Genetics researchers have developed a customized gene chip to rapidly scan tumor samples for specific DNA changes that offer clues to prognosis in cases of neuroblastoma, a common form of children's cancer. Rather than covering the entire genome, the microarray focuses on suspect regions of chromosomes for signs of deleted genetic material known to play a role in the cancer.

The investigators, from The Children's Hospital of Philadelphia and Thomas Jefferson University, say their technique may be readily adapted for other types of cancer. The proof-of-principle study appears in the August issue of Genome Research.

One advantage of their technique is its flexibility, said co-author John M. Maris, M.D., a pediatric oncologist at The Children's Hospital of Philadelphia. "As future research identifies other genes active in neuroblastoma, we can modify the microarray to include such regions," he added...

Microarrays are silicon chips that contain tightly ordered selections of genetic material upon which sample material can be tested. When DNA bases from a sample bind to complementary sequences on the microarray, they cause fluorescent tags to shine under laser light. This is a signal that a particular gene variation is present in the sample.

"We can test DNA from peripheral blood and from the tumor, and we should see a loss of signal in the cancer," said Dr. Fortina. He noted that the researchers can simultaneously evaluate seven chromosomal regions known to be involved in neuroblastoma.

Unlike gene expression microarrays, which detect varying levels of RNA to measure the activity levels of different genes as DNA transfers information to RNA, the current microarray directly identifies changes in DNA. "These DNA changes, involving gain or loss of genetic material, are important for neuroblastoma prognosis," said Dr. Maris.

Researchers also report that this technique could potentially be used to identify other forms of cancer.

The press release...

More at the BBC...

One device is ElectroNeedles, micron-sized electrodes capable of measuring molecules such as glucose that can donate or accept electrons (redox behavior). The other is µPosts, micron-sized posts that have the potential of painlessly measuring proteins and other macromolecules, including protein markers released during a heart attack, using optical measurements. The platforms complement each other and together create a diagnostic suite capable of detecting many important biological markers.

"The tiny ElectroNeedles, expected to be constructed of cheap throw-away plastic, would not only make glucose testing simple and painless, but would significantly cut the diagnostics time involved in protein analysis," says Jeb Flemming, Sandia project leader. "Because the analysis is done inside the body, the need to withdraw body fluid is eliminated, and because the needles are so small the measurements are painless..."

The team realized that the tips of each of the ElectroNeedles and µPosts could be coated with a biologically active layer capable of measuring concentrations of specific lipids, proteins, antibodies, toxins, viruses, and carbohydrates (such as glucose). Using the ElectroNeedles and rapid electrochemical methods for analysis, a measurement can be made in a few seconds. Likewise, using coated µPosts to capture proteins and other non-redox behaving molecules, optical measurements can potentially be made in less than a half hour.

"Multiple chemical platforms, such as µPosts, will change medical diagnostics by giving the physician a greater understanding of the health of the patient in a shorter amount of time than standard laboratory analysis used today in medicine," Buckley says.

The arrays may be configured in a variety of formats--larger or smaller to accommodate different applications.

And did we tell you that the test results would be instantaneous?

More at Sandia...

The machine uses the chemistry of fireflies to generate a flash of light each time a unit of DNA is correctly analyzed. The flashes from more than a million DNA-containing wells, arrayed on a credit-card-sized plate, are monitored by a light-detecting chip, of the kind used in telescopes to detect the faintest light from distant stars. Then, they are sent to a computer that reconstructs the sequence of the genome...

Jonathan Rothberg, board chairman of 454 Life Sciences, said the company was already able to decode DNA 400 units at a time in test machines. It was working toward sequencing a human genome for $100,000, and if costs could be further reduced to $20,000 the sequencing of individual genomes would be medically worthwhile, Dr. Rothberg said.

To read more about the technology go to 454 LifeSciences website...

UPDATE (Aug. 05/2004): The press release from Harvard Medical School...

One item that got very high strangeness marks was an auction labeled thusly:

"PLEASE HELP!WHAT'S GROWING ON MY HEAD!! MYSTERY AUCTION"

I checked on a the item a few times -- a man was selling four blurry pictures of a golfball-sized growth, partially obscured by hair, between the occiput and the left mastoid. His plan was to sell enough $1 copies of the photos to get a diagnosis and pay for whatever intervention would be necessary (he had scheduled a doctor's visit for some point in August).

Despite thousands of visitors and several dozen buyers, the auction was closed down over the weekend.

It's probably for the best. No reputable physician would make a diagnosis based on some out-of-focus jpegs and a history IN ALL CAPS. Still, we hope whatever the guy had is benign (and yes, we're keeping our irresponsible speculations to ourselves).

We're not sure if online auctions have been used for this purpose before, though some sleuthing turned up an instance of an eBay medical fundraiser, earlier this year. In that case, the patient's family
successfully treated a brain tumor by selling bumper stickers.

So, the take home message from today: patients with masses in their head are not shy about going online.

Maybe in the future, surgeons can bid or "name their price" to operate on some of the rarer ailments. Until then, it's mostly a strange, sad sideshow.

Recently graduated designer Malcolm Kimberley has decided to take your health seriously. His Pistake Urinal takes samples of your urine, analyses them for sexually transmitted diseases, and sends the results to your cell phone via Bluetooth.

Finally, we like the idea of bathrooms communicating with your phone -- someday, toilets will send text message reminders when we forget to flush.

More from Malcolm Kimberly's design site...

UPDATE: Mr. Kimberly writes to inform us that the name of the installation is Relief, the working title was not changed in time for printing.

Now, ARS scientists in Peoria, Illinois, have devised a new DNA-based approach for identifying these pathogens that's faster, easier to use, and more precise than some currently used methods.

For example, pulsed-field gel electrophoresis (PFGE) is considered the gold standard for genetically identifying L. monocytogenes bacteria that cause food poisoning. But PFGE is difficult to run, takes about 3 days, and has several disadvantages that complicate efforts to determine the relationships between different isolates.

In contrast, "Our method can be performed in a single day," says microbiologist Todd Ward, at ARS's National Center for Agricultural Utilization Research, in Peoria, "and can target single nucleotide variations within specific genes..."

On the medical front, the test may enable hospital clinicians to cast a broader net for the 30 to 40 Candida species that can cause human infections, particularly in immunocompromised people. Page says the various culture-plate testing methods now used to diagnose Candida infection are limited to a few species--notably C. albicans--and the turnaround time is 24 hours to a few weeks, delaying treatment. Genetic fingerprinting tests used in some labs may be faster, but they too detect only a few Candida species.

By comparison, the test from Kurtzman's unit identifies 32 total species--simultaneously and in less than 5 hours.

In a machine called a "flow cytometer," which can handle up to 100 samples at a time, molecules called "probes" find and bind to corresponding pieces of species-specific DNA. The researchers created the probes using DNA-sequence information from their unit's microbial-genomics database. The probes have a fluorescent marker that tells the cytometer which DNA sequence was detected. The machine clearly displays the species' identity as color-coded bar graphs.

More...

To keep down their costs during the drug discovery process, companies and universities are turning to miniaturization processes. But there's a catch: standard lab equipment was not designed for dispensing tiny traces of substances. Labcyte has developed a proprietary technology for using focused acoustics, or ultrasound, to precisely transfer droplets down to 2.5 nanoliters. By transferring compounds directly into assay plates, the technology eliminates the need for tips, washing, and intermediate dilutions. Their system retails for around $225,000.

According to the company, six major pharmaceutical companies have purchased its systems, including GlaxoSmithKline and Astro Zeneca, as well as schools, including Vanderbilt University. Clients report improved results in the form of time savings, according to the company, which leads to a return on investment in the new equipment within about a year. Labcyte also expects to deploy its acoustic technologies for nano-dispensing liquids in the fields of genomics and proteomics.

More at Labcyte...

The UC Berkeley engineers found a way to get the best of both worlds by transforming optical energy to electrical energy through the use of a photoconductive surface. The idea is similar to that used in the ubiquitous office copier machine. In xerography, a document is scanned and transferred onto a photosensitive drum, which attracts dyes of carbon particles that are rolled onto a piece of paper to reproduce the image.

In this case, the researchers use a photosensitive surface made of amorphous silicon, a common material used in solar cells and flat-panel displays. Microscopic polystyrene particles suspended in a liquid were sandwiched between a piece of glass and the photoconductive material. Wherever light would hit the photosensitive material, it would behave like a conducting electrode, while areas not exposed to light would behave like a non-conducting insulator. Once a light source is removed, the photosensitive material returns to normal.

More from Dr. Ming Wu's article in this week's Nature...

The sensor, which includes a Pentium microprocessor just 2mm square, will initially be implanted in diabetics. Trials will begin by Christmas at St Mary's hospital, London. The implant will be programmed to send an emergency text message via a mobile phone, alerting medical staff to changes in blood-sugar levels.

If the problem is serious, the patient will be given immediate medical advice. Once patients become familiar with the system, they could monitor their condition themselves.

The only restriction is that the computer's low power output means that it needs a receiver--generally a mobile phone--to be within a metre of the patient to pick up the sensor's wireless signal from its miniaturised antenna.

Chris Toumazou, director of the Institute of Biomedical Engineering at Imperial, is hoping eventually to link the sensor to an insulin pump that can be operated remotely by a doctor. The sensor could also be used to protect people with heart and respiratory diseases. The researchers are exploring ways to detect chemical changes in a patient's blood.

"The computer in your body can take away anxiety and allow medics to take control of your care from miles away," said Toumazou.

The Institute of Biomedical Engineering at Imperial site...

(hat tip: Medical Conectivity Consulting)

In a place that hadn't seen a blade of grass or a bug for ages, and contending with dust and temperature extremes that left her either freezing or sweating, Skelley ran 340 tests that proved the instrument could unambiguously detect amino acids, the building blocks of proteins. More importantly, she and Mathies were able to detect the preference of Earth's amino acids for left-handedness over right-handedness. This "homochirality" is a hallmark of life that Mathies thinks is a critical test that must be done on Mars.

"We feel that measuring homochirality - a prevalence of one type of handedness over another - would be absolute proof of life," said Mathies, professor of chemistry at UC Berkeley and Skelley's research advisor. "We've shown on Earth, in the most Mars-like environment available, that this instrument is a thousand times better at detecting biomarkers than any instrument put on Mars before."

The instrument has been chosen to fly aboard the European Space Agency's ExoMars mission, now scheduled to launch in 2011...

More at Berkeley's Astrobiology Center...