Archive | July 2014

Math model can help fight HIV

A new mathematical model may help scientists develop effective drugs to not only treat, but actually cure HIV. HIV is Human Immunodeficiency Virus, and it causes AIDS—Acquired Immune Deficiency Syndrome.

Current antiretroviral medicines attack cells that act as active virus factories to mass produce and spread the virus so it can infect more cells. However, any cure for HIV must deal with latently-infected cells.

AIDS orphans from Cambodia. By Cambodia4kids.org, Beth Kanter from Massachusetts, USA (HIV Kids) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons.

AIDS orphans from Cambodia. By Cambodia4kids.org, Beth Kanter from Massachusetts, USA (HIV Kids) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons.

Instead of actively reproducing, the virus in these long-lived CD4+T cells is basically resting. And virus in those cells can survive, even after patients have been taking HIV medicines for years. Think of the latently-infected cells as sitting on the bench and waiting at some point to get into the game, as it were.

Unfortunately, HIV and AIDS are no game. Roughly 35 million people are living with HIV, reports the Joint United Nations Programme on HIV/AIDS (UNAIDS). AIDS-related causes killed about 1.5 million people last year, and the total death toll since the 1980s is 39 million.

Research is underway on latency-reversing agents, or LRAs. Until now, though, it’s been hard to say how strong those drugs would have to be to have a real cure.

“For HIV, a cure means being able to stop taking all drugs, without a risk of the virus growing back to high levels,” says Alison Hill, a researcher in evolutionary dynamics at Harvard University.

Now Hill and other researchers have developed a computer model to gauge how effective a medicine must be to really tackle those latently-infected cells. The team includes scientists from Harvard, Columbia, and Johns Hopkins universities in the United States, the Howard Hughes Medical Center, and the Institute of Integrative Biology in Zurich, Switzerland. PNAS, Proceedings of the National Academy of Sciences, is publishing the research.

As with any computer model, the researchers use math to see what might happen under different scenarios. Programming includes detailed algorithms—sets of instructions that tell the computer what to do with data.

The team found that a latency-reversing agent would have to reduce the number of infected cells by about 2,000-fold in order to let a majority of patients skip antiretroviral therapy, or ART, for one year. After that time, however, rebound could occur suddenly.

“We were able to determine that a 90%, 99%, or even 99.9% reduction in the latent pool is unlikely to lead to a cure,” notes Hill. “We predicted that if patients stop their drug cocktails after this type of reduction, they may appear to be cured for many months, but the virus is very likely to eventually reappear.”

“This means we likely need drugs much stronger than anything tested so far in the lab,” Hill continues. In order to prevent rebound altogether, the research team concluded, treatments would have to reduce infected cells by more than 10,000-fold, the team found.

That sounds like a daunting task, and it is. Moreover, the team’s results predict there would be large variation in when patients would rebound.

Nonetheless, the model can ultimately help speed up the search for a cure.

“This study was important because using math, we could help answer an important medical question that cannot yet be answered experimentally,” Hill says. “It may hopefully save researchers and patients from clinical trials that are unlikely to be successful.”

The research also helps explain why some apparent cures, such as treatment immediately after birth or bone marrow transplants, were not in fact permanent, Hill notes.

The more scientists can understand about HIV and what the challenges in fighting it are, the closer we all are to winning the battle against AIDS.

 

 

It’s All Happening at the Zoo

See how solar energy is a start at the Cincinnati Zoo & Botanical Garden. Check out my latest post at Midwest Energy News:

Cincinnati Zoo solar array

Note to Facebook: Non-apology Apologies Don’t Count

Earlier this week, Facebook COO Sheryl Sandberg offered a half-hearted apology after it became clear that data collected by the online social network was used in a social science study. Sandberg didn’t say the company was sorry for collecting the data without its users’ informed consent—only that it had been “poorly communicated.”

“We never meant to upset you,” Sandberg said.

As Time’s Jared Newman has pointed out, her words were basically a “corporate non-apology.” In other words, Facebook wasn’t sorry for what it did—only that it got caught and that people were upset.

The study in question set out to manipulate emotions based on the types of posts people saw in their Facebook Newsfeeds. In general, people whose Newsfeeds showed less positive posts were more likely to use negative words in their own status updates. Fewer negative posts produced an opposite pattern.

“The results show emotional contagion,” report study authors Adam Kramer, Jamie Guillory, and Jeffrey Hancock in PNAS, the Proceedings for the National Academy of Sciences, which published the study last month.

Now PNAS has issued an “Editorial Expression of Concern.” Because Facebook collected the data based on its internal policies, the Cornell researchers had determined they were not subject to the “Common Rule.” That’s the general federal policy for the protection of human subjects. Despite that, the editors note:

It is nevertheless a matter of concern that the collection of the data by Facebook may have involved practices that were not fully consistent with the principles of obtaining informed consent and allowing participants to opt out.

This may be more than the half-hearted apology Facebook offered, but it leaves a lot of open questions.

A primary reason for requiring informed consent is to protect potential test subjects. The Common Rule also establishes a level playing field for conducting scientific research.

The researchers in this case may have had good motives in using the Facebook data. But should any researchers be able to evade the Common Rule’s requirements just because their data comes from a corporation, rather than the laboratory?

It’s times like this that I wish Facebook had a “dislike” button.

 

What Happens in Vegas….

Las Vegas is hosting two notable conferences this month, and the groups couldn’t be more different.

Next Monday through Wednesday, the Heartland Institute will present its 9th Annual Conference on Climate Change at the Mandalay Bay Resort and Casino. However, it’s unlikely the conference will offer practical solutions to the impacts identified in the U.S. Global Change Research Program’s Third National Climate Assessment, which was released this spring. Rather, the Heartland Institute’s website promises that its conference will be “the largest gathering of global warming ‘skeptics’ in the world.”

Mandalay Bay Hotel. Image by Sascha Brück from Wikimedia.

Mandalay Bay Hotel. Image by Sascha Brück from Wikimedia.

A 2011 editorial in the journal Nature notes that there’s a big difference between asking legitimate questions to fill gaps in knowledge and seizing on any degree of uncertainty to reject sound science. “[T]he Heartland Institute and its ilk are not trying to build a theory of anything,” says the editorial. “They have set the bar much lower, and are happy muddying the waters.”

The Center for Media and Democracy has noted close ties between the Heartland Institute and ALEC, the American Legislative Exchange Council. ALEC actively opposes laws that promote renewable energy technologies and set energy efficiency goals through enforceable standards. ALEC’s board members include Ohio State Senator Bill Seitz, who championed Ohio’s recent “freeze” and substantial cutbacks to the state’s standards for energy efficiency and renewable energy.

Two weeks later, the NAACP will hold its annual convention at Mandalay Bay. Part of the organization’s work on civil and human rights includes its Climate Justice Initiative. “Global climate change has a disproportionate impact on communities of color in the United States and around the world,” explains the organization’s website.

Toward this end, the NAACP particularly opposes coal-powered electric generation. Its reports include “Coal-Blooded: Putting Profits Before People.” Another report released last December is “Just Energy Policies: Reducing Pollution and Creating Jobs.”

Both reports note that coal-fired power plants tend to be located in or close to poor communities whose residents often include substantial numbers of people of color. Pollution from the plants contributes to health problems, including lung disease, note the reports. “Therefore, many will die early from exposure to pollution if we do not change now,” said Alabama NAACP President Bernard Simelton when the “Just Energy Policies” report was released.

Contrary to the host city’s long-running ad campaign, neither organization wants what happens in Vegas to stay there. Both groups hope to influence public policy—in dramatically different ways.

The topic of climate change continues to be hot. And Las Vegas this July will be very hot–in more ways than one.