New natural urease inhibitors from Ranunculus repens

Phytochemical investigations on the chloroform and ethyl acetate soluble fractions of the roots of Ranunculus repens led to the isolation of methyl 3,4,5-trihydroxybenzoate 1, R(+)- 4-methoxydalbergione 2 and R(+)-dalbergiophenol 3. The structures of these compounds were established through spectral studies including 1D and 2D NMR experiments and by comparison with literature data. These compounds showed potent inhibitory activity against urease.     

An optimised protocol for plant regeneration from embryogenic suspension cultures of date palm,Phoenix dactylifera L., cv. Deglet Nour

An improved protocol is described for the large-scale micropropagation of an elite date palm ( Phoenix dactylifera L.) cultivar, Deglet Nour. Clonal plants were regenerated from somatic embryos derived from highly proliferating suspension cultures. Friable embryogenic calli were initiated from both leaf and inflorescence explants. Suspension cultures consisting of pro-embryonic masses were established from calli showing a high competency for somatic embryogenesis. The subculture of suspensions in liquid medium enriched with low amounts of plant growth regulators (1 mg l(-1) 2,4-dichlorophenoxyacetic acid with 300 mg l(-1) charcoal) resulted in the differentiation of large numbers of somatic embryos. The productivity of the cultures increased 20-fold (from 10 to 200 embryos per month per 100 mg fresh weight of embryogenic callus) when embryogenic suspensions were used instead of standard cultures on solid media. The overall production of somatic embryos reached 10,000 units per litre per month. Partial desiccation of the mature somatic embryos, corresponding to a decrease in water content from 90% to 75%, significantly improved germination rates (from 25% to 80%). The cutting back of the cotyledonary leaf was also found to stimulate embryo germination. Flow cytometric analysis showed that the micropropagation protocol followed here did not affect the ploidy level of somatic embryo-derived plantlets.     

Uncoupling protein 2, but not uncoupling protein 1, is expressed in the female mouse reproductive tract

Uncoupling proteins (UCPs) are transporters of the inner mitochondrial membrane. Whereas UCP1 is uniquely present in brown adipose tissue where it uncouples respiration from ATP synthesis and activates respiration and heat production, UCP2 is present in numerous tissues, and its exact function remains to be clarified. Two sets of data provided the rationale for this study: (i) the intriguing report that UCP1 is present in uterus of mice (Nibbelink, M., Moulin, K., Arnaud, E., Duval, C., Penicaud, L., and Casteilla, L. (2001) J. Biol. Chem. 276, 47291-47295); and (ii) an observation that Ucp2(-/-) female mice (homozygous matings) have smaller litters compared with Ucp2(+/+) animals (S. Rousset and A.-M. Cassard-Doulcier, unpublished observations). These data prompted us to examine the expression of UCP1 and UCP2 in the reproductive tract of female mice. Using wild type, Ucp1(-/-) mice, and Ucp2(-/-) mice, we were unable to detect UCP1 in uterus of mice with appropriate antibodies, and we conclude that the signal assigned to UCP1 by others was neither UCP1 nor UCP2. Using a polyclonal antibody against UCP2 and tissues from Ucp2(-/-) mice as controls, UCP2 was detected in ovary, oviduct, and uterus. Expression of Ucp2 mRNA was also observed in ovary and uterus using in situ hybridization analysis. Bone marrow transplantation experiments revealed that the UCP2 signal of the ovary was restricted to ovarian cells. UCP2 level in ovary decreased during follicular growth and increased during the pre-ovulatory period, during which aspects of an inflammatory process are known to exist. Because UCP2 down-regulates reactive oxygen species, a role in the regulation of inflammatory events linked to the preparation of ovulation is suggested.     

Glyoxylate metabolism and fatty acid oxidation in mango fruit during development and ripening

Throughout the development (maturation) of mango fruit the contents of citric and glyoxylic acids increased steadily. As the fruit matured the levels of isocitrate lyase, malate lyase and alanine: glyoxylate aminotransferase increased and reached maximum values prior to the time of harvesting. At and after harvest the levels of malate lyase and alanine : glyoxylate aminotransferase began to decrease but that of isocitrate lyase remained high until after the harvest when it decreased. The level of glyoxylate reductase was highest in the early developmental stage but declined as the fruit matured and ripened. As the fruit ripened, after harvest, the amounts of citric and glyoxylic acids decreased concomitant with a considerable increase in the levels of isocitrate dehydrogenase, malic dehydrogenase, malic enzyme and glyoxylate dehydrogenase.Fatty acid oxidizing capacity of mitochondria isolated from immature (developing) and postclimacteric fruit pulps was much less than that observed with mitochondria from preclimacteric and climacteric fruit. Glyoxylate stimulated the oxidation of caprylic, lauric, myristic and palmitic acids and inhibited the activity of isocitrate dehydrogenase in vitro.     

Chemiluminescence determination of chlorpheniramine using tris(1,10‐phenanthroline)–ruthenium(II) peroxydisulphate system and sequential injection analysis

A sequential injection (SI) method was developed for the determination of chlorpheniramine (CPA), based on the reaction of this drug with tris(1,10‐phenanthroline)–ruthenium(II) [Ru(phen)₃²⁺] and peroxydisulphate (S₂O₈^2–) in the presence of light. The instrumental set‐up utilized a syringe pump and a multiposition valve to aspirate the reagents [Ru(phen)₃²⁺ and S₂O₈^2–] and a peristaltic pump to propel the sample. The experimental conditions affecting the chemiluminescence reaction were systematically optimized, using the univariate approach. Under the optimum conditions linear calibration curves of 0.1–10 µg/ml were obtained. The detection limit was 0.04 µg/ml and the relative standard deviation (RSD) was always < 5%. The procedure was applied to the analysis of CPA in pharmaceutical products and was found to be free from interferences from concomitants usually present in these preparations. Copyright © 2008 John Wiley & Sons, Ltd.     

Contribution of PTPN22, CD28, CTLA-4 and ZAP-70 variants to the risk of type 1 diabetes in Tunisians

Type 1 diabetes (T1D) is caused by an immune-mediated destruction of the insulin-producing β-cells. Several studies support the involvement of T cell activation molecules. In order to underline the role of the genes involved in this pathway, we investigated, using the Sequenom MassARRAY platform, polymorphisms of sixteen single-nucleotide polymorphisms (SNPs) belonging to PTPN22, CD28, CTLA-4, and ZAP-70 genes in 76 T1D patients and 162 unrelated healthy controls from Southern Tunisia.     

3D culture model and computer-assisted videomicroscopy to analyze migratory behavior of noninvasive and invasive bronchial epithelial cells

To date, most of the studies in the field of cell migration have been applied to two-dimensional (2D) models. To mimic the three-dimensional (3D) conditions similar to those observed in vivo during tumor invasion, we developed a 3D model of cell migration in which cells were embedded in a collagen I matrix placed in a double-compartment chamber. Using time-lapse videomicroscopy and interactive cell tracking in a four-dimensional data set, we determined the cell trajectories and their migration kinetics. We compared the 2D and 3D migratory behavior of a noninvasive cell line (16HBE) with the migratory behavior of an invasive cell line (BZR). Our results show that the 3D migration kinetics of the noninvasive cell line were lower than the migration kinetics of the invasive cell line. In contrast, in 2D models, no significant difference was observed between the two cell lines. To validate our 3D model, we further investigated the effect of epidermal growth factor (EGF), a promoter of tumor cell motility and invasion on the noninvasive cell line (16HBE). EGF increased significantly the migration kinetics of the noninvasive cell line. Our results show that the 3D model of cell migration allowed us to differentiate the migratory behavior of invasive and noninvasive cells and that such a model can help in the development of molecular targeted therapy as it approaches the in vivo conditions. tumor invasion; metastasis; image analysis; kinetic migration; epidermal growth factor     

Individually recognizable scent marks on flowers made by a solitary bee

The marking of flowers with ephemeral scent is an underappreciated but vital element in the foraging behaviour of social bees. Using observational and experimental data, we tested whether a solitary bee (female Anthophora plumipes) uses scent marking while foraging on flowers of Cerinthe major in Portugal. Females used scent marks with at least two components that differed in their volatility and, furthermore, recognized the marks of different individuals. A very short-term component (<3 min) was attractive, resulting in the observed high level of immediate revisits: this component appeared to be adjusted according to the foraging needs of the moment. A longer-term component (<30 min) was initially repellent and matched the rate of nectar renewal; it, or the response to it, also appeared to be adjusted to the perceived level of nectar reward. There may be even longer-term effects associated with the specific foraging areas of individual bees. Observed differences in the way in which individuals responded to scent marks indicate that they may play a role as part of a dominance or exclusion mechanism among females. Copyright 2001 The Association for the Study of Animal Behaviour.     

Impact of the factors shaping gut microbiota on obesity

Obesity is considered as a risk factor for chronic health diseases such as heart diseases, cancer and diabetes 2. Reduced physical activities, lifestyle, poor nutritional diet and genetics are among the risk factors associated with the development of obesity. In recent years, several studies have explored the link between the gut microbiome and the progression of diseases including obesity, with the shift in microbiome abundance and composition being the main focus. The alteration of gut microbiome composition affects both nutrients metabolism and specific gene expressions, thereby disturbing body physiology. Specifically, the abundance of fibre-metabolizing microbes is associated with weight loss and that of protein and fat-metabolizing bacteria with weight gain. Various internal and external factors such as genetics, maternal obesity, mode of delivery, breastfeeding, nutrition, antibiotic use and the chemical compounds present in the environment are known to interfere with the richness of the gut microbiota (GM), thus influencing weight gain/loss and ultimately the development of obesity. However, the effectiveness of each factor in potentiating the shift in microbes’ abundance to result in significant changes that can lead to obesity is not yet clear. In this review, we will highlight the factors involved in shaping GM, their influence on obesity and possible interventions. Understanding the influence of these factors on the diversity of the GM and how to improve their effectiveness on disease conditions could be keys in the treatment of metabolic diseases.