The first effective anti-retroviral treatment for HIV, Azidothymidine (AZT), was approved for treatment in 1987. But HIV is highly prone to mutations and thus likely to develop drug resistance. It wasn't until researcher David Ho thought to combine three different anti-retrovirals, in what is called a Highly Active Antiretroviral Treatment (HAART) cocktail, that AIDS became a truly controllable disease. Below, Ho talks about the "eureka moment" that led his team of researchers to develop HAART.
The HIV virus contains strands of RNA genetic material packaged along with a protein called Reverse Transcriptase. When HIV infects a T-cell (the white blood cells that normally protect the body against cellular invaders), it unloads its RNA into the T-cell. There the Reverse Transcriptase reads and transcribes the single-stranded RNA nucleotide bases into double-stranded viral DNA. Then another protein called Integrase fuses that viral DNA into the cell's genome. That infected DNA is later transcribed back into viral RNA, which is translated into virus proteins. The protein Protease cuts up and packages these proteins into new viruses that rupture from the cell and spread the infection.
There are three major classes of drugs that combat HIV at various stages of infection. Today, an effective HIV cocktail therapy will include three or four different types of the following drugs, but the exact regimen varies from person to person.
1. Nucleoside Analog Reverse Transcript Inhibitors (NRTIs) - These drugs, including AZT, disrupt reverse transcription, thereby preventing viral DNA from being created. NRTI's have a similar chemical structure as deoxynucleotides, the building blocks of DNA, and they compete with these naturally-occurring deoxynucleotides to be incorporated into the growing DNA chain during reverse transcription. But when an NRTI is incorporated into viral DNA, it terminates the production of that DNA strand, halting viral DNA synthesis.
2. Non-Nucleoside Reverse Transcript Inhibitors (NNRTIs) - These drugs, like NRTIs, halt viral DNA synthesis, but they do so through a different mechanism. NNRTIs target the Reverse Transcriptase enzyme itself, preventing it from transcribing DNA and thereby barring the virus from infecting the cell's genome.
3. Protease Inhibitors (PIs) - Pioneered for use in HIV patients by Ho, these drugs act on cells that have already been infected by viral DNA. PIs inhibit the protein Protease, which is required to produce and package new viruses that emerge from an infected cell and can attack other T-cells.
Swipe right to make the connections that could change your career.
Swipe right. Match. Meet over coffee or set up a call.
No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.
Research by neuroscientists at MIT's Picower Institute for Learning and Memory helps explain how the brain regulates arousal.
The big day has come: You are taking your road test to get your driver's license. As you start your mom's car with a stern-faced evaluator in the passenger seat, you know you'll need to be alert but not so excited that you make mistakes. Even if you are simultaneously sleep-deprived and full of nervous energy, you need your brain to moderate your level of arousal so that you do your best.
A disturbing interview given by a KGB defector in 1984 describes America of today and outlines four stages of mass brainwashing used by the KGB.
- Bezmenov described this process as "a great brainwashing" which has four basic stages.
- The first stage is called "demoralization" which takes from 15 to 20 years to achieve.
- According to the former KGB agent, that is the minimum number of years it takes to re-educate one generation of students that is normally exposed to the ideology of its country.
When these companies compete, in the current system, the people lose.
- When a company reaches the top of the ladder, they typically kick it away so that others cannot climb up on it. The aim? So that another company can't compete.
- When this happens in the pharmaceutical world, certain companies stay at the top of the ladder, through broadly-protected patents, at the cost of everyday people benefitting from increased competition.
- Since companies have worked out how to legally game the system, Amin argues we need to get rid of this "one size fits all" system, which treats product innovation — "tweaks" — the same as product invention.
SMARTER FASTER trademarks owned by The Big Think, Inc. All rights reserved.