Category Archives: Life Science

Are Antibiotics Killing Us?

Are Antibiotics Killing Us? by Jessica Snyder Sachs:

To counteract these killers, some physicians have turned to lengthy or lifelong courses of antibiotics. At the same time, other researchers are counterintuitively finding that bacteria we think are bad for us also ward off other diseases and keep us healthy. Using antibiotics to tamper with this complicated and little-understood population could irrevocably alter the microbial ecology in an individual and accelerate the spread of drug-resistant genes to the public at large.

Articles on the overuse of antibiotics.

Salyers says her research shows that decades of antibiotic use have bred a frightening

degree of drug resistance into our intestinal flora. The resistance is harmless as long as the bacteria remain confined to their normal habitat. But it can prove deadly when those bacteria contaminate an open wound or cause an infection after surgery.

Organs Engineered in a Lab

Straight Out of Science Fiction: Organs Engineered in a Lab:

Several years after receiving new bladders engineered entirely in a laboratory, seven young patients are all still healthy.

It marks the first long-term success of total-organ tissue regeneration, an area of medicine that until now was more the stuff of science fiction than clinical reality.

Wake Forest Institute for Regenerative Medicine

UW-Madison Scientist Solves Bird Flu Puzzler

UW-Madison scientist solves bird flu puzzler by David Wahlberg:

Before the H5N1 virus can cause a human pandemic, the new findings suggest, it must mutate and become able to recognize human flu virus receptors, Kawaoka said.

The virus, which has led to the death or slaughter of millions of birds in Asia, Africa and Europe, has killed 103 of the 184 people known to be infected since 2003, nearly all of them thought to be sickened by birds.

If the virus starts spreading from person to person, health officials say, it could cause a pandemic like the one in 1918 that killed up to 50 million people worldwide.

Nanofibers Knit Severed Neurons Together

Hamster Study Shows Nanofibers Knit Severed Neurons Together, Restore Vision by David Biello, Scientific American:

“We have healing of the brain, which we’ve never seen before. We have axons growing through the center of the cut, which we’ve never seen before, and we have axons connecting to the target tissue,” Rutledge notes. “If we could use something like this to mitigate the damage caused by cutting the brain with a knife, that would be great.” The research appears online this week in Proceedings of the National Academy of Sciences.

Swimming Ants

Scientists discover swimming ants

North Queensland scientists have discovered a new type of ant, believed to be the only species that can live, swim and navigate under water.
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The ants nest in submerged mangroves and survive by hiding in air pockets and then swimming to the surface.
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“I was actually working with a film crew working on insects in the mangroves and they wanted to film one of these ants and I said, ‘Well, lets put it on a rock in a puddle of water and that’ll stop it going away and then you’ll be able to film it,’ and the ant promptly just leapt off the edge of the rock and swam across the water and disappeared.

“We were sort of dumbfounded.”

Dr Robson says it is amazing that the ants can survive in such a hostile environment.

“We’ve been doing a lot of studies on their foraging behaviour and there’s a lot of things that eat them, so when they’re swimming, fish will sometimes eat them, mud skippers will eat them, crabs will attack them,” he said.

It is great to see experts can still be so suprised by nature.

Unique northern ants gain global attention

Avian Flu

Photo of the Bird Flu virus, courtesy of 3DScience.com.

Avian Flu (site broke link so I removed it), World Health Organization Meeting to Discuss Avian Flu Pandemic as Bird Flu Continues to Spread Through Europe

World Health Organization officials are meeting in Geneva to consider the possibility of a global human bird flu pandemic as the deadly H5N1 strain continues to spread rapidly in birds.

Top influenza official Margaret Chan said the outbreak in poultry is historically unprecedented. She said the deadly virus presents a greater challenge to the world than any other emerging infectious disease.

The meeting was called to plan a response in case the bird flu virus mutates into a widespread human flu virus.

Drinking Soda and Obesity

Scientists in food fight over soda (bozos at CNN deleted the webpage):

Biologically, the calories from sugar-sweetened beverages are fundamentally different in the body than those from food.

The main sweetener in soda — high-fructose corn syrup — can increase fats in the blood called triglycerides, which raises the risk of heart problems, diabetes and other health woes.

This sweetener also doesn’t spur production of insulin to make the body “process” calories, nor does it spur leptin, a substance that tamps down appetite, as other carbohydrates do, explained Dr. George Bray of the Pennington Biomedical Research Center in Baton Rouge, Louisiana.

“There’s a lack of fullness or satiety. The brain just seems to add it on,” said Dr. Louis Aronne, a Weill-Cornell Medical College doctor who is president of the Obesity Society.

As with so much life science the “answers” are not clear (Medical Study Results Questioned – Why Most Published Research Findings Are False). The article presents arguments from those who disagree about the link between drinking soda and the dramatic rise in obesity in the USA.

Another article on the topic: Cutting Sugary Drinks at Home Helped Teens Shed Pounds by Judith Groch.

Leonardo da Vinci

Leonardo da Vinci drawings including a larger version of the image above.

Math and the Mona Lisa : The Art and Science of Leonardo da Vinci is an excellent book exploring the visionary science of Leonardo da Vinci. More excellent science books that we recommend.

An excellent site for learning more about Leonardo – Museum of Science Leonardo web site (includes classroom activities):

Leonardo da Vinci may seem an unusual topic to study in science. But the more you learn about this remarkable Renaissance man, the more you will realize that he was a terrific role model for applying the scientific method creatively in every aspect of life including art and music. Although he is best known for his dramatic and expressive artwork, Leonardo also conducted dozens of carefully thought out experiments and created futuristic inventions in a time before modern science and invention had really begun.

Leonardo: Master Draftsman exhibit at the Met

Algae as Hydrogen Factory

Mutant Algae Is Hydrogen Factory by Sam Jaffe, Wired:

Researchers at the University of California at Berkeley have engineered a strain of pond scum that could, with further refinements, produce vast amounts of hydrogen through photosynthesis.

The work, led by plant physiologist Tasios Melis, is so far unpublished. But if it proves correct, it would mean a major breakthrough in using algae as an industrial factory, not only for hydrogen, but for a wide range of products, from biodiesel to cosmetics.
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Melis got involved in this research when he and Michael Seibert, a scientist at the National Renewable Energy Laboratory in Golden, Colorado, figured out how to get hydrogen out of green algae by restricting sulfur from their diet. The plant cells flicked a long-dormant genetic switch to produce hydrogen instead of carbon dioxide. But the quantities of hydrogen they produced were nowhere near enough to scale up the process commercially and profitably.

“When we discovered the sulfur switch, we increased hydrogen production by a factor of 100,000,” says Seibert. “But to make it a commercial technology, we still had to increase the efficiency of the process by another factor of 100.

Reducing Antibiotic Use

‘Natural’ chickens take flight by Elizabeth Weise

Four of the nation’s top 10 chicken producers have virtually ended a practice that health and activist groups for years charged was causing a public health crisis: feeding broiler chickens low doses of antibiotics to make them grow faster and stay healthy.

Tyson Foods, Gold Kist, Perdue Farms and Foster Farms say they stopped using antibiotics for growth promotion. In addition to ending a practice that Europe banned and McDonald’s ended a month ago, the four companies also have severely limited antibiotic use for routine disease prevention, though antibiotics are still used to treat disease outbreaks.

Are health groups against healthy chickens? No. They worry about the danger of creating resistance to antibiotics. Our past, and current, misuse of antibiotics is leading us to a future where our currently effective antibiotics will not be effective.

Tyson Foods, the nation’s largest chicken producer, has led the way with a 93% reduction, from 853,000 pounds in 1997 to just 59,000 in 2004. In 2004, less than 1% of the company’s broilers received antibiotics, says chief veterinarian Patrick Pilkington.

Perdue Farms stopped using antibiotics for growth promotion about five years ago. “It became obvious that it was a concern,” says chief veterinarian Bruce Stewart-Brown. Now at any given farm in the system, only one flock in five years receives antibiotics, either to halt a disease outbreak or because birds are threatened with infection, he says.

Positive steps to reducing our overuse of anti-biotics still leave us with much more to improve.