oxysterols and T cells

To my thinking, control mechanisms always have the potential for a role for nutrition,somewhere nutrition will fit into the scheme. Adaptive immune responses depend on the activation and expansion of specific subsets of white blood cells such as T cells in response to antigens. Although it has long been known that such proliferative responses are linked to the uptake and de novo synthesis of cholesterol for membrane formation, whether cholesterol-efflux pathways can limit cell division has not been considered. Reporting in Cell, Bensinger et al: have produced evidence that cholesterol efflux inhibits the proliferation of resting T cells, T cells that have not yet encountered an antigen.
Intracellular cholesterol levels are tightly regulated by two complementary pathways that are mediated by the gene transcription factors SREBP and LXR. The SREBP-dependent pathway induces the expression of proteins that are required for cholesterol biosynthesis and uptake, such as HMG CoA reductase and the LDL receptor, thereby increasing cellular cholesterol levels. This pathway is regulated by feedback inhibition, but it cannot eliminate excess cholesterol once this lipid has accumulated. That task is in part accomplished by cholesterol-efflux pathways that are regulated by LXRα, and LXRβ, members of the nuclear-receptor superfamily Oxidized cholesterol derivatives (oxysterols) activate LXRs, which then control the transcription of genes that have diverse roles in cholesterol homeostasis and innate immunity.In many cell types LXRs promote a reduction in cellular cholesterol levels by inducing the expression of the ABCA1 and ABCG1 transporters, which mediate cholesterol efflux from the cell to extracellular acceptors.
Glass and Saijo 2008 Oxysterols hold T cells in check Nature vol 455 pp 40-41

benefits of exercise in the elderly

This study in Northern Italy in elderly Italians ( 65-91 years old ) showed that physical activity in an elderly Italian protected against the characteristic features of the metabolic syndrome. Physical Activity Scale for the Elderly was inversely correlated with waist circumference, triglyceride and fasting insulin concentration. Any leisure time activity , walking, dancing or sport activity is equally beneficial. Even those who began to exercise later in life benefited and those who used to exercise and gave exercise up did less well. Walking for 45-75 min / week gives substantial benefit.
Bianchi et al 2008 Physical activity is negatively associated with the metabolic. syndrome in the elderly QJM vol 101 pp 713-721
Song 2008 Physical activity in the elderly-is it never too late QJM vol 101 pp 743-744

Myocardial infarctionprevalence modern Greece

Greece is a country where in the original 7 countries study the prevalence of myocardial infarction in rural Greece was only 0.3% in middle aged men. Now the prevalence is comparable to the USA and rising. This is in contrast to other countries where the prevalence is falling.
Importantly here is a country where the Mediterranean diet is the rule. Or is it any more. Diets are changing , modes of life are changing, smoking is increasing as is the prevalence of diabetes, smoking, high blood pressure hypercholesterolaemia.
Who knows if the amount and type of cigarette is important. But why are people abandoning their traditional food for a more unhealthy diet? Or is there another element to this story?
Gikas et al 2008 Prevalence trends for myocardial infarction and conventional risk factors among Greek adults ( 2002-06) QJM vol 101 705-712
Birtwhistle What ever happened to the Mediterranean diet 2008 vol 101 741-742

Holstein-Friesian dairy cows

When I was in my teens I milked a large herd of Friesian cows. I have always had affection for these gentle massive converters of green grass into white milk.
They are the largest dairy breed in the world
8.57 million in USA
2.6 1 millions Poland
2.17 Millions UK
2.15 millions German
1.4 millions Italy
1.2 millions Ireland
Their average weight is 675 kg and now produces some 7000 litres of milk per year. The advent of artificial insemination has increased the capacity of any one bull to inseminate many cows, one bull has 50,000 daughters by this method.
There are however 240 million dairy cows in the world.
Lavelle FT weekend September 6/7 2008

scurvy is still here

As a the waiting physician in a busy Accident and Emergency Department there was always the chance of seeing classical diseases including scurvy. This was usually in outcasts of society living rough.
The Lancet of September 13th 2008 p 1008 describes a poor unemployed divorced man livig on the edge of society and schizophrenic. He had advanced scurvy and responded to treatment and social rehabilitation
A timely reminder

Added iodine to salt, a warning

There is an important letter in the Lancet
Lazarus and Smyth 2008 Lancet Iodine deficiency in the UK and Ireland p 88
which is a reminder of the need for added iodine in our diets. The principle source is added iodine to salt but this practice is now rarely used.
50% of pregnant women in North East England, Wales and Scotland are at risk of iodine deficiency. . This is something we should be aware of.

Primary health care and Alma-Ata Declaration

30 years ago, 134 WHO member states gathered as a conference on international primary health care. On Sept 12, 1978, the Alma-Ata Declaration was signed, with the ambitious target of achieving "Health for All by 2000".
In 1978, 2000 million people were estimated to have no access to adequate health care. There were large inequalities between rich and poor countries, and between rich and poor populations within countries. The Alma-Ata Declaration revolutionised the world's interpretation of health. Its message was that inadequate and unequal health care was unacceptable: economically, socially, : and politically. Unfortunately, the goal of "health for all", while a rallying call to action, was not met.
30 years on, primary health care is still offering global health a lifeline. Weak health systems have restricted the success of efforts to improve maternal, newborn, and child health, and to reduce the disease burden from malaria and tuberculosis. New epidemics of chronic disease threaten to reverse what small gains have been achieved. Countries need to strengthen their health systems through the implementation of effective primary health care.
Many of the challenges faced in 1978 remain, such as infectious diseases (eg, the ongoing threat of H5N1 avian influenza and HIV/AIDS), political instability and conflict (most recently seen in Iraq and Zimbabwe), and worsening poverty (the World Bank last month estimated that 1-4 billion people now live in poverty).
The Lancet of September 13th 2008 page 863 revisits, updates, and relaunches the key messages from Alma-Ata. A series of eight papers outlines the picture. A magnificent overview of a vital subject and one which is central to Nutrition.

The potato

Propitious esculent : The potato in World History John Reader Publisher William Heinemann
Reviewed in Nature by Sandra Knapp Potatoes and poverty Nature 2008 vol 455 pp 170-71
This book is devoted to a most important vegetable , the potato which has sustained impoverished populations world wide. Originating in South America. One of the great sights in a country such as Bolivia is to see farmers wife’s sitting by heaps of potatoes in the markets, each pile a different potato.
The reviewer does not gush about this book, but it must be a valuable contribution to our knowledge of this important item of food.

hospital food plans

In the olden days ward sisters ruled over the in patient community. One of her treasured skills was the provision of dietary treats to the ill, regardless of the time of day and night. Now we have Health and Safety , food bought long distances in lorries and strict and brief timetables for eating. No wonder that patients loose weight in Hospital
The penny takes some time to drop but now the National Patient Safety Agency is suggesting that all patients should have access to food and fluid 24 hours a day and that there is a food plan in place for each patient and nutritional screening.
Not before time.
See www.npsa.nhs.uk

microRNA and control of proteins

MicroRNAs ( m1RNAs) are RNA sequences some 23 nucleotides long. They are crucial to gene expression. As part pf a RNA-protein complexes they form complementary bas pairs with their target complementary RNA sequences. These influence mRNA degradation and repress the translation of the mRNA into protein. Individual micro RNA sequences can suppress the production of hundreds of proteins, the effect is subtle and modest but very important in the fine tuning of protein synthesis. An important route whereby miRNA interact with the target mRNAs is through “seed sites”. These are specific short sequences in both miRNA and the corresponding sequence in the mRNA.
Selbach et al have shown many of these control systems in a recent paper in Nature. Does this matter to a nutritionist. First it is important biology and somewhere in her food must have a role
Selbach et al Nature 2008 Widespread changes in protein synthesis induced by microRNAs vol 455 pp 58-63
Baek et al Nature 2008 The impact of microRNAs on protein output vol 455 pp 64-71
Mourelatos Z Nature 2008 The seeds of silence vol 455 pp 44-45

microRNA and control of proteins

MicroRNAs ( m1RNAs) are RNA sequences some 23 nucleotides long. They are crucial to gene expression. As part pf a RNA-protein complexes they form complementary bas pairs with their target complementary RNA sequences. These influence mRNA degradation and repress the translation of the mRNA into protein. Individual micro RNA sequences can suppress the production of hundreds of proteins, the effect is subtle and modest but very important in the fine tuning of protein synthesis. An important route whereby miRNA interact with the target mRNAs is through “seed sites”. These are specific short sequences in both miRNA and the corresponding sequence in the mRNA.
Selbach et al have shown many of these control systems in a recent paper in Nature. Does this matter to a nutritionist. First it is important biology and somewhere in her food must have a role
Selbach et al Nature 2008 Widespread changes in protein synthesis induced by microRNAs vol 455 pp 58-63
Baek et al Nature 2008 The impact of microRNAs on protein output vol 455 pp 64-71
Mourelatos Z Nature 2008 The seeds of silence vol 455 pp 44-45

Hunger strikers

Hunger strikes
Hunger strikes are the terrible consequences of a deeply felt conviction. This form of protest, often the only one available has been used over the years. In India, by the Suffragettes , Irish IRA prisoners and Guantanamo Bay. . One of my ancestors survived this form of protest in Holloway Prison as a Suffragette.
The Offender Health section of the UK Department of Health is publishing a guideline for the care of these protesters.
Care is complicated as there is electrolyte imbalance, vitamin and mineral depletion infection, hypothermia and renal failure. Failure can lead to Wernicke-Korsakoff syndrome
Sometimes a prisoner may survive for as long as 19 months. It would be a terrible and important comparison with the prisoners in German Concentration camps during the 1938-45 period..
Doctors are sometimes called upon to force feed.This is forbidden by the World Health Association in Declarations.
Editorial Lancet 2008 Clinical Care of hunger strikers vol 372 p777