Iron Overload in a Murine Model of Hereditary Hemochromatosis Is Associated with Accelerated Progression of Osteoarthritis Under Mechanical Stress

OBJECTIVE: Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress. DESIGN: OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery. RESULTS: Hfe-KO mice showed a systemic iron overload and an increased iron accumulation in the knee synovial membrane following surgery. The histological OA score was significantly higher in the Hfe-KO mice at 8 weeks after surgery. Micro CT study of the proximal tibia revealed increased subchondral bone volume and increased trabecular thickness. Gene expression and immunohistochemical analysis showed a significant increase in the expression of matrix metallopeptidase 3 (MMP-3) in the joints of Hfe-KO mice compared with control mice at 8 weeks after surgery. CONCLUSIONS: HH was associated with an accelerated development of OA in mice. Our findings suggest that synovial iron overload has a definite role in the progression of HH-related OA

Porokeratosis Ptychotropica of the Scrotum: Dermoscopic Evaluation of an Atypical Presentation

Porokeratosis ptychotropica is a rare variant of porokeratosis that is classically located on the gluteal and perianal regions, seldom extending to the genitalia. The authors report an atypical presentation of porokeratosis ptychotropica and discuss the use of dermoscopy in evaluating this dermatosis. Dermoscopic findings, although not specific to this variant of porokeratosis, are helpful in the differential diagnosis of other genital disorders. Histopathology, through the visualization of multiple cornoid lamellae, prevails as the gold standard for the definite diagnosis of porokeratosis ptychotropica.

Development of biocolonization resistant mortars: preliminary results

Restoration of Buildings and Monuments, vol. 13, nº 6 (2007), p.389-400

Clinical and laboratorial study of 19 cases of mucopolysaccharidoses

The mucopolysaccharidoses (MPS) are a heterogeneous group of inborn errors of lysosomal glycosaminoglycan (GAG) metabolism. The importance of this group of disorders among the inborn errors of metabolism led us to report 19 cases. METHOD: We performed clinical, radiological, and biochemical evaluations of the suspected patients, which allowed us to establish a definite diagnosis in 19 cases. RESULTS: Not all patients showed increased GAG levels in urine; enzyme assays should be performed in all cases with strong clinical suspicion. The diagnosis was made on average at the age of 48 months, and the 19 MPS cases, after a full clinical, radiological, and biochemical study, were classified as follows: Hurler -- MPS I (1 case); Hunter -- MPS II (2 cases); Sanfilippo -- MPS III (2 cases); Morquio -- MPS IV (4 cases); Maroteaux-Lamy -- MPS VI (9 cases); and Sly -- MPS VII (1 case). DISCUSSION: The high relative frequency of Maroteaux-Lamy disease contrasts with most reports in the literature and could express a population variability.

Role of colonoscopy in colorectal cancer

Colorectal cancer (CRC) represents the third most common malignancy throughout the world. Little or no improvement in survival has been effectively achieved in the last 50 years. Extensive epidemiological and genetic data are able to identify more precisely definite risk-groups so screening and early diagnosis can be more frequently accomplished. CRC is best detected by colonoscopy, which allows sampling for histologic diagnosis. Colonoscopy is the gold standard for detection of small and premalignant lesions, although it is not cost-effective for screening average-risk population. Colonoscopic polypectomy and mucosal resection constitute curative treatment for selective cases of invasive CRC. Similarly, alternative trans-colonoscopic treatment can be offered for adequate palliation, thus avoiding surgery.

Hypothyroidism following struma ovarii tumor resection: a case report

Struma ovarii is an infrequent ovarian tumor, and there are only few reports with detailed data of thyroid function. In several cases, malignant struma ovarii have been shown to produce hyperthyroidism, but there is no reported case of hypothyroidism following struma ovarii tumor resection. A 62-year-old white woman underwent right ovary resection that had a pathologic diagnosis of struma ovarii. After 6 days, she developed weakness, myalgia, somnolence, nausea, and arterial hypotension. Laboratory tests showed a high level of thyroid-stimulating hormone (TSH) and a decreased level thyroxin. Thyroxin replacement therapy was initiated, and the patient became completely asymptomatic. This is the first reported case of a previously asymptomatic woman who developed a definite clinical hypothyroidism after resection of a struma ovarii tumor.

Orthogonal models, structure crossing, nesting and inference

We intend to study the algebraic structure of the simple orthogonal models to use them, through binary operations as building blocks in the construction of more complex orthogonal models. We start by presenting some matrix results considering Commutative Jordan Algebras of symmetric matrices, CJAs. Next, we use these results to study the algebraic structure of orthogonal models, obtained by crossing and nesting simpler ones. Then, we study the normal models with OBS, which can also be orthogonal models. We intend to study normal models with OBS (Orthogonal Block Structure), NOBS (Normal Orthogonal Block Structure), obtaining condition for having complete and suffcient statistics, having UMVUE, is unbiased estimators with minimal covariance matrices whatever the variance components. Lastly, see ([Pereira et al. (2014)]), we study the algebraic structure of orthogonal models, mixed models whose variance covariance matrices are all positive semi definite, linear combinations of known orthogonal pairwise orthogonal projection matrices, OPOPM, and whose least square estimators, LSE, of estimable vectors are best linear unbiased estimator, BLUE, whatever the variance components, so they are uniformly BLUE, UBLUE. From the results of the algebraic structure we will get explicit expressions for the LSE of these models.

The algal flora of two distinct habitats along the Moa River in the state of Acre, Brazil

Twenty-eoght algal samples were collected in September-October, 1984, from two distinct habitats in the state of Acre, Brazil. Eleven were from the Moa River, and 17 were from a sulfur water spring which flows into the Moa River. A total of 74 species, representing 48 genera of algae, were identified from these samples. Forty-nine species were found in the Moa River and 67 in the sulfur water spring. Both coolection site had rich assemblages of cyanophycean algae, chlorophycean algae, and diatoms. Chlorophycean species dominated the algae flora at both sites, cut were more numerous at the sulfur water spring. There was also a definite difference in the relatives proportions of desmids to filamentous chlorophycean algae at the two sites.

A onda de calor de Agosto de 2003 e os seus efeitos sobre a mortalidade da população portuguesa

RESUMO - Portugal continental, como outros países europeus, foi afectado por uma onda de calor de grande intensidade no Verão de 2003, com efeitos na mortalidade da população. O excesso de óbitos associados à onda de calor foi estimado pela comparação do número de óbitos observados entre 30 de Julho e 15 de Agosto de 2003 e o número de óbitos esperados se a população tivesse estado exposta às taxas de mortalidade médias do biénio 2000-2001 no respectivo período homólogo. Os óbitos esperados foram calculados com ajustamento para a idade. O número de óbitos observados (O) foi superior ao número esperado (E) em todos os dias do período estudado e o seu excesso global foi estimado em 1953 óbitos (excesso relativo de 43%), dos quais 1317 (61%) ocorreram no sexo feminino e 1742 no grupo de 75 e + anos (89%). A nível distrital, Portalegre teve o maior aumento relativo do número de óbitos (+89%) e Aveiro o menor (+18%). Numa área geográfica contínua do interior do território (Guarda, Castelo Branco, Portalegre e Évora) houve aumentos relativos superiores a 80%. Em termos absolutos, o maior excesso de óbitos ocorreu no distrito de Lisboa (mais cerca de 396) e no do Porto (mais cerca de 183). As causas de morte «golpe de calor» e «desidratação e outros distúrbios metabólicos» tiveram os aumentos relativos mais elevados (razões O/E de, respectivamente, 70 e 8,65). Os maiores aumentos absolutos do número de óbitos ocorreram no grupo das «doenças do aparelho circulatório» (mais 758), nas «doenças do aparelho respiratório» (mais 255) e no conjunto de «todas as neoplasias malignas» (mais 131). No período da onda de calor e no período de comparação, a percentagem dos óbitos que ocorreu nos hospitais (52% e 56%), no domicílio (32 e 33%) e em «outros locais» foi semelhante. A discussão sobre os factores que condicionaram a obtenção dos valores apresentados, relativos ao excesso de óbitos por sexo, grupo etário, distrito, causa e local da morte, permite concluir que os mesmos se afiguram adequados para medir a ordem de grandeza e caracterizar o efeito da onda de calor na mortalidade. O erro aleatório, medido pelos intervalos de confiança, e alguns possíveis erros sistemáticos associados ao período de comparação escolhido não deverão afectar de modo relevante as estimativas.

A conspiracy theory for clefts : the syntax and interpretation of cleft constructions

O objetivo final deste estudo é contribuir para a discussão sobre qual a medida em que conceitos semânticos e discursivos estão sintaticamente codificados. Mais especificamente, investiga-se se existe alguma correlação consistente entre alguns aspetos interpretativos e sintáticos de quatro construções clivadas do Português Europeu, e como se deve dar conta teoricamente destas potenciais correlações. As clivadas consideradas são as clivadas canónicas, as pseudoclivadas, as clivadas de é que e as clivadas de SER. Sintaticamente podemos distinguir dois tipos: clivadas bioracionais (canónicas e pseudoclivadas) e clivadas mono-oracionais (clivadas de é que e de SER). Todas as estruturas têm um constituinte clivado focalizado que pode constituir tanto um foco informacional como um foco contrastivo, e uma oração clivada que introduz uma pressuposição existencial. Adicionalmente, o constituinte clivado identifica exaustivamente uma posição vazia na oração clivada. Adota-se a semântica alternativa para o foco (Rooth 1985), segundo a qual o foco entoacional contribui uniformemente um conjunto de alternativas na Forma Lógica. Regras pragmáticas operando neste conjunto dão origem a duas implicaturas que podem ser suspensas: pressuposição existencial e exaustividade. Dado que as clivadas de é que e as de SER têm a mesma interpretação que orações não-clivadas, conclui-se que a sua estrutura sintática particular não contribui para estas propriedades interpretativas. Em contrapartida, as clivadas bioracionais, que são orações copulativas especificacionais, têm uma presuposição existencial e uma interpretação exaustiva que não pode ser suspensa, tal como as orações especificacionais não-clivadas. Argumenta-se que isto se deve ao facto de o constituinte clivado identificar uma variável introduzida por uma descrição definida. Demonstra-se que a oração clivada, uma relativa em posição de complemento de um determinador definido nas clivadas canónicas e uma relativa livre nas pseudoclivadas, tem a mesma denotação que um DP definido, e portanto tem uma pressuposição existencial inerente. A interpretação exaustiva deve-se à relação identificacional entre o constituinte clivado e a descrição definida. Além disso, defende-se que em Português Europeu um traço de foco não desencadeia movimento-A’ para um FocP especializado. Os constituintes focalizados movem-se antes por razões independentes do foco. Isto é confirmado pelo facto de apenas o constituinte clivado das clivadas de é que ter propriedades de movimento A’, os outros parecem estar in situ. Propõe-se que o constituinte clivado das clivadas de é que é um tópico com um traço de foco que se move para um TopP. Esta análise dá conta da existência de restrições discursivas semelhantes para tópicos não focalizados e para o constituinte clivado das clivadas de é que. O traço quantificacional de foco arrastado pela topicalização dá origem a efeitos de intervenção, causando a não-recursividade do foco na periferia esquerda e a sua incompatibilidade com movimento de outros constituintes com traços quantificacionais. A análise prediz as restrições de encaixe observadas para as clivadas de é que. Finalmente, desenvolve-se uma análise sintática das clivadas de SER que aproxima estas estruturas das estruturas com partículas de foco. Propõe-se que a cópula é um operador sensível ao foco que é merged juntamente com o constituinte clivado. As restrições distribucionais da cópula devem-se a requisitos selecionais de núcleos.

On the Hill estimator: a comparison of methods

Extreme value theory (EVT) deals with the occurrence of extreme phenomena. The tail index is a very important parameter appearing in the estimation of the probability of rare events. Under a semiparametric framework, inference requires the choice of a number k of upper order statistics to be considered. This is the crux of the matter and there is no definite formula to do it, since a small k leads to high variance and large values of k tend to increase the bias. Several methodologies have emerged in literature, specially concerning the most popular Hill estimator (Hill, 1975). In this work we compare through simulation well-known procedures presented in Drees and Kaufmann (1998), Matthys and Beirlant (2000), Beirlant et al. (2002) and de Sousa and Michailidis (2004), with a heuristic scheme considered in Frahm et al. (2005) within the estimation of a different tail measure but with a similar context. We will see that the new method may be an interesting alternative.

Short-term corneal changes with gas-permeable contact lens wear in keratoconus subjects: a comparison of two fitting approaches

Purpose: To evaluate changes in anterior corneal topography and higher-order aberrations (HOA) after 14-days of rigid gas-permeable (RGP) contact lens (CL) wear in keratoconus subjects comparing two different fitting approaches. Methods: Thirty-one keratoconus subjects (50 eyes) without previous history of CL wear were recruited for the study. Subjects were randomly fitted to either an apical-touch or three-pointtouch fitting approach. The lens’ back optic zone radius (BOZR) was 0.4 mm and 0.1 mm flatter than the first definite apical clearance lens, respectively. Differences between the baseline and post-CL wear for steepest, flattest and average corneal power (ACP) readings, central corneal astigmatism (CCA), maximum tangential curvature (KTag), anterior corneal surface asphericity, anterior corneal surface HOA and thinnest corneal thickness measured with Pentacam were compared. Results: A statistically significant flattening was found over time on the flattest and steepest simulated keratometry and ACP in apical-touch group (all p < 0.01). A statistically significant reduction in KTag was found in both groups after contact lens wear (all p < 0.05). Significant reduction was found over time in CCA (p = 0.001) and anterior corneal asphericity in both groups (p < 0.001). Thickness at the thinnest corneal point increased significantly after CL wear (p < 0.0001). Coma-like and total HOA root mean square (RMS) error were significantly reduced following CL wearing in both fitting approaches (all p < 0.05). Conclusion: Short-term rigid gas-permeable CL wear flattens the anterior cornea, increases the thinnest corneal thickness and reduces anterior surface HOA in keratoconus subjects. Apicaltouch was associated with greater corneal flattening in comparison to three-point-touch lens wear.

Pointlike reducibility of pseudovarieties of the form V*D

In this paper, we investigate the reducibility property of semidirect products of the form V *D relatively to (pointlike) systems of equations of the form x1 =...= xn, where D denotes the pseudovariety of definite semigroups. We establish a connection between pointlike reducibility of V*D and the pointlike reducibility of the pseudovariety V. In particular, for the canonical signature consisting of the multiplication and the (omega-1)-power, we show that V*D is pointlike-reducible when V is pointlike-reducible.

Neurocognitive profile and cognitive intervention in Alzheimer's disease

Tese de Doutoramento em Psicologia (Especialidade de Psicologia Clínica)

Hume e o problema moral

Tese de Doutoramento em Filosofia (área de especialização em Filosofia Moderna e Contemporânea).