Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Jan 2008
Poverty: the double burden of malnutrition in mothers and the intergenerational impact.
Women are doubly vulnerable to malnutrition, because of their high nutritional requirements for pregnancy and lactation and also because of gender inequalities in poverty. Undernutrition and overnutrition coexist in developing countries undergoing rapid nutrition transition, and women are susceptible to this double burden of "dysnutrition," often cumulating stunting or micronutrient malnutrition with obesity or other nutrition-related chronic diseases. ⋯ Addressing malnutrition and nutrition-related chronic diseases simultaneously is a challenge facing developing countries, and examples of promising initiatives are provided. Focusing on women along the lifecycle, according to the continuum of care approach, is essential to achieving the Millennium Development Goals and to breaking the intergenerational cycle of poverty, malnutrition, and ill-health.
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Ann. N. Y. Acad. Sci. · Jan 2008
Peptide-toxin tools for probing the expression and function of fetal and adult subtypes of the nicotinic acetylcholine receptor.
Although the neuromuscular nicotinic acetylcholine receptor (nAChR) is one of the most intensively studied ion channels in the nervous system, the differential roles of fetal and adult subtypes of the nAChR under normal and pathological conditions are still incompletely defined. Until recently, no pharmacological tools distinguished between fetal and adult subtypes. Waglerin toxins (from snake venom) and alphaA(S)-conotoxins (from cone-snail venom) have provided such tools. ⋯ We have used the peptides and their fluorescent derivatives to explore the expression and function of the fetal and adult nAChR subtypes. While fluorescent derivatives of these peptides indicated a gradual transition from fetal to adult muscle nAChRs in mice during the first 2 weeks postnatal, we unexpectedly observed a steeper transition in functional expression in the mouse diaphragm muscle using electrophysiology. As a toolkit of pharmacological agents with complementary specificity, alphaA-OIVA[K15N] and Waglerin-1 should have further utility in determining the roles of fetal and adult nAChR subtypes in development, in mature tissues, and under pathological conditions.
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Ann. N. Y. Acad. Sci. · Jan 2008
Structural factors influencing the efficacy of neuromuscular transmission.
Neuromuscular junctions (NMJs) in different species share many features of structure and function. At the same time, important differences distinguish, for example, human NMJs from those in other species. An understanding of the biological context of the human NMJ helps in the interpretation of the effects of disease on the biophysical properties of neuromuscular transmission. ⋯ A genetic influence on NMJ size has recently been discovered in some patients with limb-girdle myasthenia (LGM). Mutations of the gene encoding Dok-7, an essential component of the agrin-muscle-specific kinase pathway that controls postsynaptic differentiation at the mammalian NMJ, results in impaired transmission because the NMJs are abnormally small and have reduced folding but have a normal local density of normal acetylcholine receptors. This condition emphasizes the importance of structural features in achieving reliability of neuromuscular transmission.