Effect of exogenous circulating anti-bPL antibodies on bovine placental lactogen measurements in foetal samples

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating antibodies are present together with the hormone, the procedure for hormonal measurement becomes considerably complex. The aim of this study was the immunoneutralization of bovine placental lactogen (bPL) concentrations in bovine foetal circulation by direct infusion of rabbit anti-bPL purified immunoglobulins (IgG) via a foetal catheter (in vivo study). The ability of a RIA based on guinea pig anti-bPL antiserum, for the measurement of bPL concentrations in samples containing exogenous rabbit anti-bPL immunoglobulins, was also analyzed in in vitro and in vivo conditions. METHODS: Six bovine foetuses were chronic cannulated on the aorta via the medial tarsal artery. Infusion of rabbit anti-bPL IgG was performed during late gestation. Pooled rabbit anti-bPL antisera had a maximal neutralization capacity of 25 microg bPL/mL of immunoglobulin. Interference of rabbit anti-bPL immunoglobulin with radioimmunoassay measurement using guinea pig anti-bPL as primary antibody was first evaluated in vitro. Polyclonal anti-bPL antibodies raised in rabbit were added in foetal sera to produce 100 samples with known antibodies titers (dilutions ranging from 1:2,500 till 1:1,280,000). RESULT(S): Assessment of the interference of rabbit anti-bPL antibody showed that bPL concentrations were significantly lower (P < 0.05) in samples added with dilutions of rabbit antiserum lower than 1:80,000 (one foetus) or 1:10,000 (four foetuses). It was also shown that the recovery of added bPL (12 ng/mL) was markedly reduced in those samples in which exogenous rabbit anti-bPL were added at dilutions lower than 1:20,000. Concentrations of foetal bPL were determined in samples from cannulated foetuses. In foetuses 1 and 6, bPL concentrations remained almost unchanged (<5 ng/mL) during the whole experimental period. In Foetus 3, bPL concentrations decreased immediately after IgG infusion and thereafter, they increased until parturition. CONCLUSION(S): The use of a bPL RIA using a guinea pig anti-bPL as primary antiserum allowed for the measurement of bPL concentrations in foetal plasma in presence of rabbit anti-bPL IgG into the foetal circulation. Long-term foetal catheterization allowed for the study of the influence of direct infusion of anti-bPL IgG on peripheral bPL concentrations in bovine foetuses

Preliminary results of lifetime measurements in neutron-rich 53Ti

To study the nuclear structure of neutron-rich titanium isotopes, a lifetime measurement was performed at the Grand Accélérateur National d'Ions Lourds (GANIL) facility in Caen, France. The nucleiwere produced in a multinucleon-transfer reaction by using a 6.76 MeV/u 238U beam. The Advanced Gamma Tracking Array (AGATA) was employed for the γ-ray detection and target-like recoils were identified event-by-event by the large-acceptance variable mode spectrometer (VAMOS++). Preliminary level lifetimes of the (5/2−) to 13/2− states of the yrast band in the neutron-rich nucleus 53Ti were measured for the first time employing the recoil distance Doppler-shift (RDDS) method and the compact plunger for deep inelastic reactions. The differential decay curve method (DDCM) was used to obtain the lifetimes from the RDDS data

Correction: Protocol of the Healthy Brain Study:An accessible resource for understanding the human brain and how it dynamically and individually operates in its bio-social context

[This corrects the article DOI: 10.1371/journal.pone.0260952.]

HAND2 is a novel obesity-linked adipogenic transcription factor regulated by glucocorticoid signalling

Aims/hypothesis Adipocytes are critical cornerstones of energy metabolism. While obesity-induced adipocyte dysfunction is associated with insulin resistance and systemic metabolic disturbances, adipogenesis, the formation of new adipocytes and healthy adipose tissue expansion are associated with metabolic benefits. Understanding the molecular mechanisms governing adipogenesis is of great clinical potential to efficiently restore metabolic health in obesity. Here we investigate the role of heart and neural crest derivatives-expressed 2 (HAND2) in adipogenesis.MethodsHuman white adipose tissue (WAT) was collected from two cross-sectional studies of 318 and 96 individuals. In vitro, for mechanistic experiments we used primary adipocytes from humans and mice as well as human multipotent adipose-derived stem (hMADS) cells. Gene silencing was performed using siRNA or genetic inactivation in primary adipocytes from loxP and or tamoxifen-inducible Cre-ERT2 mouse models with Cre-encoding mRNA or tamoxifen, respectively. Adipogenesis and adipocyte metabolism were measured by Oil Red O staining, quantitative PCR (qPCR), microarray, glucose uptake assay, western blot and lipolysis assay. A combinatorial RNA sequencing (RNAseq) and ChIP qPCR approach was used to identify target genes regulated by HAND2. In vivo, we created a conditional adipocyte Hand2 deletion mouse model using Cre under control of the Adipoq promoter (Hand2AdipoqCre) and performed a large panel of metabolic tests.Results We found that HAND2 is an obesity-linked white adipocyte transcription factor regulated by glucocorticoids that was necessary but insufficient for adipocyte differentiation in vitro. In a large cohort of humans, WAT HAND2 expression was correlated to BMI. The HAND2 gene was enriched in white adipocytes compared with brown, induced early in differentiation and responded to dexamethasone (DEX), a typical glucocorticoid receptor (GR, encoded by NR3C1) agonist. Silencing of NR3C1 in hMADS cells or deletion of GR in a transgenic conditional mouse model results in diminished HAND2 expression, establishing that adipocyte HAND2 is regulated by glucocorticoids via GR in vitro and in vivo. Furthermore, we identified gene clusters indirectly regulated by the GR-HAND2 pathway. Interestingly, silencing of HAND2 impaired adipocyte differentiation in hMADS and primary mouse adipocytes. However, a conditional adipocyte Hand2 deletion mouse model using Cre under control of the Adipoq promoter did not mirror these effects on adipose tissue differentiation, indicating that HAND2 was required at stages prior to Adipoq expression.Conclusions/interpretation In summary, our study identifies HAND2 as a novel obesity-linked adipocyte transcription factor, highlighting new mechanisms of GR-dependent adipogenesis in humans and mice.Data availability Array data have been submitted to the GEO database at NCBI (GSE148699).</p

Development of a new compact three-foil plunger device and Lifetime measurements using the Recoil Distance Doppler-shift method

This thesis presents the development of a new compact differential three-foil plunger (Cologne Compact Differential Plunger - CoCoDiff) for the measurement of lifetimes of excited states in nuclei with the Recoil Distance Doppler-shift (RDDS) method as well as auxiliary techniques and methods to aid the usage of this new plunger and of other plunger devices. The new plunger apparatus has been commissioned in an experiment on level lifetimes in 50Cr which was carried out at the Cologne FN tandem accelerator. There, lifetimes of the first 2+ and 4 +states have been measured with good precision which match with literature values and shell-model calculations. To enhance the precision of plunger experiments that need absolute foil separations, a new method to measure these has been developed, using an optical sensor. This method has been tested using an experiment on known level lifetimes in 181Ta also conducted in Cologne. Furthermore, an RDDS experiment on level lifetimes in 144Ce was carried out, which is a candidate for octupole deformation. Lifetimes of the first 2+, 4+, 6+ and 3- states haven been measured with good precision, the latter three for the first time. From these lifetimes, B(E2) and B(E1) transition strengths could be determined that give further proof for possible octupole deformation. Additionally, the lifetime of the 3- state is important for a possible future Coulomb excitation measurement in search of the yet unobserved 3- -> 0+ transition. Lastly, level lifetimes of the first 2+ and 4+ states in 60Ni have been measured using the RDDS method. They shed light into a prior confusing situation of contradicting literature values that allowed for no clear physical interpretation of the onset of collectivity of Ni isotopes regarding the tentative N=40 sub-shell closure

Recherches sur l'équation d'état des hydrocarbures facilement liquéfiables, II: Nouvelle détermination du poids du litre du butane normal

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Note on the vacuum contraction of density bulbs

The contraction of density globes on evacuation has been investigated in connection with a physicochemical examination of easily liquefied saturated hydrocarbons. A hydrostatic method of measurement has been applied to the problem, as well as the method of Travers; the results by both methods are in good agreement. The empirical equation proposed by Moles and Miravalles for the calculation of the compressibility of density globes is given additional confirmation by the results of the measurements. Data have been obtained which lend support to the hypothesis that the contraction of density globes is a linear function of the pressure difference to which the bulb is submitted. © 1929, American Chemical Society. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Recherches sur l'équation d'état des hydrocarbures facilement liquéfiables, IV: Poids du litre et coefficient de compressibilité du butane normal

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Recherches sur l'équation d'état des hydrocarbures paraffiniques gazeux

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