Determinations of serum concentrations of total insulin-like growth factor I (tIGF-I) are important in the diagnosis, monitoring of treatment and safety evaluation of patients with growth disorders and/or metabolic disease. It is well established that tIGF-I status varies over time. Changes in tIGF-I levels in relation to an acute bout of exercise or repeated bouts, known as training, are likely to contribute to this variation. Serum tIGF-I has also been found to be of predictive value in growth prediction models employed before the start of growth hormone (GH) treatment. Furthermore, IGF-I generation tests have been suggested to be of value in the assessment of the growth response to GH administration in patients suspected of GH deficiency with or without some degree of GH insensitivity. This is discussed elsewhere in this issue. Recent progress in our understanding of growth hormone-dependent and -independent expression of the IGF1 gene in skeletal muscle and the role of sufficient energy intake during training for muscle and liver generation of IGF-I raises important questions regarding their relative contribution to the circulating pool of IGF-I. The present review is focused on circulating levels of tIGF-I in relation to a single bout of exercise or to a period of training. In addition, the expression of IGF-I locally in muscle in response to these stimuli will be discussed.

No abstract

Nonbonded interactions play an important role in determinng the three-dimensional structure and reactivity of organic molecules. The interaction energy, positive or negative, is usually interpreted in terms of repulsion between electron clouds as a result of the Pauli principle (van der Waals repulsion), London dispersion forces, Coulombic interactions, and delocalization of electrons due to through-space or through-bond interactions between atomic orbitals.Particular interest exists in interactions between alkyl groups, for which van der Waals and London forces

No abstract

An intramolecular NEMO potential is presented for the N-formylglycinamide molecule together with an intermolecular potential for the N-formylglycinamide-water system. The intramolecular N-formylglycinamide potential can be used as a building block for the backbone of polypeptides and proteins. Two intramolecular minima have been obtained. One, denoted as C5, is stabilized by a hydrogen bonded five member ring, and the other, denoted as C7, corresponds to a seven membered ring. The interaction between one water molecule and the N-formylglycinamide system is also studied and compared with Hartree-Fock SCF calculations and with the results obtained for some of the more commonly used force fields. The agreement between the NEMO and SCF energies for the complexes is in general superior to that of the other force fields. In the C7 region the surfaces obtained from the intramolecular part of the commonly used force fields are too flat compared to the NEMO potential and the ab initio calculations. We further analyze the possibility of using a charge distribution obtained from one conformation to describe the charge distribution of other conformations. We have found that the use of polarizabilities and generic dipoles can model most of the changes in charge density due to the different geometry of the new conformations, but that one can expect additional errors in the interaction energies that are of the order of 1 kcal/mol.