Global strategy for asthma management and prevention

So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

Human biochemical genetics

A review of 144 published studies of the relationship between socioeconomic status (SES) and obesity reveals a strong inverse relationship among women in developed societies. The relationship is inconsistent for men and children in developed societies. In developing societies, however, a strong direct relationship exists between SES and obesity among men, women, and children. A review of social attitudes toward obesity and thinness reveals values congruent with the distribution of obesity by SES in different societies. Several variables may mediate the influence of attitudes toward obesity and thinness among women in developed societies that result in the inverse relationship between SES and obesity. They include dietary restraint, physical activity, social mobility, and inheritance.

Socioeconomic Status and Obesity: A Review of the Literature

Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

https://www.zora.uzh.ch/id/eprint/77770/1/physiol_rev_93.pdf

About sleep's role in memory

During the past decade, possible advancement in timing of puberty has been reported in the United States. In addition, early pubertal development and an increased incidence of sexual precocity have been noticed in children, primarily girls, migrating for foreign adoption in several Western European countries. These observations are raising the issues of current differences and secular trends in timing of puberty in relation to ethnic, geographical, and socioeconomic background. None of these factors provide an unequivocal explanation for the earlier onset of puberty seen in the United States. In the formerly deprived migrating children, refeeding and catch-up growth may prime maturation. However, precocious puberty is seen also in some nondeprived migrating children. Attention has been paid to the changing milieu after migration, and recently, the possible role of endocrine- disrupting chemicals from the environment has been considered. These observations urge further study of the onset of puberty as a possible sensitive and early marker of the interactions between environmental conditions and genetic susceptibility that can influence physiological and pathological processes.

/pdf/the-timing-of-normal-puberty-and-the-age-limits-of-sexual-4uewdfubug.pdf

The timing of normal puberty and the age limits of sexual precocity: variations around the world, secular trends, and changes after migration

Secular changes in growth and maturation in recent decades have been reviewed for various populations. The secular increase in attained height during the growth period is continuing in most countries, but has slowed down. The increase in adult stature over the past decades has varied between 0.3 and 3.0 cm/decade. The secular trend in the tempo of growth (earlier menarche and peak height velocity, and shortening of the growth cycle) has come to a halt in some populations, but is continuing or has been reversed in others. The secular trend in attained height and in the tempo of growth is usually more pronounced in children from low socioeconomic backgrounds, in those with poorly educated parents or in those from rural areas. It is concluded that updates of growth standards are required in all populations. More marked secular changes appear to occur in the lower height centiles, which may have direct implications on the future definition of 'short stature' in a population.

Secular changes in growth and maturation: an update.

SummaryStudy has been made of 37 anthropometric measurements in a socially selected sample of 125 Belgian families, comprising parents and adult children. The parent-child and mid-parent-child correlation coefficients indicate that the extent of genetic determination varies considerably from one measurement to another, being greatest in the longitudinal body measurements, least in the circumferences involving soft tissues and in measures of the nose and mouth.Further analysis of the intrafamilial correlation, and variance analysis by the method of Fisher and Gray (1937), shows that neither dominant nor X-linked loci exert any appreciable effects.

Genetic and environmental influences on morphological characteristics

Secular changes in growth have occurred in almost all industrialized countries during the last century. Almost all of the secular increase seen in adult height occurs during childhood. These changes can be considered to be indicators of the changes in the nutritional, hygienic and health status of a population. The secular trend in adult height has slowed down since the second world war, but is still continuing in most industrialized countries.

Secular changes in growth

Nutrition and growth

Growth in height, bone age, and sexual maturation have been studied in asthmatic boys 2 to 20 yr of age. The mean pattern of growth in height has been analyzed mixed-longitudinally in 531 patients (1,754 measures) and seemed to be determined by a delay in physiologic maturation. The asthmatic boys' growth in height showed no retardation during infancy, a small but consistent retardation during childhood, a more pronounced delay at adolescence, and a catch-up growth toward adulthood. The mean adolescent growth spurt is delayed by about 1.3 yr. Bone age has been analyzed mixed-longitudinally in a subsample of 370 patients (660 observations) and showed a slight retardation at all ages between 6 and 13 yr. Development of pubic hair of 91 subjects analyzed cross-sectionally was definitely retarded when compared to adequate reference data. Evidence was given that factors secondary to the asthmatic syndrome are involved in the retardation of growth and development.

https://www.jacionline.org/article/0091-6749(77)90150-6/pdf

Charles Susanne

Papers

Secular changes in growth and maturation: an update.

Genetic and environmental influences on morphological characteristics

Secular changes in growth

Nutrition and growth

Maturational delay and temporal growth retardation in asthmatic boys.