10,005 research outputs found
Spontaneous melanotic lesions in axillary seabream, Pagellus acarne (Risso)
In this paper, we describe spontaneous melanotic lesions in the skin of axillary seabream, Pagellus acarne (Risso) from a defined area of the Portuguese Coast, located in Cabo da Roca and Foz do Arelho. The lesions corresponded to black pigmentation spots on the skin of the head, fins, lips and conjunctiva and, additionally, black nodules on the skin of the head and lips. In some specimens, the nodular formations in the head changed their anatomical conformation. Histologically, there were melanophores scattered along the basement membrane or forming aggregates in the dermis, infiltrating the subcutaneous tissue but not invading the adjacent muscle tissue. The aim of this study was to characterize the macroscopic and microscopic features of the pigmented lesions. These fish show sessile hyperpigmented lesions (spots) that correspond to proliferative lesions of melanophores in the dermis and nodular lesions that correspond to neoplastic lesions, melanophoromas. The melanophores in such lesions showed high concentration of melanin in the cytoplasm, moderate pleomorphism and compact distribution throughout all of the dermis
Reading literature today: a study of E. M. Forster s and George Orwell s fiction
Tese de doutoramento em Estudos de Cultura (Cultura Inglesa), apresentada à Universidade de Lisboa através da Faculdade de Letras, 200
Toxicity provoked by a commonly used nonsteroidal anti-inflammatory agent (ibuprofen) on the freshwater microalga "Scenedesmus quadricauda" (Turpin) Brebisson
[Resumen] Los contaminantes emergentes, entre los que se encuentran los productos farmacéuticos, son una preocupación creciente debido a su posible efecto tóxico sobre la biota acuática, especialmente sobre las microalgas, ya que son productores primarios de los medios acuáticos y esenciales en el reciclado de nutrientes y en el mantenimiento del balance de oxígeno.
El fármaco antiinflamatorio ibuprofeno es uno de los medicamentos más utilizados en el mundo, por lo que es importante evaluar su potencial toxicidad.
En este trabajo se estudió el efecto tóxico del ibuprofeno sobre la microalga dulceacuícola Scenedesmus quadricauda. Concretamente, sobre el crecimiento, la actividad celular medida como actividad esterasa y el contenido en pigmentos fotosintéticos. Se utilizaron diferentes concentraciones de ibuprofeno, tomando como control cultivos sin el fármaco.
El crecimiento se redujo significativamente (p<0.05) al aumentar la concentración de ibuprofeno, excepto en los cultivos con menor concentración del mismo. El contenido en pigmentos y la actividad celular también se redujeron significativamente al aumentar la concentración del fármaco. Asimismo, se observaron alteraciones morfológicas en las células afectadas por el ibuprofeno, que pasaron a estar aisladas, con formas más redondeadas y menor coloración verde debido a la disminución del contenido en pigmentos.[Abstract] Emerging pollutants as pharmaceuticals are a growing concern due to their potential toxic effects on aquatic biota, specially on microalgae, because they are primary producers of aquatic ecosystems and essential for the recycling of nutrients and the maintenance of oxygen balance. The anti-inflammatory drug ibuprofen is one of the most used medicines in the world, so it is important to assess its potential toxicity. In this work, the toxic effect of ibuprofen on the freshwater microalga Scenedesmus quadricauda was studied. Parameters assessed were cellular growth, cellular activity (measured as esterase activity) and photosynthetic pigments content. Different concentrations of ibuprofen were assayed, and cultures without drug were included as control. Growth was significantly reduced (p<0.05) when the concentration of ibuprofen increased, except for the lower concentrations assayed. Pigments content and cellular activity were also significantly reduced with increasing drug concentration. Likewise, morphological alterations were observed in cells affected by ibuprofen, which appeared isolated, with round shape and bleached due to the decrease in pigments content with the highest concentrations of ibuprofen.Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2014/201
Unraveling the role of astrocytes in the onset and spread of Parkinson's Disease: Important contributors to neurodegeneration.
135 p.La enfermedad de Parkinson (EP) se caracteriza principalmente por la presencia de inclusiones citoplasmáticas llamadas cuerpos de Lewy, cuyo principal componente es la ¿-sinucleína y la pérdida de neuronas dopaminérgicas en la sustancia negra. Los astrocitos constituyen el subtipo glial más abundante en el cerebro, que cubre funciones esenciales para la homeostasis cerebral y la salud neuronal. La disfunción de la biología de los astrocitos en el mesencéfalo puede derivar en el daño de las neuronas dopaminérgicas y una mayor propagación de la EP.En este estudio, hemos utilizado dos modelos diferentes con el objetivo de comprender el papel de los astrocitos en el inicio y la propagación de la EP y descifrar el mecanismo celular que caracteriza el metabolismo de astrocitos en la patología. Por un lado hemos utilizado una quimera in vitro tratando células de rata con extractos de LB humanos. Por otro lado hemos generado y caracterizado astrocitos humanos derivados de iPS de pacientes con EP que portan la mutación LRRK2G2019S.Hemos podido concluir que los astrocitos disfuncionales cubren un papel esencial en el inicio y la progresión de la EP. Tanto la acumulación de ¿-syn como la mutación LRRK2G2019S inducen un desequilibrio mitocondrial que conduce al daño celular y a la degeneración neuronal final. Este estudiopropone un nuevo objetivo terapéutico posible dirigido a mantener la funcionalidad astrocítica. Se necesitan más experimentos para establecer las vías mediante las que los astrocitos podrían inducir la muerte dopaminérgic
The C-terminal extension of the beta 7 subunit and activator complexes stabilize nascent 20 S proteasomes and promote their maturation
The eukaryotic 20 S proteasome is formed by dimerization of two precursor complexes containing the maturation factor Ump1. beta 7/Pre4 is the only one of the 14 subunits forming the 20 S proteasome that is absent from these precursor complexes in Saccharomyces cerevisiae. Increased expression of Pre4 leads to a reduction in the level of precursor complex, indicating that Pre4 incorporation into these complexes is rate-limiting for their dimerization. When we purified these precursor complexes, we observed co-purification of Blm10, a large protein known to attach to the alpha ring surface of proteasomes. In contrast to single mutants lacking either Blm10 or the C-terminal extension of Pre4, a mutant lacking both grew extremely poorly, accumulated very high levels of precursor complexes, and was impaired in beta subunit maturation. The effect of blm10 Delta on proteasome biogenesis is modest, apparently because the 19 S regulatory particle is capable of substituting for Blm10, as long as precursor complex dimers are stabilized by the Pre4Cterminus. We found that a mutation (sen3/rpn2) affecting the Rpn2 subunit inhibits attachment of the 19 S activator to the 20 S particle or its precursors. Although the sen3 mutation alone had no apparent effect on precursor complex dimerization and active site maturation, the sen3 blm10 double mutant was impaired in these processes. Together these data demonstrate that Blm10 and the 19 S activator have a partially redundant function in stabilizing nascent 20 S proteasomes and in promoting their activation.info:eu-repo/semantics/publishedVersio
Entwicklung von Fluor-19 und Protonen-Magnetresonanztomographie und ihre Anwendung bei Neuroentzündung
The experimental autoimmune encephalomyelitis (EAE) is used to study multiple sclerosis (MS) pathology and develop novel technologies to quantify inflammation over time. Magnetic resonance imaging (MRI) with gadolinium-based contrast agents (GBCAs) is the state-of-the-art method to assess inflammation in MS patients and its animal model.
Fluorine (19F)-MRI is one novel technology to quantify inflammatory immune cells in vivo using 19F-nanoparticles. T1 mapping of contrast-enhancing images is another method that could be implemented to quantify inflammatory lesions. Transient macroscopic changes in the EAE brain confound quantification and necessitate registration methods to spatially align images in longitudinal studies.
For 19F-MRI, an additional challenge is the low signal-to-noise ratio (SNR) due to low number of 19F-labeled immune cells in vivo. Transceive surface radiofrequency (RF) probes and SNR-efficient imaging techniques such as RARE (Rapid Acquisition with Relaxation Enhancement) are combined to increase sensitivity in 19F-MRI. However, the strong spatially-varying RF field (B1 inhomogeneity) of transceive surface RF probes further hampers quantification. Retrospective B1 correction methods typically use signal intensity equations, unavailable for complex acquisition methods like RARE.
The main goal of this work is to investigate novel B1 correction and registration methods to enable the study of inflammatory diseases using 1H- and 19F-MRI following GBCA and 19F-nanoparticle administration, respectively. For correcting B1 inhomogeneities in 1H- and 19F-MR transceive surface RF probes, a model-based method was developed using empirical measurements and simulations, and then validated and compared with a sensitivity method and a hybrid of both. For 19F-MRI, a workflow to measure anatomical images in vivo and a method to compute 19F-concentration uncertainty after correction using Monte Carlo simulations were developed. To overcome the challenges of EAE brain macroscopic changes, a pipeline for registering images throughout longitudinal studies was developed.
The proposed B1 correction methods demonstrated dramatic improvements in signal quantification and T1 contrast on images of test phantoms and mouse brains, allowing quantitative measurement with transceive surface RF probes. For low-SNR scenarios, the model-based method yielded reliable 19F-quantifications when compared to volume resonators. Uncertainty after correction depended linearly on the SNR (≤10% with SNR≥10.1, ≤25% when SNR≥4.25). The implemented registration approach provided successful image alignment despite substantial morphological changes in the EAE brain over time. Consequently, T1 mapping was shown to objectively quantify gadolinium lesion burden as a measure of inflammatory activity in EAE.
The 1H- and 19F-MRI methods proposed here are highly relevant for quantitative MR of neuroinflammatory diseases, enabling future (pre)clinical investigations.Die experimentelle Autoimmun-Enzephalomyelitis (EAE) wird zur Untersuchung Multipler Sklerose (MS) und zur Entwicklung neuer Technologien zur Entzündungsquantifizierung eingesetzt. Magnetresonanztomographie (MRT) mit Gadolinium-haltigen Kontrastmitteln (GBCAs) ist die modernste Methode zur Beurteilung von Entzündungen bei MS-Patienten und im Tiermodell.
Fluor (19F)-MRT unter Verwendung von 19F-Nanopartikeln ist eine neue Technologie zur Quantifizierung entzündlicher Immunzellen in vivo. T1-Kartierung ist eine MRT-Methode, die zur Quantifizierung entzündlicher Läsionen eingesetzt werden könnte. Temporäremorphologische Veränderungen im EAE-Gehirn erschweren die Quantifizierung und erfordern Registrierungsmethoden, um MRT-Bilder in Längsschnittstudien räumlichabzugleichen.
Das niedrige Signal-Rausch-Verhältnis (SNR) ist aufgrund der geringen Anzahl 19F-markierter Immunzellen in vivo eine zusätzliche Herausforderung der 19F-MRT. Um deren Empfindlichkeit zu erhöhen, werden Sende-/Empfangsoberflächen-Hochfrequenzspulen (TX/RX-HF-Spule) und SNR-effiziente MRT-Techniken wie RARE (Rapid Acquisition with Relaxation Enhancement) kombiniert. Jedoch verhindert die starke räumliche Variation des HF-Feldes (B1-Inhomogenität) dieser Spulen die Signalquantifizierung. Retrospektive B1-Korrekturmethoden verwenden in der Regel Signalintensitätsgleichungen, die für komplexe MRT-Techniken wie RARE nicht existieren.
Das Hauptziel dieser Arbeit ist die Untersuchung neuartiger B1-Korrektur- und Bildregistrierungsmethoden, um in vivo 1H- und 19F-MRT Studien von Entzündungsprozessen zu ermöglichen. Zur Korrektur von B1-Inhomogenitäten wurde eine modellbasierte Methode entwickelt. Diese verwendet empirische Messungen und Simulationen, wurde in Phantomexperimenten validiert und mit Referenzmethoden verglichen. Für 19F-MRT wurden ein Protokoll zur Messung anatomischer Bilder in vivo und eine Methode zur Berechnung der 19F-Konzentrationsunsicherheit nach Korrektur mittels Monte-Carlo-Simulationen entwickelt. Um morphologische Veränderungen im EAE-Gehirn in longitudinalen Studien zu kompensieren, wurde zur Bildregistrierung eine Software-Bibliothek entwickelt.
Die B1-Korrekturmethoden zeigten in Testobjekten und Mäusehirnen drastische Verbesserungen der Signal- und T1 Quantifizierung und ermöglichten so quantitative Messungen mit TX/RX-HF-Spulen. Die modellbasierte Methode lieferte für geringe SNRs zuverlässige 19F-Quantifizierungen, deren Genauigkeit mit dem SNR korrelierte. Die implementierte Registrierungsmethode ermöglichte einen erfolgreichen Abgleich von Bildserientrotz erheblicher morphologischer Veränderungen im EAE-Hirn. Folglich wurde gezeigt, dass MRT basierte T1-Kartierung die Gadolinium-Läsionslast als Maß entzündlicher Aktivität bei EAE objektiv quantifizieren kann.
Die hier unterscuhten Methoden sind für quantitative 1H- und 19F-MRT neuroinflammatorischer Erkrankungen sehr relevant und ermöglichen künftige (prä)klinische Untersuchungen
Caracterização de Puccinia hemerocallidis causadora do primeiro surto de ferrugem de lírio-de-um-dia na Europa
Daylily (Hemerocallis spp.) is an ornamental plant widely used in gardens. Daylily rust, caused by the fungus Puccinia
hemerocallidis, has disseminated through all continents only in the 21th century, except in Europe, where it has been
considered a quarantine disease by the European Plant Protection Organisation. In Portugal, since November 2015,
typical rust symptoms were observed in daylily plants in gardens in Lisbon, Alentejo, Algarve and Madeira, attaining
high prevalence, incidence and severity. The causal agent was identified as P. hemerocallidis and the Koch’s postulates
were fulfilled. Phylogenetic data suggest that this fungus may have been introduced from North America. Using
flow cytometry, the genome size of the P. hemerocallidis populations present in Portugal was estimated to be 345 Mbp
(0.3533 pg DNA/1C). For such analysis Rhamnus alaternus was validated as a DNA standard, exhibiting a nuclear content
of 0.680 pg DNA/2C. The identification of this disease in diverse locations in Portugal represents a threat to European
breeding and nursery industries, since there are the appropriate conditions for inoculum maintenance and propagation
from Portugal to the rest of Europeinfo:eu-repo/semantics/publishedVersio
Emergency medical team intra-hospital: decision process not resuscitate
O presente artigo tem como objetivo caracterizar o
processo de tomada de decisão de não reanimar
nas Equipas de Emergência Médica Intrahospitalares,
elegendo como ponto nuclear de
pesquisa o papel do enfermeiro, do doente e/ou
família neste processo, bem como as diretivas
antecipadas de vontade, que benefícios/
implicações na tomada de decisão.
Para a realização deste estudo de investigação
recorreu-se à revisão sistemática da literatura, com
o horizonte temporal de janeiro de 2005 a
novembro de 2015. Para a seleção dos artigos foram
definidos critérios de inclusão e exclusão bem
como, descritores de pesquisa, utilizando o método
PICOD. Pesquisando a partir de bases de dados de
texto integral e de referência, foram incluídos 9
artigos dos quais 2 de natureza qualitativa e 7 de
natureza quantitativa.
Com este trabalho ficou explicita a necessidade de
definir normas de orientação, para que os
profissionais de saúde tenham clara noção do
referencial de atuação ética e legal em doentes
terminais, implementando boas práticas no que se
refere à suspensão ou abstenção de tratamentos
desproporcionados. As decisões antecipadas de
vontade (a seu comunicação deve ser semelhante
ao consentimento informado) e o envolvimento dos
enfermeiros nessas decisões devem ser incluídos.
Só desta forma a Decisão de Não Reanimar (DNR) é
considerada uma prática digna, enquadrada na
visão da ortotanásia.ABSTRACT: This paper main goal is to describe the do not
resuscitate process in which Hospital Emergency
Medical Teams are involved. The aim of this
research is to understand the role of the nurse and
the patient and/or family, as well to know the
implications that advance healthcare directives
have on decision making.
This research is the result of a systematic review of
the literature, with the time frame form January
2005 to November 2015. For the selection of items
it were established inclusion and exclusion criteria
as well research descriptors using the PICOD
method. The search was performed in data bases of
full text and reference data. It were found 9 papers
of which 1 was of qualitative research and 7 of
quantitative research.
With this systematic review of the literature it was
found that healthcare professionals need to have an
ethical and legal framework in which they can resort
before engaging life saving procedures. This
document should include advance healthcare
directives and the foundations in which nurses take
part of the do not resuscitate decision making
Avaliação do conhecimento dos estudantes do curso de graduação em medicina na Universidade Federal de Santa Catarina sobre o processo de doação de córneas para transplante
Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Dapartamento de Clínica Cirúrgica
- …