Performance Analysis between Two Sparsity Constrained MRI Methods: Highly Constrained Backprojection(HYPR) and Compressed Sensing(CS) for Dynamic Imaging

One of the most important challenges in dynamic magnetic resonance imaging (MRI) is to achieve high spatial and temporal resolution when it is limited by system performance. It is desirable to acquire data fast enough to capture the dynamics in the image time series without losing high spatial resolution and signal to noise ratio. Many techniques have been introduced in the recent decades to achieve this goal. Newly developed algorithms like Highly Constrained Backprojection (HYPR) and Compressed Sensing (CS) reconstruct images from highly undersampled data using constraints. Using these algorithms, it is possible to achieve high temporal resolution in the dynamic image time series with high spatial resolution and signal to noise ratio (SNR). In this thesis we have analyzed the performance of HYPR to CS algorithm. In assessing the reconstructed image quality, we considered computation time, spatial resolution, noise amplification factors, and artifact power (AP) using the same number of views in both algorithms, and that number is below the Nyquist requirement. In the simulations performed, CS always provides higher spatial resolution than HYPR, but it is limited by computation time in image reconstruction and SNR when compared to HYPR. HYPR performs better than CS in terms of SNR and computation time when the images are sparse enough. However, HYPR suffers from streaking artifacts when it comes to less sparse image data

Human Infection Caused by Leptospira fainei

We report a human case of leptospirosis in which the spirochete was detected by dark-field microscopy examination of cerebrospinal fluid (CSF) and isolated from both CSF and blood. Leptospira fainei was identified by sequencing the 16S rDNA gene, which had been amplified by polymerase chain reaction. This case confirms the role of L. fainei as a human pathogen and extends its distribution to southern Europe

Application of Artificial Intelligence in Cardiology : A Bibliometric Analysis

Peer reviewe

Accuracy of Loop-Mediated Isothermal Amplification for Diagnosis of Human Leptospirosis in Thailand

There is a lack of diagnostic tests for leptospirosis in technology-restricted settings. We developed loop-mediated isothermal amplification (LAMP) specific for the 16S ribosomal RNA gene (rrs) of pathogenic and intermediate group Leptospira species. The lower limit of detection was 10 genomic equivalents/reaction, and analytical specificity was high; we observed positive reactions for pathogenic/intermediate groups and negative reactions for non-pathogenic Leptospira species and other bacterial species. We evaluated this assay in Thailand by using a case–control study of 133 patients with laboratory-proven leptospirosis and 133 patients with other febrile illnesses. Using admission blood, we found that the rrs LAMP showed positive results in 58 of 133 cases (diagnostic sensitivity = 43.6, 95% confidence interval [CI] = 35.0–52.5) and in 22 of 133 controls (diagnostic specificity = 83.5, 95% CI = 76.0–89.3). Sensitivity was high for 39 patients who were culture positive for Leptospira spp. (84.6, 95% CI = 69.5–94.1). The rrs LAMP can provide an admission diagnosis in approximately half of patients with leptospirosis, but its clinical utility is reduced by a lower specificity

Approches actuelles de la régénération tissulaire parodontale

Periodontitis is an inflammatory disease from an infectious origin of the superficial and deep periodontium. This periodontal disease can be treated but leaves irreversible tissue damage. The big challenge of current therapies is to regenerate the periodontium. The decision of the regenerative therapy must intervene after an initial therapy well leaded and when we have persistent deep sockets. Over the past 40 years, many discoveries and surgical techniques have leaded to an evolution of periodontology; the management of periodontal defects is no longer the same and a multitude of treatment options are possible. Today, this diversity of products used make the pratician’s decision difficult. This thesis work tries to review all the techniques currently used; study the histological and clinical evidence of their effectiveness and to gather the elements to put the indications of each method.On the other hand, this thesis focuses on the various medical advances that are still at the research stage but which, thanks to their promising results, will become the treatments of tomorrow.La parodontite est une maladie d’origine infectieuse à composante inflammatoire du parodonte superficiel et profond. Cette maladie parodontale se traite mais laisse des lésions tissulaires irréversibles. Le grand défi des thérapies actuelles est donc de parvenir à régénérer le parodonte. La décision de thérapie régénérative doit intervenir après une thérapeutique initiale bien menée et s’il y a persistance de poches profondes. Au cours des 40 dernières années, de nombreuses découvertes et techniques chirurgicales ont permis une évolution de la parodontologie ; la prise en charge des défauts parodontaux n’est plus la même et une multitude d’options thérapeutiques sont possibles. Aujourd’hui, cette diversité de produits disponibles sur le marché rend le choix du praticien confus. Ce travail de thèse essaie, d’une part, de faire un point sur l’ensemble des techniques utilisées actuellement ; en étudiant les preuves histologiques et cliniques de leur efficacité, et de réunir les éléments pour poser les indications de chaque méthode. D’autre part, cette thèse s’intéresse aux différents progrès médicaux qui sont encore à l’étape de recherche mais qui, grâce à leurs résultats prometteurs, pourront devenir les traitements de demain

Le parodonte des séniors

La compréhension des acteurs du vieillissement est nécessaire pour adapter nos stratégies thérapeutiques et de prévention lorsque la démographie s’oriente vers une augmentation importante du nombre des plus âgés. En ce qui concerne le parodonte, le vieillissement s’additionne au risque de maladies parodontales déjà présent chez une personne sur deux, et reste au cœur des problématiques du vieillissement bucco-dentaire et de santé. Une meilleure compréhension des effets de l’âge et de ses conséquences permettrait une meilleure prise en charge thérapeutique pour rester en bonne santé plus long-temps

Using mesenchymal stromal cells in islet transplantation

Summary Islet transplantation has the potential to cure type 1 diabetes, but current clinical transplantation protocols are inefficient because of the extensive loss of functional islets during the immediate post-transplantation period. Studies in rodent models have demonstrated that co-transplanting mesencyhmal stromal cells (MSCs) with islets improves graft functional survival and transplantation outcomes, and some of the beneficial effects of MSCs are attributable to bioactive molecules secreted by MSCs. Clinical islet transplantation is almost exclusively via the hepatic portal vein, which does not facilitate co-engraftment of islets and MSCs, so attention is currently focused on using cell-free cocktails of MSC-derived products to treat islets prior to transplantation. This approach has the potential to overcome many of the technical and regulatory hurdles associated with using MSCs as an adjuvant therapy for human islet transplantation.</jats:p