The Science Journal Nature as part of the celebrations of Darwin’s birth has set up a web site www.nature.com/evolutiongemsan accessible facility for papers published over the last 10 years in Nature which explains and gives examples of the dynamics of evolution by natural selection.
Read moreTwo linked studies, by Fowler and Christakis, and Cohen-Cole and Fletcher, discuss the transmission of health related factors through social networks. That behaviours may spread over time from one person to another through their immediate and more distant social contacts. Social epidemiology has established the relevance of social connectedness for health, and social network transmission…
Read moreCobalamin or vitamin B12 deficiency is common in elderly patients but because of the varied manifestations of this condition may not be recognised. There is a very good review in the QJM by Dali-Yousef and Andres detailing the wide range of clinical, some subtle consequences of B12 deficiency. There is the classical but uncommon pernicious…
Read moreJohn Cummings and others explain a new definition of dietary fibre in the Lancet published January 31st 2009.On November 20th the 30th session of Codex Committee on Nutrition and Foods for Special Dietary Uses met in South Africa and agreed a definition for dietary fibre. Dietary fibre means carbohydrate polymers with ten or more monomeric…
Read moreMustelin et al 2009 Physical activity reduces the influence of genetic effects on BMI and waist circumference: a study in young adult twins. International Journal of Obesity 33, 29–36; Obesity and exercise are influenced by genetic and environmental factors. However, whether obesity and physical inactivity share the same genetic versus environmental etiology has not been…
Read moreHotamisligil has reviewed obesity and its related low grade inflammatory changes. Obesity is associated with chronic low-grade inflammation. Inflammatory signals interfere with insulin action and disrupt metabolic homeostasis. The c-Jun N-terminal kinase (JNK) has been identified as a central mediator of insulin resistance. Recent studies showed that in obesity compromising endoplasmic reticulum (ER) function results…
Read moreVillanueva and M G Myers Jr review the knowledge of Leptin receptor signaling and the regulation of mammalian physiologyThe adipocyte-derived hormone, leptin, signals the status of body energy stores to the central nervous system to regulate appetite and energy expenditure. A specific long-form leptin receptor (LepRb), a type I cytokine receptor, mediates leptin action on…
Read moreThere are five basic tastes- bitter, sweet, umami, sour and salty. Umami is the savoury flavour. The molecular biology of this taste is being revealed by Li and colleagues. The umami taste is due to the amino acid glutamate and enhanced by the ribonucleotides IMP and GMP. Appreciating this taste depends on G-protein coupled receptors…
Read moreSnyder and colleagues ( Environmental Sci Technol 2008 ) have looked for and measured chemicals with biological properties in drinking water from treatment stations across the USA.Of the 51 compounds looked for 34 were detected in at least one sample although not at significant concentrations. The herbicide atrazine and the drugs meprobamate( used in pain…
Read moreMayor has written a fascinating review of the role of telomeres in ageing in the BMJ of 17th January 2009.Chromosome in the body carries a marker that counts down from the day of birth to death, rather like a cellular sand clock. These biological timers are telomeres-repeat sequences of DNA that, together with associated proteins,…
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