The spiny dogfish
What’s the News: Researchers found that squalamine, a steroid present in the bodies of the dogfish shark, has a protective effect against several human viruses, all of which are difficult or impossible to cure with existing drugs. The chemical has so far been shown to be relatively safe in humans and can be synthesized, suggesting it could have promise as an antiviral drug in humans.
How the Heck:
- In one test, scientists injected hamsters with the yellow fever virus, which kills 30,000 people per year. Half of the hamsters got squalamine and half got nothing (a placebo). By day 11, all of the untreated hamsters were dead, but 60 percent of the squalamine-treated rodents survived.
- Next, researchers bathed lab-grown human endothelial cells—the type that line blood vessels—in varying concentrations of squalamine before introducing dengue virus. At the highest concentration of the chemical, none of the human cells became infected, nor suffered any visible ill effects from the squalamine.
- Researchers also tested squalamine’s ability to prevent replication of the hepatitis B and D viruses in cultured human liver cells. In cells treated with squalamine, viral replication was reduced 10-fold.
What’s the Context:
- Squalamine has antibiotic, fungicidal, and anti-protozoan properties. It kills a wide variety of pathogens and one study found it could be used to treat multidrug-resistant bacteria. Researchers are also investigating its ability to treat cancer and fight macular degeneration.
- A positively charged steroid similar in structure to cholesterol, squalamine binds to cell surfaces and deactivates the membrane’s negative charge before entering the cell. Researchers suspect this activity may interfere with viruses’ ability to bind to and replicate within their host.
- The chemical was first found in the spiny dogfish, or Squalus acanthias, in 1993 and named for it. Dogfish and other sharks show a remarkable resistance to viruses and other pathogens that scientists think may be due in part to squalamine.
Not So Fast:
- As with any research at this stage, results from tests in animals and lab-grown cells may not translate as expected to humans, and many steps remain before using squalamine as a antiviral drug in people.
- Squalamine only binds to certain cell types, such as liver and endothelial cells. This limits the number of bugs it might be able to fight. It also has a relatively short half-life of one to five hours in humans, potentially limiting its usefulness in certain conditions.
- Researchers don’t know the exact mechanism by which squalamine inhibits or fights viruses, and it may turn out to cause unforeseen limitations or side effects at certain dosages, although it has generally been well-tolerated in trials to date.
- Squalamine doesn’t cross the blood-brain barrier and thus is unlikely to treat viruses that affect the brain. Curiously, the researchers did test the chemical’s impact on hamsters infected with Eastern equine encephalitis virus, a pathogen that attacks the central nervous system of horses and people. Although hamsters given squalamine lived slightly longer on average than their untreated brethren, all of them still died within two weeks.
The Future Holds:
- Squalamine shows promise as a potential antiviral drug in humans, but many questions must be answered and steps taken before that can happen. In the near term, if current tests pan out, it will probably first be used to treat certain cancers or macular degeneration—which would in itself be impressive.
- If squalamine is to be used widely in the future, it’s important that it is synthesized and doesn’t come from the sharks themselves. (Squalamine used in the study was synthesized, as pointed out in the comments.) Once one of the world’s most abundant sharks, the dogfish is now listed by the IUCN Red List of Threatened Species as vulnerable, one step above “endangered.” And yet very little is being done to prevent its further decline.
Reference: Michael Zasloff et al. Squalamine as a broad-spectrum systemic antiviral agent with therapeutic potential. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1108558108
Image: OCVA / Flickr
What’s the News: We may strive for humility, but we benefit from a little hubris, too, according to a 
Keith's note: It would seem that Rep. Adams and her staff see her as some sort of crusader on this issue. They have gleefully posted her 5 minutes of questions on YouTube. Alas, she doesn't seem to be willing or able to directly accuse the current NASA Administrator, his staff - or the White House - of sabotage, ignoring Congress, etc. Instead, she used this odd line of questioning - one that can only elicit an answer of "No" from Griffin (or anyone else). The implication (apparently) being that if he didn't do these things then perhaps someone else (not in the room) may have. Mike Griffin seemed to be caught off guard by this line of questioning and answered curtly "no" each time - as if he was being interrogated by some snarky TV lawyer. 
Keith's note: Bolden's comments are in stark contrast to the 
Keith's note: Once again Rep. Hall has stacked the deck without even the slightest attempt at being objective and allowing opinions that differ from his own. Oh well, at least we know what Griffin, Armstrong, and Cernan will say since they keep saying the same thing over and over again - all pre-coordinated with each other. And Rep. Hall will ask them the same questions he has asked them a dozen times before. This is nothing more than pre-staged political theater.
Think about this: One would think that with this announcement - one that comes on the heels of the Tatooine discovery last week - that the Kepler team would be working overtime on a way to throw more of its data out - sooner - such that they can harness the crowd-sourced power of interested citizens motivated to make a contribution to the discovery of worlds circling other stars. Not only does this help in times of limited budgets, it allows the citizenry a chance to truly participate in their space agency's exploration of the universe - and therein transform that formerly distant, lofty activity into a personal one. When things get personal, people tend to want to stand up and fight for those things.
Keith's note: At one point today the panelists stated that "no one is talking about canceling Webb". Obviously they are unaware of what House Appropriators have been saying. Also, planetary scientist Jon Lunine stated that he did not think that social media was the place to be having discussions about space policy matters. Alas, Lunine was responding to a question I posted via Twitter and did so on a webinar heavily promoted via social media by its organizers. Rick Howard from NASA could not say where the cost overruns (final cost now pegged at $8.7 billion) would be taken from at NASA other than that half would come from SMD and the rest would come from, well, he did not know exactly where other than it would come from within NASA. And of course no one (including AURA, STScI, and AAS) really wanted to talk about differing opinions withing the space and planetary science community about Webb other than to suggest that internal squabbling was to be discouraged. Instead they repeatedly offered up happy talk about how the world loves Webb. The whole thing is online 
Keith's note: Why shouldn't every state in the union have a chance to participate in human space flight? People who live in other states pay tax dollars too - and they have watched their tax dollars go to Florida for half a century for human space flight activities.
