Posts from the ‘science’ Category

David Baltimore talks AAV

GAINESVILLE, Fla. – 1975 Nobel Prize winner and HIV pioneer David Baltimore was the keynote speaker last Wednesday at the Florida Genetics 2012 Symposium. The program this year was dedicated to University of Florida’s Kenneth Berns, the father of adeno-associated virus therapy. Baltimore’s presentation, “AAV to the Rescue,” reflected the great strides research has achieved since Berns’ initial studies on the virus at the UF Genetics Institute.

Baltimore began by describing the unique problems HIV presents to human immune systems and vaccination attempts.

He said that despite its reputation, HIV is “not a particularly powerful virus.” He noted that it can take a hundred instances of unprotected sexual contact for infection to occur.

What HIV lacks in potency it makes up for by being extremely elusive to the human immune system, primarily because the virus is unaffected by most human antibodies. This is due to a thick outer carbohydrate layer, a binding site inaccessible to most antibodies and an additional binding site that is only accessible after the virus has already infected immune system cells by way of CD4 receptors. HIV also mutates quickly, requiring any vaccine attempts to be especially potent.

Years into the HIV pandemic, researchers were finally able to identify antibodies capable of fighting the virus on a broad scale, and while they were discovered too late to protect their hosts, Baltimore said they are the source of much of the current HIV vaccine research.

“…By that time, the people who make them have so much virus in their system that they can mutate against any antibody that come along, even the best,” Baltimore said.

However, the logistics of producing and dispersing the capable antibodies in viable quantities, especially in the developing countries where HIV is pandemic, are nearly insurmountable. Baltimore’s research focuses on leveraging specific genes from these antibodies so that the host body will produce vaccine-level amounts itself, a process called vectored immunoprophylaxis (VIP).

The key to the process is the family of adeno-associated viruses. Berns was the first to utilize its unique qualities that now make it a gene therapy leader. The virus is harmless to humans, has long-lived expression from a single administration, expresses inserted genes strongly and is already present in about 80 percent of humans. Its only drawback is a small genome, only about 5000 bases to humans’ 3 billion, which limits the size of genes it can carry.

Baltimore’s lab chose a strand of AAV in which to insert the genes necessary to produce b12, one of the HIV antibodies. The altered AAV was injected into the muscles of mice, which began to produce b12 in copious amounts for an extended period of time. Mice, genetically modified to have immune systems similar to humans, were injected with the AAV and then unnaturally large doses of HIV before weekly monitoring of their CD4 levels.

The presence of HIV is indicated by an almost immediate drop of CD4 counts in the blood. Mice injected with the AAV maintained or increased their CD4, demonstrating the potency of the process. The b12 antibodies are only effective against a limited number of HIV strands, however, so their genes were soon replaced in the AAV by another, VRC01, which is effective against almost all known strands.

Following the conclusion of their study in January, Baltimore and his team have continued to explore the possibilities of VIP. They tested it against HIV strands with slightly different mechanics and delivery through a mucosal membrane, its normal transmission method. All experiments found the VRC-type antibodies produced by modified AAV extremely effective in protecting mice against HIV.

With extensive experimental data to support it, the VIP process is transitioning to clinical development in humans. Although it is cheap and stable, Baltimore had to find a way to reverse the production of antibodies in patients in the case that they responded to them detrimentally. Using a Cre-Lox process, he was able to overcome limits set by AAV’s small genome to successfully stop the antibody’s production.

“The cost for us to make a batch of virus for clinical tests is enormous,” Baltimore said. “But I can only imagine that if we had a mechanized process to make virus that the yield from cells is so enormous, that we could make it at quite a reasonable cost.”

Baltimore said VIP can work for other viruses as well. Due to the rapid mutation of HIV once it is established in the immune system however, he believes it is unlikely that VIP can be used as a cure.

CEDAR center encourages evidence-based evaluations, training

Last Thursday, the U.S. Department of Education awarded a $25 million, 5-year grant to University of Florida researchers for the Collaboration for Educator Development, Accountability and Reform (CEDAR) Center. The Center hopes to use current research to improve training and evaluation practices for special education teachers.

The third center of its kind for UF, the CEDAR Center works with the education systems of 5 states and a number of non-profit groups (especially the American Institutes for Research) to develop standards that agree with up-to-date research on special education. It also provides technical assistance and supplies for the teachers involved.

“Our goal is to ensure that all teachers entering the classroom can meet standards and are receiving the right support,” said Dr. Mary Brownell, a  lead researcher for the CEDAR Center and a professor of special education in UF’s College of Education.

Brownell also said that while the focus is on special educators, general education teachers will also benefit from it.

At a time when our education system is under fire for poor performance levels, it’s important that the most recent research be applied to all levels of of our schools. Not only to improve scores, but also to genuinely educate a section of our populace that is often ignored.

Dark Matter in Rap Form

jtotheizzoe:

Dark Matter In Rap Form

Coma Niddy drops the knowledge on ya about something funky in the universe. Download the tune here.

Please continue to make fun science raps for me, everyone.

“The universe is like bread and dark matter is the cheese.”

(by comaniddy)

The more science raps there are, the more awesome the world is. True fact.

Five holes blasted by Curiosity using its super-awesome laser on some Martian ground. Not only does it shoot, but it can break down the resulting plasma and determine what molecules are present.

Previous Post

Some eerily beautiful fluid dynamics in the form of slow-mo water balloons. They don’t break, and the rebound is sometimes even cooler than the initial impact.

To reflect the ongoing structural changes in the adolescent and twenty-something brain, many journalists and scientists use words and phrases like “unfinished,” “work in progress,” “under construction” and “half-baked.” Such language implies that the brain eventually reaches a kind of ideal state when it is “done.” But there is no final, optimal state. The human brain is not a soufflé that gradually expands over time and finally finishes baking at age 30. Yes, we can identify and label periods of dramatic development—or windows of heightened plasticity—but that should not eclipse the fact that brain changes throughout life.

[…]

Whether we can, at this moment in time, meaningfully link this life stage to neuroscience seems a tenuous proposition at best. By itself, brain biology does not dictate who we are. The members of any one age group are not reducible to a few distinguishing structural changes in the brain. Ultimately, the fact that a twenty-something has weaker bridges between various brain regions than someone in their thirties is not hugely important—it’s just one aspect of a far more complex identity.

The Neuroscience of 20-Somethings by Scientific American’s Ferris Jabr (via explore-blog)

As with most things related to the human condition, it is nearly impossible to describe it with one or two words. The brain, an incredibly complex organic computer, can certainly not be summed up by “half baked” at any stage.

holymoleculesbatman:

Cobalt Chloride (Pink), Chrome Alum (Purple), Copper Nitrate (Blue), Copper Sulfate (Blue), Copper Acetate (Blue), Nickel Sulfate (Green), Potassium Chromate (Yellow), Cerium Sulfate (Yellow), Potassium Dichromate (Orange), Sodium Dichromate (Orange)