Ticks can be attracted across air gaps several times larger than themselves by the naturally accumulated static electricity of their hosts, researchers at the University of Bristol have discovered. This makes it much easier to finding hosts to parasitise because ticks cannot jumping, making this is the only mechanism by which they would be able to latch onto hosts that are beyond the reach of their tiny legs.
The findings, published today in Current Biology, are the first known example of static electricity being implicated in the attachment of an animal to another animal.
Lead author Sam England from Bristol’s School of Biological Sciences explained: “We knew that many animals, including humans, can accumulate quite significant electrostatic charges.
“We see this when we get a static shock after bouncing on a trampoline, or when rubbing a balloon on our hair, for example. But this electrostatic charging also happens to animals in nature when they rub against objects in their environment like grass, sand, or other animals. These charges are surprisingly high, and can be equivalent to hundreds if not thousands of volts — more than you get out of your plug sockets at home! Importantly, static charges exert forces on other static charges, either attractive or repulsive depending whether they are positive or negative.
“We wondered whether the static charges that mammals, birds, and reptiles naturally accumulate could be high enough that parasitic ticks could be lifted through the air by electrostatic attraction onto these animals, therefore improving their efficiency at finding hosts to feed on.”
The team initially tested the idea by bringing statically charged rabbit fur and other materials close to ticks and observing whether they were attracted to them.
They witnessed the ticks being readily pulled through the air across air gaps of several millimetres or centimetres (the equivalent of humans jumping up several flights of stairs) by these charged surfaces, and so investigated further.
Sam continued: “First, we used previous measurements of the typical charge carried by animals to mathematically predict the strength of the electric field that is generated between a charged animal and the grass that ticks like to sit on and wait for hosts to pass by.
“Then, we placed ticks underneath an electrode, with an air gap in between, and increased the charge on the electrode until the ticks were attracted onto the electrode. By doing this we were able to determine the minimum electric field strength at which the ticks could be attracted. This minimum electric field was within the order of magnitude predicted by the mathematical calculations of the electric field between a charged animal and grass, therefore it is likely that ticks in nature are attracted onto their hosts by static electricity.”
There are several wider implications and potential applications to these findings. Firstly, the phenomenon likely applies to many other parasitic species that want to make contact and attach to their hosts, such as mites, fleas, or lice, and so it could be a universal mechanism for animals to make contact with and attach onto each other.
Beyond the purely scientific implications, the discovery opens the door for new technologies to be developed to minimise tick bites in humans, pets, and farm animals, such as developing anti-static sprays.
Sam concluded: “We have now discovered that ticks can be lifted across air gaps several times larger than themselves by the static electricity that other animals naturally build up. This makes it easier for them to find and attach onto animals that they want to latch onto and feed from. Until now, we had no idea that an animal could benefit from static electricity in this way, and it really opens up one’s imagination as to how many invisible forces like this could be helping animals and plants live their lives.”
Now the team plan to investigate whether the ticks are capable of sensing the approaching electrostatic charge of their prospective hosts.
A new study published in The Lancet has revealed the most extensive analysis to date on what led to the eventual heart failure in the world’s first successful transplant of a genetically modified pig heart into a human patient. This groundbreaking procedure was conducted by University of Maryland School of Medicine (UMSOM) physician-scientists in January 2022.
The patient, 57-year-old David Bennett, was treated at the University of Maryland Medical Center. He experienced strong cardiac function with no obvious signs of acute rejection for nearly seven weeks after the surgery. A sudden onset of heart failure led to his death two months after the transplant. Since then, the transplant team has been extensively studying the physiologic processes that led to the heart failure to identify what needs to be prevented in future transplants to improve the odds of success.
“Our paper provides crucial insight into how a multitude of factors likely played a role in the functional decline of the transplanted heart,” said study lead author Muhammad M. Mohiuddin, MD, Professor of Surgery and Scientific/Program Director of the Cardiac Xenotransplantation Program at UMSOM. “Our goal is to continue moving this field forward as we prepare for clinical trials of xenotransplants involving pig organs.”
Mr. Bennett, who was in end-stage heart failure and nearing the end of his life, did not qualify for a traditional heart transplant, but the experimental procedure was authorised by the US Food and Drug Administration under compassionate use.
“We were determined to shed light on what led to the heart transplant dysfunction in Mr. Bennett, who performed a heroic act by volunteering to be the first in the world,” said study co-author Bartley Griffith, MD, Professor of Surgery and The Thomas E. and Alice Marie Hales Distinguished Professor in Transplantation at UMSOM. “We want our next patient to not only survive longer with a xenotransplant but to return to normal life and thrive for months or even years.”
To better understand the processes that led to dysfunction of the pig heart transplant, the research team performed extensive testing on the limited available tissues in the patient. They carefully mapped out the sequence of events that led to the heart failure demonstrating that the heart functioned well on imaging tests like echocardiography until day 47 after surgery.
The new study confirms that no signs of acute rejection occurred during the first several weeks after the transplant. Likely, several overlapping factors led to heart failure in Mr. Bennett, including his poor state of health prior to the transplant that led him to become severely immunocompromised. This limited the use of an effective anti-rejection regimen used in preclinical studies for xenotransplantation. As a result, the researchers found, the patient was likely more vulnerable to rejection of the organ from antibodies made by the immune system. The researchers found indirect evidence of antibody-mediated rejection based on histology, immunohistochemical staining and single cell RNA analysis.
The use of an intravenous immunoglobulin, IVIG, a drug that contains antibodies, may also have contributed to damage to the heart muscle cells. It was given to the patient twice during the second month after the transplant to help prevent infection, likely also triggering an anti-pig immune response. The research team found evidence of immunoglobulin antibodies targeting the pig vascular endothelium layer of the heart.
Lastly, the new study investigated the presence of a latent virus, called porcine cytomegalovirus (PCMV), in the pig heart, which may have contributed to the dysfunction of the transplant. Activation of the virus may have occurred after the patient’s anti-viral treatment regimen was reduced to address other health issues. This may have initiated an inflammatory response causing cell damage. However, there is no evidence that the virus infected the patient or spread to organs beyond the heart. Improved PCMV testing protocols have been developed for sensitive detection and exclusion of latent viruses for future xenotransplants.
“Valuable lessons can be learned from this groundbreaking surgery and the courageous first patient, Mr. Bennett, that will better inform us for future xenotransplants,” said UMSOM Dean Mark T. Gladwin, MD, Vice President for Medical Affairs, University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor. “In the future, our team of surgeon-scientists will utilise newly designed immune cell assays to monitor the patient more precisely in the days, weeks, and months following the xenotransplant. This will provide stricter control of the earliest signs of rejection and the promise of a truly lifesaving innovation.”
An analysis on the positive effects of exercise on blood sugar levels in people with Type 2 diabetes mellitus (T2DM) shows that while all exercise helps, certain activities – and their timing – are especially beneficial. The study, published in The American Journal of Medicine, provides a comprehensive but straightforward summary of the benefits of exercise on controlling blood glucose levels in people with T2DM.
“The challenge with this is that most, if not all, people know exercise is good for them but they don’t know the best approach,” said Steven Malin, an associate professor in the Department of Kinesiology and Health at the Rutgers School of Arts and Sciences and an author of the study. “We targeted this issue by focusing on a few key parameters: the utility of aerobics versus weightlifting, the time of day that is optimal for exercise, whether to exercise before or after meals and whether we have to lose weight to get benefits or not.”
As part of the analysis, researchers sifted through dozens of studies and extracted common conclusions. Some of the key findings include:
Habitual aerobic exercise: increases the heart rate and the body’s use of oxygen helps manage blood glucose.
Resistance exercise: benefits insulin sensitivity in those with Type 2 diabetes.
Movement throughout the day by breaking up sitting time benefits blood glucose control and insulin levels.
Performing exercise later in the day can result in better control of blood sugar levels as well as improve insulin sensitivity.
“In short, any movement is good and more is generally better,” Malin said. “The combination of aerobic exercise and weightlifting is likely better than either alone. Exercise in the afternoon might work better than exercise in the morning for glucose control, and exercise after a meal may help slightly more than before a meal. And, you don’t have to lose weight to see the benefits of exercise. That is because exercise can lower body fat and increase muscle mass.”
While insulin resistance in T2DM is harmful, scientists believe increased insulin sensitivity is beneficial. High insulin sensitivity allows the cells of the body to use blood glucose more effectively, reducing blood sugar.
Malin researches insulin sensitivity and teaches kinesiology, the study of human movement. He and several other faculty members at Rutgers support the concept of “exercise as medicine.” The idea, which is supported by the American College of Sports Medicine and is increasingly being borne out by research, is that exercise can be considered a first-line therapy.
“I’m one of those individuals who subscribes to that notion, and in that way, I think of exercise as a drug,” Malin said.
Malin and colleagues authored the study to offer the medical community up-to-date practical advice for their patients.
“Together, this idea of exercise timing and type is important because it helps medical professionals more accurately recommend exercise prescriptions to combat high blood glucose,” Malin said.
Compared with white women, Black women have elevated risks of being diagnosed with advanced uterine cancer – also known as endometrial cancer – and of developing aggressive tumours. Researchers recently compared the incidence and trends for endometrial cancer, both overall and by subtype, between African descent women in Florida and women in the French Caribbean, specifically, the islands of Martinique and Guadeloupe. The findings are published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.
Endometrial cancer is classified as endometrioid or non-endometrioid (a more aggressive form) based on tumour cells’ appearance and genetic alterations. When Heidy N. Medina, PhD, MPH, of the University of Miami School of Medicine, and her colleagues analysed data on 34 789 endometrial cancer cases from Florida (US) and the French Caribbean from 2005–2018, they observed the following:
Caribbean Black women had the lowest rates for both endometrioid and non-endometrioid subtypes.
Non-endometrioid types were most common among US Black women (9.2 per 100 000), 2.6-times greater than the rate for US white women.
For endometrioid cancer, rates increased 1.8% yearly from 2005–2018 for US Black women and 1.2% for US white women, while no change was observed for Caribbean Black women.
For the more aggressive non-endometrioid cancers, rates increased among all women: 5.6% yearly among US Black women, 4.4% among Caribbean Black women, and 3.9% among US white women.
“This study informs the current scientific evidence about endometrial cancer risk among a diverse sample of African descent women, highlighting that within group differences matter among Black women,” said Dr Medina. “Our study suggests that these differences among Black women in different regions of the world are partly due to social factors associated with assigned race rather than purely African ancestry – related factors based on genetic origin.”
Dr Medina added that the study emphasises the need to not generalise results from Black women in the US to other African descent populations worldwide where limited data exist. “This signals the need for coordinated efforts around the world in identifying disparities, emphasising the importance of strong cancer surveillance systems and registries throughout different regions, and the necessity for there to be a greater priority among the global health community in allocating resources to improve data collection for cancer registries worldwide,” she said.
Dr Medina also stressed the importance of tracking the increasing rates of the deadlier non-endometrioid types of endometrial cancer and identifying risk factors associated with these malignancies.
Technical work on the discovery of new medicines is not commonly done in Africa, but Kelly Chibale, a professor in organic chemistry and founder of H3D at the University of Cape Town is changing this. PHOTO: Nasief Manie/Spotlight
Inside Professor Kelly Chibale’s office the bookshelves are packed with awards. On the walls, framed photographs include his class photo at Cambridge University in the United Kingdom, dated 1989.
Chibale is a professor of organic chemistry and founder of the pioneering Holistic Drug Discovery and Development Centre – H3D – at the University of Cape Town. While many important clinical trials have been conducted by Africans in Africa, the kind of drug discovery work that Chibale is doing is rare on the continent.
Chibale relays how he sees molecules everywhere – in hair, in clothes, in all of life around us. His animated voice fills the space as he speaks. “With organic chemistry, we are very visual. We look at chemical structures. If you give me a chemical structure, oh my goodness, my head starts racing about what I can do with it, or how I can change it to create new properties or new materials.”
H3D has 76 staff members investigating novel chemical compounds that could become new lifesaving medicines, with a focus on malaria, tuberculosis, and antibiotic-resistant microbial diseases.
Effectively a small biotech company embedded within the university, to date, H3D’s most notable discovery was a compound in 2012 which they named MMV390048, which had the potential to become a single-dose cure for malaria. Phase I clinical trials saw MMV390048 tested on human volunteers in South Africa and in Australia.
“In Australia, the testing model used is a volunteer infection study where human beings volunteer to be injected with the malaria parasite, which they know can be treated using available medicines,” says Chibale. “And then a section of those are given the experimental drug. And it worked beautifully there.”
‘Fail your way to success’
He adds, “People don’t realise this – there’s no medicine that will be given to people if it wasn’t tested on people first. Even me as an African. Oh man, I suffered from malaria as a child in Zambia many times. Thanks to our government then I’d be taken to a health facility and get malaria tablets, which I took and got well again. Otherwise, I would have died. Malaria kills very quickly. Now this is something I didn’t know then, something I took for granted. Only much later in life did I realise, goodness the medicine I took – someone somewhere invested in its research and development. And someone, somewhere, another human being, volunteered for that drug to be tested on them for my benefit.”
In 2017, the compound made it to Phase II clinical trials in patients with the disease, but further development was halted in 2020 when extensive further tests showed toxicity signals in rats – not rabbits though, Chibale says, adding that they had to err on the side of caution.
“In drug discovery, you have to kiss many frogs before you meet the prince,” he says. “Many drugs fail to progress. People focus on one product that makes it onto the market, right? But there are many failures that don’t even see the light of day. In this industry, you fail your way to success.”
H3D’s most notable discovery was a compound in 2012 which they named MMV390048, which had the potential to become a single-dose cure for malaria. PHOTO: Nasief Manie/Spotlight
Their work continues. In April last year at a function at Cape Town’s Vineyard Hotel, multinational pharmaceutical company Johnson & Johnson announced H3D as one of its three satellite centres for global health discovery. The other centres are in London and Singapore. At the time, Johnson & Johnson stated, “Driven by some of the leading researchers in Africa and discovery science, the satellite center [H3D] is focused on outpacing the rising threat of antimicrobial resistance by accelerating innovation against multidrug-resistance gram-negative bacteria.”
Seated at a boardroom table in his office, Chibale laughs deep from his belly. “We associate Johnson & Johnson with baby powder, but there’s much more…”
His left arm is in a sling following shoulder surgery – an injury stemming from lockdown when he slipped and fell while hiking on Table Mountain. “It happened just here, above the university,” he gestures, with his other arm.
Chibale and his wife Bertha live on the university’s campus, where he has served as warden of student residence Upper Campus Residence, formerly Smuts Hall, since 2015. Here he weathered the #rhodesmustfall and #feesmustfall protests, which saw students torch vehicles and police deploy stun grenades a stone’s throw away from his home.
Referring to his injured arm, he says at least his writing arm wasn’t hurt and that he can still type with one hand.
From a village in Zambia
Mentions of gratitude underpin the story of his journey, which starts in a village without electricity or running water in Zambia’s Mpika district. His father died when he was two months old. Laughing, he relays how hearing in his one ear is still impaired after being ambushed as a kid while stealing mangoes.
“This was a township,” he says. “So I’m climbing up a tree to steal mangoes and I was coming down. This gang, or well guys who were playful, had surrounded us. There were only about four of us, of who three managed to escape. And I was the only one left. Oh my goodness. And they took a big rock and smashed it to my ear. And then, when they saw me bleeding, they actually ran away. They were so scared of the damage they had done. Oh, that day! Anyway, so I went home and lied to my mother and said, no I went to school and tripped over a hole.”
During high school classes, thanks to an excellent teacher, he became fascinated with chemistry experiments. He went on to study organic chemistry at the University of Zambia, where he fell in love with the logical nature of organic molecules. “These things cannot be planned. I simply fell in love with organic chemistry, in the same way I fell in love with my wife Bertha,” he says.
From early on he realised education was a way out of poverty. “To get out of poverty, you either play sport or you follow education,” he says. “So I started applying for scholarships, writing letters to universities around the world. And I got rejected. I kept applying and kept on being rejected. But I didn’t give up. I kept applying.”
His first job was at Kafironda Explosives in the mining town Mufulira, on Zambia’s Copperbelt, where he made detonators, dynamite, and other explosives for use in Zambian mines. Laughing, he says this would come to haunt him later while applying for a visa to enter the United States. “There was a section on the form where you had to declare whether you’ve worked with explosives,” he says. “Of course, I said ‘yes’, and fortunately nothing happened.”
During two years at Kafironda, he continued applying for scholarships. “And I remember this,” he says. “It was January of 1989. I got a letter saying you have been shortlisted for a Cambridge Livingstone Trust Scholarship. Please present yourself for an interview on the 26th of January at the Anglo-American Corporation offices in Harare, Zimbabwe… So that was my first time out of Zambia. The first time to fly on an aeroplane.”
‘This was my turn’
Competition for the scholarship was tight, with shortlisted candidates from several African countries. “So in that year, there were six of us from Zambia, from different disciplines. I was the only scientist. And of course, I’d been failing all this time, getting rejected. But this was my turn. It was God’s appointed time for me. Actually, I was the only successful candidate.”
At Cambridge, without having completed an honours or master’s degree, Chibale enrolled for a PhD under the late organic chemist Professor Stuart Warren. “So Stuart, this amazing, incredible man, just gave me a chance. I mean there was such a gap between me and my colleagues who had all done their undergraduates at Cambridge. But in life, you can moan and complain about a disadvantage, or you can turn it into a challenge. I mean, the first three to six months were rough. Stuart would recommend to me that I sneak into first-year undergraduate classes to catch up. Stuart, he saw something in me that I didn’t even see in myself, and really gave me a chance.”
Chibale’s work at Warren’s lab, developing new synthetic methods for optically active molecules, helped secure his first post-doctoral position at the University of Liverpool, in the United Kingdom, after which he joined the Scripps Research Institute in La Jolla, California, funded through a Wellcome Trust International Prize Travelling Research Fellowship.
“That was another miracle,” he says. “I was eligible for this fellowship only because I had lived in England for three years, which was a minimum requirement. And the scholarship was so good, it even gave me an allowance for my family. I haven’t forgotten. It was 1 000 pounds per month. In those days, the pound was much stronger than the US dollar. So I went from rags to riches. In Liverpool, I was walking most of the time while in California, I actually had a car!”
Over the years, he was gaining insight into the pharmaceutical sector – the science but also the entrepreneurial side that pushes innovation, all the while longing to bring this knowledge to Africa. Peers suggested he consider South Africa, and particularly the University of Cape Town [UCT]. Around 1994, then UCT Department of Chemistry head, Professor James Bull actually made Chibale an offer to pursue postdoctoral research – which he declined. “Because I thought there was going to be a civil war in South Africa! I remember watching the release of Nelson Mandela on TV in England, quiet, just watching.”
Towards the end of 1995, inside a copy of the British scientific journal Nature, Chibale found an advertisement for a position as a lecturer in organic chemistry at UCT and applied. “It was a calling,” he says. The family moved to Cape Town.
Then in 2010 at UCT, with five post-doctoral staff, Chibale founded H3D. At the time his mentors included Dr Anthony Wood, former Pfizer senior vice-president, now head of GlaxoSmithKline’s Research and Development, who arranged for Chibale to have a four-month sabbatical with Pfizer in the United Kingdom to learn about the practicalities of innovative pharma. Thirteen years later, H3D has blossomed.
Chibale says he is a Christian as well as a soccer and boxing fan. His wife Bertha runs a Cape Town catering business called Hearts and Tarts. They have three sons.
As the interview draws to a close, he looks up at his 1989 Cambridge class photo. “You won’t believe it,” he says. “Last year I visited my college at Cambridge with my wife and second son and they pulled out a copy of my handwritten scholarship application letter, written to them from Zambia all those years back.”
This precious relic of Chibale’s journey is not in his office. He keeps it on his desk at home.
