How many genomes do you have? | SmartPlanet

How many genomes do you have? | SmartPlanet.

By John Rennie | November 29, 2011, 3:00 AM PST

The era of personal genomics is fast approaching, as headlines constantly remind us. With the cost of sequencing someone’s DNA rapidly falling toward just $1,000 (or less), it seems all but inevitable that soon we and our physicians will use that information to guide our health decisions.

 

 

454 Life Sciences gene sequencing machines. (Credit: Jon Callas, via Flickr)

 

But here’s an inconvenient biological truth that the triumphant talk about personal genomics sometimes skirts: we don’t each have just one genome. Yes, one may stand out most prominently for each of us, but we have others. And biology is still sorting out how much our health may depend on learning to pay attention to those we normally overlook.

 

All the cells in an organism like a human being certainly seem as though they should have the same genome. A fertilized egg divides repeatedly to give rise to the body’s cells, passing along the same set of chromosomes to every one of its cellular progeny. A few exceptional tissues might deviate from that rule — for example, red blood cells entirely discard the nucleus holding their genes, and the white blood cells called B lymphocytes scramble part of their DNA so that they can make an almost infinite number of different antibodies. But fundamentally, all the cells in the skin, the liver, the brain, the muscles and other tissues ought to share the same genome.

Or so it was thought. Yet exceptions to the rule keep cropping up, and they may help to explain some of the variation seen in tissues like the brain.

Variation on the brain

The hundred billion neurons in the human brain obviously differ from one another in their interconnections and in the specific neurochemical messenger molecules that they secrete. But a more subtle difference that has come to light over the past decade, largely thanks to the work of Michael J. McConnell and his colleagues at the Salk Institute for Biological Studies in La Jolla, Calif., resides in the DNA. They have shown extensive variation in the genomes of individual neurons, a condition called aneuploidy. The neurons have deleted, duplicated, and rearranged portions of their chromosomes, such that no two have exactly the same DNA sequence anymore…..

 

Related articles

• Personalized Medicine – Scientific & Commercial Aspects (prnewswire.com)
• Molecular Diagnostics – Technologies, Markets and Companies (prnewswire.com)
• New research brings personal genomics closer than ever (digitaltrends.com)

Exercise helps us to eat a healthy diet

Exercise helps us to eat a healthy diet

From the 29 November Eureka News alert 

		IMAGE: Exercise helps us to eat a healthy diet.Click here for more information.

A healthy diet and the right amount of exercise are key players in treating and preventing obesity but we still know little about the relationship both factors have with each other. A new study now reveals that an increase in physical activity is linked to an improvement in diet quality.

Many questions arise when trying to lose weight. Would it be better to start on a diet and then do exercise, or the other way around? And how much does one compensate the other?

“Understanding the interaction between exercise and a healthy diet could improve preventative and therapeutic measures against obesity by strengthening current approaches and treatments,” explains Miguel Alonso Alonso, researcher at Harvard University (USA) who has published a bibliographical compilation on the subject, to SINC.

The data from epidemiological studies suggest that tendencies towards a healthy diet and the right amount of physical exercise often come hand in hand. Furthermore, an increase in physical activity is usually linked to a parallel improvement in diet quality.

Exercise also brings benefits such as an increase in sensitivity to physiological signs of fullness. This not only means that appetite can be controlled better but it also modifies hedonic responses to food stimuli. Therefore, benefits can be classified as those that occur in the short term (of metabolic predominance) and those that are seen in the long term (of behavioural predominance).

According to Alonso Alonso, “physical exercise seems to encourage a healthy diet. In fact, when exercise is added to a weight-loss diet, treatment of obesity is more successful and the diet is adhered to in the long run.”

The authors of the study state how important it is for social policy to encourage and facilitate sport and physical exercise amongst the population. This should be present in both schools and our urban environment or daily lives through the use of public transport or availability of pedestrianised areas and sports facilities….

Related articles

• Exercise can make it easier to eat healthy (news.bioscholar.com)
• Exercise helps people eat healthier: study (vancouversun.com)
• Exercise ‘makes people eat better’ (thehindu.com)
• Obesity Gene’s Effect Reduced By Exercise (medicalnewstoday.com)

Clean Cooking Options Could Save Millions Of Lives And Protect Our Climate

author: EIA, source URL: http://www.eia.doe.gov/oiaf/ieo/pdf/0484(2007).pdf

(I am very interested in this topic, as a Peace Corps volunteer in West Africa, I noticed nearly all in the village used wood as a cooking fuel back in the early 80’s. On a short return trip two years ago, the preferred fuel seemed to be charcoal)

 

From the 30 November 2011 Medical News Today article

For many people in the developing world getting enough food to eat is a persistent challenge. However the challenge does not stop there. A new issue of the international journal Energy Policy details the human and environmental cost of cooking food using the only energy source available to many people, woody biomass.

The Special Issue explores the type of decision frameworks that are needed to guide policy development for clean cooking fuels and to ensure that the provision of clean energy becomes a central component of sustainable development. Additionally, it presents a research agenda and an action agenda to facilitate the development and adoption of cleaner cooking fuels and technologies and analyses why past programs to improve access to clean cooking fuels have succeeded or failed. …

…

The articles presented in the Special Issue consider the options for transitioning the nearly 2.7 billion people globally who are reliant on traditional biomass fuels to cleaner cooking fuels, such as LPG, biogas, ethanol and biodiesel, as well as electricity. “Much of the emphasis to date has been on increasing access to electricity, which while important may be too slow a path and may not address cooking energy needs (electricity is rarely used for cooking in many developing countries). Providing improved cooking stoves to households will have an immediate positive impact on people and the environment. …

Related articles

• Saving millions of lives and protecting our climate through clean cooking options (physorg.com)
• Saving millions of lives and protecting our climate through clean cooking options (eurekalert.org)
• Clean Cooking Options Could Save Millions Of Lives And Protect Our Climate (medicalnewstoday.com)
• Combating Poverty with Clean Energy (aspectenergy.wordpress.com)
• In Rwanda, clean-burning cookstoves use crowdsourced biofuel (springwise.com)

Environment And Diet Leave Their Prints On The Heart

From the 30 November 2011 Medical News Today article 

A University of Cambridge study, which set out to investigate DNA methylation in the human heart and the ‘missing link’ between our lifestyle and our health, has now mapped the link in detail across the entire human genome.

The new data collected greatly benefits a field that is still in its scientific infancy and is a significant leap ahead of where the researchers were, even 18 months ago.

Researcher Roger Foo explains: “By going wider and scanning the genome in greater detail this time – we now have a clear picture of the ‘fingerprint’ of the missing link, where and how epigenetics in heart failuremay be changed and the parts of the genome where diet or environment or other external factors may affect outcomes.” …

…

DNA methylation leaves indicators, or “marks”, on the genome and there is evidence that these “marks” are strongly influenced by external factors such as the environment and diet. The researchers have found that this process is different in diseased and normal hearts. Linking all these things together suggest this may be the “missing link” between environmental factors and heart failure.

The findings deepen our understanding of the genetic changes that can lead to heart diseaseand how these can be influenced by our diet and our environment. The findings can potentially open new ways of identifying, managing and treating heart disease.

The DNA that makes up our genes is made up of four “bases” or nucleotides – cytosine, guanine, adenine and thymie, often abbreviated to C, G, A and T. DNA methylation is the addition of a methyl group (CH3) to cytosine.

When added to cytosine, the methyl group looks different and is recognised differently by proteins, altering how the gene is expressed i.e. turned on or off.

DNA methylation is a crucial part of normal development, allowing different cells to become different tissues despite having the same genes. As well as happening during development, DNA methylation continues throughout our lives in a response to environmental and dietary changes which can lead to disease.

As a result of the study, Foo likens DNA methylation to a fifth nucleotide: “We often think of DNA as being composed of four nucleotides. Now, we are beginning to think there is a fifth – the methylated C.”

Foo also alludes to what the future holds for the study: “…and more recent basic studies now show us that our genome has even got 6th, 7th and 8th nucleotides… in the form of further modifications of cytosines. These are hydroxy-methyl-Cytosine, formylCytosine and carboxylCytosine = hmC, fC and caC! These make up an amazing shift in the paradigm…”

As in most studies, as one question is resolved, another series of mysteries form in its place. The study shows that we are still on the frontier of Epigenetics and only just beginning to understand the link between the life we lead and the body we have. 

DNA methylation in E.coli

Related articles

• Environment and diet leave their prints on the heart (eurekalert.org)
• Diet, environment leave their prints on the heart (scienceblog.com)
• Controlling patterns of DNA methylation (medicalxpress.com)
• Epigenetic changes often don’t last, probably have limited effects on long-term evolution, research finds (sciencedaily.com)
• Epigenetics again: will it cause a revolution in evolution? (whyevolutionistrue.wordpress.com)
• Your Living Conditions as a Child May Be Detectable In Your DNA for Life By Clay Dillow (imullins89.wordpress.com)
• Welcome to the Genome Engineering Wordle (genome-engineering.com)
• Genome Engineering guest blog on BioNews: Europe leads the way in epigenome mapping (genome-engineering.com)
• Genome engineering – Method 3: Correction (genome-engineering.com)
• Carnival of Evolution #39 (genome-engineering.com)

Commercial Sexual Exploitation of Children (CESC) and Youth Homelessness

From the 15 November 2011 Summary

CSEC is A Growing Problem It is commonly estimated that 100,000 children are victims of commercial sexual exploitation each year. Futher, there is evidence that the number of children being exploited is increasing. The U.S. Department of Justice (DOJ) reports there is an increase in the online solicitation and “grooming” of children for CSEC, the incidence and violence of online pornography involving children, and online advertisements of children available for prostitution. CSEC may be growing in part because it is highly lucrative. DOJ reports CSEC is growing in popularity because it conveys greater financial gains with fewer risks than the drug trade and other illegal activities. It is also challenging for law enforcement to combat. Solicitation of prostitution is moving from city streets to online forums and pimps move children frequently between cities. It is difficult, therefore, to identify children victimized by CSEC and when children are identified they are more likely to be arrested for prostitution than those who solicited or exploited them.

Related articles

• RCASA Friday Facts: Housing Protections for Victims of Sexual Assault (rcasa.wordpress.com)
• Letter: Children in Slavery (nytimes.com)
• Tell the World ‘Girls Are Not for Sale’ (venusgenus.com)
• Grants to help agencies fight child prostitution (seattletimes.nwsource.com)
• Senate report calls for national child sexual exploitation strategy (canada.com)
• Gangs ‘sexually abuse thousands’ (bbc.co.uk)
• Huge Percentage of Homeless Youths Identify as LGBT (onebluestocking.wordpress.com)
• National Homeless Youth Awareness Month (prweb.com)
• Sex Trafficking: Some Resources To Help Stop This Tragedy (onedesertrose.wordpress.com)
• Probe of Prostitution Prosecution Failures Sought (israelnationalnews.com)
• America’s Dirty Little Secret: Sex Trafficking (blogcritics.org)
• Some Resources to End Human Sex Trafficking (onedesertrose.wordpress.com)
• Call for new law on trafficking (bbc.co.uk)

Why doctors can’t say no

Often it’s easier to just say yes. But there are ways to say no that are better for both physician and patient

BY RAHUL K. PARIKH at the 28 November 2011 edition of Salon

Doctors routinely meet with patients who make requests for specific medicines, tests and referrals to specialists. In this era of the Internet, consumer-driven healthcare and direct-to-consumer drug marketing, this is no surprise. And while an informed patient is a good thing, what may surprise you is just how hard it is for doctors to say no when a patient makes a specific request for something he or she doesn’t really need.

Right now, Dr. Conrad Murray sits in jail because he couldn’t say no to Michael Jackson when Propofol came up in conversation between them. But even doctors who aren’t tempted by an enormous monthly retainer and access to one of the world’s biggest celebrities are challenged by the word “no.”

American medicine is a business — but a weird one.  In any other sector of our economy, businesses are determined to give their customers what they want, however they want it. But in medicine, the “have it your way” mind-set doesn’t always jive. First, physicians have a duty to avoid doing harm.  The choice of a drug or test based solely on a patient’s request can undermine that.  Second, as everybody knows, we spend a big slice of our GDP on healthcare. Since the person who has control over expensive tests and the prescription pad is your doctor, there’s ever-increasing scrutiny to be responsible stewards of healthcare dollars….

…

The lesson here is that it’s best for the doctor and the patient to get everything out in the open, and for a healthcare system that affords the right amount of access and time — especially in primary care — to make that to happen.

Read the entire Salon article

 

Related articles

• Dr. Conrad Murray Sentenced to Four Years Behind Bars in Death of Michael Jackson (foxnews.com)
• Why doctors need to be better negotiators (kevinmd.com)

Surprising Decline in Consumers Seeking Health Information

Surprising Decline in Consumers Seeking Health Information

Tracking Report No. 26
November 2011
Ha T. Tu

In 2010, 50 percent of American adults sought information about a personal health concern, down from 56 percent in 2007, according to a new national study from the Center for Studying Health System Change (HSC). The likelihood of people seeking information from the Internet and from friends and relatives changed little between 2007 and 2010, but their use of hardcopy books, magazines and newspapers dropped by nearly half to 18 percent. While the reduced tendency to seek health information applied to consumers across nearly all demographic categories, it was most pronounced for older Americans, people with chronic conditions and people with lower-education levels. Across all individual characteristics, education level remained the factor most strongly associated with consumers’ inclination to seek health information. Consumers who actively researched health concerns widely reported positive impacts: About three in five said the information affected their overall approach to maintaining their health, and a similar proportion said the information helped them to better understand how to treat an illness or condition.

• Overall Health Information Seeking Declines
• Print Media Use Falls Sharply
• Education Level Remains Key
• Impact of Information Seeking
• Implications
• Notes
• Data Source
• Supplementary Tables

Related articles

• Study Finds Decline in Patients Seeking Consumer Health Info (climbingthestacks.wordpress.com)
• Consumer Interest In Health Information Wanes (informationweek.com)
• Seeking information and making approriate health choices is not optional (face2facemedia.wordpress.com)