Thursday, November 21, 2013

Global CO2 Emissions Continue to Rise

A recent report by the Netherlands Environmental Assessment Agency documents that global emissions of CO2 continue to the rise.  After declining 1% in 2009, CO2 emissions rose 5% in 2010 and increased another 3% in 2011, the latest year for which data are available.  Overall, the increase has averaged 2.7% per year over the past 10 years.  The top five CO2 emitters (in order of emissions) are China, the U.S., the European Union (27 countries combined), India, and the Russian Federation. China alone now accounts for nearly 30% of global CO2 emissions.

The overall upward trend masks wide differences between countries’ individual trends in CO2 emissions.   CO2 emissions rose much more than the global average in China (up 9%) and India (up 6%) in 2011, in part due to their increased reliance on fossil fuels, particularly coal, for power generation.   However, emissions in the U.S and the European Union actually decreased slightly (down 2% and 3%, respectively).  A shift from coal to natural gas by some power plants (which reduces CO2 emission), high oil prices (which discourage gasoline consumption), and weak economic conditions all appear to have contributed to the decline in CO2 emissions the U.S and the EU.   Whether CO2 emissions will swing upward again if/when economic conditions improve or the price of oil declines remains to be seen.

All in all, there’s not much good news here.   We’re still seeing a steady rise in global CO2 emissions.  Despite all the talk at international meetings about the need to halt the rise to prevent further global warming, little action has been taken.   In the future we can probably expect to hear that global warming continues unabated as well.

Wednesday, November 20, 2013

An Exception to the FDA’s Drug Approval Policies?

Princeton University has asked the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration) FDA for special one-time approval to treat Princeton students with a vaccine not yet approved in the U.S., according to university officials. The vaccine, called Bexsero, is currently used in Europe (but not the U.S.) to treat a particular type of meningitis bacterium known as serogroup B.

The request was prompted by an unusual outbreak of serogroup B meningitis on the Princeton campus. Seven students have contracted the disease so far, but fortunately none has died. Unlike most strains of bacteria that can cause meningitis, this particular strain can be transmitted fairly easily. Princeton students have been advised not to share drinks and to avoid kissing. (?)

In the event that FDA approval is granted (which is likely) the vaccine will be available for free by early December to Princeton undergraduate students, graduate students living in dorms, and students with specific health problems. At the moment, the vaccine’s use at Princeton is considered by the FDA to be a one-time exception to its policies. However, perhaps this incident will cause the FDA to consider fast-tracking its approval process for this particular vaccine, because at the moment there are no FDA-approved vaccines to treat this particular strain.

Saturday, November 16, 2013

The E-cigarette Industry Notches a Win

The fledgling e-cigarette industry has a lot of powerful enemies, including the tobacco industry, the pharmaceutical industry, government regulatory agencies, and even some anti-smoking groups.   The reason for opposition from tobacco companies is obvious; they fear a loss of sales of cigarettes.  Pharmaceutical companies see e-cigarettes as competition for their own smoking-cessation products, such as nicotine patches and gum.  The Unites States Food and Drug Administration (FDA) is worried about the possible long-term health effects of what is essentially an untested product.  Finally, some anti-smoking groups oppose e-cigarettes because they worry that if e-cigarettes become the next “in thing”, they might create a whole new generation of nicotine addicts who never smoked in the first place.

With this much opposition to e-cigarettes, how is it that the European Parliament recently suddenly dropped its plans to regulate e-cigarettes as “medicinal products”, to be sold only in pharmacies?  It turns out that e-cigarette users, many of them ex-smokers, believe passionately that e-cigarettes are a good thing.  Faced with growing opposition to e-cigarettes, they mounted a vigorous grassroots lobbying campaign that ultimately caused the European Parliament to back down.  They even have their own website, called  Although the website is hyped as a grassroots effort, it’s actually backed by at least one of the major e-cigarette companies, according to a New York Times article.

It’s not often that a fledgling industry and a few product users are able to take on the Goliaths of industry and win.  But the battle over e-cigarettes is just beginning.  In the United States the FDA is still considering whether or not e-cigarettes should be regulated as nicotine-delivery devices.  Since the e-cigarette lobbying effort worked so well in Europe, perhaps we’ll see a similar "grassroots" lobbying effort (backed by e-cigarette companies) in this country.

Monday, November 11, 2013

An Anti-HIV Protein in Human Milk

The HIV virus that causes AIDS is present in the milk of HIV-infected mothers, yet only about 10% of infants who nurse from HIV-infected mothers get infected. In the past it was thought that ingestion is simply a poor route to HIV infection. Now it turns out there’s another reason – human milk contains a protein that latches onto the surface coating of the virus, preventing it from infecting the infant. The protein, called Tenascin-C, normally plays a role in wound healing and fetal development. Its antiviral properties are apparently just a lucky coincidence; it couldn’t have evolved during the course of human evolution to combat HIV, because HIV didn’t exist until recently.

Will Tenascin-C become an important weapon in the fight against HIV infection? Probably not. HIV-infected mothers are already given antiretroviral drugs and they already have Tenascin-C in their milk, so purified Tenascin-C might not add much of a benefit to them or their infants. And it’s unlikely that Tenascin C would work if it were to be given intravenously to patients with established HIV infections. Nevertheless, the finding that a natural human protein can inactivate the HIV virus before it infects the host is leading to renewed hope that a drug with similar properties could be developed. An AIDS-free world may just be within our reach.

Tuesday, November 5, 2013

How Many Species of Primitive Humans Were There?

Based on structural differences between a few skulls and some partial skeletons, the prevailing thought among paleoanthropologists has been that once humans left Africa for the first time they evolved into at least five or six distinct species of primitive humans, including Homo erectus, H. georgicus, H. ergaster, H. heidelbergensis, H. rudolfensis, and H. neanderthalensis. Historically, paleontologists were quick to assign a new species name to nearly every unique skull or skeleton discovered. In part, that’s because discovering a new species generally advances the discoverer’s career. But were all these alleged species really all that different? Were they even different species?

As more skulls and skeletons are discovered, the “multiple-species” argument is beginning to be challenged. The discovery of the most complete Homo skull yet in the Georgia region of Russia brings the controversy to a head (no pun intended). The discoverers compared the newest skull to four others found previously in the same region. They note that there are substantial structural differences between them, even though they presumably belonged to the same species. Indeed, there are just as many differences between the skulls of currently living humans, all of whom belong to just one species (Homo sapiens). Based on these findings, the researchers hypothesize that all of the known skulls of primitive Homo belong to a single evolving lineage (a single species)

Generally speaking, a species is loosely defined as a group of organisms that under natural conditions tend to breed within that group. A key question, then, is whether individuals of the so-called different species could (or did) interbreed. So far we don’t know the answer. Absent that critical information, we can expect the “multiple species” versus “single species” controversy to remain with us for a while.

Saturday, November 2, 2013

Canada Launches a National Public Umbilical Cord Blood Bank

Canadians are now able to donate umbilical cords to a national public cord blood bank instead of discarding them after the birth of a child, according to Canadian Blood Services. The first donation site is in Ottawa, but additional donation sites will open in three other cities (Toronto, Edmonton, and Vancouver) by next year. The cord blood will be made available to patients nationwide who need stem cells for medical procedures, such as bone marrow (stem cell) transplants following treatment for leukemia.

Canada has several other public and private cord blood banks, but this is the first one of a national scale. The new national bank will increase the likelihood that needy patients who are not able to locate a suitable donor among their relatives or friends will ultimately be able to find a match in a unit of cord blood from an unrelated donor. Currently, only about 30% of patients needing a stem cell transplant find donors within their own families.

Canada is the last of the G8 nations (U.S., Canada, Great Britain, Germany, France, Italy, Japan, and Russia) to establish a national umbilical cord blood banking system. Officials hope that the presence of a national bank will increase awareness about the value of stem cells derived from cord blood in treating diseases, leading to an increase in donations. Currently, nearly a thousand Canadians are waiting for stem cell transplants.