Obese, overweight, desirable, ideal: where to draw the line in 1986?

In February 1985, the National Institutes of Health sponsored the Consensus Development Conference on the Health Implications of Obesity. The panel of experts concluded that height and weight tables based on mortality data and the body mass index (BMI) are helpful measures to determine the presence of obesity and the need for treatment. For the dietitian, however, practical concerns arise regarding which index to select. The usefulness of the BMI in patient education and contradictions between the 1959 and 1983 Metropolitan Life Insurance height-weight tables are discussed. A temporary solution is offered in light of the need for further investigation into morbidity experience at weights recommended in the 1983 table.     

Response of rats to diets of equal chemical score: effect of lysine or threonine as the limiting amino acid and of an amino acid excess

The effect of lysine or threonine deficiency with or without excesses of all other amino acids was evaluated in a 21-d feeding study with male rats. Four amino acid mixtures were designed to be first limiting for the rat in lysine or threonine and contained either 0 or 50% excess of nonlimiting amino acids. These mixtures were incorporated into purified diets to provide seven levels [20-140% of the National Research Council (NRC) requirement] of the limiting amino acid. Food intake, body weight gain and carcass composition were measured for each rat to determine the effects of the identity of the limiting amino acid and of amino acid excess on the response to dietary chemical score. Significant effects and/or interactions of the identity of the limiting amino acid (i.e., Lys or Thr) and the presence of excess amino acids were seen for each of the measured responses. At equivalent dietary percentages of the NRC requirement, threonine deficiency supported greater body weight gain than did lysine deficiency. At equivalent deficiencies (Lys vs. Thr) threonine-deficient rats were more susceptible to adverse effects of excess amino acids. When the limiting amino acids were incorporated into the diet through incremental addition of the deficient amino acid mixture, rats responded to levels of lysine or threonine in excess of the NRC requirement. These results suggest that the current NRC requirements for these amino acids are too low and that aspects of the dietary amino acid composition other than the percentage deficit of the limiting amino acid can be important determinants of animal response.     

Etiological heterogeneity in Hodgkin's disease: HLA linked and unlinked determinants of susceptibility independent of histological concordance

Forty-one multiplex families, from published sources and new data from the National Cancer Institute, segregating for Hodgkin's disease and HLA, have been studied. A reanalysis of these data strongly suggests a recessive mode of inheritance for susceptibility to Hodgkin's disease. The HLA haplotype sharing data between affected relatives demonstrate that approximately 60% of cases in multiplex families are due to an HLA-linked susceptibility gene, the remaining 40% being due to other familial factors. The data clearly support the hypothesis of etiological heterogeneity for Hodgkin's disease, with both HLA-linked and HLA-unlinked factors being responsible. Finally, there is an increased concordance of histological types between affected relatives, but this concordance seems independent of HLA sharing.     

Modelling the interaction of small organic molecules with biomacromolecules. III. Interaction of benzoates with anti-p-(p'-azophenylazo)benzoate antibody

A novel approach for modelling the biological activity of organic molecules, which requires simultaneous consideration of the influence of all factors (topological, steric, hydrophobic, and electronic) that determine the bioactivity, is used to study the interaction of a series of benzoates with anti-p-(p'-azophenylazo)benzoate antibody. The results obtained suggest that this biological interaction proceeds by a two-step stereospecific mechanism. The first step requires a geometrical correspondence between the benzoates and the cavity in the biomacromolecule, which enables the pharmacophore to come into close contact with the receptor. The second step is the orbitally controlled electronic interaction between the active parts of the benzoates and the antibody. The electronic interaction results from pi-charge transfer from the pharmacophore to the biomacromolecule and from the formation of pi-complexes. A proposed mathematical model for this biological interaction exhibits some statistical advantages over existing models.