The ability to sequence DNA begat many genomics projects, including the human genome. Once the entire human DNA sequence was in hand, it begat the possibility of understanding all the gene products, i.e., the proteome. And now that we are beginning to understand the complexity, function, and organization of cellular proteins, we can imagine defining the results of all these enzymes acting together: the metabolome.

Or borrowing from the use-with-care Wikipedia: “‘metabolomics is the systematic study of the unique chemical fingerprints that specific cellular processes leave behind’—specifically, the study of their small-molecule metabolite profiles.”

A recent paper gives a reality test to metabolomics (Nature, 15 May 2008, pp. 396-400). The authors—all 16 of ‘em from 5 insitutions in Asia, Europe, and the U.S.—quantified thousands of urinary metabolites from 4,630 individuals. They then looked for associations between diet (which determines the array of metabolites) and high blood pressure (which predisposes one to heart disease and stroke). In the mass of data, there are two findings of particular note:

1. The ability to discriminate among people with different geographic origins by their metabolic profile; and
2. The ability to correlate several simple chemical metabolites with elevated blood pressure.

So metabolomics is useful, at least in principle, for identifying biomarkers of disease. Whether or not this information is useful in controlling disease remains to be seen. One additonal note though: the metabolome wasn’t as good a discriminator of gender as of geographic origin. Perhaps men and women aren’t as different as we thought!

 Everywhere you look these days you see references to nanotechnology. For the curious generalist there is even a Nanotechnology for Dummies volume in the familiar yellow-covered series.

The scientific literature, too, is replete with nanotech work from all manner of researchers and all corners of the globe. Two caught my eye recently, exemplifying both the promise and the peril, at least in biomedical application.

On the positive side of the ledger, a bicoastal research team from California and Massachusetts published new results on the use of “nanoworms” in anticancer diagnostics and therapy (Advanced Materials 20 (2008): 1630-1635). Such beasties are composed of both iron oxides and dextran, the former useful in MRI imaging and the latter helpful in escaping the normally rapid and efficient body elimination processes. By controlling the size and shape of the nanoworms, the researchers were able to demonstrate very effective tumor targeting in mice.

A darker cloud was raised by an English/American collaboration demonstrating asbestos-like toxicity when carbon nanotubes are injected into the abdominal cavity of mice. (Nature Nanotechnology, published online 20 May 2008). Such nanotubes are widely available, so toxicity studies were eminently predictable. So far, though, the results do not address the biggest bugaboo about asbestos, namely induction of the nasty type of lung cancer called mesothelioma.

Since the aspect ratio of the fibers (and the nanoworms) is more important than the chemical composition in determining biological response, one anticipates that clever materials scientists will be able to engineer out dangerous toxicities. Still, the juxtaposition of these two studies illustrates the inevitable yin and yang of all emerging technologies.

Readers of this blog will naturally be familiar with chemistry. But spiders? Aren’t they those eight-legged creatures that spin silky webs, trap insects, and scurry about in unsavory places?

Well, yes, but those aren’t the only kind of spiders. There are also Web spiders (aka Web crawlers, bots, indexers, etc.) that roam the World Wide Web harvesting information for search engines. This is how Google and friends gather information and make it available in the twinkling of an eye.

So now, naturally enough, we have ChemSpider. This is a free site that provides access to huge amounts of data on chemicals. Simple things like structures, molecular weights, boiling points, etc. But also more complex matters like predicting physical properties, linking structures to other public databases like PubChem and Wikipedia, and even online tutoring on chemical subjects.

Of course the largest online resource for chemical data is the venerable Chemical Abstracts Service of the American Chemical Society. But CAS isn’t free, so one anticipates an unfolding dilemma similar to open-access vs. commercial journal publishing. Should be fun to watch how this one plays out, hopefully to the benefit of scientists everywhere.

“We measured the interfacial tension of a three-component system containing the oil trans-anethol, water, and ethanol.” So say Scholten et al. in a recent paper in the venerable chemistry journal Langmuir (24 January 2008: 24 [5], 1701–1706). 

Why take note? For one, the science is interesting in its own right, since it deals with the solution properties of a three-component system.

But for those who aren’t aficionados of phase diagrams, the appeal of the work probably derives from the fact that, under proper conditions, the emulsion in question causes certain popular alcoholic drinks to form mesmerizing milky white suspensions. Think Pastis, Pernod, Sambuca, and the ever mysterious Absinthe.

Now we know why the clear liquid you purchase in the liquor store magically transforms into a cloudy opalescence when mixed with sugar and cold water.

Isn’t science wonderful?