Improved Liquid Chromatographic Method for Determination of Carotenoids in Carrot

 Improved Liquid Chromatographic Method for Determination of Carotenoids in Carro

La baisse de la densité osseuse au cours des maladies inflammatoires chroniques de l’intestin : prévalence et facteurs de risqué

Introduction: La baisse de la densité minérale osseuse représente la principale manifestation osseuse décrite au cours des maladies inflammatoires chroniques de l'intestin. En Tunisie, très peu d'études ont rapportés sa prévalence et ses facteurs de risque. Le but de ce travail était de déterminer la prévalence de la perte osseuse au cours des maladies inflammatoires chroniques de l'intestin, et rechercher ses facteurs de risque. Méthodes: Patients et méthodes: étude ouverte transversale, réalisée de 2007 jusqu'à 2012. Résultats: 146 cas étaient colligés, dont 105 avaient une maladie de Crohn (71,9%) et 41 avaient une rectocolite hémorragique (28,1%). Il s'agissait de 62 hommes et 84 femmes. L'âge moyen était de 33,18 ans. La perte osseuse était trouvée chez 85 patients (58,2%). Il s'agissait d'une ostéopénie dans 57 cas et d'ostéoporose dans 28 cas. Les facteurs de risque de perte osseuse étaient une activité physique limitée  (p=0,013), un indice de masse corporel '20 kg/m2 (p=0,015), une maladie active (p=0,035), l'étendue de l'atteinte intestinale (p=0,006) et une dose cumulée de corticothérapie dépassant 4,5g de Prednisone (p=0,003). Conclusion: La déminéralisation osseuse est une complication fréquente mais non constante. Ceci justifie un dépistage précoce chez les patients à risque, qui pourront ainsi bénéficier d'un traitement substitutif.Key words: Maladie de Crohn, recto-colite hémorragique, densité minérale osseuse, ostéopénie, ostéoporos

Improved liquid chromatographic method for determination of carotenoids in carrot

Carotenoids are a large class of plant metabolites with a function of either essential nutrients or health promoting compounds for humans. Carrot root is a well-known and significant source of dietary carotenoids, mainly: α- and β-carotene, lutein and lycopene. These pigments are the main carotenoids separated and quantified routinely by HPLC analysis. However, little is known about minor carotenoids, carotenoid esters and the carotenoids present in leaves despite their potential interest in metabolic and physiological studies. Previous works used C-18 columns but these stationary phases provide a poor resolution of structurally similar compounds and geometrical isomers. In recent years, C-30 columns have been developed and successfully applied at the separation of carotenoids from various plant materials, the number of resolved carotenoids being significantly improved. Based on literature procedures, we have developed a HPLC-DAD method with a C-30 column, adapted to the quantification of carotenoid compounds from carrot roots and leaves. A simple and rapid extraction method was optimized for both these types of samples on a panel of 5 genotypes displaying distinct root colours (different carotenoid composition and contents). Carotenoids from roots were separated in 23 minutes while carotenoids and chlorophylls from leaves were separated in 42 minutes. Compounds were identified according to their retention time and UV-visible spectrum in comparison with authentic standards (analysed individually and in combination, in the same conditions), or with data from literature, when standards were unavailable. Results showed that carrot root exhibited a simple profile with only 1 to 3 main carotenoids whereas a more complex composition was noticed in leaves, containing both identified and unidentified carotenoids and chlorophylls. Moreover, the composition was quite conservative for leaves but depended on the genotype for roots

Differential Pigment Accumulation in Carrot Leaves and Roots during Two Growing Periods

Carotenoids are important secondary metabolites involved in plant growth and nutritional quality of vegetable crops. These pigments are highly accumulated in carrot root but the knowledge about the environmental factors on their accumulation is limited. The purpose of this work was to investigate the impact of environmental variations on carotenoid accumulation in carrot leaves and roots. In this work, carrots were grown during two contrasted periods to maximize bioclimatic differences. In leaves, carotenoid and chlorophyll contents were lower in the less favorable growing condition while relative contents were well conserved for all genotypes suggesting a common regulatory mechanism. The down-regulation of all genes under environmental constraints demonstrates that carotenoid accumulation is regulated at transcriptional level. In roots, the decrease in α-carotene and lutein contents was accompanied by an increase of β-carotene relative content. At transcriptional level, LCYB and ZEP expression increased while LCYE expression decreased in the less favorable condition, suggesting that carotenoid biosynthesis is switched toward the β-branch

Occupational Noise Exposure and Diabetes Risk

Introduction. Noise is one of the most common worldwide environmental pollutants, especially in occupational fields. As a stressor, it affects not only the ear but also the entire body. Its physiological and psychological impacts have been well established in many conditions such as cardiovascular diseases. However, there is a dearth of evidence regarding diabetes risk related to noises. Aim. To evaluate the relationship between occupational exposure to noise and the risk of developing diabetes. Methods. This is a cross-sectional analytical study enrolling two groups of 151 workers each. The first group (noise exposed group: EG) included the employees of a Tunisian power plant, who worked during the day shift and had a permanent position. The second group (unexposed to noise group: NEG) included workers assigned to two academic institutions, who were randomly selected in the Occupational Medicine Department of the Farhat Hached University Hospital in Sousse, during periodical fitness to work visits. Both populations (exposed and unexposed) were matched by age and gender. Data collection was based on a preestablished questionnaire, a physical examination, a biological assessment, and a sonometric study. Results. The mean equivalent continuous sound level was 89 dB for the EG and 44.6 dB for the NEG. Diabetes was diagnosed in 24 workers from EG (15.9%) and 14 workers from NEG (9.3%), with no statistically significant difference (p=0.08). After multiple binary logistic regression, including variables of interest, noise did not appear to be associated with diabetes. Conclusion. Our results did not reveal a higher risk of developing diabetes in workers exposed to noise. Further studies assessing both level and duration of noise exposure are needed before any definitive conclusion

Adiponectin expression and metabolic markers in obesity and Type 2 diabetes

International audienceBackground: Adiponectin has emerged over the last decade as a key adipokine linking obesity, insulin resistance, and Type 2 diabetes. However, the molecular mechanisms controlling adiponectin expression in adipose tissue are not fully elucidated. Furthermore, increasing evidence indicates that peroxisome proliferator-activated receptor-gamma (PPAR-gamma) plays an important, and beneficial, role in modulating adiponectin expression. Aim: The aim of the present study was to assess the separate role of obesity and Type 2 diabetes in the relationship between endogenous PPAR-gamma signaling and adiponectin expression in subcutaneous adipose tissue. Subjects and methods: Enzyme-linked immunosorbent assay and real time quantitative PCR analysis were carried out in overweight, obese, and/or diabetic Tunisian patients who underwent an abdominal surgery. Results: These results collectively indicate that circulating levels of adiponectin were decreased in all over-weight, obese, and/or diabetic (p<0.001). However, the subcutaneous mRNA expression of adiponectin was reduced only in diabetics (p<0.01) but presents some discrepancies in obese individuals. Moreover, mRNA levels of adiponectin were positively correlated with levels of mRNA encoding PPAR gamma and its heterodimeric partner retinoid X receptor-alpha (RXR-alpha), in both obese and diabetic patients. Conclusion: Our study on Tunisian patients shows impaired regulation of circulating and mRNA adiponectin levels dependent of metabolic disorders in obesity and Type 2 diabetes. The data suggest that subcutaneous adipose tissue may play an important role in modulating adiponectin expression in diabetes and obesity. Moreover, adiponectin mRNA could be potentially regulated by endogenous PPAR gamma/RXR alpha-dependent pathways. (J. Endocrinol. Invest. 34: e16-e23, 2011) (C) 2011, Editrice Kurti

Prospective Data Model and Distributed Query Processing for Mobile Sensing Data Streams

International audienceWith the rapid advancements of sensor technologies and mobile computing, Mobile Crowd-Sensing (MCS) has emerged as a new paradigm to collect massive-scale rich trajectory data. Nomadic sensors empower people and objects with the capability of reporting and sharing observations on their state, their behavior and/or their surrounding environments. Processing and analyzing this continuously growing data raise several challenges due not only to their volume, their velocity, and their complexity but also to the gap between raw data samples and the desired application view in terms of correlation between observations and in terms of granularity. In this paper, we put forward a proposal that offers an abstract view of any spatio-temporal data series as well as their manipulation. Our approach allows to support this high-level logical view and provides efficient processing by mapping both the representation and the manipulation to an internal physical model. We explore an implementation within a distributed framework and envision the adaptation of data organization methods combining aggressive indexing and partitioning over time and space. The mapping from the logical view and the actual data storage will lead to revisiting the traditional database query rewriting and optimization techniques. This proposal is a first step in the objective of coping with the complexity, the imperfection of large data sizes in the MCS context