University of Bordeaux

About: University of Bordeaux is a education organization based out in Bordeaux, France. It is known for research contribution in the topics: Population & Laser. The organization has 28811 authors who have published 55536 publications receiving 1619635 citations. The organization is also known as: UB.

Corticosterone in the range of stress-induced levels possesses reinforcing properties: implications for sensation-seeking behaviors.

Abstract: In both humans and animals certain individuals seek stimuli or situations that are considered stressful and consequently avoided by others. A common feature of such situations is an activation of the hypothalamo-pituitary-adrenal axis leading to secretion of glucocorticoids. Since glucocorticoids have euphoric effects in some individuals and have been shown to potentiate the reinforcing properties of drugs of abuse in animals, we hypothesized that corticosterone secretion during stress-like situations may have reinforcing effects and that a higher sensitivity to the reinforcing effects of glucocorticoids might be a biological basis of sensation seeking. In this report we show that (i) corticosterone has reinforcing properties, as evidenced by the development of intravenous self-administration, (ii) self-administration of corticosterone is observed at plasma levels that are comparable to those induced by stress, and (iii) there are individual differences in corticosterone self-administration, which are related to individual reactivity to novelty and sensitivity to drugs of abuse, behavioral features akin to certain traits of high-sensation seekers. These findings provide insight into the physiological role of glucocorticoids and the biology of sensation seeking and may have clinical implications.

ETFAD/EADV Eczema task force 2015 position paper on diagnosis and treatment of atopic dermatitis in adult and paediatric patients.

Abstract: Atopic dermatitis (AD) is a clinically defined, highly pruritic, chronic inflammatory skin disease of children and adults. The diagnosis is made using evaluated clinical criteria. Disease activity is best measured with a composite score assessing both objective signs and subjective symptoms, such as SCORAD. The management of AD must consider the clinical and pathogenic variabilities of the disease and also target flare prevention. Basic therapy includes hydrating topical treatment, as well as avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment of visible skin lesions is based on topical glucocorticosteroids and the topical calcineurin inhibitors tacrolimus and pimecrolimus. Topical calcineurin inhibitors are preferred in sensitive locations. Tacrolimus and mid-potent steroids are proven for proactive therapy, which is long-term intermittent anti-inflammatory therapy of the frequently relapsing skin areas. Systemic anti-inflammatory or immunosuppressive treatment is indicated for severe refractory cases. Biologicals targeting key mechanisms of the atopic immune response are promising emerging treatment options. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Systemic antihistamines (H1R-blockers) may diminish pruritus, but do not have sufficient effect on lesions. Adjuvant therapy includes UV irradiation, preferably UVA1 or narrow-band UVB 311 nm. Dietary recommendations should be patient specific and elimination diets should only be advised in case of proven food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Psychosomatic counselling is recommended to address stress-induced exacerbations. 'Eczema school' educational programmes have been proven to be helpful for children and adults.

Soft microgels as Pickering emulsion stabilisers: role of particle deformability

Abstract: We synthesised soft uncharged microgels made of poly(N-isopropylacrylamide) of variable cross-linking degrees and we probed their efficiency as stabilisers to fabricate oil-in-water emulsions. Interestingly, such particles undergo a swollen-to-collapsed transition above a critical temperature. By combining several microscopy methods and by exploiting the limited coalescence process, we were able to determine both the particle concentration and structure at the interface, as a function of the cross-linking density. Being deformable, the initially spherical microgels adopt a “fried egg-like” structure when adsorbed at the oil/water interface. As expected, the interfacial deformation is increasingly pronounced as the cross-linking degree decreases. The most deformable microgels tend to form 2D connected networks characterised by significant overlapping of the peripheral parts. When the deformability is lost, by increasing the cross-linking density or the temperature, the stabilisation efficiency is considerably reduced. Our results strongly suggest that emulsion stability is mainly determined by the microgels' deformability and we discuss the origin of that empirical link in terms of lateral overlapping and interfacial elasticity.

Oscillations of cytosolic Ca2+ in pituitary cells due to action potentials.

Abstract: Electrical activity in non-neuronal cells can be induced by altering the membrane potential and eliciting action potentials. For example, hormones, nutrients and neurotransmitters act on excitable endocrine cells1. In an attempt to correlate such electrical activity with regulation of cell activation, we report here direct measurements of cytosolic free Ca2+ changes coincident with action potentials. This was achieved by the powerful and novel combination of two complex techniques, the patch clamp2 and micro-fluorimetry using fura 2 methodology3,4. Changes in intracellular calcium concentration were monitored in single cells of the pituitary line GH3B6. We show that a single action potential leads to a marked transient increase in cytosolic free calcium. The size of these short-lived maxima is sufficient to evoke secretory activity. The striking kinetic features of these transients enabled us to identify oscillations in intracellular calcium concentration in unperturbed cells resulting from spontaneous action potentials, and hence provide an explanation for basal secretory activity. Somatostatin, an inhibitor of pituitary function5, abolishes the spontaneous spiking of free cytosolic Ca2+ which may explain its inhibitory effect on basal prolactin secretion. Our data therefore demonstrate that electrical activity can stimulate Ca2+-dependent functions in excitable non-neuronal cells.