“Coming Back from the Dead” Is No Longer Science Fiction
Last year, there were widespread reports of a 53-year-old Frenchman who had suffered a cardiac arrest and "died," but was then resuscitated back to life 18 hours after his heart had stopped.
The once black-and-white line between life and death is now blurrier than ever.
This was thought to have been possible in part because his body had progressively cooled down naturally after his heart had stopped, through exposure to the outside cold. The medical team who revived him were reported as being "stupefied" that they had been able to bring him back to life, in particular since he had not even suffered brain damage.
Interestingly, this man represents one of a growing number of extraordinary cases in which people who would otherwise be declared dead have now been revived. It is a testament to the incredible impact of resuscitation science -- a science that is providing opportunities to literally reverse death, and in doing so, shedding light on the age-old question of what happens when we die.
Death: Past and Present
Throughout history, the boundary between life and death was marked by the moment a person's heart stopped, breathing ceased, and brain function shut down. A person became motionless, lifeless, and was deemed irreversibly dead. This is because once the heart stops beating, blood flow stops and oxygen is cut off from all the body's organs, including the brain. Consequently, within seconds, breathing stops and brain activity comes to a halt. Since the cessation of the heart literally occurs in a "moment," the philosophical notion of a specific point in time of "irreversible" death still pervades society today. The law, for example, relies on "time of death," which corresponds to when the heart stops beating.
The advent of cardiopulmonary resuscitation (CPR) in the 1960s was revolutionary, demonstrating that the heart could potentially be restarted after it had stopped, and what had been a clear black-and-white line was shown to be potentially reversible in some people. What was once called death—the ultimate end point— was now widely called cardiac arrest, and became a starting point.
From then on, it was only if somebody had requested not to be resuscitated or when CPR was deemed to have failed that people would be declared dead by "cardiopulmonary criteria." Biologically, cardiac arrest and death by cardiopulmonary criteria are the same process, albeit marked at different points in time depending on when a declaration of death is made.
The apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body.
Clearly, contrary to many people's perceptions, cardiac arrest is not a heart attack; it is the final step in death irrespective of cause, whether it be a stroke, a heart attack, a car accident, an overwhelming infection or cancer. This is how roughly 95 percent of the population are declared dead.
The only exception is the small proportion of people who may have suffered catastrophic brain injuries, but whose hearts can be artificially kept beating for a period of time on life-support machines. These people can be legally declared dead based on brain death criteria before their hearts have stopped. This is because the brain can die either from oxygen starvation after cardiac arrest or from massive trauma and internal bleeding. Either way, the brain dies hours or possibly longer after these injuries have taken place and not just minutes.
A Profound Realization
What has become increasingly clear is that the apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body. This is consistent with a mounting understanding: it is only after a person actually dies that the cells in the body start to undergo their own process of death. Intriguingly, this process is something that can now be manipulated through medical intervention. Being cold is one of the factors that slows down the rate of cellular decay. The 53-year-old Frenchman's case and the other recent cases of resuscitation after prolonged periods of time illustrate this new understanding.
Last week's earth-shattering announcement by neuroscientist Dr. Nenad Sestan and his team out of Yale, published in the prestigious scientific journal Nature, provides further evidence that a time gap exists between actual death and cellular death in cadavers. In this seminal study, these researchers were able to restore partial function in pig brains four hours after their heads were severed from their bodies. These results follow from the pioneering work in 2001 of geneticist Fred Gage and colleagues from the Salk Institute, also published in Nature, which demonstrated the possibility of growing human brain cells in the laboratory by taking brain biopsies from cadavers in the mortuary up to 21 hours post-mortem.
The once black-and-white line between life and death is now blurrier than ever. Some people may argue this means these humans and pigs weren't truly "dead." However, that is like saying the people who were guillotined during the French Revolution were also not dead. Clearly, that is not the case. They were all dead. The problem is not death; it's our reliance on an outdated philosophical, rather than biological, notion of death.
Death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place.
But the distinction between irreversibility from a medical perspective and biological irreversibility may not matter much from a pragmatic perspective today. If medical interventions do not exist at any given time or place, then of course death cannot be reversed.
However, it is crucial to distinguish between biologically and medically: When "irreversible" loss of function arises due to inadequate treatment, then a person could be potentially brought back in the future when an alternative therapy becomes available, or even today if he or she dies in a location where novel treatments can slow down the rate of cell death. However, when true irreversible loss of function arises from a biological perspective, then no treatment will ever be able to reverse the process, whether today, tomorrow, or in a hundred years.
Probing the "Grey Zone"
Today, thanks to modern resuscitation science, death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place. How many hours? We don't really know.
One of the wider implications of our medical advances is that we can now study what happens to the human mind and consciousness after people enter the "grey zone," which marks the time after the heart stops, but before irreversible and irretrievable cell damage occurs, and people are then brought back to life. Millions have been successfully revived and many have reported experiencing a unique, universal, and transformative mental state.
Were they "dead"? Yes, according to all the criteria we have ever used. But they were able to be brought back before their "dead" bodies had reached the point of permanent, irreversible cellular damage. This reflects the period of death for all of us. So rather than a "near-death experience," I prefer a new terminology to describe these cases -- "an actual-death experience." These survivors' unique experiences are providing eyewitness testimonies of what we will all be likely to experience when we die.
Such an experience reportedly includes seeing a warm light, the presence of a compassionate perfect individual, deceased relatives, a review of their lives, a judgment of their actions and intentions as they pertain to their humanity, and in some cases a sensation of seeing doctors and nurses working to resuscitate them.
Are these experiences compatible with hallucinations or illusions? No -- in part, because these people have described real, verifiable events, which, by definition are not hallucinations, and in part, because their experiences are not compatible with confused and delirious memories that characterize oxygen deprivation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down.
For instance, it is hard to classify a structured meaningful review of one's life and one's humanity as hallucinatory or illusory. Instead, these experiences represent a new understanding of the overall human experience of death. As an intensive care unit physician for more than 10 years, I have seen numerous cases where these reports have been corroborated by my colleagues. In short, these survivors have been known to come back with reports of full consciousness, with lucid, well-structured thought processes and memory formation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down. The fact that these experiences occur is a paradox and suggests the undiscovered entity we call the "self," "consciousness," or "psyche" – the thing that makes us who we are - may not become annihilated at the point of so-called death.
At New York University, the State University of New York, and across 20 hospitals in the U.S. and Europe, we have brought together a new multi-disciplinary team of experts across many specialties, including neurology, cardiology, and intensive care. Together, we hope to improve cardiac arrest prevention and treatment, as well as to address the impact of new scientific discoveries on our understanding of what happens at death.
One of our first studies, Awareness during Resuscitation (AWARE), published in the medical journal Resuscitation in 2014, confirmed that some cardiac arrest patients report a perception of awareness without recall; others report detailed memories and experiences; and a few report full auditory and visual awareness and consciousness of their experience, from a time when brain function would be expected to have ceased.
While you probably have some opinion or belief about this based upon your own philosophical, religious, or cultural background, you may not realize that exploring what happens when we die is now a subject that science is beginning to investigate.
There is no question more intriguing to humankind. And for the first time in our history, we may finally uncover some real answers.
How Genetic Testing and Targeted Treatments Are Helping More Cancer Patients Survive
Late in 2018, Chris Reiner found himself “chasing a persistent cough” to figure out a cause. He talked to doctors; he endured various tests, including an X-ray. Initially, his physician suspected bronchitis. After several months, he still felt no improvement. In May 2019, his general practitioner recommended that Reiner, a business development specialist for a Seattle-based software company, schedule a CAT scan.
Reiner knew immediately that his doctor asking him to visit his office to discuss the results wasn’t a good sign. The longtime resident of Newburyport, MA, remembers dreading “that conversation that people who learn they have cancer have.”
“The doctor handed me something to look at, and the only thing I remember after that was everything went blank all around me,” Reiner, 50, reveals. “It was the magnitude of what he was telling me, that I had a malignant mass in my lung.”
Next, he recalls, he felt ushered into “the jaws of the medical system very quickly.” He spent a couple of days meeting with a team of doctors at Beth Israel Deaconess Medical Center in nearby Boston. One of them was from a medical field he hadn’t even known existed, a pulmonary interventionist, who would perform a biopsy on the mass in his lung.
“Knowing there was a medicine for my particular type of cancer was like a weight lifted off my shoulders."
A week later he and his wife Allison returned to meet with the oncologist, radiologist, pulmonary interventionist – his medical team. They confirmed his initial diagnosis: Stage 4 metastatic lung cancer that had spread to several parts of his body. “We just sat there, stunned,” he says. “I felt like I was getting hit by a wrecking ball over and over.”
An onslaught of medical terminology about what they had identified flowed over the shocked couple, but then the medical team switched gears, he recalls. They offered hope. “They told me, ‘Hey, you’re not a smoker, so that’s good,’” Reiner says. “‘There’s a good chance that what’s driving this disease for you is actually a genetic mutation, and we have ways to understand more about what that could be through some simple testing.’”
They told him about Foundation Medicine, a company launched in neighboring Cambridge, MA, in 2009 that develops, manufactures, and sells genomic profiling assays. These are tests that, according to the company’s website, “can analyze a broad panel of genes to detect the four main classes of genomic alterations known to drive cancer growth.” With these insights, certain patients can be matched with therapies targeted specifically for the genetic driver(s) of their cancer. The company maintains one of the largest cancer genomic databases in the world, with more than 500,000 patient samples profiled, and they have more than 65 biopharma partners.
According to Foundation Medicine, they are the only company that has FDA-approved tests for both tissue- and blood-based comprehensive genomic profiling tests. One other company has an FDA-approved biopsy test, and several other companies offer tissue-based genomic profiling. Additionally, several major cancer centers like Memorial Sloan Kettering in New York and Anderson Cancer Center in Texas have their own such testing platforms.
Currently, genomic profiling is more accessible for patients with advanced cancer, due to broader insurance coverage in later stages of disease.
“Right now, the vast majority of patients either have cancers for which we don’t have treatments or they have genetic alterations that are not known,” says Jorge Garcia, MD, Division Chief, Solid Tumor Oncology, UH Cleveland Medical Center, which has its own CGP testing platform. “However, a significant proportion of patients with advanced cancer have alterations that we can tap for therapeutic purposes.”
Foundation Medicine estimates that in 2017, just over 5 percent of advanced solid cancer patients in the U.S. received CGP testing. In 2021, they estimate that number is between 25 to 30 percent of advanced solid cancer patients in the U.S., which doesn’t include patients who are tested with small (less than 50 genes) panels. Their panel tests for more than 300 cancer-related genes.
“The good news is the platforms we are developing are better and more comprehensive, and they’re going to continue to be larger data sets,” Dr. Garcia adds.
In Reiner’s case, his team ordered comprehensive genetic profiling on both his tissue and blood, from Foundation Medicine.
At this point, Reiner still wasn’t sure what genetic mutations were or how they factored into cancer or what comprehensive genomic profiling entailed. That day, though, his team ushered the Reiners into the world of precision oncology that placed him on much more sure footing to learn about and fight the specific lung cancer that had been troubling him for more than a year.
What genetic alterations were driving his cancer? Foundation Medicine’s tests were about to find out.
At the core of these tests is next generation sequencing, a DNA sequencing technology. Since 2009, this has revolutionized genomic research, according to the National Center for Biotechnology Information, because it allows an entire human genome to be sequenced within one day. Cancer genomics posits that cancer is caused by mutations and is a disease of the genome. Now, cancer genomes can be systemically studied in their entirety. For cancer patients such as Reiner, NGS can provide a more precise diagnosis and classification of the disease, more accurate prognosis, and potentially the identification of targeted drug treatments. Ultimately, the technology can provide the basis of personalized cancer management.
The detailed reports supply patients and their oncologists with extensive information about the patient’s genomic profile and potential treatment options that they can discuss together. Reiner trusted his doctors that this approach was worth the two- or three-week wait to receive the Foundation Medicine report and the specifically targeted treatment, rather than immediately jump into a round of chemotherapy. He is especially grateful now, he says, because the report delivered a great deal of relief from his previously exhausting and growing anxiety about having cancer.
Reiner and his team learned his lung cancer contained the epidermal growth factor receptor (EGFR) mutation. That biomarker enabled his oncologist to prescribe Tagrisso (osimertinib), a medication developed to directly target that genetic mutation.
“Knowing there was a medicine for my particular type of cancer was like a weight lifted off my shoulders,” he says. “It only took a week or two before my cough finally started subsiding. This pill goes right after the particular piece of genetic material in the tumor that’s causing its growth.”
Dr. Jerry Mitchell, director field medical oncology, Foundation Medicine, in Columbus, Ohio, explains that genomic profiling is generating substantial impacts today. “This is a technology that is the standard of care across many advanced malignancies that takes patients from chemotherapy-only options to very targeted options or immunotherapy options,” he says. “You can also look at complex biomarkers, and these are not specific genetic changes but different genes across the tumor to get a biomarker.”
According to Dr. Mitchell, Foundation Medicine’s technology can test more than 324 different cancer-related genes in a single test. Thus, a growing number of patients are benefitting from comprehensive genetic profiling, due to the rapidly growing number of targeted therapies. While not all of the cancers are treatable yet, the company uses that information to partner with researchers to find new potential therapies for patient groups that may have rare mutations.
Since his tumor’s diagnosis, Reiner has undergone chemotherapy and a couple surgeries to treat the metastatic cancer in other parts of his body, but the drug Tagrisso has significantly reduced his lung tumor. Now, having learned so much during the past couple of years, he is grateful for precision oncology. He still reflects on the probability that, had the Tagrisso pill not been available in May 2019, he might have only survived for another six months or a year.
“Comprehensive Genomic Profiling is not some future state, but in both the U.S. and Europe, it is a very standard, accepted, and recommended first step to knowing how to treat your cancer,” says Dr. Mitchell, adding that he feels fortunate to be an oncologist in this era. “However, we know there are still people not getting this recommended testing, so we still have opportunities to find many more patients and impact them by knowing the molecular profile of their cancer.”
The Cellular Secrets of “Young Blood” Are Starting to Be Unlocked
The quest for an elixir to restore youthful health and vigor is common to most cultures and has prompted much scientific research. About a decade ago, Stanford scientists stitched together the blood circulatory systems of old and young mice in a practice called parabiosis. It seemed to rejuvenate the aged animals and spawned vampirish urban legends of Hollywood luminaries and tech billionaires paying big bucks for healthy young blood to put into their own aging arteries in the hope of reversing or at least forestalling the aging process.
It was “kind of creepy” and also inspiring to Fabrisia Ambrosio, then thousands of miles away and near the start of her own research career into the processes of aging. Her lab is at the University of Pittsburgh but on this cold January morning I am speaking with her via Zoom as she visits with family near her native Sao Paulo, Brazil. A gleaming white high rise condo and a lush tropical jungle split the view behind her, and the summer beach is just a few blocks away.
Ambrosio possesses the joy of a kid on Christmas morning who can't wait to see what’s inside the wrapping. “I’ve always had a love for research, my father was a physicist," she says, but interest in the human body pulled her toward biology as her education progressed in the U.S. and Canada.
Back in Pittsburgh, her lab first extended the work of others in aging by using the simpler process of injecting young blood into the tail vein of old mice and found that the skeletal muscles of the animals “displayed an enhanced capacity to regenerate.” But what was causing this improvement?
When Ambrosio injected old mice with young blood depleted of EVs, the regenerative effect practically disappeared.
The next step was to remove the extracellular vesicles (EVs) from blood. EVs are small particles of cells composed of a membrane and often a cargo inside that lipid envelope. Initially many scientists thought that EVs were simply taking out the garbage that cells no longer needed, but they would learn that one cell's trash could be another cell's treasure.
Metabolites, mRNA, and myriad other signaling molecules inside the EV can function as a complex network by which cells communicate with others both near and far. These cargoes can up and down-regulate gene expression, affecting cell activity and potentially the entire body. EVs are present in humans, the bacteria that live in and on us, even in plants; they likely communicate across all forms of life.
Being inside the EV membrane protects cargo from enzymes and other factors in the blood that can degrade it, says Kenneth Witwer, a researcher at Johns Hopkins University and program chair of the International Society for Extracellular Vesicles. The receptors on the surface of the EV provide clues to the type of cell from which it originated and the cell receptors to which it might later bind and affect.
When Ambrosio injected old mice with young blood depleted of EVs, the regenerative effect practically disappeared; purified EVs alone were enough to do the job. The team also looked at muscle cell gene expression after injections of saline, young blood, and EV-depleted young blood and found significant differences. She believes this means that the major effect of enhanced regenerative capacity was coming from the EVs, though free floating proteins within the blood may also contribute something to the effect.
One such protein, called klotho, is of great interest to researchers studying aging. The name was borrowed from the Fates of Greek mythology, which consists of three sisters; Klotho spins the thread of life that her sisters measure and cut. Ambrosio had earlier shown that supplementing klotho could enhance regenerative capacity in old animals. But as with most proteins, klotho is fragile, rapidly degrading in body fluids, or when frozen and thawed. She suspected that klotho could survive better as cargo enclosed within the membrane of an EV and shielded from degradation.
So she went looking for klotho inside the EVs they had isolated. Advanced imaging technology revealed that young EVs contained abundant levels of klotho mRNAs, but the number of those proteins was much lower in EVs from old mice. Ambrosio wrote in her most recent paper, published in December in Nature Aging. She also found that the stressors associated with aging reduced the communications capacity of EVs in muscle tissue and that could be only partially restored with young blood.
Researchers still don't understand how klotho functions at the cellular level, but they may not need to know that. Perhaps learning how to increase its production, or using synthetic biology to generate more copies of klotho mRNA, or adding cell receptors to better direct EVs to specific aging tissue will be sufficient to reap the anti-aging benefits.
“Very, very preliminary data from our lab has demonstrated that exercise may be altering klotho transcripts within aged extracellular vesicles" for the better Ambrosio teases. But we already know that exercise is good for us; understanding the cellular mechanism behind that isn't likely to provide additional motivation to get up off the couch. Many of us want a prescription, a pill that is easy to take, to slow our aging.
Ambrosio hopes that others will build upon the basic research from her lab, and that pharmaceutical companies will be able to translate and develop it into products that can pass through FDA review and help ameliorate the diseases of aging.