Impact of the somatotrope Growth Hormone (GH)/Insulin-like Growth Factor 1 (IGF-1) axis upon thymus function: Pharmacological implications in regeneration of immune functions

in Immunology, Endocrine & Metabolic Agents - Medicinal Chemistry (2011), 11

The thymus is the central lymphoid structure where T-cell differentiation takes place, and a crucial organ for the maintenance of homeostasis in the immune system. Thymopoiesis includes intrathymic ... [more ▼]

The thymus is the central lymphoid structure where T-cell differentiation takes place, and a crucial organ for the maintenance of homeostasis in the immune system. Thymopoiesis includes intrathymic proliferation of T-cell precursors, selection and output of both self-tolerant and competent effector T cells, as well as of natural regulatory T cells (nTreg). In the crosstalk between the neuroendocrine and immune systems, peptide hormones have been more and more implicated in immunomodulation for the last thirty years. The somatotrope growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis in particular has been repeatedly shown to play a major regulatory role upon thymus function and T-cell development. This review will focus on the important thymotropic properties of the somatotrope GH/IGF-1 axis, and will try to discriminate these properties in function of the endocrine or paracrine/autocrine pathways involved in their mediation. Most importantly, in light of an increasing number of recent studies, GH and IGF-1 now appear as a novel therapeutic agents that could be used for enhancing thymopoiesis in different cases of immune deficiencies, including aging-related immune dysfunction. [less ▲]

Impact of the spatial resolution on the Greenland ice sheet surface mass balance modelling using the regional climate model MAR.

Conference (2011, January 14)

IMPACT OF THE TEMPERAMENT OF YOUNG STALLIONS ON THEIR STRESS REACTIONS WHEN SUBJECTED TO A STANDARDISED VETERINARY EXAMINATION

in Journal of Veterinary Behavior: Clinical Applications and Research (2011, September), 6

Impact of the thymus emergence on integrated evolution of the adaptative immune and neuroendocrine systems

E-print/Working paper (2011)

Impact of the treatment conditions of a formic/acetic acid delignification method on chemical structure and antioxidant activity of beech wood lignin

Poster (2011)

The interest in lignocellulosic substrates is increasing because they are clearly identified for their high potential of development in energy and value-added molecules production. Indeed lignocellulosic ... [more ▼]

The interest in lignocellulosic substrates is increasing because they are clearly identified for their high potential of development in energy and value-added molecules production. Indeed lignocellulosic biomass constitutes a promising resource for a sustainable production of organic compounds and biobased products that could progressively replace molecules from the petrochemical industry. Until now lignocellulosic substrates were mainly used for the valorization of cellulose. Hemicelluloses and lignins were less valorized and often degraded after the process. However, due to their phenolic structure, lignins can be valorized in a lot of high-valued applications like vanillin production, replacement of petrochemical polymers, antioxidants for cosmetics and food industry, resins… In this study, a representative sample of beech wood (Fagus sylvatica L.) was collected in the region of Gaume in Belgium. Beech wood was delignified at atmospheric pressure by an organosolv process using a mixture of formic acid/acetic acid/water. The effect of cooking time and temperature was evaluated on the structure, physico-chemical properties and antioxidant activity of the lignins obtained from the black liquor after treatments. The structural and physico-chemical characteristics of the lignins were investigated with different tools like infrared spectrometry, thermogravimetric analysis, gel permeation chromatography after acetylation of lignins, NMR 1H, 13C and HSQC. The antioxidant activity was assessed by a spectrophotometric method using the α,α-diphenyl-β-picrylhydrazyl radical (DPPH). [less ▲]

Impact of the use of the Manufacturer's published reference range for PTH vs. the reference range established in the Laboratory for the classification of the haemodialyzed patients with the KDIGO Guidelines.

Poster (2011, July 28)

Impact of thresholding techniques on X-ray soil microtomogram analyses

in Geophysical Research Abstracts (2011), 13

Using X-ray microtomography, 3D soil structure can be visualised and analysed through useful factors like pore size distribution, shape, connectivity, orientation, etc. X-ray scans yield grey-level 2D ... [more ▼]

Using X-ray microtomography, 3D soil structure can be visualised and analysed through useful factors like pore size distribution, shape, connectivity, orientation, etc. X-ray scans yield grey-level 2D images, which can be recombined to form 3D structures. Treatments of the grey-level images can consist of either a binarization -distinguishing soil and pores- or a permeability level attribution directly linked to the grey-level values. The latter leads to problems in order to assign a permeability for each point (in soil a same grey level value can be assigned to points with a different permeability), as well as to analyse the 3D structure. On the other hand, treatment of black and white 3D structures is well-handled. However, the impact of the choice of one thresholding technique on the resulting images has already been demonstrated. Moreover, thresholding methods are various and numerous. Many of them are based on the image histogram analysis. But because of the soil complexity, the relevance of these techniques becomes debatable, with a risk of producing non reliable images. We propose to palliate this with a simple new algorithm based on physical measurements: it uses a loop fixing the threshold value in order to match the measured porosity for each sample. In this communication, our point is to highlight the impact of different thresholding techniques on the analysis and interpretation of our soil microtomograms. The underlying questions could be: Does the thresholding method influence our conclusions? Are the results depending on the sample itself or on the methodology? In order to answer these questions we tested the Otsu technique and our physically based algorithm. Soils samples were removed from the upper layer (Ap horizon) of a silty soil (Gentinnes, Brabant Walloon, Belgium) in plots with different management practices. In fact, since 2004, the field has been cultivated in conventional tillage (CT) or reduced tillage (RT). In order to empty the meso- and macroporosity, samples were placed under a 1.5 MPa pressure (Richards apparatus). Samples were then scanned by X-ray microtomography using a Skyscan-1172 high-resolution desktop micro-CT system (Skyscan, Kontich, Belgium). The cone beam source operated at 100 kV, using an aluminium filter. The detector configuration, i.e. 1048x2000 pixels with a 16-bit X-ray camera, and the distance source-object-camera were adjusted to produce images with a pixel size of 17 µm. Porosity was measured for each scanned sample. Then the threshold methods -the Otsu technique on one hand and our developed algorithm on the other - were applied, and morphological factors were calculated for both methods. A comparison of the first results shows a threshold influence on average porosity and number of pores, but also on connectivity factors and size distribution. The apparent porosity of the images, as well as connectivity, is underestimated with the Otsu technique. Despite the fact that the changes induced by thresholding are more important for RT than CT, global conclusions about the comparison of these agricultural practices are approximately the same in this case. However, differences between tillage systems are less important with the Otsu method, confirming the impact of choosing the adapted threshold method. [less ▲]

Impact of training and exercise intensity on blood antioxidant markers in healthy Standardbred horses

in Equine & Comparative Exercise Physiology (2004), 1(3), 211-220

This study investigated the effect of training and exercise intensity on blood antioxidant markers in six healthy Standardbred horses. Markers studied were uric acid (UA), ascorbic acid (AA), α-tocopherol ... [more ▼]

This study investigated the effect of training and exercise intensity on blood antioxidant markers in six healthy Standardbred horses. Markers studied were uric acid (UA), ascorbic acid (AA), α-tocopherol, vitamin A (Vit A), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione – reduced (GSH) and oxidized (GSSG), glutathione redox ratio (GRR), copper (Cu), zinc (Zn) and selenium (Se). The horses performed a standardized exercise test (SET) when they were untrained (T0), after 4 weeks of light training (T4) and after 8 weeks of interval training (T12). Forty-eight hours after SET T4 and SET T12, a SET with run up to fatigue (TTF4 and TTF12) was performed. Maximal oxygen consumption (V˙O2max) was determined within 3–5 days after TTF4 and TTF12. At each test (SET T(i) and TTF(i)), venous blood was sampled at rest (R), peak-exercise (Emax), 15 (E15) and 60 (E60) min after the test. UA, AA and GRR were increased significantly by the exercise, whereas GSH and Vit A were decreased significantly (P<0.05). Training-related increases (T0 vs. T4 vs. T12) were observed for UA, SOD, GPx and Se, whereas GSH, α-tocopherol and Zn decreased (P<0.05). Exercise intensity (TTF(i) vs. T(i)) increased UA and AA significantly and decreased GSH significantly (P<0.05). A significant correlation between ΔSOD and ΔV˙O2max (r=0.86, p<0.05) determined at SET T4 and SET T12 was found. Taken together, these results indicate that training and exercise intensity significantly influence blood antioxidant markers in healthy Standardbred horses [less ▲]

The impact of translated tests on student' performances

Conference (2006, July)

Impact of Transport and Dynamical Processes Upon Stellar Oscillation Frequencies

in EAS Publications Series (2007)

In order to prepare the theoretical interpretation of the oscillation frequencies detected by CoRoT, comparisons of results from standard stellar models by the ESTA group have proven to be very useful ... [more ▼]

In order to prepare the theoretical interpretation of the oscillation frequencies detected by CoRoT, comparisons of results from standard stellar models by the ESTA group have proven to be very useful. The next issue which is briefly addressed here is ``what are the additional physical processes that must be included in stellar models computed with different evolutionary codes for the next comparison exercises?'' We therefore discuss the impact on oscillation frequencies of several physical processes which are still poorly understood and/or poorly modelled but cannot be fully discarded. [less ▲]