The transparent zebrafish.

A newly bred fish bares all in the lab, revealing brain, heart and other internal organs in the name of research.
Scientists are breeding zebrafish with see-through bodies in order to make studying disease processes easier, including the spread of cancer, according to LiveScience.com.
The transparent fish, described in the Feb. 7 issue of the journal Cell Stem Cell, are allowing researchers at Children’s Hospital Boston to directly view fish’s internal organs and observe processes such as tumor growth in real-time in living organisms.
Scientists previously studied disease in the embryos of zebrafish, which are naturally transparent. But their clear bodies turn opaque when they grow into adults. The newly created zebrafish stays transparent throughout its lifetime.
“Everything after four weeks has been invisible to us,“ said study team member Richard White, a clinical fellow in the Stem Cell Program at Children’s Hospital Boston.
Zebrafish are genetically similar to humans in many ways and serve as good models for human biology and disease.
Traditionally, researchers have relied on information collected after the diseased animal died to infer anything about human ailments.
But for rapidly changing processes such as cancer, this snapshot method is bound to miss something. “It’s like taking a photograph when you need a video,“ said White, also an instructor of medicine at the Dana-Farber Cancer Institute in Boston.
White created the transparent fish, which he nicknamed Casper, by mating two existing zebrafish breeds, one that lacked a reflective skin pigment and the other without black pigment. The offspring had only yellow skin pigment, essentially appearing clear.
In one experiment, White and his colleagues inserted a fluorescent melanoma tumor into the abdominal cavity of the transparent fish.
By observing the fish under a microscope, they found that the cancer cells started spreading within five days. White could actually see individual cells spreading.
“The process by which a tumor goes from being localized to widespread and ultimately fatal is the most vexing problem that oncologists face,“ White said. “We don’t know why cancer cells decide to move away from their primary site to other parts in the body.“

Tattoos of the future may be good for your health rather than just your image.
German scientists said work on mice showed that tattooing was a more effective way to deliver a new generation of experimental DNA vaccines than standard injections into muscle, Reuters wrote.
Using fragments of DNA to stimulate an immune response is seen as a promising way of making better vaccines for everything from flu to cancer. Until now, however, the concept has been hampered by its low efficiency.
“Delivery of DNA via tattooing could be a way for a more widespread commercial application of DNA vaccines,“ said Martin Mueller of the German Cancer Research Center in Heidelberg.
There are currently no approved DNA vaccines on the market but several drug companies are conducting clinical trials and investing in the technology.
Pfizer Inc, the world’s biggest drug maker, placed a sizeable bet on DNA vaccines in October 2006 when it bought British pioneer PowderMed.
Mueller and his colleagues tested tattooing by vaccinating mice with a protein fragment of human papillomavirus, or HPV, a sexually transmitted virus that causes cervical cancer. No ink was used, so the tattoo left no permanent mark.
They found three doses of DNA vaccine given by tattooing produced at least 16 times higher antibody levels than three intramuscular injections.
The far stronger response reflects the fact that giving a tattoo with a vibrating needle causes a wound and inflammation. As a result, the tattoo--measuring around 1 centimeter square--is more painful but more efficient than a normal injection.
“This is probably what makes it work better than normal injections because the tissue is damaged and this affects the immune cells, which then look out for antigens,“ Mueller said in a telephone interview.
His team’s research was published in the online open access journal Genetic Vaccines and Therapy.
Tattoo vaccines are unlikely to be for everyone. But they could be valuable for delivering certain therapeutic vaccines to fight cancer or other serious conditions, where some pain is acceptable, Mueller said.
Therapeutic, as opposed to prophylactic, vaccines are being developed to treat disease, rather than just prevent it.
Mueller said tattooing could also have a role to play in routine vaccination of cattle.

Undated handout image shows a biomechanical energy harvester mounted on a customized orthopedic knee brace.

Scientists in the United States and Canada said they have developed a unique device that can be strapped on the knee that exploits the mechanics of human walking to generate a usable supply of electricity.
It generates enough power to charge up 10 cell phones at once, the researchers report in the journal Science, Telegraph.co.uk said.
Researchers have been working on ways to harness the motion of the human body to create power.
A shoe-mounted device was nice and light, but did not generate much electricity. A backpack device that generated power as it bounced up and down while a person walks generated a lot of electricity, but was heavy to lug.
The new energy-capturing knee brace, its inventors said, seems to find a happy medium--generating decent amounts of power while still being relatively light.
The scientists envisioned numerous applications for such a device.
It could be of value to hikers or soldiers who may not have access to electricity, they said. It also could be built into prosthetic knees or other implantable devices whose users occasionally must undergo surgery for a battery replacement.
Arthur Kuo, a University of Michigan mechanical engineer who worked on the device, said it works similarly to the way regenerative braking charges a battery in hybrid cars.
These regenerative brakes collect kinetic energy that normally dissipates as heat when the car slows down. The knee device collects energy lost when a person brakes the knee after swinging the leg forward to take a step, the researchers said.
“It generates a fairly substantial amount of power compared to previous devices and it does so in a way that doesn’t affect the user very much,“ Kuo said in a telephone interview.
“You could easily power 10 cell phones at once. There are some low power computers that you could power. You could imagine devices like GPS locaters, satellite phones,“ he said.
With a device placed on each leg, volunteers walking on treadmills generated about 5 watts of electricity walking at a leisurely 2.2 mph (3.5 kph). Each of the devices weighs about 3.5 pounds (1.6 kg), which Kuo said was still too unwieldy.
“Even though we’ve demonstrated this new way to generate power, we don’t mean to say this is a usable product at this time. The principal limitations are that our prototype is pretty heavy and bulky,“ Kuo said, adding that he thinks it can be made smaller and more
practical.