Urban Health Challenges in Europe

This article synthesizes diverse official reports, statistics, and scientific papers that present demographic, economic, environmental, and social trends impacting on the health and quality of life of citizens living in European cities. A literature review led to the identification of some key challenges including an aging society, migration flows, inequalities in health, global change, and risk behaviors that should be addressed in order to promote urban health. Other challenges, such as food production and consumption, are also relevant, but not included. Cities that have participated in one or more of the phases of the WHO European Healthy Cities Network have implemented a number of policies, programs, and measures to deal with the challenges discussed in this article. Some contributions are presented to illustrate how health and quality of life in urban areas can be promoted by local authorities.     

Permeability of Fluid-Phase Phospholipid Bilayers: Assessment and Useful Correlations for Permeability Screening and Other Applications

Permeability data (P^lip/w) for liquid crystalline phospholipid bilayers composed of egg lecithin and dimyristoylphosphatidylcholine (DMPC) are analyzed in terms of a mathematical model that accounts for free surface area and chain-ordering effects in the bilayer as well as size and lipophilicity of the permeating species. Free surface area and chain ordering are largely determined by temperature and cholesterol content of the membrane, molecular size is represented by molecular weight, and lipophilicity of the barrier region is represented by the 1,9-decadiene/water partition coefficient, following earlier work by Xiang, Anderson, and coworkers. A correlating variable χ = MWⁿσ /(1–σ) is used to link the results from different membrane systems, where different values of n are tried, and σ denotes a reduced phospholipid density. The group (1–σ)/σ is a measure of free surface area, but can also be interpreted in terms of free volume. A single exponential function of χ is developed that is able to correlate 39 observations of P^lip/w for different compounds in egg lecithin at low density, and 22 observations for acetic acid in DMPC at higher densities, spanning nine orders of magnitude to within an rms error for log₁₀ P^lip/w of 0.20. The best fit found for n = 0.87 ultimately makes χ much closer to the ratio of molecular to free volumes than surface areas. The results serve as a starting point for estimating passive permeability of cell membranes to nonionized solutes as a function of temperature and cholesterol content of the membrane.     

Practice Paper of the Academy of Nutrition and Dietetics Abstract: Promoting Ecological Sustainability within the Food System

Registered dietitians (RDs) and dietetic technicians, registered (DTRs) can implement environmentally responsible practices in their workplace and personal lives. RDs and DTRs who conserve natural resources while minimizing environmental degradation will help maintain sustainability of the food system, which requires knowledge of the external costs of operational and personal decisions. These external costs include energy to produce, transport, and process food; water for food production, preparation, and sanitation; removal of air pollutants; and waste management. As client and public educators, RDs and DTRs are uniquely positioned to meet the growing needs of those seeking guidance on food choices as they relate to ecological sustainability. In an effort to promote ecologically sustainable diets, it is important to consider natural resources as they relate to food production, transformation, distribution, access, and consumption. It is essential that the dietetics community takes a more active leadership role in support of ecological sustainability and social responsibility. RDs and DTRs can influence policy at the institutional, community, local, state, and national levels by presenting results of operational practices and science-based natural resource information. RDs and DTRs are encouraged to become educated and active in implementing sustainable practices and shaping policy in an effort to promote healthier individuals, communities, and the nation as a whole.     

Review of the Toxicology of Three Alkyl Diamines

Three alkyl diamines, which are by-products formed and separated during the production of hexamethylene diamine, have been tested, mostly for their acute toxicity. This paper reviews methodologies used and the results obtained from these three chemicals. All three tested [2-methyl-1,5-pentanediamine (2-MP), 1,3-diaminopentane (DAMP), and 1,2-cyclohexanediamine (DCH)] were 95% pure and were supplied by the DuPont Company. The acute toxicity of all three chemicals is relatively low with acute oral lethal levels in the rat ranging from 1000 to 2300 mg/kg. Single 4-h inhalation exposures show similarly low toxicity with lethality produced in the rat at concentrations ranging from 2.9 to 4.3 mg/L. These diamines are severe skin irritants in both the rabbit and the guinea pig and are also severe eye irritants (studied only in 2-MP). Dermal sensitization was seen in the guinea pig with DAMP and DCH but not with 2-MP. The irritant dose of these materials was shown in repeated exposure inhalation studies when 2-MP and DCH produced irritation in the upper respiratory tract (point of contact) with some lower lung involvement but no significant systemic effects. 2-MP when fed to rats produced a slight body weight effect at dose equivalents of 800 mg/kg with no other parameters affected. All three materials were inactive in Salmonella, and 2-MP did not produce chromosomal aberrations in cultured human lymphocytes. The main effects of this series of diamines appear related to their irritant properties, and attention needs to be paid to their delayed hypersensitivity potential.     

The Potassium Load From Blood Transfusion

The blood components used in transfusion are a source of exogenous potassium, a critical factor if a patient's potassium intake should be limited. The physician cannot evaluate the total potassium load in a transfusion from plasma values alone; he must also consider red blood cell lysis. The potassium level of stored blood increases with duration of storage, and during the first 24 hours after transfusion, the erythrocytes lyse in vivo, releasing potassium to the extracellular fluid.