Month: August 2021

New Medical Device Slashes Surgery Risk

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A new electromedical device provides important data about possible cardiovascular and pulmonary risks before an operation.

Before any operation, it is important to properly assess the individual risk: Are there perhaps circulatory or pulmonary problems that need special consideration? To what extent can special risks be taken into account when planning the anaesthesia? Previously, clinicians have had to rely on rather subjective empirical values or carry out more elaborate examinations when in doubt. To address this, a novel device has been developed by TU Wien and MedUni Wien to objectively measure the cardiovascular and pulmonary system fitness of patients.

Pre-op interviews are important—but subjective
Complications often occur after surgical interventions. In addition to blood loss and sepsis, perioperative cardiovascular and pulmonary problems are among the most common causes of death in the first 30 days after surgery.

To minimise this risk, anesthesiologists routinely talk to patients before surgery, in addition to measuring their blood pressure, performing an electrocardiogram, or conducting more laborious examinations. But assessing responses can be highly individualised. “There are also objectively measurable parameters by which one could easily identify possible risks,” said Prof Eugenijus Kaniusas (TU Wien, Faculty of Electrical Engineering and Information Technology). “So far, however, they have not been routinely measured.”

Just hold your breath
This new device uses multiple sensors to determine key metrics in a completely non-invasive way. All the patient has to do is hold their breath for a short time to slightly outbalance their body, which responds reflexively with various biosignals. “Holding your breath is a mild stress for the body, but that is already enough to observe changes in the regulatory cardiovascular and pulmonary systems,” explained Eugenijus Kaniusas. “Oxygen saturation in the blood, heart rate variability, certain characteristics of the pulse waveform—these are dynamic parameters that we can measure in a simple way, and from them we could ideally infer individual fitness in general, especially before surgery.”

Since the device is non-invasive, medical training is not needed to operate it, and has no side effects. The result is easy to read: A rough assessment according to the three-color traffic light system or a score between 0 and 100 is displayed. The measurement can also be carried out at the bedside without any problems for people with limited mobility.

“Our laboratory prototype is being tested at MedUni Wien in cooperation with Prof. Klaus Klein from the University Department of Anesthesia, General Intensive Care Medicine and Pain Therapy. We hope to bring the device to market in the next 5 years with the help of research and transfer support,” said Eugenijus Kaniusas.

Source: Vienna University of Technology

Cancer Surgery Patients Have a Reduced Hospital Stay with ‘Prehabilitation’

Photo by Martha Dominguez de Gouveia on Unsplash


A new approach to improve their fitness for surgery reduced the length of hospital stay for cancer patients, according to a new study.

Termed ‘prehabilitation’, the study’s approach includes exercise, nutrition and psychological and social interventions to bolster physical and mental health before surgery.

The study, published in the Annals of Surgery, found that prehabilitation interventions of between one and four weeks reduced cancer patients’ stay in hospital by 1.8 days compared with usual care.

Study author Dr Chris Gaffney from Lancaster Medical School said: “Surgery is like a marathon in terms of stressing the body, and you wouldn’t run a marathon without training.”

The researchers found that as little as one week can still benefit patient outcomes, indicating that prehabilitation should be recommended to accelerate recovery from cancer surgery, as shown by a reduced hospital length of stay.

Study author Dr Joel Lambert, now a postgraduate student at Lancaster Medical School and a surgeon at East Lancashire Teaching Hospitals NHS Trust, said: “We think that it may also confer a survival advantage for cancer patients as they can get to follow up treatments like chemotherapy more quickly.

“We think that the patient groups most likely to benefit are the ones with lower levels of fitness at baseline. In the Northwest we have some of the most socioeconomically deprived populations in the UK. This subset tend to have more co-morbid conditions hence less fit.”  

The patients studied were those with liver, colorectal, and upper gastrointestinal cancer, and who are often less fit than other cancer patients.

The study interventions were grouped into three types

  • Multimodal prehabilitation: exercise, which included both nutrition and psychosocial support,
  • Bimodal prehabilitation: exercise and nutrition or psychosocial support
  • Unimodal prehabilitation: exercise or nutrition alone

The exercise interventions included aerobic, resistance, and both aerobic and resistance exercises at all levels of intensity, some supervised by a kinesiologist or physiotherapist, while others were home-based exercise regimes. These ranged from one to four weeks and all interventions were within the current NHS surgery targets for cancer surgery.

The researchers concluded: “Future studies should focus on identifying patients who would benefit most from prehabilitation and the mechanistic underpinning of any improvement in clinical outcomes. Studies should closely monitor nutrition intake to determine if the response to exercise prehabilitation is dependent upon nutritional status. Lastly, mortality should be monitored for 12 months post surgery to determine if prehabilitation has any effect beyond 30 or 90 days.”

Source: Lancaster University

Sleep Deprivation Common in Surgeons, Impacting Performance

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New research has found that surgeons were sleep deprived prior to on-call shifts and afterwards even more so, and crucially, that sleep deprivation impacted surgical performance. 

The study is the first to focus on Irish surgeons and is published in the Journal of Surgical Research. A separate study found that short naps of 30 to 60 minutes do little to reduce sleep deprivation.

Focussing on the effects of being ‘on-call’, a frequent state for surgeons, the study explored subjective and objective metrics around sleep and performance using ‘on-call’ as a particular influencer for increased fatigue.

Surgeons frequently work 24 straight hours (or more) resulting in unavoidable sleep disturbance. This is partly due to historical associations of the Halstedian Era of Surgery to ‘reside’ in the hospital in order to properly learn, but also current staffing levels mandating surgeons to complete regular on-call work.

Participants were hooked up to electroencephalogram (EEG) machines and a validated modified Multiple Sleep Latency Test testing was used to objectively measure sleep on the morning of their on-call shift. The researchers also record other validated tests for subjective sleep and fatigue measurement. ‘Sleep latency’ refers to the time it takes to go from being fully awake to sleeping and is often an indicator of sleepiness. The surgeons in the study had early onset sleep latency before on-call, which was exacerbated further in post-call settings.

Performance was measured with standardised and validated tools. Technical performance of surgeons was assessed using the validated Simendo © surgical simulator, while cognitive performance was measured using the Psychomotor Vigilance Task (PVT) to assess objective alertness and reaction time, a known aspect of cognitive performance.

The study is the first to attempt to control for a series of confounding variables such as experience, quality and quantity of sleep, the influence of caffeine and circadian rhythm influences.

The study found that:

  • Surgeons had poor baseline sleep quality and were objectively sleep-deprived, even pre-call, when they should be in a ‘rested state’.
  • In all study participants, early onset sleep latency was seen in pre-call settings and worsened in post-call settings.
  • Early onset sleep latency was worse in trainees compared to consultants, though both groups experienced early onset sleep latency post-call.
  • As sleep-deprivation increased, diminished performance was seen in cognitive tasks and surgical tasks with greater cognitive components.
  • Higher levels of self-reported fatigue and daytime sleepiness were recorded post-call.

Technical skill performance was relatively preserved in acutely sleep deprived states but may be influenced by learning curve effects and experience in surgical tasks.

Existing models of surgical on-call were not conducive to optimising sleep for surgeons, the research found. But making changes for better sleep has challenges, such as loss of continuity of patient care, loss of trainee exposure, and reduced service delivery.

Dale Whelehan, PhD researcher in Behaviour Science at the School of Medicine and lead researcher commented: “The findings of this study tell us that current provision of on-call models preclude the opportunity for surgeons to get enough rest. Similarly, surgeons are sleep deprived before going on-call which further perpetuates the issue. The implications for performance suggest aspects of surgeons performance is diminished, particularly tasks which might be more cognitively demanding. 

“We need meaningful engagement from all stakeholders in the process, working towards the common goal of optimising performance in surgeons. This involves looking at the multifactorial causes and effects of fatigue. Part of that discussion involves consideration around how current models of on-call influence sleep levels in healthcare staff, and how it creates barriers to fatigue management in staff.”

Professor Paul Ridgway, Department of Surgery at Trinity, who supervised the study, said: “Our study is further evidence that the way we deliver emergency work alongside normal work in Ireland has to change. We need to learn from our colleagues in aviation who have mandatory rest periods before flights.”

Source: Trinity College Dublin

Delta-infected Vaccinated Adults Have Similar Virus Levels to Unvaccinated

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If infected with the Delta variant, virus levels in fully vaccinated adults are as high as unvaccinated people, according to a UK analysis. This adds to evidence indicating that achieving herd immunity is unlikely.

While COVID vaccination has been shown to protect against hospitalisation and death, recent data shows that fully vaccinated people, when infected, carry the same levels of virus as those unvaccinated.

How this affects transmission remains unclear, the researchers have cautioned. “We don’t yet know how much transmission can happen from people who get COVID after being vaccinated – for example, they may have high levels of virus for shorter periods of time,” said Sarah Walker, a professor of medical statistics and epidemiology at the University of Oxford.

“But the fact that they can have high levels of virus suggests that people who aren’t yet vaccinated may not be as protected from the Delta variant as we hoped.”

Recently in the UK, positive tests, hospitalisations and deaths linked to COVID have been rising slowly. In South Africa, the third wave has still not yet abated, with a slight uptick in test positivity rates as noted by Ridhwaan Suliman at the CSIR.

https://twitter.com/rid1tweets/status/1428050053508239364?s=20

The study, awaiting peer review, found vaccine effectiveness fell against Delta compared to Alpha.

The analysis did not directly investigate whether the lower level of vaccine protection against Delta affected jabs’ ability to prevent severe disease, but low rates of hospitalisation shows it is conferring protection.

The study compared the results of swabs taken from more than 384,500 adults between December 2020 and mid-May 2021, against those from 358,983 adults between mid-May and 1 August 2021 (when Delta became dominant).

The UK findings on peak virus levels after Delta infections in vaccinated people echoed data from a small study cited by the US Centers for Disease Control and Prevention (CDC) last month which prompted the agency to recommend continued mask wearing.

These datasets highlight that vaccinated individuals could still transmit COVID, and testing and self-isolation are still important to cut transmission, said Dr Koen Pouwels, a senior Oxford University researcher. This potential for transmission makes achieving herd immunity even more challenging, he suggested.

It had been hoped the vaccinated would protect the unvaccinated, added Prof Walker. “I suspect that, partly, the higher levels of virus that we’re seeing in these [Delta] infections in vaccinated people are consistent with the fact that unvaccinated people are just going to be at higher risk.”

Compared with AstraZeneca, two doses of the Pfizer vaccine has about 15% greater initial effectiveness against new infections, but its protection declines faster compared with two doses of AstraZeneca. Four to five months after being fully vaccinated, the vaccines’ effectiveness is the same, said Prof Walker.

“Even with these slight declines in protection against all infections and infections with high viral burden, it’s important to note that overall effectiveness is still very high because we were starting at such a high level of protection,” added Dr Pouwels.

Source: The Guardian

Keeping an Eye on B.1.621’s Immune Escape Potential

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First detected in Colombia in January, the SARS-CoV-2 variant B.1.621 was recently named a ‘variant of interest’ by the European Centre for Disease Prevention and Control, reports MedPage Today. So far, neither the World Health Organization nor the CDC has elevated it to this status and it hasn’t received a greek letter designation yet.

B.1.621 has been detected in the US, though it (along with version B.1.621.1) currently accounts for just about 1% of all cases in the country. In the state of Florida, though, recent data from the University of Miami showed that 9% of cases in the Jackson Memorial Health System were B.1.621 as of the second week of July.

Last week, seven residents in a Belgian nursing home died after being infected with B.1.621, despite the fact that all of them had been vaccinated (though which vaccine was not disclosed. All of the deceased were in their 80s or 90s, and some were in poor health already, according to virologist Marc Van Ranst, who conducted tests on the virus found in the nursing home, Reuters reported. A total of 21 residents had been infected with the variant, along with several staff members. However, infected staff only had mild symptoms. B.1.621 makes up less than 1% of known cases in Belgium overall, according to Reuters.

Public Health England said that as of 2 August, there have been 32 cases (PDF) of the variant in England, with the majority (19%) being detected in London. This new variant has E484K and K417N mutations, making it similar to the Beta variant (B.1.351), prompting concern that B.1.621 could have similar immune escape properties, the agency noted.

In a recent risk assessment (PDF), Public Health England said that there is lab evidence of a reduction in pseudovirus neutralisation in the serum of vaccinated or previously Delta-infected individuals.
However, the agency noted that the trajectory of this new variant depends on its growth and expansion, and currently there’s no sign that it’s outcompeting Delta and it also seems unlikely that it’s more contagious. Still, its immune escape properties could contribute to future changes in growth, they warned, and other epidemiological events could influence whether it becomes established in the UK.

A recent paper in Lancet Infectious Diseases found two cases of B.1.621 involving community transmission, at a time when 99% of cases were due to the Delta variant. Both of these cases however occurred among unvaccinated individuals.

However, the dominance of Delta seems to be keeping other variants at bay, at least for now.

Source: MedPage Today

Histamine Involvement in Depression Revealed

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Histamine from inflammation dampens serotonin levels and antidepressants’ ability to boost them, according to experiments in mice models.

The findings, published in The Journal of Neuroscience add to mounting evidence that inflammation, and the accompanying release of the molecule histamine, affects serotonin, a key molecule responsible for mood in the brain.

Inflammation triggers the release of histamine in the body, increasing blood flow to affected areas to flood them with immune cells. While these effects help the body fight infections, both long-term and acute inflammation is increasingly linked to depression. There is already strong evidence that patients with both depression and severe inflammation are the ones most likely not to respond to antidepressants.

Dr Parastoo Hashemi, Lead Author, Imperial’s Department of Bioengineering, said: “Our work shines a spotlight on histamine as a potential key player in depression. This, and its interactions with the ‘feel-good molecule’ serotonin, may thus be a crucial new avenue in improving serotonin-based treatments for depression.”

Chemical messengers
Serotonin is a key target for depression-tackling drugs, and selective serotonin reuptake inhibitors (SSRIs) inhibit the re-absorption of serotonin in the brain, allowing it to circulate for longer and improve mood.

However, although SSRIs bring relief to many who take them, an increasing number of people are resistant to it. This could be due to the specific interactions between chemical messengers, or neurotransmitters, including serotonin and histamine.

With this in mind, researchers set out to investigate the relationship between histamine, serotonin, and SSRIs. They created tiny serotonin-measuring microelectrodes and put them into the hippocampus of the brains of live mice, an area known to regulate mood. The technique, known as fast scan cyclic voltammetry (FSCV), allowed them to measure brain serotonin levels in real time..

After placing the microelectrodes, they injected half the mice with lipopolysaccharide (LPS), an inflammation-causing toxin found in some bacteria, and half the mice with a saline solution as a control.

Within minutes of LPS injection, brain serotonin levels dropped, whereas they remained the same in control mice, demonstrating the rapid action of inflammatory responses on the brain and serotonin. Since LPS cannot cross the blood-brain barrier, it could not cause the drop in serotonin.
The inflammatory response triggered histamine in the brain which directly inhibited the release of serotonin by attaching to inhibitory receptors. 

To counter this, the researchers administered SSRIs to the mice, but they were much less able to boost serotonin levels than in control mice. They posited that this is because the SSRIs directly increased the amount of histamine in the brain, cancelling out its serotonin boosting action.

The researchers then administered histamine reducing drugs alongside the SSRIs to counter histamine’s inhibitory effects, and saw serotonin levels rise back to control levels. This appears to confirm the theory that histamine directly dampens serotonin release in the mouse brain. These histamine reducing drugs cause a whole-body reduction in histamine and are distinct from antihistamines taken for allergies, which block histamine’s effects on neurons.

A new molecule of interest
More work is needed before progressing to human studies. However, it is not currently feasible to use microelectrodes to make similar measurements in human brains, so the researchers are now looking at other ways to get a snapshot of the brain by looking at other organs which use serotonin and histamine, like the gut.

Source: Imperial College London

Fewer Side Effects in New Breast Cancer Therapy

Breast cancer cells. Image source: National Cancer Institute on Unsplash

Researchers have shown that a new treatment for breast cancer using an antibody linked to a cytotoxic drug is as effective as the previous combination, but with less side effects. The study was published in JAMA Oncology.

The development of treatment with antibodies directed towards HER2 positive breast cancer trastuzumab and pertuzumab, has proven the possibility of improved treatment and cure of this cancer type if these antibodies are combined with chemotherapy, often taxaner. Preoperative (neoadjuvant) treatment with this combination confers complete response in a high proportion of cases. Trastuzumab emtansine (T-DM1) consists of trastuzumab (T) and the cytotoxic substance emtansine (DM1) which clinical trials have shown have good efficacy and low toxicity.

The randomised phase II study PREDIX HER2 was conducted at 9 Swedish clinics to investigate the effect (the proportion of complete response after neoadjuvant treatment) of this treatment in relation to frequency and degree of side effects. The standard treatment was a combination of docetaxel, trastuzumab and pertuzumab which was compared with T-DM1 as experimental treatment, and patients received 6 treatments every 3rd week. The treatment effect was monitored with mammography and PET-CT with 18- fluorodeoxyglucose (18F-FDG). Tissue and blood samples were regularly taken from the patients for later analysis.

The study showed that the effect measured as pathologic complete response was similar in both treatment groups. With T-DM1 treatment, the frequency and degree of side effects was significantly lower and quality of life was higher during treatment. After a median follow up time of 40,4 months no difference was observed between the treatment groups.

In conclusion, the study showed that both treatments were equally efficient, but with fewer side effects in patients treated with T-DM1. A phase III study will allow definitive conclusions to be drawn regarding the efficiency. Meanwhile, the collected samples are being analysed to investigate factors which can explain the response in individuals.

Source: Karolinska Institute

Extra Vitamin D Does not Boost Muscles

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Vitamin D supplementation does not have beneficial effects on muscle function, strength, or mass, according to a new meta-analysis, and may even have detrimental effects on muscle strength in people with normal levels of the vitamin.

Vitamin D deficiency, causes a generalised decrease in bone mineral density, resulting in osteopenia and osteoporosis. In young children who have little mineral in their skeleton, this defect results in a variety of skeletal deformities classically known as rickets. It is also believed to cause muscle weakness; affected children have difficulty in standing and walking, whereas the elderly have increasing sway and more frequent falls,thereby increasing their risk of fracture.

The analysis, which is published in the Journal of Bone and Mineral Research, included 54 trials involving 8747 individuals. Overall, no benefits of vitamin D over placebo were observed for improving muscle health. On the contrary, vitamin D appeared to have detrimental effects in terms of increased time spent performing what’s called the Timed Up and Go test, a decrease in maximum strength at knee flexion, and a tendency towards a reduced score of the Short Physical Performance Battery.

“Care should be taken recommending vitamin D supplementation to improve muscle strength and function in people with normal or only slightly impaired vitamin D status,” said lead author Lise Sofie Bislev, MD, PhD, of Aarhus University Hospital, in Denmark. “We need to study further whether it may benefit muscles in those with severe vitamin D deficiency, however.”

Source: Wiley

Allergies in Childhood Linked to Developing Tree Nut Allergies

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A Swedish study found that while allergic sensitivity to tree nuts was common in adults, most people never experienced symptoms.

Allergies to tree nuts are common and have become an important health concern as availability has increased. Tree nuts include hazelnuts, walnuts, pecans, cashews, pistachios, almonds, and brazil nuts.Tree nuts, as a group, are one of the eight most common allergens, and allergic reactions to them can be severe. Availability of tree nuts has increased both in the raw form and within processed foods and bakery products; tree nut utilisation has increased by 1kg per capita from 1980 to 2015. Research has shown that the consumption of nuts has positive cardiovascular effects, such as decreasing cholesterol, triglycerides, and fasting blood glucose, and this has encouraged consumption.

The study, with a total of 2215 participants, found that eczema, asthma, and egg allergies at an early age were associated with developing a tree nut allergy by adulthood. Additionally, the researchers found allergen molecules to be better diagnostic tools for predicting allergic symptoms to tree nuts compared with analysing allergen extracts. The study was published in Clinical and Experimental Allergy.

“This study increases the understanding of tree nut allergy in a general population, followed from infancy up to adulthood. For example, our study reveals that most extract‐based tree nut‐sensitised individuals do not have tree nut allergy and hence extract-based testing for tree nuts without a specific clinical suspicion should not be performed,” said co–lead author Jessica Bager, of the Karolinska Institute.

Source: Wiley

SA’s Department of Tourism Aims to Join Vaccine Passport System

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The Department of Tourism says that it wants to introduce a vaccine passport for South Africa, but a number of international and legislative obstacles have to be overcome.

A lack of standardisation around vaccine passports worldwide is a key issue, said tourism director-general Nkhumeleni Victor Tharage in a briefing to Parliament on 17 August.

“Even in some jurisdictions that have opted to apply this (passport), there isn’t yet a sense of uniformity. When we don’t have a single, standardised specimen, it is a little bit difficult to say which one is which.

“If South Africa introduces (a passport), and there is access to information from the National Institute for Communicable Diseases (NICD) that confirms that a person has been vaccinated, the question is if that person arrives Lagos (Nigeria), what resources will they use to verify this information that is stored on a database in South Africa?”

South Africa has the same problem when it comes to verification of incoming tourists, Tharage said. The government was also cautious about introducing a vaccine passport system that is discriminatory against certain groups of people, he noted.

“When we reopen, and when everyone is starting to travel, it should not be discriminatory. And that principle has been reiterated time and time again.”

The vaccine passport could be a requirement for events, and Tharage said he was confident that this is something that the government could introduce with ease on short notice.

“At the end of the day, it’s about being able to get the necessary confidence from consumers, tourists and trade. If we don’t do that, then there will be a negative impact on our recovery.”

However, Department of Health spokesperson Foster Mohale affirmed that South Africa has no immediate plans to require proof of vaccination for any purpose.

Open for tourism
Transport minister Fikile Mbalula has said that his department is working with businesses to ensure that South Africa successfully reopens for international travel. Presenting his departmental budget speech at the end of May, Mbalula said that South Africa must ensure that it joins the increasing number of countries which accept the International Air Transport Association’s (IATA) mobile travel pass.

The travel pass is a mobile app that helps travellers store and manage their verified certifications for COVID tests or vaccines, and is more secure and efficient than current paper processes, IATA said. This is important given the potentially enormous scale of testing or vaccine verifications that the group must securely manage. IATA said it is looking to introduce further changes, such as QR code scanning by immigration officials.

Source: BusinessTech