Researchers exploring the role memory plays in alcohol consumption believe it could help people reduce their intake. They published their findings in Food Quality and Preference.
Previous work has found people don’t eat as much food when they are reminded of an earlier meal just before tucking in. The latest study, led by the University of Portsmouth, wanted to further investigate the relationship between memory and consumption, but with alcohol instead.
The team carried out a study involving 50 women aged 18 to 46-years-old who were randomly split into two groups: The first group were asked to recall a recent alcohol experience in detail, and the second had to recall a car journey, as a control. Participants were then asked to consume a vodka-based drink, at a rate that felt comfortable to them.
Participants watched a mood-neutral program while drinking to provide a more naturalistic environment and distract them from any suspicion that their rate of consumption was being recorded.
The findings revealed individuals asked to recall a previous drinking episode took longer to consume the alcoholic beverage, which suggests a lower motivation for alcohol.
Dr Lorenzo Stafford, a multisensory researcher at the University of Portsmouth, said: “Following on from previous work, we think an important part of the observed effect was that individuals in the alcohol memory cue condition had to estimate the number of alcohol calories they consumed.
“Our theory is that females may have had less desire for alcohol because they wish to avoid excess calories, which could also be linked to work showing that females are more likely to change their consumption habits because they are more receptive to the risks alcohol poses to health and weight.”
Despite this, it is estimated that more than a quarter (28%) of drinkers consume more than the recommended 14 units a week in England alone.
The study also found that those individuals who drink regularly – categorising them at a high risk – consumed the alcohol faster than those in the low risk group. The authors say this demonstrates that the speed of consumption is a valid measure of alcohol motivation.
In two related studies, Dr Stafford and his colleagues found that strong health warning labels on alcohol products also reduced desire for alcohol and slowed down their drinking rate. While these approaches were more effective than memory cues, they could both offer a potentially useful way to help avoid excess alcohol consumption.
The paper, , recommends further research to help understand the alcohol memory effect in males, especially as males typically consume more alcohol than females and are therefore at a heightened risk.
Metropolitan Health, a subsidiary of Momentum Health Solutions, partners with The SA Red Cross Air Mercy Service (AMS) to offer eye-care outreach to communities in need
Johannesburg, South Africa – 26 August 2024 – In South Africa, where a staggering 80% of the population relies on public healthcare1, the issue of eye health often goes unnoticed. With the majority of eye care professionals operating in the private sector, accessible eye care remains a privilege for the remaining 20% of South Africa’s population. A startling revelation from a survey by Statistics South Africa2 shows that only about 9.2% of the population use spectacles as a corrective device. Even more concerning is the fact that visual impairment ranks as the most prevalent disability, affecting 10.3% of the population3.
To address these challenges, Metropolitan Health has proudly partnered with The SA Red Cross Air Mercy Service (AMS) to enhance the vision and quality of life for underserved communities across South Africa. This collaboration will see Momentum’s health business donating funds to provide screening, refractions, and spectacles to recipients during the months of August and September 2024.
Vision care is a critical aspect of overall health and well-being. Poor vision can significantly impact an individual’s quality of life, affecting their ability to work, learn, and engage in daily activities. By providing spectacles to those in need, this partnership aims to improve the vision of many and, in so doing, create opportunities for education and employment.
The AMS is a non-profit aero-medical organisation that provides essential medical services to remote and underserved communities in South Africa. By utilising aviation and other resources, AMS ensures that critical health services are accessible to those in need. Their mission is to bridge the gap in healthcare access by delivering aero-medical services, rescue and health outreach programmes to communities that are often overlooked.
“Partnerships are essential in driving impactful change across South Africa’s communities. This initiative will not only enhance the vision of those in need but also empower them to lead more productive and fulfilling lives. Our approach and commitment to Corporate Social Investment (CSI) projects is to deliver long-term, sustainable impact. By addressing critical health needs, we continue to support initiatives that foster community wellbeing and development,” says Dr Ali Hamdulay, CEO of Metropolitan Health.
Committed to making a real difference in the lives of people by creating access to affordable, quality healthcare services and offerings amidst a challenging and ever-changing operating environment, Momentum Health Solutions and its subsidiary Metropolitan Health believe in the power of impactful CSI initiatives that create lasting change. By partnering with organisations such as AMS, it aims to extend its reach and make a meaningful difference in the lives of individuals and communities.
“The AMS is dedicated to driving meaningful change in remote rural areas through our close collaboration with the KwaZulu-Natal Department of Health. Our partnership with Metropolitan Health is crucial for ensuring our outreach programme has a lasting and sustainable impact on these underserved communities. Addressing eye care needs in rural communities is vital to improving overall health and quality of life. The outreach programme is dedicated to bridging the gap in access to essential healthcare services ensuring that even the most remote areas receive the support they need. By focusing on these underserved populations, we address critical health needs and strengthen our commitment to providing equitable healthcare across our country. We are grateful to Metropolitan Health for this valuable partnership that makes a meaningful contribution towards social impact in South Africa,” says Farhaad Haffejee, AMS CEO.
“This collaboration exemplifies our commitment to improving health outcomes and fostering sustainable development. We look forward to working closely with AMS and other partners to continue addressing critical health needs and creating lasting change. Together, we can build a healthier, more equitable future for all South Africans,” concludes Dr Hamdulay.
The investigational drug elinzanetant significantly reduces the frequency and severity of hot flashes associated with menopause while improving women’s sleep and quality of life, new UVA Health research published in JAMA shows.
The nonhormonal drug, which contains no oestrogen, was tested in two phase 3 trials, Oasis 1 and 2, at dozens of locations in the United States, Europe and Israel, including UVA Health. Postmenopausal women ages 40–65 with moderate to severe hot flashes were randomised to receive either 120mg of elinzanetant daily for 26 weeks or a placebo for 12 weeks followed by 14 weeks on elinzanetant.
The women who received elinzanetant reported rapid improvements in their symptoms and quality of life. The trials revealed statistically significant reductions in hot flash frequency and severity within the first week in both trials. At the same time, sleep quality and overall quality of life improved in both trials by week 12.
“The effectiveness for relief of hot flashes in highly symptomatic women along with improvements in sleep and mood across multiple trials and favourable safety profile of elinzanetant suggests it has potential as a non-oestrogen treatment for women with bothersome menopausal symptoms,” said researcher JoAnn V. Pinkerton, MD, UVA Health’s director of midlife health. “Elinzanetant is a dual neurokinin receptor antagonist in testing, meaning it works on two receptors in the brain to improve hot flashes, night sweats, sleep and overall mood.”
Hot Flash Treatment
Hot flashes are caused by decreased oestrogen levels during menopause and, for some women, for years after. While there are existing treatment options, such as hormone therapy, some women cannot tolerate them or do not wish to take them because of potential side effects or contraindications. Because of that, the researchers say, menopausal women need a new, effective and safe non-oestrogen alternative.
“There is a huge unmet need for new treatments for burdensome hot flashes and sweats, which have been shown to affect workplace productivity and relationships, both at work and home,” said Pinkerton, professor of obstetrics and gynaecology at the University of Virginia School of Medicine and executive director emeritus of The Menopause Society “Sleep disturbances are one of the most bothersome symptoms reported by menopausal women and can impact mood, fatigue, emotional lability, work productivity and their quality of life.”
Pinkerton and her colleagues tested elinzanetant in the double-blinded Oasis studies to see if it could safely and effectively offer a new alternative for women struggling with hot flashes.
In addition to evaluating the drug’s effect on hot flashes, sleep disruptions and quality of life, the researchers also looked for potential side effects. Headache and fatigue were the most common, and these were mild. Importantly, there were no severe side effects, which is reassuring for the drug’s safety.
“I am excited about the potential of elinzanetant to serve as a nonhormonal treatment option for women with highly bothersome menopausal symptoms who can’t or won’t take hormone therapy,” Pinkerton said. “I hope that it may become a safe and effective non-oestrogen option for menopausal women suffering from the triad of moderate to severe VMS, sleep disruption and decreased menopause-related quality of life.”
Enhancing prefrontal cortex (PFC) cognitive functions requires identifying suitable exercises that increase cerebral blood flow. A recent study using functional near-infrared spectroscopy found that short-duration, low-intensity physical exercises, except static stretching with monotonous movements, increased oxygenated haemoglobin (oxy-Hb) levels, thereby activating the PFC and enhancing blood flow in children. This study marks a significant step toward improving both the physical and mental health of children.
Cognitive functions, also known as intellectual functions, encompass thinking, understanding, memory, language, computation, and judgment, and are performed in the cerebrum. The prefrontal cortex (PFC), located in the frontal lobe of the cerebral cortex, handles these functions. Studies have shown that exercise improves cognitive function through mechanisms such as enhanced cerebral blood flow, structural changes in the brain, and promotion of neurogenesis. However, 81% of children globally do not engage in enough physical activity, leading to high levels of sedentary behavior and insufficient exercise. This lack of physical activity raises concerns about its negative impact on children’s healthy brain development and cognitive function.
A recent study from Waseda University published in Scientific Reports, by doctoral student Takashi Naito from the Graduate School of Sport Sciences, along with Professors Kaori Ishii and Koichiro Oka from the Faculty of Sport Sciences, offers insights into potential solutions. The study investigated the effects of short-duration and light-intensity exercise on increasing cerebral blood flow in children. “Our goal is to develop a light-intensity exercise program that is accessible to everyone, aiming to enhance brain function and reduce children’s sedentary behaviour. We hope to promote and implement this program in schools through collaborative efforts,” says Naito.
To enhance cognitive performance, it is essential to develop exercise programs that increase cerebral blood flow. While previous studies have established the benefits of moderate-to-vigorous exercise on cognitive functions, changes in cerebral blood flow during light-intensity exercise, particularly in children, is yet to be investigated. To address this gap, the team conducted an experimental study to examine the effects of short-term, light-intensity exercises on prefrontal cortex (PFC) hemodynamics. They focused on exercises that can be easily performed on the spot without special equipment, such as stretching. Functional near-infrared spectroscopy (fNIRS), an imaging technique that measures changes in cerebral blood flow through oxy-Hb concentrations, was used for this purpose.
The study enrolled 41 healthy children ranging from fifth-grade elementary to third-year junior high school students. The children were taught seven different types of low-intensity exercises along with associated safety measures. These exercises included Upward Stretch, Shoulder Stretch, Elbow Circles, Trunk Twist, Washing Hands, Thumb and Pinky, and Single-leg Balance. The exercises were performed while seated except Single-leg Balance, with movement patterns lasting for 10 and 20 seconds. Researchers recorded and compared oxy-Hb levels at rest and during exercise.
The study’s results were highly promising, showing a significant increase in oxy-Hb levels in multiple regions of the PFC during all forms of exercise compared to the resting state. However, no significant change in oxy-Hb levels was observed during static stretching with movement in one direction. “By combining the types of exercise that easily increase blood flow in the PFC identified in this study, it is possible to develop an exercise program that everyone can easily engage in to improve children’s executive functions. It may also be used in the future to prevent cognitive decline in adults and the elderly,” explains Naito optimistically.
In conclusion, this groundbreaking study represents a significant step forward in combating sedentary lifestyles and activating brain functions in children, thereby supporting their physical and mental growth. Although this study demonstrated that even short-duration, low-intensity exercise can increase cerebral blood flow in the prefrontal cortex, future research is needed to confirm whether such exercises actually lead to improved cognitive function.
The placebo effect is very real. This we’ve known for decades, as seen in real-life observations and the best double-blinded randomised clinical trials researchers have devised for many diseases and conditions, especially pain. And yet, how and why the placebo effect occurs has remained a mystery. Now, neuroscientists have discovered a key piece of the placebo effect puzzle, reporting it in Nature.
Researchers at the University of North Carolina School of Medicine – with colleagues from Stanford, the Howard Hughes Medical Institute, and the Allen Institute for Brain Science – discovered a pain control pathway that links the cingulate cortex in the front of the brain, through the pons region of the brainstem, to cerebellum in the back of the brain.
The researchers, led by Greg Scherrer, PharmD, PhD, associate professor in the UNC Department of Cell Biology and Physiology, the UNC Neuroscience Center, and the UNC Department of Pharmacology, then showed that certain neurons and synapses along this pathway are highly activated when mice expect pain relief and experience pain relief, even when there is no medication involved.
“That neurons in our cerebral cortex communicate with the pons and cerebellum to adjust pain thresholds based on our expectations is both completely unexpected, given our previous understanding of the pain circuitry, and incredibly exciting,” said Scherrer. “Our results do open the possibility of activating this pathway through other therapeutic means, such as drugs or neurostimulation methods to treat pain.”
Scherrer and colleagues said research provides a new framework for investigating the brain pathways underlying other mind-body interactions and placebo effects beyond the ones involved in pain.
The Placebo Paradox
In conjunction with millennia of evolution, our brains can search for ways to alleviate the sensation of pain, in some cases quantifiably as with released chemicals, and less quantifiably through positive thinking and even prayer which have some documented benefit. And then there is the placebo effect.
In clinical research, the placebo effect is often seen in the “sham” treatment group that receives a fake pill or intervention that is supposed to be inert; no benefit is expected. Except that the brain is so powerful and individuals so desire to feel better that some experience a marked improvement in their symptoms. Some placebo effects are so strong that individuals are convinced they received a real treatment meant to help them.
In fact, it’s thought that some individuals in the “actual” treatment group also derive benefit from the placebo effect, complicating experimental design and driving larger sample sizes. One way to help scientists account for this is to first understand what precisely is happening in the brain of someone experiencing the placebo effect.
Enter the Scherrer lab
The scientific community’s understanding of the biological underpinnings of pain relief through placebo analgesia came from human brain imaging studies, which showed activity in certain brain regions. Those imaging studies did not have enough precision to show what was actually happening in those brain regions. So Scherrer’s team designed a set of meticulous, complementary, and time-consuming experiments to learn in more detail, with single nerve cell precision, what was happening in those regions.
First, the researchers created an assay that generates in mice the expectation of pain relief and then very real placebo effect of pain relief. Then the researchers used a series of experimental methods to study the intricacies of the anterior cingulate cortex (ACC), which had been previously associated with the pain placebo effect. While mice were experiencing the effect, the scientists used genetic tagging of neurons in the ACC, imaging of calcium in neurons of freely behaving mice, single-cell RNA sequencing techniques, electrophysiological recordings, and optogenetics – the use of light and fluorescent-tagged genes to manipulate cells.
These experiments helped them see and study the intricate neurobiology of the placebo effect down to the brain circuits, neurons, and synapses throughout the brain.
The scientists found that when mice expected pain relief, the rostral anterior cingulate cortex neurons projected their signals to the pontine nucleus, which had no previously established function in pain or pain relief. And they found that expectation of pain relief boosted signals along this pathway.
“There is an extraordinary abundance of opioid receptors here, supporting a role in pain modulation,” Scherrer said. “When we inhibited activity in this pathway, we realised we were disrupting placebo analgesia and decreasing pain thresholds. And then, in the absence of placebo conditioning, when we activated this pathway, we caused pain relief.
Lastly, the scientists found that Purkinje cells – a distinct class of large branch-like cells of the cerebellum – showed activity patterns similar to those of the ACC neurons during pain relief expectation. Scherrer and first author Chong Chen, MD, PhD, a postdoctoral research associate in the Scherrer lab, said that this is cellular-level evidence for the cerebellum’s role in cognitive pain modulation.
“We all know we need better ways to treat chronic pain, particularly treatments without harmful side effects and addictive properties,” Scherrer said. “We think our findings open the door to targeting this novel neural pain pathway to treat people in a different but potentially more effective way.”
Researchers in Berlin and Düsseldorf have implicated a new gene in the progression of Huntington’s disease in a brain organoid model. The gene may contribute to brain abnormalities much earlier than previously thought. The study is out now in Nature Communications.
The researchers are the first to implicate the gene CHCHD2 in Huntington’s disease (HD) – an incurable genetic neurodegenerative disorder – and identified the gene as a potentially new therapeutic target. In a brain organoid model of the disease, the researchers found that mutations in the Huntington gene HTT also affect CHCHD2, which is involved in maintaining the normal function of mitochondria.
Six different labs at the Max Delbrück Center participated in the study, led by Dr Jakob Metzger of the “Quantitative Stem Cell Biology” lab at the and the “Stem Cell Metabolism” lab of Professor Alessandro Prigione at Heinrich Heine University Düsseldorf (HHU). Each lab contributed their unique expertise on Huntington’s disease, brain organoids, stem cell research and genome editing. “We were surprised to find that Huntington’s disease can impair early brain development through defects associated with mitochondrial dysfunction,” says Dr Pawel Lisowski, co-lead author in the Metzger lab at the Max Delbrück Center.
Moreover, “the organoid model suggests that HTT mutations damage brain development even before clinical symptoms appear, highlighting the importance of detecting the late-onset neurodegenerative disease early,” Selene Lickfett, co-lead author and a doctoral student in the Faculty of Mathematics and Natural Science in the lab of Prigione at HHU adds.
The unusual repetition of three letters
Huntington’s disease is caused when the nucleotides Cytosine, Adenine and Guanine are repeated an excessive number of times in the in the Huntington gene HTT. People with 35 or less repeats are generally not at risk of developing the disease, while carrying 36 or more repeats has been associated with disease. The greater the number of repeats, the earlier the disease symptoms are likely to appear, explains Metzger, a senior author of the study. The mutations cause nerve cells in the brain to progressively die. Those affected, steadily lose muscle control and develop psychiatric symptoms such as impulsiveness, delusions and hallucinations. Huntington’s disease affects approximately five to 10 in every 100 000 people worldwide. Existing therapies only treat the symptoms of the disease, they don’t slow its progression or cure it.
The challenge of HTT gene editing
To study how mutations in the HTT gene affect early brain development, Lisowski, first used variants of the Cas9 gene editing technology and manipulation of DNA repair pathways to modify healthy induced pluripotent stem cells such that they carry a large number of CAG repeats. This was technically challenging because gene editing tools are not efficient in gene regions that contain sequence repeats, such as the CAG repeats in HTT, says Lisowski.
The genetically modified stem cells were then grown into brain organoids – three-dimensional structures a few millimetres in size that resemble early-stage human brains. When the researchers analysed gene expression profiles of the organoids at different stages of development, they noticed that the CHCHD2 gene was consistently under expressed, which reduced metabolism of neuronal cells. CHCHD2 is involved in ensuring the health of mitochondria – the energy producing structures in cells. CHCHD2 has been implicated in Parkinson’s disease, but never before in Huntington’s.
They also found that when they restored the function of the CHCHD2 gene, they could reverse the effect on neuronal cells. “That was surprising,” says Selene Lickfett. “It suggests in principle that this gene could be a target for future therapies.”
Moreover, defects in neural progenitor cells and brain organoids occurred before potentially toxic aggregates of mutated Huntingtin protein had developed, adds Metzger, indicating that disease pathology in the brain may begin long before it is clinically evident.
“The prevalent view is that the disease progresses as a degeneration of mature neurons,” says Prigione. “But if changes in the brain already develop early in life, then therapeutic strategies may have to focus on much earlier time-points.”
Wide reaching implications
“Our genome editing strategies, in particular the removal of the CAG repeat region in the Huntington gene, showed great promise in reversing some of observed developmental defects. This suggests a potential gene therapy approach,” says Prigione. Another potential approach could be therapies to increase CHCHD2 gene expression, he adds.
The findings may also have broader applications for other neurodegenerative diseases, Prigione adds. “Early treatments that reverse the mitochondrial phenotypes shown here could be a promising avenue for counteracting age-related diseases like Huntington’s disease.”
Dementia with Lewy bodies is a type of dementia that is similar to both Alzheimer’s disease and Parkinson’s disease but studies on long-term treatments are lacking. A new study from Karolinska Institutet, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, highlights the potential cognitive benefits of cholinesterase inhibitor treatment.
Lewy body disease, which includes dementia with Lewy bodies (DLB) and Parkinson’s disease with and without dementia, is the second most common neurodegenerative disorder, following Alzheimer’s disease.
DLB accounts for approximately 10–15% of dementia cases and is characterised by changes in sleep, behaviour, cognition, movement, and regulation of automatic bodily functions.
“There are currently no approved treatments for DLB, so doctors often use drugs for Alzheimer’s disease, such as cholinesterase inhibitors and memantine, for symptom relief,” says Hong Xu, assistant professor at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and first author of the paper. “However, the effectiveness of these treatments remains uncertain due to inconsistent trial results and limited long-term data.”
In the current study, researchers have examined the long-term effects of cholinesterase inhibitors (ChEIs) and memantine compared with no treatment for up to ten years in 1,095 patients with DLB.
Slower cognitive decline
They found that ChEIs may slow down cognitive decline over five years compared to memantine or no treatment. ChEIs were also associated with a reduced risk of death in the first year after diagnosis.
Due to the study’s observational nature, no conclusions can be drawn about causality. The researchers did not have data on patient lifestyle habits, frailty, blood pressure, and Alzheimer’s disease co-pathology, which may have influenced the findings. Another limitation of the study is that it remains challenging to diagnose DLB accurately.
The only effective treatment for severe snakebite envenomation from a potentially deadly snake is antivenom. (Picture: Johan Marais, African Snakebite Institute)
In recent years, shortages of snake antivenom have plagued South Africa and much of the globe. Even when antivenom is available, potentially serious side effects often limit its use. Jesse Copelyn unpacks the fascinating details behind the antivenom products that might save your life and takes a look at a promising experimental treatment.
Every day, somewhere between 220 and 380 people die from snakebite around the world, yet according to Doctors Without Borders (MSF) the problem remains “chronically underfunded and neglected”.
MSF’s senior advisor on neglected tropical diseases, Koert Ritmeijer, tells Spotlight that in 2019 the World Health Organization (WHO) committed to halve the number of snakebite deaths by 2030. But this hasn’t been followed by any significant support from donor countries or philanthropic foundations, he says, with programmes that aim to “increase patients’ access to antivenoms [remaining] very underfunded”.
Antivenom is the primary registered class of treatments for snakebite. Long-running global shortages of the treatment continue to leave patients in poorer parts of the world without the care they need. That’s in part because pharmaceutical companies haven’t always found it profitable to produce. The treatment takes a long time to manufacture and it has to be geared to a specific or small group of snake species. The clientele are often those that are least able to pay, namely Africa and Asia’s rural poor.
With a limited number of suppliers, and thus a lack of market competition, prices remain high, making it difficult for many African governments to import antivenom without donor assistance.
South Africa has long been an exception. It’s the only country in Sub-Saharan Africa that produces its own antivenom – which is internationally recognised and outperforms several comparable products when studied in mice. Additionally, research done in the Western Cape shows that hospital pharmacies have traditionally had stock on hand.
However, last year production delays at the country’s state-run manufacturer, the South African Vaccine Producers (SAVP), led to a nation-wide shortage of antivenom, leaving many snakebite victims with limited options. The locally made SAVP products (previously the SAIMR) have historically been the main source of antivenom in the country.
While the nation-wide stockouts were reportedly resolved within a few months, this appears to have been more than a one-time blip. Even before the national shortage made news headlines last year, neighbouring countries that rely on South African antivenom were struggling to procure enough of the product. For instance, a 2022 study states that supply to Eswatini was becoming “increasingly and disturbingly intermittent” and that a charitable foundation there had “been unable to secure a supply of this antivenom for several months”.
Meanwhile, CEO of the African Snakebite Institute, Johan Marais told Spotlight that vets in South Africa have been struggling to access sufficient supplies for the last three years (the same SAVP products that are used to treat humans are sometimes used on pet dogs that get bitten). He said stocks in the country were low heading into snakebite season – spring and summer.
Southern Africa has 176 different types of snakes. (Infograph: African Snakebite Institute)
Compounding the problem is that even at the best of times, people in poor rural areas often struggle to access antivenom shortly after being bitten (even though the issue can be extremely time-sensitive). That’s because patients can’t simply get the drug at a local pharmacy or out of their medicine cabinet. Instead, they need to wait until they arrive at an intensive care unit before doctors can assess whether they require the treatment – and if they do, it has to be administered intravenously under carefully monitored conditions.
This is because antivenom comes with a range of side-effects. For instance, research at a Kwazulu-Natal hospital found that over three in five patients had some adverse reaction to the antidote, with nearly half of all patients going into anaphylactic shock, a severe allergic reaction that causes a person’s blood pressure to drop and makes it difficult to breathe. Consequently, health workers need to be on standby with adrenaline.
People who get bitten in rural areas far away from large healthcare facilities are thus often left in a precarious position despite being most at risk.
But why do antivenom products have so many side-effects in the first place? And why are they so difficult and time-consuming to manufacture? The answer has to do with the archaic way that antivenom is made.
A life-saving drug made of ‘horse junk’
In South Africa, the SAVP, which is a subsidiary of the National Health Laboratory Services (NHLS), makes antivenom by injecting small amounts of snake venom into a horse, so that the animal’s immune system can learn to recognise and combat the toxins. This is done repeatedly over a period of nine months until the horse becomes hyperimmunised, meaning its body produces massive numbers of antibodies which target the venom.
NHLS spokesperson, Mzi Gcukumana, says that once this happens, the horse’s “plasma is collected” (this is the liquid part of blood that contains the antibodies), and is then “carefully filtered in a sterile environment”.
The result is an antivenom product which targets the snake species that was used on the horse in the first place. At present, the SAVP makes three antivenoms: one for boomslang bites, another which is used for the saw-scaled viper, and a third, which treats bites from 10 different snake species found across the country, including the puff adder and rinkhals (which are some of the most common culprits of snakebite in South Africa). This multi-species product, known as a polyvalent antivenom, is made by injecting the horse with venom from different snake species.
There’s nothing unusual about the SAVP’s method – it’s the way everyone has made commercial snake antivenoms since the late 19th century (in some countries sheep are used instead of horses) and while it’s effective, it is also well-understood why it often induces serious side-effects.
Dr Kurt Wibmer, a scientist who is researching a new snakebite treatment, explains that with antivenom “only 10 to 20 percent of the medicine you’re getting is specific to the venom, and the other 80% is junk horse protein that your body doesn’t [need].” The result is that by injecting antivenom “you’re putting a bunch of foreign substances into your body, that the body then recognises as ‘not you’, and it develops an immune response to that [which can sometimes be extreme]”.
To add to these problems, antivenom is expensive. According to price lists shared with Spotlight by staff at the Tygerberg Poison Information Centre, the SAVP’s polyvalent product is currently priced at R2 400 per vial, while the boomslang product is sold for R7 700. And since most of the vial is “junk horse protein”, snakebite victims require multiple hits to get enough of the active ingredient. This could be 6 vials or it could be over 20.
With a high price tag, a laborious production process, and a host of side-effects that prevent health workers from saving snakebite victims at primary healthcare facilities, new treatments are badly needed – either to replace traditional antivenom or to complement it. Fortunately, many are being designed to address exactly these problems.
Over a hundred years later, anti-inflammatory drug may expand treatment options
One promising treatment in development is a synthetic anti-inflammatory medicine called Varespladib. This drug was originally developed as a treatment for conditions like acute coronary syndrome. After these efforts were abandoned, scientists discovered that the product may be able to play a role in treating snakebite victims.
That’s because Varespladib works by inhibiting an enzyme called sPLA2. sPLA2 is a core component of the venom of roughly 95% of vipers and elapids (two prominent venomous snake families). In fact, the enzyme plays a key role in many of the most harmful effects of this venom, including its ability to damage body tissue, paralyse victims, and cause heavy bleeding.
It is early days. Until now, the only evidence that suggests that Varespladib can block these effects is from studies done on mice and in petri dishes. However, a phase 2 clinical trial on humans, which has yet to be published, was just completed in the United States and India. In this research, snakebite victims who arrived at hospitals were randomly split into two groups: one got the Varespladib alongside standard treatment (like antivenom), while the other group got a placebo, plus ordinary treatment.
The results from the trial are currently under peer-review, though preliminary findings have been presented at conferences. Dr Matthew R Lewin, a co-author of the study and founder of a public benefit company that is developing the drug, told Spotlight that it looked like Veraspladib may help snakebite patients if used immediately (and when used alongside traditional treatment): “In the [trial] we took patients as long as 10 hours [after they had been bitten]. Up to 5 hours, we saw promising outcomes [from those who got Varespladib]… after 5 hours, the benefit was not apparent with respect to the primary outcome of the study”.
Time will tell whether these results will be confirmed not only in the peer-review process, but also in larger clinical trials (the present study only aimed to enrol 94 participants). If successful, Varespladib could represent an important advance.
That’s because safety trials show that unlike antivenom, the synthetic drug does not appear to cause any major side-effects. It can also be taken in pill-form, rather than being injected. This means that while snakebite victims would still have to wait until they got to a hospital to take antivenom, they would at least have something which they could take right away. While the study only looked at the effects of varespladib in combination with antivenom, Lewin suggests that “it is reasonable to expect that there will be a range of salutary [health-giving] effects” from varespladib alone, since it blocks sPLA2. He notes, however, that more research is needed.
And Varespladib isn’t the only new treatment in development. Others include a chelating agent which targets a metal-based component of snake venom. Though the evidence for this is so far only from studies in mice.
Nonetheless, since our primary treatment option for snakebite remains similar to what it was over a century ago, researchers are hopeful that we might finally begin to take a few steps forward.
Note: This is part 1 of a two-part Spotlight series on snakebite treatment in South Africa. In part 2 we will, among others, look at promising advances that may help reduce antivenom shortages.
Even when participants knew they had placebos, their COVID anxiety reduced
Photo from Pixabay CCO
A study out of Michigan State University found that non-deceptive placebos, or placebos given with people fully knowing they are placebos, effectively manage stress – even when the placebos are administered remotely.
Researchers recruited participants experiencing prolonged stress from the COVID pandemic for a two-week randomised controlled trial. Half of the participants were randomly assigned to a non-deceptive placebo group and the other half to the control group that took no pills. The participants interacted with a researcher online through four virtual sessions on Zoom. Those in the non-deceptive placebo group received information on the placebo effect and were sent placebo pills in the mail along with instructions on taking the pills.
The study, which appears in Applied Psychology: Health and Well-Being, found that the non-deceptive group showed a significant decrease in stress, anxiety and depression in just two weeks compared to the no-treatment control group. Participants also reported that the non-deceptive placebos were easy to use, not burdensome and appropriate for the situation.
“Exposure to long-term stress can impair a person’s ability to manage emotions and cause significant mental health problems, so we’re excited to see that an intervention that takes minimal effort can still lead to significant benefits,” said Jason Moser, co-author of the study and professor in MSU’s Department of Psychology. “This minimal burden makes non-deceptive placebos an attractive intervention for those with significant stress, anxiety and depression.”
The researchers are particularly hopeful in the ability to remotely administer the non-deceptive placebos by health care providers.
“This ability to administer non-deceptive placebos remotely increases scalability potential dramatically,” said Darwin Guevarra, co-author of the study and postdoctoral scholar at the University of California, San Francisco, “Remotely administered non-deceptive placebos have the potential to help individuals struggling with mental health concerns who otherwise would not have access to traditional mental health services.”
Chronic cough is among the most common reasons for seeking medical care, with middle-aged women the group most affected. A pair of new studies published in ERJ Open Research and PLOS ONE suggest that this may be a hereditary condition.
“More than 10% of the population has a chronic cough, which has been shown to entail several negative consequences: reduced quality of life, reduced ability to work and voice problems. At present, we have insufficient knowledge about what causes coughing and how best to treat it,” notes Össur Ingi Emilsson, Docent in Lung, Allergy and Sleep Research at the Department of Medical Sciences at Uppsala University.
The two studies from the department have investigated both how cough is currently managed in Swedish healthcare, and whether chronic cough can be hereditary.
The PLOS ONE study, based on data from the Swedish healthcare register, showed that 1–2% of the entire Swedish population sought care for chronic cough between 2016 and 2018, usually in primary care. Of those who sought care, the majority appear to have had a long-standing cough. The prevalence is highest among women between the ages of 40 and 60, with around 21 000 women seeking treatment for cough in these three years.
“Women generally seem to have a slightly more sensitive cough reflex, so the threshold for abnormal coughing is lower in women than in men. For me, it was unexpected that only one to two percent of patients seek help for a troublesome cough when over ten percent are affected. This can be partly explained by the lack of effective treatments. There also appeared to be some differences in care between different parts of the country, suggesting that better guidelines are needed for investigating and treating chronic cough,” continues Emilsson.
The other study, in ERJ Open Research, has provided a clue as to why some individuals develop chronic cough. Cough appears to be a hereditary phenomenon. In a large population study in northern Europe of 7155 parents and their 8176 adult children aged 20 years and over, it was found that if one parent has had chronic dry cough, their offspring were over 50% more likely to have chronic dry cough. This link was independent of confounding factors such as asthma, biological sex and smoking.
“A similar relationship was seen for productive cough, but in those cases smoking had a greater impact on prevalence. These results suggest that there is a genetic link to chronic cough,” adds Emilsson.
The research team has already begun a treatment study into chronic cough. Based on these new findings, the group is now moving forward with studies on genetic variants in collaboration with the Icelandic company deCODE genetics, which analyses the human genome. The aim is to identify which genetic variants are linked to chronic cough.
“This could provide a better understanding of the occurrence of chronic cough, which may ultimately result in better treatments for this difficult-to-treat condition,” explains Emilsson.
