Category: Medical Research & Technology

Upgrading the Diagnostic Power of Dipsticks

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Popularly known as ‘dipsticks’, lateral flow assays (LFAs) have long been a standard point-of-care testing system, and continue to grow in popularity, especially in developing countries.

These disposable, paper-based diagnostic devices are inexpensive, readily available, have a long shelf life, and they’re fast, typically delivering results in under 20 minutes. They’re also easy to use at home, most commonly for pregnancy tests but also now for COVID.

“These tests have been extremely popular for years, mainly because they are so simple to use. You don’t send anything to the lab or clinic because these tests don’t require any external equipment to operate. This is an advantage,” said engineering researcher Fatih Sarioglu at the Georgia Institute of Technology. “But there also is a disadvantage. There are limitations to what they can do.”

Sarioglu and his team are overcoming the limitations of LFAs with development of a flow control technology, turning these simple tests into complex biomedical assays.

Their research is outlined in two papers in Science Advances and ACS Sensors. One explains the development of their technology and the other applies the technology in a toolkit to diagnose SARS-CoV-2, as well as influenza.

LFAs make use of capillary liquid flow to detect analytes. Sarioglu explained that conventional LFAs are not practical for performing multi-step assays – capillary flow precludes them from coordinating a complex process involving the application of multiple reagents in a specific sequence with specific delays in between.

The researchers describe a technique to control capillary flow by imprinting roadblocks on a laminated paper with water insoluble ink. The blocked liquid flow is thus manipulated into a void formed at the interface of the ink-infused paper and the polymer tape laminate. By modifying the roadblocks, the researchers can essentially set the time it takes for a void to form – creating timers that hold capillary flow for a desired period.

“By strategically imprinting these timers, we can program the assays to coordinate different capillary flows,” said Sarioglu, professor in the School of Electrical and Computer Engineering. “That enables multiple liquids to be introduced, and multistep chemical reactions, with optimal incubation times – so, we can perform complex, automated assays that otherwise would normally have to be performed in laboratories. This takes us beyond the conventional LFA.”

For the user, the new dipstick test works the same way as the reliable standard – a sample is added at one end and the results present themselves minutes later in living color(s) at the other end. Sarioglu and his colleagues simply enhanced and expanded the process in between.

Basically, they drew patterns on paper – a dipstick – and created immunoassays that rival other diagnostic tests requiring labs and extra equipment, in the effective detection of pathogenic targets like Zika virus, HIV, hepatitis B virus, or malaria, among others.

The paper in ACS Sensors describes a PCR-based point-of-care toolkit based on the lab’s flow technology. The assay is programmed to run a sequence of chemical reactions to detect SARS-CoV-2 and/or influenza A and influenza B. A traditionally labour-intensive genetic assay can now be done on a disposable platform which will enable frequent, on-demand self-testing, filling a critical need to track and contain outbreaks.

The lab is studying the technology’s application for other assays targeting other pathogens, with plans to publish in the coming months. Sarioglu is optimistic about the work’s potential.

“We believe this flow technology research will have widespread impact,” he said. “This kind of dipstick test is so commonly used by the public for biomedical testing, and now it can be translated into other applications that we do not traditionally consider to be cut out for these simple tests.”

Source: Georgia Institute of Technology

Dental Acid Damage Imaged in Real Time

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Researchers have developed a new technique to improve understanding of how acid damages teeth over time at the microstructural level, creating a clear picture of how the damage happens. 

Dentine forms the main bulk of human teeth and supports the enamel, which covers the crown surface, helping to make teeth strong and resilient, but acids from dental plaque can cause tooth decay affecting the dental structure’s integrity. This research aims to develop knowledge that leads to new treatments that can restore the structure and function of dentine.

Using in situ synchrotron X-ray microtomography to scan dentine samples while they were being treated with acid, researchers built clear 3D images of dentine’s internal structure with sub-micrometre resolution (a micrometre being one-thousandth of a millimetre). By analysing these images over the six hours of the experiment, the researchers conducted the first-ever time-resolved 3D study (otherwise known as 4D studies) of the dentine microstructural changes caused by acid.

The study, published in Dental Materials, shows that acid dissolves minerals in different structures of dentine at different rates. 

Research leader Dr Tan Sui, Senior Lecturer in Materials Engineering at the University of Surrey, known for her work creating improved bio-inspired materials, said:

“Relatively little is known about how exactly acid damages the dentine inside our teeth at a microstructural level. This new research technique changes that and opens the possibility of helping identify new ways to protect dental tissues and develop new treatments.”

Source: University of Surrey

Most Trials in Clinical Practice Hold Up Over Time

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According to a new paper in Family Practice, medical practice can often be undermined by later research, randomised trials relevant to primary care generally hold up over time.

Medical reversal describes a problem whereby new research causes doctors to stop using a popular medication, procedure or test based on previous evidence. Vinayak Prasad, associate professor at the University of California, San Francisco, had found that up to 46% of original studies on adopted medical practices led to a reversal or shift in evidence of effect.

Evidence-based medicine lets doctors be confident when their decisions are grounded in high quality research. But decisions supported by robust evidence from randomised controlled trials can be reversed. For example, although aspirin is prescribed commonly to prevent cardiovascular disease, new studies indicate this treatment is unlikely to be effective.

Researchers studied the extent to which evidence from randomised control trials relevant to primary care were contradicted in subsequent research. Examining 408 randomised controlled trials from 2002 to 2005 relevant to primary care, the researchers found that over 12-17 years of follow up time, there were just 35 occurrences of evidence reversal, or roughly two a year. About nine in ten of such randomised control trials were not reversed.

“Conclusions from randomised trials relevant to primary care that also meet criteria for validity are stable over time,” said study lead author Christian Ruchon.

Source: EurekAlert!

Muscles are Timekeepers for the Liver

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Researchers have found that skeletal muscles play a large part in regulating the liver’s biological clock. The findings were published in Science Advances.

The circadian rhythm is coordinated by the brain at a general level, but each organ or tissue is also subjected to specific regulation, adjusting to time to optimise their processes. However it was not known how the liver “knows” whether it is day or night.

The liver’s main role is digestion, mainly of fats and sugars: the brain is the main consumer of sugar while skeletal muscle is the main consumer of fat.

Scientists at IRB Barcelona discovered a surprising relationship: that it is skeletal muscle which regulates liver function and determines fat metabolism. Skeletal muscle accomplishes this by secreting a that is transported to the liver through serum is responsible for modulating around 35% of the metabolic functions of the liver. The remaining basal functions of this organ and others related to carbohydrate metabolism are independent of muscle activity and are regulated by the basal circadian rhythm from the brain.

“It’s a very nice discovery because it is the first demonstration of the need for communication between the circadian clocks of tissues and organs outside the brain, and we can see that this communication between muscle and liver is altered by aging,” said study leader Dr Salvador Aznar-Benitah at IRB Barcelona. “When we get older, cells stop obeying the biological clock and begin to perform functions in a non-optimal manner, leading to errors that cause tissues to age.”

The researcher’s results show that the liver does not independently regulate the metabolism of fats and that it is muscle that sends the message that it is time to switch on fatty acid metabolism and how it should go about this. “We didn’t expect to find this connection between the liver and muscle because it wasn’t known previously, but, on second thought, it makes complete sense that fat management is coordinated by one of its main consumers,” said Dr Aznar-Benitah. Carbohydrate metabolism meanwhile is dependent on the basal coordination exercised by the brain.

Source: Institute for Research in Biomedicine (IRB Barcelona)

Plant Virus-based Treatment Protects Against Lung Tumours

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Using a virus that grows in black-eyed pea plants, nanoengineers developed a new treatment that could keep metastatic cancers at bay from the lungs. 

Not only did the treatment slow tumour growth in the lungs of mice with either metastatic breast cancer or melanoma, it also prevented or drastically minimised the spread of these cancers to the lungs of healthy mice that were challenged with the disease. The research was published in Advanced Science.

Researchers developed an experimental treatment that combats metastatic spread. This involves a plant virus called the cowpea mosaic virus, harmless to animals and humans, but which the body still registers as a foreign invader, thus triggering an immune response that could also boost the body’s cancer-fighting ability.

The idea is to use the plant virus to help the body’s immune system recognise and destroy cancer cells in the lungs. The virus itself is not infectious in our bodies, but it has all these danger signals that alarm immune cells to go into attack mode and search for a pathogen, said Nicole Steinmetz, professor of nanoengineering at the University of California San Diego.

To draw this immune response to lung tumours, Prof Steinmetz’s lab engineered nanoparticles made from the cowpea mosaic virus to target a protein in the lungs. The protein, called S100A9, is expressed and secreted by immune cells that help fight infection in the lungs. Overexpression of S100A9 has been observed to play a role in tumour growth and spread.

“For our immunotherapy to work in the setting of lung metastasis, we need to target our nanoparticles to the lung,” said Prof Steinmetz. “Therefore, we created these plant virus nanoparticles to home in on the lungs by making use of S100A9 as the target protein. Within the lung, the nanoparticles recruit immune cells so that the tumors don’t take.”

“Because these nanoparticles tend to localise in the lungs, they can change the tumor microenvironment there to become more adept at fighting off cancer — not just established tumors, but future tumors as well,” said Eric Chung, a bioengineering PhD student in Steinmetz’s lab who is one of the co-first authors on the paper.

To make the nanoparticles, the researchers infected black-eyed pea plants with cowpea mosaic virus, and harvested the virus in the form of ball-shaped nanoparticles. They then fixed S100A9-targeting molecules to the particles’ surfaces.

The researchers performed both prevention and treatment studies. In the prevention studies, they first injected the plant virus nanoparticles into the bloodstreams of healthy mice, and then later injected either triple negative breast cancer or melanoma cells into these mice. Treated mice showed a dramatic reduction in the cancers spreading to their lungs compared to untreated mice.

In the treatment studies, the researchers administered the nanoparticles to mice with metastatic tumours in their lungs. The treated mice exhibited smaller lung tumours and survived longer than untreated mice.

Prof Steinmetz envisions that the treatment could be useful after tumourectomy. “It wouldn’t be meant as an injection that’s given to everyone to prevent lung tumours. Rather, it would be given to patients who are at high risk of their tumors growing back as a metastatic disease, which often manifests in the lung. This would offer their lungs protection against cancer metastasis,” she said.

More detailed immunotoxicity and pharmacology studies are needed before this can progress to a treatment. Future studies will also explore combining this with standard cancer therapies such as chemotherapy.

Source: University of California – San Diego

Is Heart Pump Development Dead in the Water?

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At an annual meeting of the Heart Failure Society of America (HFSA), heart failure specialists agreed that recalling the HeartWare heart pump was good but debated whether its departure leaves the field of mechanical circulatory support (MCS) dead in the water.

In June, Medtronic stopped sales of its HeartWare Ventricular Assist Device (HVAD), citing excess neurological events and mortality with the device. As a result, Abbott’s HeartMate 3 became the only FDA-approved, durable left ventricular assist device (LVAD) on the market.

“Competition breeds innovation. When competition is absent or minimal, there is little incentive for corporations to innovate,” said Jennifer Cowger, MD, MS, of Henry Ford Hospital in Detroit, during the annual scientific meeting.

“While I believe the removal of the HVAD from the market was the ethical thing to do, unless we as a field start embracing MCS technology and change our messaging to the general cardiology community, our field is going to be viewed as niche to referring cardiologists and we’re going to face irrelevance and we’re going to have bad times ahead,” she added.

However Nancy Sweitzer MD, PhD, of the University of Arizona in Tucson, disagreed, pointing out that there are plenty of advances on the horizon.

Nine companies worldwide are developing heart pumps for this $3-4 billion market, Dr Sweitzer noted. Several devices under investigation — implantable ones with no external component — will probably proceed to first-in-man trials in the next year, she said. “There’s a lot of money if you do this well,” she added

Internal competition alone may be enough to advance the field, Sweitzer argued, citing Thoratec’s HeartMate II superseding their old HeartMate XVE.

“They put their own device up against their own device. So I would argue that corporate competition isn’t necessary when the stakeholders realize that we need to get better at this. I think the companies in this space realize there’s a huge unmet need here if we develop a really good MCS that was truly portable, gave people excellent quality of life, and had lower complications,” she said.

Yet given the pace of LVAD research, “in the next decade, we have cause for concern in the MCS field,” Dr Cowger countered.

Both debaters suggested that MCS technology shouldn’t stop at HeartMate 3, even with its relatively impressive performance.

“Outcomes on HeartMate 3 are not the outcomes we really want for these patients. There are still innumerable complications. Hospitalization rates are extraordinarily high in these patients post-implant even if they’re successful implants. They bleed, they get infected, they get strokes. That still happens,” noted Dr Sweitzer.

Innovation issues aside, Dr Cowger pointed out that HeartMate 3 is also much larger than the HVAD, and the smaller device’s loss leaves a gap for patients. She said negative media views had not helped the recent “sense of apathy and loss of enthusiasm for MCS”.

“Physicians don’t want to use technology that will harm or be perceived to harm patients,” she said, noting that sentiment has shifted from “VADs are sexy, cool” to “we would not choose LVADs over [heart] transplant.”

Source: MedPage Today

Men’s Sleep Affected by Phases of the Moon

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The phases of the moon may have a far greater effect on men’s sleep than women’s, according to a new study published in Science of the Total Environment.

Prior research has produced somewhat conflicting results on the link between the lunar cycle and sleep, with some reporting an association whereas others did not. There are several possible explanations for these discrepant findings, such as that some of the results were chance findings. However, a number of past studies investigating the link between lunar cycle and human sleep did not account for confounding factors, such as obstructive sleep apnoea and insomnia.

During the waxing period, the amount of illuminated moon surface as seen from Earth increases, and the time the moon appears highest in the sky gradually shifts to late evening hours. In contrast, during the waning period, the illuminated surface decreases and the moment that time the moon is highest gradually shifts to daytime hours.

“We used one-night at-home sleep recordings from 492 women and 360 men. We found that men whose sleep was recorded during nights in the waxing period of the lunar cycle exhibited lower sleep efficiency and increased time awake after sleep onset compared to men whose sleep was measured during nights in the waning period. In contrast, the sleep of women remained largely unaffected by the lunar cycle. Our results were robust to adjustment for chronic sleep problems and obstructive sleep apnea severity,” said Christian Benedict, Associate Professor at Uppsala University’s Department of Neuroscience, and corresponding author of the study.

One mechanism through which the moon may impact sleep is sunlight reflected by the moon around times when people usually go to bed. In addition, a recent study suggests that the male brain may be more responsive to ambient light than that of females.

“Our study, of course, cannot disentangle whether the association of sleep with the lunar cycle was causal or just correlative,” concluded Prof Benedict.

Source: EurekAlert!

New Effort to Improve Diversity in Clinical Trials

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Columbia University and Pfizer Inc. have established the Columbia-Pfizer Clinical Trials Diversity Initiative, which aims to reduce health disparities by increasing the number of minorities in clinical trials and making clinical researchers more diverse.

In the United States, 12% of the population is Black and 18% is Hispanic or Latino but in 2020, only 8% were Black and 11% were Hispanic among the 32 000 patients who participated in clinical trials that led to FDA approval of new drugs. For example, a review of clinical trials between 1999 and 2015 for cystic fibrosis only had a representation of 2.0% for Latinos, 1.0% for Black individuals, and 0.1% for Asians.

“People of different ethnicities can have different responses to the same medicine or treatment, so a lack of diversity among clinical trial participants means doctors cannot know if the treatment will be effective in all the patients they treat,” said Anil K Rustgi, MD, Interim Executive Vice President and Dean of the Faculties of Health Sciences and Medicine at Columbia University and director of the Herbert Irving Comprehensive Cancer Center. “Increasing diversity in trials will improve the treatment of patients from underrepresented groups and is a moral imperative as well as a fundamental medical issue.”

Rod MacKenzie, PhD, Executive Vice President and Chief Development Officer at Pfizer, said, “Diversity of representation in clinical trials is a matter of equity, which is a core Pfizer value. We are deeply committed to ensuring our clinical trials reflect the diversity of the communities like New York in which they are conducted. We look forward to working with Columbia University both to offer any willing individual, regardless of background, the opportunity to participate in and contribute to clinical research, and to expand the roster of diverse clinical researchers who are helping us conduct studies.”

Pfizer will provide a three-year, $10 million grant to Columbia to help establish and expand the Initiative, which will improve the diversity of participants in clinical trials by looking at the barriers that prevent participation by marginalised individuals. The Initiative will expand Columbia’s Community Health Workers Program network to connect with underserved populations and create culturally sensitive engagement tools. The efforts will include researching new ways to increase the accessibility of clinical trials through telemedicine, wearable technology, and home visits.

The Initiative also aims to improve diversity among clinical research faculty and staff. Columbia will help build an additional pipeline of diverse clinical investigators through a new National Diversity Clinical Trials Leadership Program to increase the number of faculty and staff from underrepresented groups as well.

“A diverse research staff not only helps to improve trust in clinical trials among participants from underserved groups but improves the entire clinical trial enterprise by bringing different questions, experience, and perspective to the table,” Dr Rustgi said.

Source: Columbia University Irving Medical Center

Fraud Trial of Theranos Boss Begins

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On Wednesday, the trial of Elizabeth Holmes, founder of medical technology company Theranos, began. Prosecutors alleged she “lied and cheated” for money and fame.

Ms Holmes faces 12 fraud charges over her role at the failed company which was once worth $9bn, facing up to 20 years in prison if found guilty.

She is accused of deceiving patients and investors about the company’s testing technology, which was claimed to diagnose basic illnesses from a few drops of blood. Her defence team argues that she was naive and her company simply failed.

“Failure is not a crime. Trying your hardest and coming up short is not a crime,” said defence lawyer Lance Wade in his opening statement on Wednesday.

Former Theranos executive Ramesh “Sunny” Balwani faces the same charges next year. He was romantically involved with Ms Holmes.

Ms Holmes, who founded Theranos in 2003 aged 19, was dubbed the world’s youngest self-made female billionaire and hailed as the “next Steve Jobs”.

In 2015 and 2016, investigations by the Wall Street Journal revealed Theranos’ blood-testing devices did not work and the company was doing most of its testing on commercially available machines made by other manufacturers. She initially denied these reports.

Prosecutor Robert Leach alleges that, after running out of funds, Ms Holmes and Mr Balwani turned to fraud in 2009, lying about the tests and exaggerating the firm’s performance. Mr Leach said this included falsely claiming the tests were vetted by Pfizer and being used by the US military.

The case will probably take months and Ms Holmes will likely take the stand — a necessary gamble in the face of overwhelming evidence that the technology did not work.

Ms Holmes “dazzled” Walgreens into using the company’s services, and the company brought her fame.

“She had become, as she sought, one of the most celebrated CEOs in Silicon Valley and the world. But under the facade of Theranos’ success there were significant problems brewing.”

 The defence’s Mr Wade said Ms Holmes “naively underestimated” the business challenges but did not attempt to defraud investors. Ms Holmes has also alleged years of emotional and psychological abuse by Mr Balwani, who has denied the allegations. She is likely to testify as to how this affected her.

Source: BBC News

New Medical Emoji Urged for Patient Communication

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Emoji, those colourful symbols we use in WhatsApp and other communication applications, could be a valuable medical tool which lets patients better communicate symptoms, concerns, and other clinically relevant information, researchers argue.

In a commentary in the Journal of the American Medical Association, senior author Shuhan He, MD, an emergency department attending, advises that each medical discipline start to come up with its own unique set of iconography for official adoption and incorporation into everyday practice.

“The need to listen to patients is at the core of our mission as physicians, and the use of emoji is a great opportunity to take communication to another level,” said Dr He. “Emoji could be particularly important in treating children with still-developing language skills, people with disabilities that impair their ability to communicate, and the many patients who speak a different language.”

While around 3500 emoji are currently within the domain of the Unicode Consortium – the nonprofit organisation that maintains text standards across computers – only about 45 emoji can be considered relevant to medicine. The first, introduced in 2015, were the syringe and the pill. Apple added emoji in 2017 to represent people with disabilities, followed by symbols of the stethoscope, bone, tooth and microbe in 2019. He was co-creator of the anatomical heart and the lung emoji introduced globally in 2020 and is now working with colleagues, as well as with a wide range of medical societies and organisations to advocate for an additional 15 medically related emoji.

“It’s tempting to dismiss emoji as a millennial fad, but they possess the power of standardisation, universality and familiarity, and in the hands of physicians and other health care providers could represent a new and highly effective way to communicate pictorially with patients,” said Dr He. In emergency medical settings where time is critical, emoji could lead to a point-and-tap form of communication that could facilitate important clinical decisions, he adds. The tiny graphic symbols which now span all digital platforms – from mobile to tablet to desktop – could also have utility as annotations to hospital discharge instructions, which are often confusing if not incomprehensible to some patients.

The recent surge of telemedicine presents a great opportunity for medical emojis. It is well suited for patients visually conveying to healthcare providers the intensity of pain they have experienced over time, and for those providers to incorporate it into digital health records.

His research is on emoji to help patients and doctors communicate common symptoms – such as mobility, mood, and duration and quality of pain – that are associated with various diseases and conditions. “It’s clear that emoji have become part of the global, mainstream conversation, and that medical societies and physician committees and organisations need to take them seriously,” said Dr He. “Which means they should be determining now which emoji would best serve the interests of their patients, building consensus around the medical accuracy of these emoji, then working to get them approved through the global standard-setting body and working through the long adaptation and implementation process.”

Source: EurekAlert!