Does HIV Treatment Make People Non-Infectious?
Dr. Paul Bellman, a physician in private practice in Manhattan, has treated many HIV/AIDS patients over the past 25 years. As a medical student at NYU Medical School in 1980, he was involved in the care of the very first AIDS patients, then diagnosed with what was called GRID or Gay-Related Immune Deficiency. Bellman was formerly an attending physician at Saint Vincent's Hospital in New York, and is now affiliated with New York Presbyterian Hospital.
Question: How effective are antiretroviral drugs at making people with HIV non-infectious?
Paul Bellman: I think one of the critical issues facing HIV positive patients today in terms of their quality of life and also one of the critical issues in terms of creating the atmosphere that would be conducive to people being more willing to get tested and treated is the potential for the idea that some people who are HIV are not infectious. That could really be very liberating in terms of the whole community whether individual patients are non-infectious or not.
About two years ago a very prominent Swiss doctor, Dr. Bernard Herschel, chaired a committee that was sponsored by the Swiss government to determine whether or not what we called discordant couples where one partner is positive and the other partner is negative what the risks really were in terms of transmitting HIV. And particularly in an era where we could treat patients effectively, the question that they were addressing very specifically was whether or not someone, an HIV positive individual who is on effective treatment and had a very low undetectable viral load and as defined by Dr. Herschel for over six months, could transmit HIV to their negative partner whether or not they were practicing safe sex, which, you know, is the current standard in terms of HIV prevention between discordant couples and absolutely needs to continue to be so.
But this was an important question to address and their conclusion after looking at a series of scientific studies that were done just to track what happened to discordant couples and test the negative partner frequently is they couldn’t find any negative people who were turning positive even when the couples were acknowledging that they weren’t practicing safe sex. So that led Dr. Herschel to conclude that... to at least put forth a hypothesis that effectively treated patients might indeed be noninfectious and that created a lot of controversy and it also created some concern that, if misunderstood, it could lead people to relax safe sex precautions and that the paradoxical result could be more rather than less infections.
And the Center for Disease Control, which plays a very important role in public health policy in this country and gives great deal of considerations to all of its policy decisions basically said that yes, you know, reducing the viral load definitely reduces the infectious rate, but at this point you know we insist that people still follow and practice strict safe sex precautions.
Recorded August 18, 2010
Interviewed by Max Miller
A 2008 Swiss study suggested that people on antiretroviral medication are non-infectious, which, if true, would help to combat the stigma attached to HIV.
A new method promises to capture an elusive dark world particle.
- Dark matter is estimated to take up 26.8% of all matter in the Universe.
- The researchers will be able to try their approach in 2021, when the LHC goes back online.
Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.
- Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
- They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
- The research raises many ethical questions and puts to the test our current understanding of death.
The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?
But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.
What's dead may never die, it seems
The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.
BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.
The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.
As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.
The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.
"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.
An ethical gray matter
Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.
The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.
Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.
Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?
"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."
One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.
The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.
"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.
It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.
Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?
The dilemma is unprecedented.
Setting new boundaries
Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."
She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.
Upvote/downvote each of the videos below!
SMARTER FASTER trademarks owned by The Big Think, Inc. All rights reserved.