Tag: health

Organ Development in 3D

  • Venue: Science Magazine
READ MORE
organdev3dIf you ever wanted to know how the inner organs of a mouse embryo form, this is the movie for you. The animation was created by imaging thin sections of an embryo and then stacking these images to make a 3D movie. “If you look closely, you can see the developing lungs, gut, kidney, and bladder,” says the movie’s creator, Ian Smyth, a developmental biologist at Monash University in Australia. His video was selected from among several for being the most “striking and technically excellent” of the animations submitted to this year’s Wellcome Image Awards in London. Smyth uses these animations to compare normal tissues in embryos with those whose development is disrupted because of disease or exposure to a toxin. The animation was selected because of its ability to illustrate how effective this imaging technique can be for looking at the internal structure of the organs in a noninvasive way, explains Catherine Draycott, one of this year’s judges. “You can almost travel through [the mouse] as it develops.”

:: Read original here ::

Does Bird Flu + Swine Flu = Superflu?

  • Venue: Science Magazine
READ MORE

What do you get if you cross bird flu with the 2009 pandemic human virus, widely known as swine flu? Unfortunately, the answer isn’t funny. A new study predicts that swapping genes between the avian and human influenza viruses may result in an even more dangerous flu.

The human influenza virus H1N1 that caused the 2009 flu pandemic, and H9N2, an avian influenza virus that is endemic in bird populations in Asia, are close cousins—close enough that they can swap genes if they find themselves in the same cell, resulting in new viruses that are a patchwork of the parent strains. Scientists suspect that some gene combinations may result in a particularly potent form of flu and ignite a pandemic in humans. But because these viruses are more likely to meet in the lungs of an Asian chicken farmer than under the nose of a virologist, researchers find it difficult to predict which gene combinations might be the most virulent and contagious.

So instead of waiting and seeing, researchers have played matchmaker and thrust the two viruses together in a test tube. A team in China generated 127 hybrid viruses and injected each one into lab mice. More than half of the hybrids were as good as their parent strains at infecting the mice, and eight of them proved to be more pathogenic, the team led by Jinhua Liu of the China Agricultural University in Beijing reports online today in the Proceedings of the National Academy of Sciences.

“These are important experiments”, says virologist Peter Palese of Mount Sinai Medical Center in New York City, who was not involved in the work. The viral hybrids that the Chinese team has identified are the ones that scientists might want to watch out for worldwide, he says. If these strains were recognized early, governments could launch a speedier response.

Creating highly virulent viruses in the lab is controversial, says virologist Ab Osterhaus of the Erasmus University Medical Center in Rotterdam, the Netherlands. “[But] I don’t think we should shy away from these experiments. … The more information we have, the better,” he says.

He explains, however, that the hybrids that are the most virulent in mice will not necessarily be the most dangerous in humans, nor the most contagious. “Mice mirror, to a certain extent, what happens in humans,” he says, but they are not perfect model animals. Liu agrees. He plans to investigate how contagious his new viral blends are in guinea pigs and ferrets—animals whose respiratory system better reflects our own feverish battle with flu.

:: Read more here ::

Don’t Take That Cookie!

  • Venue: Science Magazine
READ MORE
Stop it! Don’t touch that! Sit down and be quiet! Whether you heeded these commands as a child could help predict your future. A new study suggests that people who show less self-control as young children are more likely to have failing health, greater debt, and run-ins with the law later in life.

The idea that willpower is important for success is not new. In the late 1960s, Walter Mischel, a psychologist at Columbia University, tested whether 4-year-old children could resist nibbling Oreo cookies when left alone with a plate of them. He and colleagues found a huge range in willpower, and those children better at resisting the temptation went on to do better in school, scoring higher on the standardized tests. Their parents also judged them to be more attentive, competent, and intelligent. Intrigued, psychologist Terrie Moffitt of Duke University in Durham, North Carolina, and her colleagues sought real-life data to test whether individuals with more willpower and not just self-discipline when offered cookies, achieved greater success in life.

The international team tracked approximately 1000 New Zealand children, born in 1972 or 1973, from the age of 3 years until their early 30s, and another 500 British fraternal twins, born in 1994 or 1995, from the ages of 4 years to 12 years. They used a range of measures to assess the children’s self-control, including their impulsivity, persistence at a task, patience while waiting in line, and hyperactivity.

Compared with their more disciplined twins, children who had less self-control at age 5 were more likely to have begun smoking, performing badly in school, and acting out at age 12, the researchers report online today in the Proceedings of National Academy of Sciences. And these problems continued in later life. Controlling for socioeconomic status and IQ, the researchers determined that people who showed the lowest willpower as children went on to be more than twice as likely to have health problems in their 30s, including high blood pressure, weight problems, lung disease, and sexually transmitted diseases. By the age of 32, they also earned 20% less and were about three times more likely to be dependent on tobacco, alcohol, or harder drugs and to have been convicted of a crime.

Moffitt explains that people didn’t fall into two categories—disciplined or undisciplined—but existed on a spectrum. “It means all of us could benefit from improving our self-control,” she says.

Moshe Bar, a psychologist at Harvard Medical School in Boston who was not involved in the study, is impressed by the long-term data set but cautions that the study is observational and can’t establish that self-control breeds success. Still, parents of cookie nibblers shouldn’t despair, he says. He was intrigued to read that some of the children in the study improved their self-control. Bar and his 7- and 10-year-old children “play a game of ‘waiting’ with unwrapping a candy for no other reason than practicing a delay,” he says. “It works,” he says, but then, as he points out, he has a sample size of only two.

:: Read full here ::

Poop Scoop

  • Venue: Science Magazine
READ MORE
New baby? Feeling like you’re waist deep in dirty diapers? Forget diaper-collection services; just volunteer your infant for a poop study and researchers will take them off your hands for free. Dirty diapers, it seems, hold the key to measuring infant hormone levels.

Sex hormones, such as estrogen, are important for babies’ healthy development. But some endocrinologists worry that children are exposed to too much additional estrogen via soy formula, plant fertilizers, and even plastics, which could cause faster-than normal development and future problems with reproduction. However, few infants tolerate a frequent finger or heel prick, and so “very little is know about hormone levels in infants,” explains Michelle Lampl, an anthropologist at Emory University in Atlanta.

Diapers, however, can be collected frequently and over a long period of time, perfect for a
longitudinal study. Practicing on eight to 10 diapers collected from each of 32 largely breast-fed
infants over 6 months, Lampl’s group perfected a technique for extracting hormone levels from the
poop, they reported online last month in Frontiers in Systems Biology.

They also perfected their diaper-collection technique. “It took years to fi nd the right nappy
and work out how you get the diaper fresh from the home to the lab,” says Lampl. The secret: a
cotton diaper, a Ziploc bag, and an ice pack.

:: Read original here ::

Shaping up HIV

  • Venue: EMBL
READ MORE
In the 1960s, a Danish company, seeking to improve on the traditional football made from the bladder and stomach of animals, invented the modern football. The designers realised that to form a perfect ball they needed to combine 20 leather hexagons with 12 pentagons, and in so doing demonstrated one of the basic laws of shape – that you cannot wrap a sheet of six-sided hexagons around a sphere. To induce the sheet to bend, the company had to introduce five-sided pentagons alongside the hexagons.

On the micro scale, the human immunodeficiency virus (HIV), which causes AIDS, faces a similar challenge during the assembly of new viral particles: how to coerce its hexagonshaped building blocks to form the spherical envelope that
surrounds its viral innards. Lifting a page from the football manual, structural biologist John Briggs, group leader at EMBL Heidelberg, wondered if HIV likewise solved this shape conundrum by introducing pentagons between the hexagons.

:: Read more here ::

Aberrant appendages

READ MORE
Having a second pair of hands might seem like an advantage but animals born with extra limbs, because of changes in their DNA, generally do not fair well. For more than 25 years, scientists have known about the existence of a mutation in a fruit fly gene that causes just such aberrant appendages, yet the identity of this
gene remained a mystery.

That is until developmental biologist Jürg Müller and his team at EMBL Heidelberg set out to find the gene responsible. By comparing the DNA of mutant and normal flies, Jürg’s group pinpointed the mutation and found that it disrupts the genetic code for the protein Ogt, an enzyme that sticks sugar molecules to the outside of proteins.

:: Read more here ::

Waxing cutaneous

  • Venue: EMBL
READ MORE
When we’re in the bath, our skin prevents both water from moving into our bodies and essential nutrients from leaching into the tub. But because most of us don’t spend our entire lives submerged underwater, our skin’s chief role is to control how much water evaporates from our bodies. In fact, the skin’s role as a semi-impermeable barrier to fluid loss is so important that people suffering from serious burns often die, not as a direct consequence of their injuries, but from de hydration.

Each of us is covered by about 2 square meters of skin – about the area of a queen-size bed. For this waterproof suit to do its job, stem cells at the base of the skin replenish the layers above by producing a continuous stream of new cells initially like themselves and then a variety of specialised cell types. As a result of this continuous production, the specialised cells – which are destined to become the different layers of skin – move outwards until they are finally shed.

:: Read more here ::

Decloaking the germ

  • Venue: EMBL
READ MORE
The bacterium Listeria infects humans through contaminated food. Once in the gut, this pathogen can be life-threatening if contracted during pregnancy or by newborns and those with weakened immune systems.

But for most people, an encounter with Listeria causes nothing more than vomiting and diarrhoea because our immune system recognises the
long, propeller-like projections on the bacterial surface – called flagella – and
mounts an assault on Listeria until it is wiped out. Listeria, however, has evolved a way to dodge this fate.

To anyone who has ever tried to cross enemy lines, this bacterium has an enviable ruse. After detecting the warmth of the human body, Listeria shuts down the production of flagella – the equivalent of enveloping itself in an invisible cloak. It does this by activating a protein called motility gene repressor, or MogR for short, which binds to DNA close to the flagella gene and suppresses it.

:: Read more here ::

Morning sickness may be sign of a bright baby

READ MORE
SICK of morning sickness? Take heart: it may be a sign that your child is developing a high IQ.

Irena Nulman and colleagues at the Hospital for Sick Children in Toronto, Canada, contacted 120 women who years earlier had called a morning sickness hotline. Thirty did not have morning sickness, but the researchers asked the rest to recall the severity of their sickness, and gave the children of all the women, now aged between 3 and 7, a standard intelligence test. Those whose mothers had nausea and vomiting during pregnancy were more likely to get high scores than those whose mothers did not (The Journal of Pediatrics, DOI: 10.1016/j.jpeds.2009.02.005). The reported severity of the vomiting also correlated with the IQ scores.

Morning sickness, which affects most pregnant women, is thought to be a reaction to the hormones human chorionic gonadotropin and thyroxine, which are secreted at unusually high levels during pregnancy to maintain a healthy placenta. Now Nulman speculates that these hormones, which are higher in women who experience morning sickness, may protect the fetus’s developing brain.

Her team found that taking the morning sickness drug Diclectin had no effect on the IQ scores.

:: Read original here ::