Neural-immune interactions in health and disease.

Iron Deficiency Associated with Higher Blood Lead in Children Living in Contaminated Environments

“…Both iron deficiency and lead exposure disproportionately affect minority, poor, and urban children (10). Because iron deficiency has independent effects on cognitive functioning in children that are similar to those of lead poisoning (1,8,27,65,66), there should be important prophylactic benefits for children's health and development if organized intensive iron deficiency screening, nutritional counseling, and supplementation were implemented in areas where children are at high risk of both conditions (67). Because the relationship between nutritional factors and blood lead is likely to be a complex interaction of nutritional status, individual diurnal and secular nutrient intake patterns, meal frequency, behavior, caregiver ability, and environmental contamination, additional research is urgently needed to validate current hypotheses and quantify the specific benefits of sufficient iron status while accounting for calcium and other major nutrient cations.…”

“…In contrast, chronic overactivity (or underactivity) of these same mediators may result in allostatic load (i.e., potential immunosuppressive effects when the mediators are chronically secreted or not turned off). Some optimal level of mediators is needed to maintain a functional balance, and the absence of appropriate levels of gluccocorticoids and catecholamines may allow other immune mediators to overreact and increase the risk of inflammatory disorders (27). In this framework, violence can be conceptualized as a psychosocial environmental exposure that can "get into the body" and result in biological changes that may contribute to asthma morbidity.…”

“…Similarly, it is possible that Pb +2 may occupy vacant Fe +2 sites in the hematopoeitic system, thereby reducing lead excretion. Clinical studies of chelation therapy suggest that irondeficient children may retain more lead in their bodies (26,27). It is also possible that iron deficiency modifies behavior, increasing pica or hand-to-mouth behavior in children and thereby increasing ingestion exposures to lead in their environment (28,29).…”

A new animal welfare concept based on allostasis

“…When allostatic load is chronically high, pathologies may develop due to "wear and tear" [11] (Table 3). Allostatic load may also be very low as a consequence of hypostimulation, for instance, different diseases like allergic reactions, inflammatory/autoimmune disease, fatigue states and atypical depression are associated with blunted hypothalamic-pituitary adrenal axis [31]. Also, in the brain, chronic hypostimulation (e.g.…”

The immune system as the sixth sense

“…This apparently occurs via the effects of products of the hypothalamic-pituitary-adrenal axis on immune cells. An impairment of this axis to appropriately respond to inflammatory stressors, as in deficient corticotropin-releasing hormone (CRH) release, has been shown to predispose an animal to autoimmune disease as a result of lack of regulation of the immune system [65].…”