This Resistance Fighter Invented Dialysis in Nazi-Occupied Holland
One of the Netherlands’ most famous pieces of pop culture is “Soldier of Orange.” It’s the title of the country’s most celebrated war memoir, movie and epic stage musical, all of which detail the exploits of the nation’s resistance fighters during World War II.
Willem Johan Kolff was a member of the Dutch resistance, but he doesn’t rate a mention in the “Solider of Orange” canon. Yet his wartime toils in a rural backwater not only changed medicine, but the world.
Kolff had been a physician less than two years before Germany invaded the Netherlands in May 1940. He had been engaged in post-graduate studies at the University of Gronigen but withdrew because he refused to accommodate the demands of the Nazi occupiers. Kolff’s Jewish supervisor made an even starker choice: He committed suicide.
After his departure from the university, Kolff took a job managing a small hospital in Kampen. Located 50 miles from the heavily populated coastal region, the facility was far enough away from the prying eyes of Germans that not only could Kolff care for patients, he could hide fellow resistance fighters and even Jewish refugees in relative safety. Kolff coached many of them to feign convincing terminal illnesses so the Nazis would allow them to remain in the hospital.
Despite the demands of practicing medicine and resistance work, Kolff still found time to conduct research. He had been haunted and inspired when, not long before the Nazi invasion, one of his patients died in agony from kidney disease. Kolff wanted to find a way to save future patients.
He broke his problem down to a simple task: If he could remove 20 grams of urea from a patient’s blood in 24 hours, they would survive. He began experimenting with ways to filter blood and return it to a patient’s body. Since the war had ground all non-military manufacturing to a halt, he was mostly forced to make do with material he could find at the hospital and around Kampen. Kolff eventually built a device from a washing machine parts, juice cans, sausage casings, a valve from an old Ford automobile radiator, and even scrap from a downed German aircraft.
The world’s first dialysis machine was hardly imposing; it resembled a rotating drum for a bingo game or raffle. Yet it carried on the highly sophisticated task of moving a patient’s blood through a semi-permeable membrane (about a 50-foot length of sausage casings) into a saline solution that drew out urea while leaving the blood cells untouched.
In emigrating to the U.S. to practice medicine, Kolff's intent was twofold: Advocate for a wider adoption of dialysis, and work on new projects. He wildly succeeded at both.
Kolff began using the machine to treat patients in 1943, most of whom had lapsed into comas due to their kidney failure. But like most groundbreaking medical devices, it was not an immediate success. By the end of the war, Kolff had dialyzed more than a dozen patients, but all had died. He briefly suspended use of the device after the Allied invasion of Europe, but he continued to refine its operation and the administration of blood thinners to patients.
In September 1945, Kolff dialyzed another comatose patient, 67-year-old Sofia Maria Schafstadt. She regained consciousness after 11 hours, and would live well into the 1950s with Kolff’s assistance. Yet this triumph contained a dark irony: At the time of her treatment, Schafstadt had been imprisoned for collaborating with the Germans.
With a tattered Europe struggling to overcome the destruction of the war, Kolff and his family emigrated to the U.S. in 1950, where he began working for the Cleveland Clinic while undergoing the naturalization process so he could practice medicine in the U.S. His intent was twofold: Advocate for a wider adoption of dialysis, and work on new projects. He wildly succeeded at both.
By the mid-1950s, dialysis machines had become reliable and life-saving medical devices, and Kolff had become a U.S. citizen. About that time he invented a membrane oxygenator that could be used in heart bypass surgeries. This was a critical component of the heart-lung machine, which would make heart transplants possible and bypass surgeries routine. He also invented among the very first practical artificial hearts, which in 1957 kept a dog alive for 90 minutes.
Kolff moved to the University of Utah in 1967 to become director of its Institute for Biomedical Engineering. It was a promising time for such a move, as the first successful transplant of a donor heart to a human occurred that year. But he was interested in going a step further and creating an artificial heart for human use.
It took more than a decade of tinkering and research, but in 1982, a team of physicians and engineers led by Kolff succeeded in implanting the first artificial heart in dentist Barney Clark, whose failing health disqualified him from a heart transplant. Although Clark died in March 1983 after 112 days tethered to the device, that it kept him alive generated international headlines. While graduate student Robert Jarvik received the named credit for the heart, he was directly supervised by Kolff, whose various endeavors into artificial organ research at the University of Utah were segmented into numerous teams.
Forty years later, several artificial hearts have been approved for use by the Food and Drug Administration, although all are a “bridge” that allow patients to wait for a transplant.
Kolff continued researching and tinkering with biomedical devices – including artificial eyes and ears – until he retired in 1997 at the age of 86. When he died in 2009, the medical community acknowledged that he was not only a pioneer in biotechnology, but the “father” of artificial organs.
Tom Oxley is building what he calls a “natural highway into the brain” that lets people use their minds to control their phones and computers. The device, called the Stentrode, could improve the lives of hundreds of thousands of people living with spinal cord paralysis, ALS and other neurodegenerative diseases.
Leaps.org talked with Dr. Oxley for today’s podcast. A fascinating thing about the Stentrode is that it works very differently from other “brain computer interfaces” you may be familiar with, like Elon Musk’s Neuralink. Some BCIs are implanted by surgeons directly into a person’s brain, but the Stentrode is much less invasive. Dr. Oxley’s company, Synchron, opts for a “natural” approach, using stents in blood vessels to access the brain. This offers some major advantages to the handful of people who’ve already started to use the Stentrode.
The audio of this episode improves about 10 minutes in. (There was a minor headset issue early on, but everything is audible throughout.) Dr. Oxley’s work creates game-changing opportunities for patients desperate for new options. His take on where we're headed with BCIs is must listening for anyone who cares about the future of health and technology.
In our conversation, Dr. Oxley talks about “Bluetooth brain”; the critical role of AI in the present and future of BCIs; how BCIs compare to voice command technology; regulatory frameworks for revolutionary technologies; specific people with paralysis who’ve been able to regain some independence thanks to the Stentrode; what it means to be a neurointerventionist; how to scale BCIs for more people to use them; the risks of BCIs malfunctioning; organic implants; and how BCIs help us understand the brain, among other topics.
Dr. Oxley received his PhD in neuro engineering from the University of Melbourne in Australia. He is the founding CEO of Synchron and an associate professor and the head of the vascular bionics laboratory at the University of Melbourne. He’s also a clinical instructor in the Deepartment of Neurosurgery at Mount Sinai Hospital. Dr. Oxley has completed more than 1,600 endovascular neurosurgical procedures on patients, including people with aneurysms and strokes, and has authored over 100 peer reviewed articles.
Synchron website - https://synchron.com/
Assessment of Safety of a Fully Implanted Endovascular Brain-Computer Interface for Severe Paralysis in 4 Patients (paper co-authored by Tom Oxley) - https://jamanetwork.com/journals/jamaneurology/art...
More research related to Synchron's work - https://synchron.com/research
Tom Oxley on LinkedIn - https://www.linkedin.com/in/tomoxl
Tom Oxley on Twitter - https://twitter.com/tomoxl?lang=en
Tom Oxley website - https://tomoxl.com/
Novel brain implant helps paralyzed woman speak using digital avatar - https://engineering.berkeley.edu/news/2023/08/novel-brain-implant-helps-paralyzed-woman-speak-using-a-digital-avatar/
Edward Chang lab - https://changlab.ucsf.edu/
BCIs convert brain activity into text at 62 words per minute - https://med.stanford.edu/neurosurgery/news/2023/he...
Leaps.org: The Mind-Blowing Promise of Neural Implants - https://leaps.org/the-mind-blowing-promise-of-neural-implants/
For generations, the Indigenous Tjupan people of Australia enjoyed the sweet treat of honey made by honeypot ants. As a favorite pastime, entire families would go searching for the underground colonies, first spotting a worker ant and then tracing it to its home. The ants, which belong to the species called Camponotus inflatus, usually build their subterranean homes near the mulga trees, Acacia aneura. Having traced an ant to its tree, it would be the women who carefully dug a pit next to a colony, cautious not to destroy the entire structure. Once the ant chambers were exposed, the women would harvest a small amount to avoid devastating the colony’s stocks—and the family would share the treat.
The Tjupan people also knew that the honey had antimicrobial properties. “You could use it for a sore throat,” says Danny Ulrich, a member of the Tjupan nation. “You could also use it topically, on cuts and things like that.”
These hunts have become rarer, as many of the Tjupan people have moved away and, up until now, the exact antimicrobial properties of the ant honey remained unknown. But recently, scientists Andrew Dong and Kenya Fernandes from the University of Sydney, joined Ulrich, who runs the Honeypot Ants tours in Kalgoorlie, a city in Western Australia, on a honey-gathering expedition. Afterwards, they ran a series of experiments analyzing the honey’s antimicrobial activity—and confirmed that the Indigenous wisdom was true. The honey was effective against Staphylococcus aureus, a common pathogen responsible for sore throats, skin infections like boils and sores, and also sepsis, which can result in death. Moreover, the honey also worked against two species of fungi, Cryptococcus and Aspergillus, which can be pathogenic to humans, especially those with suppressed immune systems.
In the era of growing antibiotic resistance and the rising threat of pathogenic fungi, these findings may help scientists identify and make new antimicrobial compounds. “Natural products have been honed over thousands and millions of years by nature and evolution,” says Fernandes. “And some of them have complex and intricate properties that make them really important as potential new antibiotics. “
In an era of growing resistance to antibiotics and new threats of fungi infections, the latest findings about honeypot ants are helping scientists identify new antimicrobial drugs.
Bee honey is also known for its antimicrobial properties, but bees produce it very differently than the ants. Bees collect nectar from flowers, which they regurgitate at the hive and pack into the hexagonal honeycombs they build for storage. As they do so, they also add into the mix an enzyme called glucose oxidase produced by their glands. The enzyme converts atmospheric oxygen into hydrogen peroxide, a reactive molecule that destroys bacteria and acts as a natural preservative. After the bees pack the honey into the honeycombs, they fan it with their wings to evaporate the water. Once a honeycomb is full, the bees put a beeswax cover on it, where it stays well-preserved thanks to the enzymatic action, until the bees need it.
Less is known about the chemistry of ants’ honey-making. Similarly to bees, they collect nectar. They also collect the sweet sap of the mulga tree. Additionally, they also “milk” the aphids—small sap-sucking insects that live on the tree. When ants tickle the aphids with their antennae, the latter release a sweet substance, which the former also transfer to their colonies. That’s where the honey management difference becomes really pronounced. The ants don’t build any kind of structures to store their honey. Instead, they store it in themselves.
The workers feed their harvest to their fellow ants called repletes, stuffing them up to the point that their swollen bellies outgrow the ants themselves, looking like amber-colored honeypots—hence the name. Because of their size, repletes don’t move, but hang down from the chamber’s ceiling, acting as living feedstocks. When food becomes scarce, they regurgitate their reserves to their colony’s brethren. It’s not clear whether the repletes die afterwards or can be restuffed again. “That's a good question,” Dong says. “After they've been stretched, they can't really return to exactly the same shape.”
These replete ants are the “treat” the Tjupan women dug for. Once they saw the round-belly ants inside the chambers, they would reach in carefully and get a few scoops of them. “You see a lot of honeypot ants just hanging on the roof of the little openings,” says Ulrich’s mother, Edie Ulrich. The women would share the ants with family members who would eat them one by one. “They're very delicate,” shares Edie Ulrich—you have to take them out carefully, so they don’t accidentally pop and become a wasted resource. “Because you’d lose all this precious honey.”
Dong stumbled upon the honeypot ants phenomenon because he was interested in Indigenous foods and went on Ulrich’s tour. He quickly became fascinated with the insects and their role in the Indigenous culture. “The honeypot ants are culturally revered by the Indigenous people,” he says. Eventually he decided to test out the honey’s medicinal qualities.
The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus.
To do this, the two scientists first diluted the ant honey with water. “We used something called doubling dilutions, which means that we made 32 percent dilutions, and then we halve that to 16 percent and then we half that to eight percent,” explains Fernandes. The goal was to obtain as much results as possible with the meager honey they had. “We had very, very little of the honeypot ant honey so we wanted to maximize the spectrum of results we can get without wasting too much of the sample.”
After that, the researchers grew different microbes inside a nutrient rich broth. They added the broth to the different honey dilutions and incubated the mixes for a day or two at the temperature favorable to the germs’ growth. If the resulting solution turned turbid, it was a sign that the bugs proliferated. If it stayed clear, it meant that the honey destroyed them. The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus. “It was really quite amazing,” Fernandes says. “Eight milliliters of honey in 92 milliliters of water is a really tiny amount of honey compared to the amount of water.”
Similar to bee honey, the ants’ honey exhibited some peroxide antimicrobial activity, researchers found, but given how little peroxide was in the solution, they think the honey also kills germs by a different mechanism. “When we measured, we found that [the solution] did have some hydrogen peroxide, but it didn't have as much of it as we would expect based on how active it was,” Fernandes says. “Whether this hydrogen peroxide also comes from glucose oxidase or whether it's produced by another source, we don't really know,” she adds. The research team does have some hypotheses about the identity of this other germ-killing agent. “We think it is most likely some kind of antimicrobial peptide that is actually coming from the ant itself.”
The honey also has a very strong activity against the two types of fungi, Cryptococcus and Aspergillus. Both fungi are associated with trees and decaying leaves, as well as in the soils where ants live, so the insects likely have evolved some natural defense compounds, which end up inside the honey.
It wouldn’t be the first time when modern medicines take their origin from the natural world or from the indigenous people’s knowledge. The bark of the cinchona tree native to South America contains quinine, a substance that treats malaria. The Indigenous people of the Andes used the bark to quell fever and chills for generations, and when Europeans began to fall ill with malaria in the Amazon rainforest, they learned to use that medicine from the Andean people.
The wonder drug aspirin similarly takes its origin from a bark of a tree—in this case a willow.
Even some anticancer compounds originated from nature. A chemotherapy drug called Paclitaxel, was originally extracted from the Pacific yew trees, Taxus brevifolia. The samples of the Pacific yew bark were first collected in 1962 by researchers from the United States Department of Agriculture who were looking for natural compounds that might have anti-tumor activity. In December 1992, the FDA approved Paclitaxel (brand name Taxol) for the treatment of ovarian cancer and two years later for breast cancer.
In the era when the world is struggling to find new medicines fast enough to subvert a fungal or bacterial pandemic, these discoveries can pave the way to new therapeutics. “I think it's really important to listen to indigenous cultures and to take their knowledge because they have been using these sources for a really, really long time,” Fernandes says. Now we know it works, so science can elucidate the molecular mechanisms behind it, she adds. “And maybe it can even provide a lead for us to develop some kind of new treatments in the future.”
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.