are produced, onto which arrays of micro-indentations allow the fixing of liquid droplets, based on the rose-petal effect. The developed platforms are able to sustain arrays of quasi-spherical microdroplets, allowing the isolation and confinement of different combinations of substances and living cells. Distinct compartmentalized physical, chemical, and biological processes may take place and be monitored in each droplet. The devices permit the addition/removal of liquid and mechanical stirring by adding magnetic microparticles into each droplet. By facing the chip downward, it is possible to produce arrays of cell spheroids developed by gravity in the suspended droplets, with the potential to be used as microtissues in drug screening tests.The authors acknowledge the financial support from the FCT- Fundacao para a Ciencia e para a Tecnologia through the Ph.D. grants with the references SFRH/BD/73119/2010, SFRH/BD/69529/2010 and SFRH/BD/61390/2009. We also acknowledge the financial support of FEDER through the program Operacional Factores de Competitividade COMPETE and from FCT - the Fundacao para a Ciencia e para a Tecnologia under the project PTDC/CTM-Bio/1814/2012

Endothelial cells enhance the in vivo bone-forming ability of osteogenic cell sheets

Addressing the problem of vascularization is of vital importance when engineering three-dimensional (3D) tissues. Endothelial cells are increasingly used in tissue-engineered constructs to obtain prevascularization and to enhance in vivo neovascularization. Rat bone marrow stromal cells were cultured in thermoresponsive dishes under osteogenic conditions with human umbilical vein endothelial cells (HUVECs) to obtain homotypic or heterotypic cell sheets (CSs). Cells were retrieved as sheets from the dishes after incubation at 20 °C. Monoculture osteogenic CSs were stacked on top of homotypic or heterotypic CSs, and subcutaneously implanted in the dorsal flap of nude mice for 7 days. The implants showed mineralized tissue formation under both conditions. Transplanted osteogenic cells were found at the new tissue site, demonstrating CS bone-inductive effect. Perfused vessels, positive for human CD31, confirmed the contribution of HUVECs for the neovascularization of coculture CS constructs. Furthermore, calcium quantification and expression of osteocalcin and osterix genes were higher for the CS constructs, with HUVECs demonstrating the more robust osteogenic potential of these constructs. This work demonstrates the potential of using endothelial cells, combined with osteogenic CSs, to increase the in vivo vascularization of CS-based 3D constructs for bone tissue engineering purposes.We would like to acknowledge Mariana T Cerqueira for the illustration in Figure 1. This study was supported by Formation of Innovation Center for Fusion of Advanced Technologies in the Special Coordination Funds for Promoting Science and Technology 'Cell Sheet Tissue Engineering Center (CSTEC)' and the Global CUE program, the Multidisciplinary Education and Research Center for Regenerative Medicine (MERCREM), from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Financial support to RP Pirraco by the Portuguese Foundation for Science and Technology (FCT) through the PhD Grant SFRH/BD/44893/2008 is also acknowledged