Term dependency extraction using rule-based Bayesian Network for medical image retrieval.

Text-Based Medical Image Retrieval (TBMIR) has been known to be successful in retrieving medical images with textual descriptions. Usually, these descriptions are very brief and cannot express the whole visual content of the image in words, hence negatively affect the retrieval performance. One of the solutions offered in the literature is to form a Bayesian Network thesaurus taking advantage of some medical terms extracted from the image datasets. Despite the interestingness of this solution, it is not efficient as it is highly related to the co-occurrence measure, the layer arrangement and the arc directions. A significant drawback of the co-occurrence measure is the generation of a lot of uninteresting co-occurring terms. Several studies applied the association rules mining and its measures to discover the correlation between the terms. In this paper, we propose a new efficient association Rule Based Bayesian Network (R2BN) model for TBMIR using updated medically-dependent features (MDF) based on Unified Medical Language System (UMLS). The MDF are a set of medical terms that refers to the imaging modalities, the image color, the searched object dimension, etc. The proposed model presents the association rules mined from MDF in the form of Bayesian Network model. Then, it exploits the association rule measures (support, confidence, and lift) to prune the Bayesian Network model for efficient computation. The proposed R2BN model is combined with a literature probabilistic model to predict the relevance of an image to a given query. Experiments are carried out with ImageCLEF medical retrieval task collections from 2009 to 2013. Results show that our proposed model enhances significantly the image retrieval accuracy compared to the state-of-the-art retrieval models.

Sister chromatid exchange (SCE) and high-frequency cells (HFC) in peripheral blood lymphocytes of healthy Tunisian smokers.

Cigarette smoking is a major public health problem in Tunisia as it concerns up to 30-35% of the adult population, raising important national issues on tobacco-related disease. The aim of this study was to establish whether cigarette smoking increases sister chromatid exchange (SCE) in peripheral blood lymphocytes of smokers (n=14) compared with non-smokers (n=15) in Sfax, Tunisia. The smokers were subdivided in two subgroups according to the duration of the smoking habit: heavy smokers (>10 years) and light smokers (≤10 years). After signing a consent form, volunteers provided a blood sample (5ml) to establish cell cultures during 72h. For SCE analysis, 30 second-division metaphases were examined from each subject. We determined the frequency of SCE, the percentage of high-frequency cells (HFC) and that of the high-frequency cell individual (HFI). The results show a significantly higher SCE frequency in smokers (8.65±1.43) than in non-smokers (7.16±1.3; p<0.01). A significant difference in SCE frequency was also shown when comparing the two subgroups of smokers (p<0.05). Interestingly, no significant difference was found when comparing the light smokers with non-smokers (7.82±1 vs 7.16±1.3, respectively, p>0.05). The percentages of HFC and HFI were significantly higher in smokers (11.2±7.8% and 78.6%, respectively) than in non-smokers (4±2.2% and 20%, respectively, p<0.01). Our study indicates that the genotoxic effects in lymphocytes from healthy Tunisian smokers are most likely caused by cigarette-smoke constituents. This effect was mainly observed in smokers who had been smoking during more than 10 years. These results provide scientific evidence to urge the prevention of tobacco consumption.

[Thoracic involvement revealing lymphomas: report on 17 cases]. / Manifestations thoraciques revelatrices de lymphomes: a propos de 17 cas.

BACKGROUND: Thoracic manifestations of lymphomas are frequents and various. They are frequently described in secondary than as a primary manifestation. AIM: This work aims to analyze the clinical, radiological, and prognostic characteristics of initial thoracic features of lymphomas. The authors stress the diagnosis and therapeutic difficulties which they encountered. METHODS: We report a retrospective work of initial thoracic involvement of lymphomas and their radiologic features observed in 17 patients hospitalized in pneumology service of Sfax. RESULTS: There were 10 cases of non Hodgkin's lymphoma and 7 cases of Hodgkin disease. For the patients with non Hodgkin's lymphoma, the mediastinal involvement was present in 8 cases. The parenchymal involvement was noted among 2 patients such as nodules or masses, with concomitant mediastinal lymph nodes. The pleural effusion such as pleurisy or solid mass was seen in 3 cases. Pericardial and parietal involvements were noted in one case. For the patients with Hodgkin's disease, the mediastinal lymph nodes were seen among 6 patients. The parenchymal involvement was noted in one case. One case of primary thymic lymphoma involvement and one case of tracheal involvement were noted. No case of pleural effusion was deplored. CONCLUSION: Initial thoracic involvements, rarely described, cause a variety of features which are often nonspecific. The diagnosis, often difficult, has beneficiated, from imaging and endoscopy's progress. However, treatment should be optimized in order to improve the prognosis which is also reserved particularly in non Hodgkin lymphoma.

[Narcolepsy]. / La narcolepsie.

Narcolepsy is a chronic neurologic disease whose main features are excessive daytime sleepiness and cataplexy. It is a rare disorder which is most frequently sporadic. The age of onset shows tow peaks. Both genetic and environmental factors play in its pathophysiolgy. Association with a specific HLA antigen and implication of the hypocretin system are very important findings. Narcolepsy's diagnosis is based on clinical findings but polysomnographic monitoring and multiple sleep latency test are usually necessary. Treatment of narcolepsy has been substantially modified with the advent of Modafinil which is effective as amphetamine with less undesirable effects. New etiologic treatments, such as hypocretin agonists, are currently being developed.