The equilibria that allow bacterial persistence in human hosts

We propose that microbes that have developed persistent relationships with human hosts have evolved cross-signalling mechanisms that permit homeostasis that conforms to Nash equilibria and, more specifically, to evolutionarily stable strategies. This implies that a group of highly diverse organisms has evolved within the changing contexts of variation in effective human population size and lifespan, shaping the equilibria achieved, and creating relationships resembling climax communities. We propose that such ecosystems contain nested communities in which equilibrium at one level contributes to homeostasis at another. The model can aid prediction of equilibrium states in the context of further change: widespread immunodeficiency, changing population densities, or extinctions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62883/1/nature06198.pd

Bioinspired Synthesis of Monolithic and Layered Aerogels

Aerogels are the least dense and most porous materials known to man, with potential applications from lightweight superinsulators to smart energy materials. To date their use has been seriously hampered by their synthesis methods, which are laborious and expensive. Taking inspiration from the life cycle of the damselfly, a novel ambient pressure‐drying approach is demonstrated in which instead of employing low‐surface‐tension organic solvents to prevent pore collapse during drying, sodium bicarbonate solution is used to generate pore‐supporting carbon dioxide in situ, significantly reducing energy, time, and cost in aerogel production. The generic applicability of this readily scalable new approach is demonstrated through the production of granules, monoliths, and layered solids with a number of precursor materials

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

Antifreeze proteins (AFPs) are ice-binding proteins that depress the freezing point of water in a non-colligative manner without a significant modification of the melting point. Found in the blood and tissues of some organisms (such as fish, insects, plants, and soil bacteria), AFPs play an important role in subzero temperature survival. Fish Type III AFP is present in members of the subclass Zoarcoidei. AFPIII are small 7-kDa—or 14-kDa tandem—globular proteins. In the present work, we study the behavior of several physical properties, such as the low-frequency dielectric permittivity spectrum, circular dichroism, and electrical conductivity of Fish Type III AFP solutions measured at different concentrations. The combination of the information obtained from these measurements could be explained through the formation of AFP molecular aggregates or, alternatively, by the existence of some other type of interparticle interactions. Thermal stability and electro-optical behavior, when proteins are dissolved in deuterated water, were also investigated

Metabolic and psychiatric effects of acyl coenzyme A binding protein (ACBP)/diazepam binding inhibitor (DBI)

International audienceAcyl coenzyme A binding protein (ACBP), also known as diazepam binding inhibitor (DBI) is a multifunctional protein with an intracellular action (as ACBP), as well as with an extracellular role (as DBI). The plasma levels of soluble ACBP/DBI are elevated in human obesity and reduced in anorexia nervosa. Accumulating evidence indicates that genetic or antibody-mediated neutralization of ACBP/DBI has anorexigenic effects, thus inhibiting food intake and inducing lipo-catabolic reactions in mice. A number of anorexiants have been withdrawn from clinical development because of their side effects including an increase in depression and suicide. For this reason, we investigated the psychiatric impact of ACBP/DBI in mouse models and patient cohorts. Intravenously (i.v.) injected ACBP/DBI protein conserved its orexigenic function when the protein was mutated to abolish acyl coenzyme A binding, but lost its appetite-stimulatory effect in mice bearing a mutation in the γ2 subunit of the γ-aminobutyric acid (GABA) A receptor (GABAAR). ACBP/DBI neutralization by intraperitoneal (i.p.) injection of a specific mAb blunted excessive food intake in starved and leptin-deficient mice, but not in ghrelin-treated animals. Neither i.v. nor i.p. injected anti-ACBP/DBI antibody affected the behavior of mice in the dark–light box and open-field test. In contrast, ACBP/DBI increased immobility in the forced swim test, while anti-ACBP/DBI antibody counteracted this sign of depression. In patients diagnosed with therapy-resistant bipolar disorder or schizophrenia, ACBP/DBI similarly correlated with body mass index (BMI), not with the psychiatric diagnosis. Patients with high levels of ACBP/DBI were at risk of dyslipidemia and this effect was independent from BMI, as indicated by multivariate analysis. In summary, it appears that ACBP/DBI neutralization has no negative impact on mood and that human depression is not associated with alterations in ACBP/DBI concentrations

Factors associated with lamotrigine concentration/dose ratio in individuals with bipolar disorders

International audienceMonitoring of lamotrigine levels is recommended in epilepsy. However, in bipolar disorders (BD), no study has described the therapeutic range in daily practice and factors being associated to it. We used retrospective data of individuals with BD, treated with lamotrigine, and included in the FondaMental Advanced Centers of Expertise for Bipolar Disorders cohort. We extracted clinical and biological data and explored associations between these variables and lamotrigine concentration/dose (C/D) ratio. The database included 675 individuals who received lamotrigine at inclusion, whose main characteristics were female sex (68.3%) and BD type 2 (52.1%). Data about lamotrigine C/D ratio were available for 205 individuals. Lamotrigine C/D ratio was significantly associated with: Body Mass Index (BMI) (r=-0.159), estimated GFR (glomerular filtration rate) (r=-0.228), total bilirubin (r = 0.241) and at a trend level, antidepressant co-prescription (U = 3169). The model obtained was: lamotrigine C/D ratio = 1.736 - 0.013*BMI + 0.095*total bilirubin (UI/L) - 0.007*eGFR (ml/min) + 0.210*AST/ALT – 0.004*GGT (UI/L) + 0.014*age (year) + 0.303*currently smoking (yes or no) – 0.588*antidepressant co-prescription (yes or no) – 0.357*gender (F = 1.899, p = 0.057, adjusted R2 = 0.11) Information about plasma lamotrigine C/D ratio were available for only 205 out of the 675 individuals in the database and has been obtained from different laboratories. The representativeness of the included sample may be questionable. This is the first study providing information on a large sample of individuals with BD regarding factors associated with lamotrigine C/D ratio. This study allows to propose a model of lamotrigine C/D ratio that would deserve further replication