Maximum nutritional response to poor-quality protein and amino acid utilisation.

1. Although the theory of responses to amino acids suggests that, providing sufficient of the limiting amino acid is fed, it should be possible to elicit maximum growth response, maximum response is not usually elicited by poor quality proteins. 2. It has been suggested that this failure to elicit maximum response is a reflection of poorer limiting amino acid utilisation from poor-quality proteins. This interpretation conflicts with the theory of general amino acid imbalance which proposes that amino acid excesses do not impair the utilisation of the limiting amino acid. 3. Three protein mixtures of different quality were made by mixing maize gluten meal and soyabean protein concentrate in constant proportions, supplementing with tryptophan, threonine and arginine to adequacy and varying amino acid score (0.62, 0.71 or approximately 10) by varying additions of free lysine. The 3 mixtures were diluted with protein-free ingredients to produce 3 diet series, each providing 3.7, 6.5, 9.2, l2.0, 14.8 and 17.5 g lysine per kg. Each diet was fed to 4 cages of 2 chickens each from 4 to 14 d of age in a randomised block experiment. Food intake, body-weight and body-nitrogen gain were measured. 4. Differences in protein quality were confirmed by regression analyses of bodyweight response to protein intake (Net Protein Ratio) and body-nitrogen response to nitrogen intake (Net Protein Utilisation) in the linear range. Regression analyses in the linear range of body-weight or body-nitrogen response to lysine intake showed no adverse effect of protein quality on lysine utilisation. Curvilinear analysis (Reading flock response model) confirmed this finding. 5. Maximum response could not be obtained with the poorest protein quality. It is illogical to invoke impaired utilisation of the limiting amino acid to explain this. A small decrease in net energy yield of the diet may be sufficient to explain the effect, but it is more likely that the depletion of the limiting amino acid from tissue (muscle) protein which results from feeding poor-quality protein explains the effect.

Acquaintance rape.

The author examines how culturally learned sex roles and myths about rape come together to give acquaintance rape a status somewhere between accepted practice and unacceptable crime. Risk factors, barriers to reporting rape, and factors that make college students a vulnerable group, are discussed. Institutional programs and resources are highlighted, along with a new educational approach using small group workshops.

Excretion patterns of cannabinoid metabolites after last use in a group of chronic users.

The urinary excretion patterns of 86 chronic cannabis users were examined after their last cannabis use by two common screening methods, the semiquantitative EMIT-d.a.u. and the qualitative EMIT-st (Syva Company). We demonstrated that under very strictly supervised abstinence, chronic users can have positive results for cannabinoids in urine at 20 ng/ml or above on the EMIT-d.a.u. assay for as many as 46 consecutive days from admission, and can take as many as 77 days to drop below the cutoff calibrator for 10 consecutive days. For all subjects, the mean excretion time was 27 days. Subject excretion patterns were clearly biphasic, with initial higher rates of excretion not sustained. During the subsequent period of leveling off, most subjects had one or more separate sequences of cannabinoid-negative urine test results, lasting a mean of 3 days each and followed by at least one positive result. Demographic, body type, and drug history variables proved to be only moderate predictors of excretion patterns. Findings were discussed in the context of potential clinical and forensic application.

Ethanol- and isoprenaline-induced responses in pig parenchymal lung tissue.

Ethanol (8.7-34.8 mM; 0.5-0.20% v/v) had no significant effect on spontaneously developed tension in pig lung parenchyma strips, although higher cumulative concentrations caused relaxation (at 34.8-174 mM) and contraction (at 348-1392 mM). Ethanol-induced effects were not caused by activation of adrenoceptors or of cholinoceptors, since blockade of these receptors did not alter those effects. Single low concentrations of ethanol (8.7-34.8 mM) which can occur in-vivo in man, caused increases in the relaxant potency of isoprenaline in pig lung strips, although the sizes of these increases varied widely. In addition, ethanol-induced potentiation of isoprenaline was not concentration-related. This effect was not caused by inhibition of isoprenaline uptake since [3H]isoprenaline transport was found not to be significantly altered in the presence of ethanol (8.7-34.8 mM).