Granulomatoses cutanées disséminées : orientation diagnostique et prise en charge [Disseminated cutaneous granulomatosis]

Les granulomatoses cutanées disséminées (GCD) sont des dermatoses cliniquement et histologiquement hétérogènes, caractérisées à la biopsie cutanée par un infiltrat granulomateux. Même si la biopsie est utile pour poser le diagnostic de GCD, elle n'apporte que rarement des éléments étiologiques. La principale cause est la sarcoïdose cutanée, mais de nombreuses étiologies peuvent être retrouvées, car ces dermatoses correspondent vraisemblablement à un processus réactionnel cutané granulomateux à différents stimuli: infectieux, inflammatoires, néoplasiques, métaboliques ou chimiques. Par cet article, nous aborderons la conduite à tenir une fois le diagnostic clinique et histologique de GCD posé, par une approche centrée sur l'étiologie et proposerons des recommandations thérapeutiques, sur la base de cas et de séries rapportées dans la littérature.

Modelling short-term ultraviolet exposure as an alternative to individual dosimetry

Background: Excessive exposure to solar Ultra-Violet (UV) light is the main cause of most skin cancers in humans. Factors such as the increase of solar irradiation at ground level (anthropic pollution), the rise in standard of living (vacation in sunny areas), and (mostly) the development of outdoor activities have contributed to increase exposure. Thus, unsurprisingly, incidence of skin cancers has increased over the last decades more than that of any other cancer. Melanoma is the most lethal cutaneous cancer, while cutaneous carcinomas are the most common cancer type worldwide. UV exposure depends on environmental as well as individual factors related to activity. The influence of individual factors on exposure among building workers was investigated in a previous study. Posture and orientation were found to account for at least 38% of the total variance of relative individual exposure. A high variance of short-term exposure was observed between different body locations, indicating the occurrence of intense, subacute exposures. It was also found that effective short-term exposure ranged between 0 and 200% of ambient irradiation, suggesting that ambient irradiation is a poor predictor of effective exposure. Various dosimetric techniques enable to assess individual effective exposure, but dosimetric measurements remain tedious and tend to be situation-specific. As a matter of facts, individual factors (exposure time, body posture and orientation in the sun) often limit the extrapolation of exposure results to similar activities conducted in other conditions. Objective: The research presented in this paper aims at developing and validating a predictive tool of effective individual exposure to solar UV. Methods: Existing computer graphic techniques (3D rendering) were adapted to reflect solar exposure conditions and calculate short-term anatomical doses. A numerical model, represented as a 3D triangular mesh, is used to represent the exposed body. The amount of solar energy received by each "triangle is calculated, taking into account irradiation intensity, incidence angle and possible shadowing from other body parts. The model take into account the three components of the solar irradiation (direct, diffuse and albedo) as well as the orientation and posture of the body. Field measurements were carried out using a forensic mannequin at the Payerne MeteoSwiss station. Short-term dosimetric measurements were performed in 7 anatomical locations for 5 body postures. Field results were compared to the model prediction obtained from the numerical model. Results: The best match between prediction and measurements was obtained for upper body parts such as shoulders (Ratio Modelled/Measured; Mean = 1.21, SD = 0.34) and neck (Mean = 0.81, SD = 0.32). Small curved body parts such as forehead (Mean = 6.48, SD = 9.61) exhibited a lower matching. The prediction is less accurate for complex postures such as kneeling (Mean = 4.13, SD = 8.38) compared to standing up (Mean = 0.85, SD = 0.48). The values obtained from the dosimeters and the ones computed from the model are globally consistent. Conclusion: Although further development and validation are required, these results suggest that effective exposure could be predicted for a given activity (work or leisure) in various ambient irradiation conditions. Using a generic modelling approach is of high interest in terms of implementation costs as well as predictive and retrospective capabilities.

Orientation Center Newsletter, Spring 2002

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, December 1998

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, June 1997

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, December 1996

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Galveston Orientation Amnesia Test (GOAT)

O trauma crânio-encefálico contuso (TCEC) é freqüentemente seguido pela amnésia pós-traumática (APT), caracterizada como um estado transitório de confusão e desorientação. Sua duração tem sido utilizada para quantificar a gravidade do TCEC e prever distúrbios nas funções cognitivas, assim como para antever as alterações na capacidade funcional das vítimas pós-trauma. O Galveston Orientation Amnesia Test (GOAT) é o primeiro instrumento sistematizado criado e o mais amplamente utilizado para avaliar a APT. Este artigo apresenta esse instrumento, as bases conceituais para seu desenvolvimento e a adaptação e validação do GOAT para cultura brasileira. Além disso, descreve sua aplicação e comenta as restrições do seu uso. Resultados de pesquisas realizadas em nosso meio contribuíram para as evidências sobre a validade do GOAT. Também apontaram os indicadores do momento pós-trauma em que o GOAT deve ser aplicado e destacaram as dificuldades no uso desse instrumento.

T-Cell Receptors Binding Orientation over Peptide/MHC Class I Is Driven by Long-Range Interactions.

Crystallographic data about T-Cell Receptor - peptide - major histocompatibility complex class I (TCRpMHC) interaction have revealed extremely diverse TCR binding modes triggering antigen recognition. Understanding the molecular basis that governs TCR orientation over pMHC is still a considerable challenge. We present a simplified rigid approach applied on all non-redundant TCRpMHC crystal structures available. The CHARMM force field in combination with the FACTS implicit solvation model is used to study the role of long-distance interactions between the TCR and pMHC. We demonstrate that the sum of the coulomb interactions and the electrostatic solvation energies is sufficient to identify two orientations corresponding to energetic minima at 0° and 180° from the native orientation. Interestingly, these results are shown to be robust upon small structural variations of the TCR such as changes induced by Molecular Dynamics simulations, suggesting that shape complementarity is not required to obtain a reliable signal. Accurate energy minima are also identified by confronting unbound TCR crystal structures to pMHC. Furthermore, we decompose the electrostatic energy into residue contributions to estimate their role in the overall orientation. Results show that most of the driving force leading to the formation of the complex is defined by CDR1,2/MHC interactions. This long-distance contribution appears to be independent from the binding process itself, since it is reliably identified without considering neither short-range energy terms nor CDR induced fit upon binding. Ultimately, we present an attempt to predict the TCR/pMHC binding mode for a TCR structure obtained by homology modeling. The simplicity of the approach and the absence of any fitted parameters make it also easily applicable to other types of macromolecular protein complexes.

Is spinal stenosis assessment dependent on slice orientation? A magnetic resonance imaging study.

INTRODUCTION: Lumbar spinal stenosis (LSS) treatment is based primarily on the clinical criteria providing that imaging confirms radiological stenosis. The radiological measurement more commonly used is the dural sac cross-sectional area (DSCA). It has been recently shown that grading stenosis based on the morphology of the dural sac as seen on axial T2 MRI images, better reflects severity of stenosis than DSCA and is of prognostic value. This radiological prospective study investigates the variability of surface measurements and morphological grading of stenosis for varying degrees of angulation of the T2 axial images relative to the disc space as observed in clinical practice. MATERIALS AND METHODS: Lumbar spine TSE T2 three-dimensional (3D) MRI sequences were obtained from 32 consecutive patients presenting with either suspected spinal stenosis or low back pain. Axial reconstructions using the OsiriX software at 0°, 10°, 20° and 30° relative to the disc space orientation were obtained for a total of 97 levels. For each level, DSCA was digitally measured and stenosis was graded according to the 4-point (A-D) morphological grading by two observers. RESULTS: A good interobserver agreement was found in grade evaluation of stenosis (k = 0.71). DSCA varied significantly as the slice orientation increased from 0° to +10°, +20° and +30° at each level examined (P < 0.0001) (-15 to +32% at 10°, -24 to +143% at 20° and -29 to +231% at 30° of slice orientation). Stenosis definition based on the surface measurements changed in 39 out of the 97 levels studied, whereas the morphology grade was modified only in two levels (P < 0.01). DISCUSSION: The need to obtain continuous slices using the classical 2D MRI acquisition technique entails often at least a 10° slice inclination relative to one of the studied discs. Even at this low angulation, we found a significantly statistical difference between surface changes and morphological grading change. In clinical practice, given the above findings, it might therefore not be necessary to align the axial cuts to each individual disc level which could be more time-consuming than obtaining a single series of axial cuts perpendicular to the middle of the lumbar spine or to the most stenotic level. In conclusion, morphological grading seems to offer an alternative means of assessing severity of spinal stenosis that is little affected by image acquisition technique.

Predictors of political orientation among US-born Mexican Americans: cultural identification, acculturation attitudes and socioeconomic status

With each passing election, U.S. political campaigns have renewed their efforts in courting the “Latino vote,” yet the Latino population is not a culturally homogenous voting bloc. This study examined how cultural identifications and acculturation attitudes in U.S. born Mexican Americans interacted with socioeconomic status (SES) to predict political orientation. Individuals who held stronger Mexican identity and supported biculturalism as an acculturation strategy had a more liberal orientation, while belonging to a higher SES group and holding stronger assimilation attitudes predicted a less liberal orientation. Mexican cultural identification interacted with SES such that those who held a weaker Mexican identity, but came from a higher social class were less liberal and more moderate in their political orientation. Weak Mexican identification and higher SES also predicted weaker endorsement of bicultural acculturation attitudes, which in turn, mediated the differences in political orientation. The acceptance of one’s ethnic identity and endorsement of bicultural attitudes predicted a more liberal political orientation. In light of these findings, political candidates should be cautious in how they pander to Latino constituents—referencing the groups’ ethnic culture or customs may distance constituents who are not strongly identified with their ethnic culture.

Orientation Center Newsletter, Winter 2004

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, Summer 2003

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.