Day: October 25, 2023

Categories : Environmental EffectsTags : Leave a comment

Microplastics are a Danger to our Health. Here’s How to Reduce Our Exposure to Them

On By ModernMedia
Photo by FLY:D on Unsplash

By Neil Thomas Stacey for GroundUp

About ten billion tonnes of plastic have been produced to date, of which around six billion tonnes have been discarded as waste. This is a severe threat to the environment, particularly oceans and lakes.

When plastics break down into particles smaller than five millimetres we call them microplastics. They are especially worrying.

Microplastics are an emerging threat to human health. They have been detected in organs in the human body and circulating in our bloodstreams. Studies have shown microplastics may deform red blood cells, inhibiting their ability to transport and transfer oxygen.

A study on mice exposed to microplastics found them in every tissue examined, and showed behavioural changes and heightened inflammation. While the exact effects on human health are not yet known, the risk is high enough that we should be very cautious about allowing them to pervade our atmosphere and food supply.

Microplastics have even been detected in high amounts in clouds, where they may affect rainfall patterns. They can also enter our food supply through rainfall.

A recent study of sediments in the Vaal river found an alarmingly high abundance of microplastics, which may enter the local food supply through crop irrigation. The sampling in this study was done in the region of the Vaal River Barrage, which is downstream of the Vaal Dam and fed by rivers that pass through heavily populated areas including Johannesburg.

Sampling at the Barrage gives direct insight into the rates at which we are producing microplastics in major population centres. And sampling at the Vaal Dam, which is the major drinking water supply for Gauteng, provides insight into the extent to which our drinking water is affected. Both these sampling points are needed as we track the levels of microplastics. Those levels are likely to rise dramatically; the microplastics we are seeing currently are only the tip of the iceberg, as there is a lag between the production of plastic, and it breaking down into microplastics.

Microplastic proliferation is not tied directly to accumulation of waste plastic. Examination of microplastics to ascertain their source is not an exact science, but it is reported that the main sources of microplastic pollution, at least for now, are car tyres and textiles and the pollution arises, not at the end-of-life when these are discarded as waste, but during their day-to-day use.

In other words, even if we solve the problem of waste plastic, we would still face the problem of microplastics that are emitted during the normal lifespan of products made of plastic.

There are, fortunately, some concrete steps that people can take to reduce personal exposure to microplastics. While microplastics are clearly able to travel throughout the atmosphere, their levels are concentrated around the sources releasing them. Microplastic concentrations are higher in indoor than outdoor air; old-fashioned fresh air and good ventilation are beneficial. So too is regularly wiping down surfaces, as they accumulate microplastic dust. Household air filters may also reduce microplastic concentrations.

Perhaps the most useful thing we as individuals can do is to have a different relationship with clothing. Synthetic fabrics are a prolific source of microplastics. These are released in our immediate surroundings, making our exposure to them disproportionately high.

Most microplastic release from textiles occurs within the first few washes after purchase, so purchasing long-lasting clothing rather than frequently replacing items of clothing can reduce your exposure, as can choosing natural fabrics such as cotton, where possible.

The other major source of microplastics is car tyres, which shed microplastics constantly as they wear down.

There are also activities which may seem environmentally-friendly but probably exacerbate microplastics pollution.

It is increasingly common to convert waste plastic into useable products from shoes and clothing to integration of waste plastic into road surfaces.

At first glance, this appears to be an environmental win-win. But recycled products tend to be more susceptible to the abrasion that causes microplastic release. Moreover, waste and recycled plastics tend to wear out more quickly and require replacement more frequently.

This is perhaps most harmful in the case of clothing made of waste or recycled plastic; the release of microplastics in early washes will be more severe because of the weaker polymer. This is particularly worth highlighting because recent research has shown that tumble-drying of synthetic textiles results in prolific microplastic release, much of which may be discharged into the indoor environment and breathed in or otherwise consumed.

Currently we have no practical way to remove microplastics from the environment; the particles are simply too small and widely dispersed. This means that we must exercise extreme caution to minimise emissions and our personal exposure to them.

Republished from GroundUp under a Creative Commons Attribution-NoDerivatives 4.0 International License.

Source: GroundUp

Categories : Gastrointestinal Surgeries & ProceduresTags : Leave a comment

Hold the GLP-1 Agonists Before Surgery, New Advice Says

On By ModernMedia
Photo by Natanael Melchor on Unsplash

Patients taking Glucagon-like peptide-1 (GLP-1) receptor agonists should stop taking them before they have surgery, due to the risk of aspirating while under general anaesthesia. This is the latest advice from the American Society of Anesthesiologists (ASA).

Initially approved by the Food and Drug Administration (FDA) for type 2 diabetes mellitus and cardiovascular risk reduction, GLP-1 agonists have shot up in popularity due to their effectiveness in weight loss. Despite having recent FDA approval, they have been used off-label for this purpose for quite some time.

When it comes to surgery, a number of organisations have recommended to hold these drugs either the day before or day of the procedure. For patients on weekly dosing, it is recommended to hold the dose for a week, the ASA notes.

GLP-1 agonists are associated with adverse gastrointestinal effects such as nausea, vomiting and delayed gastric emptying. The effects on gastric emptying are reported to be reduced with long-term use, most likely through rapid tachyphylaxis at the level of vagal nerve activation. Based on recent anecdotal reports, there are concerns that delayed gastric emptying from GLP-1 agonists can increase the risk of regurgitation and pulmonary aspiration of gastric contents during general anaesthesia and deep sedation. Patient taking GLP-1 agonists are more likely to have increased residual gastric contents as predicted by adverse gastrointestinal symptoms (nausea, vomiting, dyspepsia, abdominal distension).

The use of GLP-1 agonists in paediatrics has primarily been reported for the management of type 2 diabetes mellitus and obesity. The published literature on GLP-1 agonists in paediatrics is predominantly from paediatric patients 10 to 18 years old and concerns are similar to those reported in adults. During the conduct of general anaesthesia/deep sedation, children on GLP-1 agonists have similar gastrointestinal adverse events at a rate similar to adults.

In a review of the literature, the ASA Task Force on Preoperative Fasting found that, beyond a few case reports, there was little evidence for guidance on preoperative management of GLP-1 agonists. Nevertheless, they made recommendations for elective procedures. In the case of urgent or emergent procedures, they suggested treating the patient as ‘full stomach’.

If the patient’s GLP-1 agonists prescribed for diabetes management are held for longer than the dosing schedule, the guidelines urge surgeons to consider consulting an endocrinologist for bridging the antidiabetic therapy in order to avoid hyperglycaemia.

They further recommend that if gastrointestinal symptoms, such as severe nausea/vomiting/retching, abdominal bloating, or abdominal pain, are present, surgeons should consider delaying elective procedures. If the patient has no gastrointestinal symptoms and the GLP-1 agonists have been held as advised, the surgical team can carry on as normal.

Source: American Society of Anesthesiologists

Categories : Diet and Nutrition PaediatricsTags : Leave a comment

Study Classifies Four Eating Eating Behaviours of Children

On By ModernMedia
Photo by cottonbro studio

Children fall broadly into four eating categories, according to new research at Aston University, and parents feed their children differently depending on those categories.

The four categories identified by Dr Abigail Pickard and the team in the School of Psychology are ‘avid’, ‘happy’, ‘typical’, and ‘fussy’. The results, which showed specific temperaments and carer feeding patterns associated with overeating, are published in the journal Appetite.

In the UK, around a fifth of children are overweight or obese when they begin school, rising to around a third by the time they leave primary school at age 11. The team sought to identify eating behaviour patterns and how these are associated with temperament, feeding practices and food insecurity, as a way to predict which children are more at risk of becoming overweight.

Typical eaters made up 44% of the children in the study, while fussy eaters accounted for 16%. But of greatest interest to the team was that around one in five young children in the study were found to show “avid eating,” including greater enjoyment of food, faster eating speed, and weaker sensitivity to internal cues of ‘fullness’. The behaviours that distinguish children with avid eating from those who show ‘happy’ eating (17.7% of children in the study), who have similarly positive responses to food, are wanting to eat (or eating more) in response to the sight, smell or taste of palatable food, and a higher level of emotional overeating. In combination, these eating behaviours can lead to overeating and subsequent weight gain.

Dr Pickard and the team have also shown that there are significant differences in children’s temperament and caregivers’ feeding practices between each of the four eating behaviour patterns. Children with avid eating are more likely to be active and impulsive, and their caregivers are more likely to give them food to regulate their emotions or to restrict food for health reasons. Children with avid eating were also less food secure than children who showed happy or typical eating behaviours.

Principal investigator of the project, Professor Jackie Blissett, said: “Whilst feeding practices are key intervention targets to change children’s eating behaviour and child weight outcomes, there has been little evaluation of how feeding practices interact with children’s food approach behaviours to predict eating behaviour.”

She explained that despite the knowledge of the influence of feeding practices on children’s weight, current public health advice is generic and does not reflect variability in children’s appetites. Parents and caregivers can be left feeling frustrated when trying to manage their child’s food intake. By defining the four eating behaviour profiles, this research project, which is funded by the Economic and Social Research Council and co-developed by Professor Claire Farrow, Dr Clare Llewellyn, Dr Moritz Herle, Professor Emma Haycraft and Dr Helen Croker will make it easier to identify the best feeding practices for each eating pattern and provide tailored, effective advice for parents.

Dr Pickard said: “Parents can use this research to help them understand what type of eating pattern their child presents. Then based on the child’s eating profile the parent can adapt their feeding strategies to the child. For example, children in the avid eating profile may benefit more from covert restriction of food, i.e., not bringing snacks into the home or not having foods on display, to reduce the temptation to eat foods in the absence of hunger. Whereas, if a child shows fussy eating behaviour it would be more beneficial for the child to have a balanced and varied selection of foods on show to promote trying foods without pressure to eat.”

The team has planned further research investigating avid eating behaviour and will invite the caregivers and their children into the specialist eating behaviour lab at Aston University to get a better picture of what avid and typical eating behaviours look like in a real-life setting. All the findings will be integrated and the researchers will work with parents to develop feasible and helpful feeding guidelines to reduce children’s intake of palatable snack foods.

Source: Aston University

Categories : Neurodegenerative DiseasesTags : Leave a comment

Surgery-free Deep Brain Stimulation Could be New Treatment for Dementia

On By ModernMedia

A new form of deep brain stimulation offers hope for an alternative treatment option for dementia, without the need for surgery.

Researchers at Imperial College London are leading the development of the technique, known as temporal interference (TI). This non-invasive method works by delivering electrical fields to the brain through electrodes placed on the patient’s scalp and head. Their initial findings, which are published in the journal Nature Neuroscience, could lead to an alternative treatment for brain diseases such as Alzheimer’s, and its associated memory loss.

Temporal interference

By targeting the overlapping electrical fields researchers were able to stimulate an area deep in the brain called the hippocampus, without affecting the surrounding areas – a procedure that until now required surgery to implant electrodes into the brain.

The approach has been successfully trialled with 20 healthy volunteers for the first time by a team at the UK Dementia Research Institute (UK DRI) at Imperial and the University of Surrey.

Their initial results show that when healthy adults perform a memory task whilst receiving TI stimulation it helped to improve memory function.

The team is now conducting a clinical trial in people with early-stage Alzheimer’s disease, where they hope TI could be used to improve symptoms of memory loss.

Dr Nir Grossman, from the Department of Brain Sciences at Imperial College London, who led the work said: “Until now, if we wanted to electrically stimulate structures deep inside the brain, we needed to surgically implant electrodes which of course carries risk for the patient, and can lead to complications.

“With our new technique we have shown for the first time, that it is possible to remotely stimulate specific regions deep within the human brain without the need for surgery. This opens up an entirely new avenue of treatment for brain diseases like Alzheimer’s which affect deep brain structures.”

Reaching deep brain regions

TI was first described by the team at Imperial College London in 2017 and shown to work in principle in mice.

This latest work, funded and carried out through the UK Dementia Research Institute, shows for the first time that TI is effective at stimulating regions deep within the human brain.

According to the researchers, this could have broad applications and will enable scientists to stimulate different deep brain regions to discover more about their functional roles, accelerating the discovery of new therapeutic targets.

Source: Imperial College London

Categories : CancerTags : Leave a comment

Combining Diagnosis and Treatment into One to Treat Pancreatic Cancer

On By ModernMedia
Pancreatic cancer cells. Credit: NIH

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide, with a 5-year survival rate of less than 10%. Many PDAC tumours go undetected in early stages since they go undetected by conventional imaging methods such as fluorodeoxyglucose positron emission tomography (PET) scans. To tackle this problem, researchers in Japan are combining diagnostic and therapeutic procedures into a single integrated process: ‘theranostics’.

In an article recently published in the Journal of Nuclear Medicine, the Osaka University-led team has developed a ‘radio-theranostics’ strategy that uses a new radioactive antibody to target glypican-1 (GPC1), a protein highly expressed in PDAC tumours. Theranostics, particularly radio-theranostics, has been receiving increasing attention because, by radio-labelling the compounds used to target certain molecules in cancer cells, diagnosis and treatment can be carried out sequentially.

“We decided to target GPC1 because it is overexpressed in PDAC but is only present in low levels in normal tissues,” explains Tadashi Watabe, lead author of the study.

The team used a monoclonal antibody (mAb) designed to target GPC1. The mAb could be labelled with isotopes of zirconium (89Zr) or astatine (211At). First, they injected the 89Zr-GPC1 mAb into a xenograft mouse model, which has a human pancreatic cancer tumour.

“We monitored 89Zr-GPC1 mAb internalisation over seven days with PET scanning,” explains Kazuya Kabayama, the second author of the article. “There was strong uptake of the mAb into the tumours, suggesting that this method could support tumour visualisation. We confirmed that this was mediated by its binding to GPC1, as the xenograft model that had GPC1 expression knocked out showed significantly less uptake.”

The researchers next tested this model with alpha therapy using 211At-GPC1 mAb, a method that could support radioactive label-based delivery of a therapeutic molecule to its target. Administration of 211At-GPC1 mAb resulted in DNA double-strand break induction in the cancer cells, as well as significantly reduced tumour growth. Control experiments showed that these antitumor effects did not occur when mAb internalisation was blocked. Additionally, non-radiolabelled GPC1 mAb did not induce these effects.

“Both radiolabeled versions of the GPC1 mAb we examined showed promising results in PDAC,” says Watabe. “89Zr-GPC1 mAb showed high humoral uptake, while 211At-GPC1 mAb could be used for targeted alpha therapy to support suppression of PDAC tumour growth.”

These highly impactful data demonstrate the potential for using a theranostics approach in PDAC, a disease in dire need of new diagnostic and therapeutic options. In the future, this could lead to early detection of PDAC with PET imaging and systemic treatment with alpha therapy.

Source: Osaka University