Developmental variations in plasma leptin, leptin soluble receptor and their molar ratio in healthy infants

<p>Abstract</p> <p>Background</p> <p>Leptin and its soluble receptor (sOB-R) are important to regulation of body composition but there are no data on the developmental variations in these plasma variables and their relationship with body composition measurements,</p> <p>Methods</p> <p>Weight, length, and body composition (bone, fat and lean mass) by dual energy absorptiometry, and plasma variables were measured in healthy infants at 2, 4, 8 and 12 months.</p> <p>Results</p> <p>15 whites and 29 African Americans (21 males and 23 females) with mean birth weight 3357 +/- 45 (SEM) g and gestation of 39.3 +/- 0.17 weeks were studied. The overall Z score for weight, length and weight for length during the study were 0.00 +/- 0.15, -0.08 +/- 0.11 and 0.12 +/- 0.14 respectively. With increasing age, plasma leptin (1.0 to 18.2, median 5.5 ng/mL) and sOB-R:leptin molar ratio (10.1 to 247.4, median 59.9) were lowered (r = -0.47, p < 0.01; and r = -0.37, p < 0.05 respectively), best predicted by weight Z score and percentage of fat mass, and higher in African American and female. Presence of body composition measurements eliminated the race and gender effect on the plasma variables. Plasma sOB-R (49.5 to 173.9, median 81.3 ng/mL) did not change significantly with age and was correlated and predicted only by body composition measurements.</p> <p>Conclusion</p> <p>In healthy growing infants, plasma leptin but not sOB-R decreases with age. Gender, race and anthropometric measurements are additional physiological determinants predictive of plasma leptin and the receptor:ligand ratio. However, body composition is the only variable that can predict plasma leptin and its soluble receptor and the receptor: ligand ratio; and body composition measurements eliminated the race and gender effect on these plasma variables.</p

A rise in NAD precursor nicotinamide mononucleotide (NMN) after injury promotes axon degeneration.

NAD metabolism regulates diverse biological processes, including ageing, circadian rhythm and axon survival. Axons depend on the activity of the central enzyme in NAD biosynthesis, nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2), for their maintenance and degenerate rapidly when this activity is lost. However, whether axon survival is regulated by the supply of NAD or by another action of this enzyme remains unclear. Here we show that the nucleotide precursor of NAD, nicotinamide mononucleotide (NMN), accumulates after nerve injury and promotes axon degeneration. Inhibitors of NMN-synthesising enzyme NAMPT confer robust morphological and functional protection of injured axons and synapses despite lowering NAD. Exogenous NMN abolishes this protection, suggesting that NMN accumulation within axons after NMNAT2 degradation could promote degeneration. Ectopic expression of NMN deamidase, a bacterial NMN-scavenging enzyme, prolongs survival of injured axons, providing genetic evidence to support such a mechanism. NMN rises prior to degeneration and both the NAMPT inhibitor FK866 and the axon protective protein Wld(S) prevent this rise. These data indicate that the mechanism by which NMNAT and the related Wld(S) protein promote axon survival is by limiting NMN accumulation. They indicate a novel physiological function for NMN in mammals and reveal an unexpected link between new strategies for cancer chemotherapy and the treatment of axonopathies

ROTATIONAL TRANSITIONS IN THE INTERACTING ν2\nu_2 , ν3\nu_3 , ν4\nu_4 AND ν6\nu_6 BANDS OF FORMALDEHYDE IN H212_2^{12}C16^{16}O THE MILLIMETER RANGE FOR ASTROPHYSICAL USE

[1]Mangum-JG ; Wootten-A ; Barsony-M , Astrophys. J.[2]D. C. Reuter, H. Takeo, S. Nadler, S.J.Daunt, and J. W. C. Johns, J. Chem. Phys.[3]F. Kwabia Tchana, A. Perrin and N. Lacome, J. Mol. Spectrosc.Author Institution: Laboratoire PhLAM, CNRS UMR 8523, Universite de Lille 1, Bat. P5, 59655 Villeneuve d'Ascq Cedex, France.; Laboratoire Inter Universitaire des Systemes Atmospheriques, CNRS UMR 7583, Universite Paris 12, 61 Av du General de Gaulle, 94010 Creteil Cedex France.; I. Physikalisches Institut, Universitat zu Koln, 50937 Koln, Germany.This work, besides its fundamental interest, is motivated by the astrophysical importance of formaldehyde. For example formaldehyde was detected by millimeter techniques in Orion-KL and in several low-mass protostars }} {\textbf{526}} 845-53 (1999)}. However, no line parameters are presently available in the spectroscopic databases for the rotational transitions within the 2$^{1}$, 3$^{1}$, 4$^{1}$ and 6$^{1}$ first excited vibrational states of formaldehyde. The goal of this study is to generate a list of line parameters for these "hot" transitions in order to help such - may be - future identifications in astrophysical spectra. For this reason, submillimeter spectra were recorded at Lille and at Koln in the 150-650 and 850-900 GHz spectral ranges, respectively. These sub millimeter data were combined in a least squares fit calculation with the infrared experimental data available in the literature for the $\nu_3$, $\nu_4$ and $\nu_6$ bands }} {\textbf91}, 646 (1989)}, and for the $\nu_2$ band }} {\textbf{245}}, 141-144, (2007)}. The Hamiltonian model accounts for the various Coriolis-type resonances which perturb the energy levels of the 3$^{1}$, 4$^{1}$ and 6$^{1}$ vibrational states. In addition a weaker and somehow unexpected anharmonic resonance coupling the 2$^{1}$ and 3$^{1}$ energy levels was accounted for.Using this theoretical model, it proved possible to reproduce satisfactorily the experimental data and to generate a list of line positions and intensities for the $\nu_2~\leftrightarrow~\nu_2$, $\nu_3~\leftrightarrow~\nu_3$, $\nu_4~\leftrightarrow~\nu_4$, and $\nu_6~\leftrightarrow~\nu_6$ rotational transitions