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Biomedical subjects

L Dye

Publications and source records attributed to L Dye.

7 recordsLinked to original sources

The assessment of menstrual synchrony: comment on Weller and Weller (1997)

A. Weller and L. Weller (1997) claimed to report "the definitive study of menstrual synchrony" (p. 148). To allow for cycle variability, they used the following criterion for synchrony: It occurred in 2 out of 3 months. The underlying assumption of the state of menstrual synchrony is that cycle length variability is minimal. The present article uses a random selection of cycle lengths from a distribution described by R. F. Vollman (1977) to illustrate how variable cycle lengths cause a fluctuation from synchrony to a synchrony. A. Weller and L. Weller's (1997) study is not, therefore, conclusive, and future studies of menstrual synchrony should include an assessment of cycle variability as well as onset difference.

Female

Infection of human primary renal epithelial cells with HIV-1 from children with HIV-associated nephropathy.

Children affected with human immunodefficiency virus (HIV)-associated nephropathy (HIVAN) usually develop significant renal glomerular and tubular epithelial cell injury. The pathogenesis of these changes is not clearly understood. Human renal tubular epithelial cells (RTEc) do not express CD4 surface receptors, and it is not clear whether these cells can be infected by HIV-1. Certain strains of HIV-1, however, have been shown capable of infecting CD4-negative epithelial cell lines. We hypothesized that the inability of laboratory strains of HIV-1 to infect renal epithelial cells may be due to a limited tropism, as opposed to wild-type viruses derived from children with HIVAN, and that viruses derived from these children are capable of infecting RTEc from the same patient. Here, we have demonstrated that HIV-1 isolates from children with HIVAN can productively infect RTEc through a CD4 independent pathway, and that infected mononuclear cells can transfer the virus to human RTEc. Human RTEc sustained low levels of viral replication and HIV-1 inhibited the growth and survival of cultured human RTEc. Thus, HIV-1 may directly induce degenerative changes in RTEc of children with HIVAN. Infected macrophages may play a relevant role in this process by transferring viruses to RTEc.

AIDS-Associated Nephropathy

Functional food science and behaviour and psychological functions.

The impact of ingesting various foods on psychological and behavioural functions is a topic of both interest and concern to the general public. In this article, the scientific literature concerning demonstrated cause-and-effect relationships is reviewed, beginning with methodological considerations specific to the quantification of particular behaviours and psychological events. The essential function of food is to satisfy hunger and the need for essential nutrients. The contributions of macronutrients to appetite and satiety are described, as well as their impact on metabolism and energy balance. Functional properties of macronutrient substitutes (high-intensity sweeteners, fat replacers) and flavour enhancers are examined in relation to their contribution to hunger, satiety, and energy balance. The effects of foods and individual nutrients on the performance of diverse psychomotor tasks are studied with consideration given to the various validated quantitative tools used to assess behaviour. The effects of food components on activation, sedation, and affective states such as dysphoria are also reviewed, with special attention given to brain function and neuroactive substances such as serotonin and the endorphins. The case of hyperactivity in children is given special emphasis with reference to the potential influence of sugar and food additives. Safety issues related to food constituents and additives are discussed. Finally, a set of criteria is proposed for the evaluation and elaboration of studies in the behavioural and psychological fields, along with suggestions for future research.

Affect

Menstrual cycle and appetite control: implications for weight regulation.

Hormonal fluctuations associated with the menstrual cycle influence appetite control and eating behaviour. Energy intake varies during the reproductive cycle in humans and animals, with a periovulatory nadir and a luteal phase peak. Patterns of macronutrient selection show less consistency but a number of studies report carbohydrate cravings in the premenstrual phase, particularly in women with premenstrual syndrome. The cyclical nature of food cravings are frequently, but not invariably, associated with depression. Fluctuations in appetite, cravings and energy intake during the menstrual cycle may occur in parallel with cyclical rhythms in serotonin, which can be accompanied by affective symptoms. The premenstrual phase can be considered as a time when women are especially vulnerable to overconsumption, food craving and depression; this is often associated with low serotonin activity.

Affect

Food craving during the menstrual cycle and its relationship to stress, happiness of relationship and depression; a preliminary enquiry.

The associations between retrospective ratings of food craving and depression during the premenstrual, menstrual and postmenstrual phases of the preceding menstrual cycle and ratings of current levels of stress and happiness of relationship were examined in 5,546 women. In each phase examined, the severity of food craving was very strongly related to the reported severity of depression. Overall levels of food craving were inversely related to happiness of relationship and there was some interaction of this effect with on-going stress. However, once the effect of depression was accounted for there was no effect of either current stress or happiness of relationship on the cycle-related pattern of food craving and in general the magnitude of the effect of these psychosocial variables was very small compared with that of depression. Food cravings were also reported in the absence of depression, tending to show a cycle-related pattern, maximal premenstrually, declining during menstruation and further postmenstrually. Whilst this is consistent with a cycle-related biological explanation, it remains unclear whether the striking amplification of food craving ratings in association with co-existing depression, in all three phases examined, is also biologically based or dependent on psychological mechanisms. In view of the retrospective nature of the ratings of mood and craving and the limited assessment of stress and happiness of relationship, these findings should be regarded as preliminary. They are, however, of potential importance and the association between these two common phenomena deserves further study.

Adult