Category Archives: Health

Study Says ZMapp Works Against Ebola

A new study provides strong evidence
that the experimental drug given to two American aid workers stricken with Ebola in Africa really works and could make a difference in the current
outbreak — if more of it could be produced.

In the study, all 18 monkeys exposed to a lethal dose of Ebola virus survived
when given the drug, known as ZMapp, even when the treatment was started five days after infection, when the animals were already sick.

Moreover, the monkeys’ symptoms, such as excessive bleeding, rashes and signs of liver toxicity, eventually
disappeared. By contrast, all three
monkeys in the control group died.
Experts said these were the best monkey results reported to date for any Ebola drug, raising hopes that the drug will work in people.

Read more here from the source

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Father’s Experiment in DNA Hacking Yields Daughter’s Diagnosis

genesequencingOf all the possibilities for “do-it-yourself” home projects—think go-carts, potato guns, and barbecue pits—chances are “sequencing DNA” isn’t on your list. But after going from doctor to doctor with his daughter Beatrice and getting little in the way of answers as to why she was unable to increase her muscle mass, Hugh Rienhoff Jr., MD, a biotech entrepreneur in California, took matters into his own hands. He bought equipment to sequence and study his daughter’s DNA at home, all by himself.

Rienhoff has become the poster boy for personal genetics, especially after a 2009 Wired piece about his daughter’s illness reached newsstands. Almost immediately after her birth in 2003, Rienhoff noticed something was wrong with his youngest child, Beatrice, or Bea for short. She appeared to have been born with some type of genetic disorder that caused her to be incredibly frail.

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Unfortunately, though her symptoms seemed to suggest Marfan or Beals syndrome, doctors couldn’t find the culprit. And while physical therapy has helped, she remains weak. Now, the worry is that her disorder could affect her heart and lead to cardiovascular complications.

Nearly a decade after his quest began, Rienhoff still doesn’t have all the answers, but he has found the small mutation that is the likely cause of his daughter’s symptoms.

In 2009, Bea and the Rienhoff family became a test group for exome-sequencing technology at Illumina, a genome-sequencing company in San Diego, Calif. Exome-sequencing is different from genome sequencing in that it looks at the protein-encoding portion of a person’s DNA. 

Bea’s exome includes an individual mutation in a gene that encodes a growth factor known as TGF-?3. Further experiments have shown that the faulty gene produces a non-functional protein, essentially disrupting the communication of and directions for a growth protein.

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Bea’s gene mutation is changing the way her genes control cell growth, differentiation, and death. This entirely new mutation wouldn’t have been found if Rienhoff hadn’t taken his daughter’s health and well being into his own hands almost 10 years ago.

Reinhoff’s Background in Genetics

Even before Bea’s birth, Rienhoff was a player in the study of genetics. In a 2000 letter to the editor, he disagreed with the sentiment that genetic information won’t aid in making diagnoses, along with medical information provided in a family history. “Genetic information will be an improvement over the family history and, like the family history, will be used largely to set prior probabilities, not to make definitive diagnoses,” wrote Rienhoff in a letter to the New England Journal of Medicine (NEJM).

The claim that no interventions based on the identification of disease-related genes have yet proved safe and effective is premature, Rienhoff wrote. “This would be akin to saying, in 1900, that no interventions based on the identification of disease-related microbes have yet proved safe and effective,” he wrote to the NEJM. That would essentially be the same as saying that identifying viruses in order to create vaccines to fight them isn’t a good use of resources, something we now know is essential to the successful production of lifesaving vaccinations.

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Let’s hope that a hundred years from now researchers look back at Rienhoff’s experiments as the start of a new approach to genetic study. While Bea’s condition isn’t yet defined, Rienhoff has a direction in which to look. The next steps include animal studies and, ideally, finding a living adult who displays Bea’s genetic mutation.

Plants ‘seen doing quantum physics’

SEM of chloroplast

Deep within plants’ energy-harvesting machinery lie distinctly quantum tricks

The idea that plants make use of quantum physics to harvest light more efficiently has received a boost.

Plants gather packets of light called photons, shuttling them deep into their cells where their energy is converted with extraordinary efficiency.

A report in Science journal adds weight to the idea that an effect called a “coherence” helps determine the most efficient path for the photons.

Experts have called the work “a nice proof” of some contentious ideas.

Prior work has shown weaker evidence that these coherences existed in relatively large samples from plants.

But the new study has been done painstakingly, aiming lasers at single molecules of the light-harvesting machinery to show how light is funnelled to the so-called reaction centres within plants where light energy is converted into chemical energy.

What has surprised even the researchers behind the research is not only that these coherences do indeed exist, but that they also seem to change character, always permitting photons to take the most efficient path into the reaction centres.

Until very recently, quantum mechanics – a frequently arcane branch of physics most often probed in laboratory settings at the coldest temperatures and lowest pressures – would not have been expected in biological settings.

The fact that plants and animals are extremely warm and soft by comparison would suggest that delicate quantum states should disappear in living things, leaving behaviour explicable by the more familiar “classical physics” that is taught in school.

But the new results join the ranks of a field that seems finally to be gaining ground: quantum biology.

‘Something shocking’

Niek van Hulst of the Institute of Photonic Sciences in Castelldefels, Spain, and colleagues studied the light-harvesting complexes of purple bacteria to address the question.

These are literally like antennas that gather up light, and are arranged like adjacent rings.

When laser light is shone on just one isolated ring, some of it is re-released in the form of what is called fluorescence.

But what the team saw is that over time, that amount of fluorescence rose and fell – a sign that the energy was coming and going elsewhere: a coherence.

This is linked to the quantum mechanical notion of a “superposition”: that a particle can effectively be in multiple places at once – or try multiple paths simultaneously.

“What you see here is this photon comes in, and it sees many energy pathways,” explained Prof van Hulst.

“Where does it go? It goes to the one that’s most efficient, the one where this quantum effect tells you it has the highest probability (of being put to use),” he told BBC News.

But the soft, flexible, warm conditions at room temperature mean that, as things move and jiggle – as life tends to do – that most efficient path can change. Remarkably, so did the evident path along the rings.

“Nature is very robust at keeping this up no matter what happens – this for me is something shocking,” Prof van Hulst continued.

“The result is that this fluffy stuff at room temperature where everything is variable, it just works – with an efficiency of 90%: way, way better than any solar cell we can make ourselves.”

‘Several questions’

Rienk van Grondelle of the Free University Amsterdam called the work “a very nice proof that the ideas that existed about these coherences are actually correct”.

“The system is able to overcome this problem by sampling two or three of those pathways at the same time and simply use the one that is best – I think it’s very, very beautiful,” he told BBC News.

Other researchers are less convinced. Daniel Turner of the University of Toronto has been working on similar problems and says that the study’s primary proof – the comings and goings of the fluorescence – are “not necessarily directly relevant to how photosynthesis works in natural conditions”.

“There are still several questions regarding how the results of this and other… measurements of highly purified protein extracts relate to the natural sunlight conditions experienced by photosynthetic organisms,” he told BBC News.

Even the notion of what is meant by “quantum effects” in relation to biology, he said, was still up for debate.

But for Prof van Grondelle, the paper is another impressive addition to this debate.

“Of course (the acceptance of quantum effects in biology) is not going to come from one single paper,” he said.

“It will take more evidence, and maybe more elaborate evidence that this is really happening. But this is how science goes.”

Source: bbc news