Tag: 30/8/23

Categories : Diseases, Syndromes and ConditionsTags :

Python Roundworm Removed from Australian Woman’s Brain

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Detection of Ophidascaris robertsi nematode infection in a 64-year-old woman from southeastern New South Wales, Australia. A) Magnetic resonance image of patient’s brain by fluid-attenuated inversion recovery demonstrating an enhancing right frontal lobe lesion, 13 × 10 mm. B) Live third-stage larval form of Ophidascaris robertsi (80 mm long, 1 mm diameter) removed from the patient’s right frontal lobe. C) Live third-stage larval form of O. robertsi (80 mm long, 1 mm diameter) under stereomicroscope (original magnification ×10). Source: Hossain et al. 2023

Australian researchers have discovered the world’s first case of a new parasitic infection in humans after they detected a live eight-centimetre roundworm from a carpet python in the brain of a 64- year-old Australian woman. The researchers at the Australian National University (ANU) and the Canberra Hospital described the novel case in the journal Emerging Infectious Diseases.

The Ophidascaris robertsi roundworm was pulled from the patient after brain surgery – still alive and squirming. It is suspected that larvae, or juveniles, were also present in other organs in the woman’s body, including the lungs and liver.

“This is the first-ever human case of Ophidascaris to be described in the world,” leading ANU and Canberra Hospital said Associate Professor Sanjaya Senanayake, infectious disease expert and co-author of the study.

“To our knowledge, this is also the first case to involve the brain of any mammalian species, human or otherwise.

“Normally the larvae from the roundworm are found in small mammals and marsupials, which are eaten by the python, allowing the life cycle to complete itself in the snake.”

Ophidascaris robertsi roundworms are common to carpet pythons. It typically lives in a python’s oesophagus and stomach, and sheds its eggs in the host’s faeces. Humans infected with Ophidascaris robertsi larvae would be considered accidental hosts.

Roundworms are incredibly resilient and able to thrive in a wide range of environments. In humans, they can cause stomach pain, vomiting, diarrhoea, appetite and weight loss, fever and tiredness.

The researchers say the woman, from southeastern New South Wales in Australia, likely caught the roundworm after collecting a type of native grass, Warrigal greens, beside a lake near where she lived in which the python had shed the parasite via its faeces.

The patient used the Warrigal greens for cooking and was probably infected with the parasite directly from touching the native grass or after eating the greens.

Canberra Hospital’s Director of Clinical Microbiology and Associate Professor at the ANU Medical School, Karina Kennedy, said her symptoms first started in January 2021.

“She initially developed abdominal pain and diarrhoea, followed by fever, cough and shortness of breath. In retrospect, these symptoms were likely due to migration of roundworm larvae from the bowel and into other organs, such as the liver and the lungs. Respiratory samples and a lung biopsy were performed; however, no parasites were identified in these specimens,” she said.

“At that time, trying to identify the microscopic larvae, which had never previously been identified as causing human infection, was a bit like trying to find a needle in a haystack.”

The patient was first admitted to a local hospital in late January 2021 after suffering three weeks of abdominal pain and diarrhoea, followed by a constant dry cough, fever and night sweats. By 2022, the patient was experiencing forgetfulness and depression, prompting an MRI scan. It revealed an atypical lesion within the right frontal lobe of the brain, Associate Professor Kennedy said.

A neurosurgeon at Canberra Hospital explored the abnormality and it was then that the unexpected eight-centimetre roundworm was found. Its identity was later confirmed through parasitology experts, initially through its appearance and then through molecular studies.

Associate Professor Senanayake said the world-first case highlighted the danger of diseases and infections passing from animals to humans, especially as we start to live more closely together and our habitats overlap more and more.

“There have been about 30 new infections in the world in the last 30 years. Of the emerging infections globally, about 75 per cent are zoonotic, meaning there has been transmission from the animal world to the human world. This includes coronaviruses,” he said.

He added that “the snake and parasite are found in other parts of the world, so it is likely that other cases will be recognised in coming years in other countries.”

The patient continues to be monitored by the team of infectious diseases and brain specialists.

“It is never easy or desirable to be the first patient in the world for anything. I can’t state enough our admiration for this woman who has shown patience and courage through this process,” Associate Professor Senanayake said.

Source: Australian National University

Categories : Allergies PaediatricsTags :

Common Gut Microbiota Link to the Development of Childhood Allergies

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Photo by Andrea Piacquadio on Unsplash

Several major childhood allergies may all stem from the gut microbiome gut, according to a new study published in Nature Communications. The research identifies gut microbiome features and early life influences that are associated with children developing any of four common allergies. The study, led by researchers at the University of British Columbia and BC Children’s Hospital, could lead to methods of predicting whether a child will develop allergies, and methods to prevent their development.

“We’re seeing more and more children and families seeking help at the emergency department due to allergies,” said Dr Stuart Turvey, paediatrics professor at UBC and co-senior author on the study, noting that as many as one in three children in Canada have allergies.

The study is one of the first to examine four distinct school-aged paediatric allergies at once: atopic dermatitis, asthma, food allergy and allergic rhinitis. While these allergic diseases each have unique symptoms, the Turvey lab was curious whether they might have a common origin linked to the infant gut microbiota composition.

“These are technically different diagnoses, each with their own list of symptoms, so most researchers tend to study them individually,” says Dr Charisse Petersen, co-senior author on the paper and postdoctoral fellow in the Turvey lab. “But when you look at what is going wrong at a cellular level, they actually have a lot in common.”

For the study, researchers examined clinical assessments from 1115 children who were tracked from birth to age five. Roughly half of the children (523) had no evidence of allergies at any time, while more than half (592) were diagnosed with one or more allergic disorders by an expert physician. The researchers evaluated the children’s microbiomes from stool samples collected at clinical visits at three months and one year of age.

The stool samples revealed a bacterial signature that was associated with the children developing any of the four allergies by five years of age. The bacterial signature is a hallmark of dysbiosis, or an imbalanced gut microbiota, that likely resulted in a compromised intestinal lining and an elevated inflammatory response within the gut.

“Typically, our bodies tolerate the millions of bacteria living in our guts because they do so many good things for our health. Some of the ways we tolerate them are by keeping a strong barrier between them and our immune cells and by limiting inflammatory signals that would call those immune cells into action,” says Courtney Hoskinson, a PhD candidate at UBC and first author on the paper. “We found a common breakdown in these mechanisms in babies prior to the development of allergies.”

Many factors can shape the infant gut microbiota, including diet, place and delivery method of birth and antibiotics exposure. The researchers examined how these types of influences affected the balance of gut microbiota and the development of allergies.

“There are a lot of potential insights from this robust analysis,” says Dr Turvey. “From these data we can see that factors such as antibiotic usage in the first year of life are more likely to result in later allergic disorders, while breastfeeding for the first six months is protective. This was universal to all the allergic disorders we studied.”

Now the researchers hope to leverage the findings to inform treatments that correct an imbalanced gut microbiota and could potentially prevent allergies from developing.

“Developing therapies that change these interactions during infancy may therefore prevent the development of all sorts of allergic diseases in childhood, which often last a lifetime,” says Dr Turvey.

Source: University of British Columbia

Categories : Implants and Prostheses Metabolic DisordersTags :

Implanted Bioreactors Functioning as Artificial Kidneys Could One Day Replace Dialysis

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Photo by Robina Weermeijer on Unsplash

Scientists at UC San Francisco are working on a new approach to treating kidney failure that could one day free people from needing dialysis or a transplant and the associated immunosuppressive drugs.

The technology, described in Nature Communications, shows for the first time that kidney cells, housed in an implantable device called a bioreactor, can survive inside the body of a pig and mimic several important kidney functions. The device can work quietly in the background, like a pacemaker, and does not trigger the recipient’s immune system to go on the attack.

Eventually, scientists plan to fill the bioreactor with different kidney cells that perform vital functions like balancing the body’s fluids and releasing hormones to regulate blood pressure, then pair it with a device that filters waste from the blood.

The aim is to produce a human-scale device to improve on dialysis, which keeps people alive after their kidneys fail but is a poor substitute for having a real working organ. In the US, more than 500 000 require dialysis several times a week. Many seek kidney transplants, but there are not enough donors, and only about 20 000 people receive them each year. An implantable kidney would be a boon.

This is a key step forward is for The Kidney Project, which is jointly headed by UCSF’s Shuvo Roy, PhD (technical director) and Vanderbilt University Medical Center’s William H. Fissell, MD (medical director).

“We are focused on safely replicating the key functions of a kidney,” said Roy, a bioengineering professor in the UCSF School of Pharmacy. “The bioartificial kidney will make treatment for kidney disease more effective and also much more tolerable and comfortable.”

Inspired by nature, honed by science

Roy and his colleagues engineered the bioreactor to connect directly to blood vessels and veins, allowing the passage of nutrients and oxygen, much like a transplanted kidney would. Silicon membranes keep the kidney cells inside the bioreactor safe from attack by the recipient’s immune cells.

The team used a proximal tubule cell, which regulates water, as a test case. Co-author H. David Humes, MD, from the University of Michigan, had previously used these cells to help dialysis patients in the intensive care unit with life-saving results.

No immunosuppression needed

The team tracked the renal cells and the recipient animals for seven days after transplantation and both did well. The next step will be month-long trials, as required for by the U.S. Food and Drug Administration (FDA), first in animals and eventually in humans.

“We needed to prove that a functional bioreactor will not require immunosuppressant drugs, and we did,” Roy said. “We had no complications and can now iterate up, reaching for the whole panel of kidney functions at the human scale.”

Source: University of California – San Francisco

Categories : Ageing Cardiovascular DiseaseTags :

Stressful Life Events Contribute to Atrial Fibrillation Risk in Postmenopausal Women

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Photo by Karolina Grabowska on Pexels

An estimated 1 in 4 postmenopausal women may develop atrial fibrillation in their lifetime, with stressful life events and insomnia being major contributing factors, according to new research published in the Journal of the American Heart Association.

Atrial fibrillation may lead to blood clots, stroke, heart failure or other cardiovascular complications. It primarily affects older adults.

“In my general cardiology practice, I see many postmenopausal women with picture perfect physical health who struggle with poor sleep and negative psychological emotional feelings or experience, which we now know may put them at risk for developing atrial fibrillation,” said lead study author Susan X. Zhao, M.D., a cardiologist at Santa Clara Valley Medical Center in California. “I strongly believe that in addition to age, genetic and other heart-health related risk factors, psychosocial factors are the missing piece to the puzzle of the genesis of atrial fibrillation.“

Researchers reviewed data from more than 83 000 questionnaires by women ages 50-79 from the Women’s Health Initiative, a major US study. Participants were asked a series of questions in key categories: stressful life events, their sense of optimism, social support and insomnia. Questions about stressful life events addressed topics such as loss of a loved one; illness; divorce; financial pressure; and domestic, verbal, physical or sexual abuse. Questions about sleeping habits focused on if participants had trouble falling asleep, wake up several times during the night and  overall sleep quality, for example. Questions about participants’ outlook on life and social supports addressed having friends to talk with during and about difficult or stressful situations; a sense of optimism such as believing good things are on the horizon; and having help with daily chores.

During approximately a decade of follow-up, the study found:

  • About 25% or 23 954 women developed atrial fibrillation.
  • A two-cluster system (the stress cluster and the strain cluster).
  • For each additional point on the insomnia scale, there is a 4% higher likelihood of developing atrial fibrillation. Similarly, for each additional point on the stressful life event scale, there is a 2% higher likelihood of having atrial fibrillation.

“The heart and brain connection has been long established in many conditions,” Zhao said. “Atrial fibrillation is a disease of the electrical conduction system and is prone to hormonal changes stemming from stress and poor sleep. These common pathways likely underpin the association between stress and insomnia with atrial fibrillation.”

Researchers noted that stressful life events, poor sleep and feelings, such as depression, anxiety or feeling overwhelmed by one’s circumstances, are often interrelated. It’s difficult to know whether these factors accumulate gradually over the years to increase the risk of atrial fibrillation as women age.

Chronic stress has not been consistently associated with atrial fibrillation, and the researchers note that a limitation of their study is that it relied on patient questionnaires from the start of the study. Stressful life events, however, though significant and traumatic, may not be long lasting, Zhao notes. Further research is needed to confirm these associations and evaluate whether customised stress-relieving interventions may modify atrial fibrillation risk.

Source: EurekAlert!

Categories : Ageing Diet and NutritionTags :

Yeast Studies Suggest that Early Diet may be Key for Lifelong Health

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Photo by Patrick Fore on Unsplash

Researchers at the Babraham Institute are proposing an alternative link between diet and ageing based on studies in yeast. In a study using yeast, a useful model organism to study ageing, researchers showed that a ‘healthier’ galactose diet in early life led to reduced senescence in those cells. The findings, published in PLOS Biology, suggest that dietary makeup at a young age may have a long-lasting impact on health throughout the lifespan.

Dr Jon Houseley and his team have published their experiments, showing that healthy ageing is achievable through dietary change without restriction by potentially optimising diet, and that ill-health is not an inevitable part of the ageing process.

Scientists have long known that caloric restriction improves health in later life and may even extend life. However, studies in mice show that caloric restriction really needs to be maintained throughout life to achieve this impact, and the health benefits disappear when a normal diet is resumed. Dr Houseley’s new research conducted in yeast suggests an alternative to calorie restriction can lead to improved health through the lifecycle.

“We show that diet in early life can switch yeast onto a healthier trajectory. By giving yeast a different diet without restricting calories we were able to suppress senescence, when cells no longer divide, and loss of fitness in aged cells.” Said Dr Dorottya Horkai, lead researcher on the study.

Rather than growing yeast on their usual glucose-rich diet, the researchers swapped their diet to galactose and observed that many molecular changes which normally accompany ageing did not occur. The cells grown on galactose remained just as fit as young cells even late in life, despite not living any longer, showing that the period of ill-health towards the end of life was dramatically reduced.

“Crucially, the dietary change only works when cells are young, and actually diet makes little difference in old yeast. It is hard to translate what youth means between yeast and humans, but all these studies point to the same trend – to live a long and healthy life, a healthy diet from an early age makes a difference.” explains Dr Houseley.

Yeast are good model organisms for studying ageing as they share many of the same cellular machinery as animals and humans. This avenue of research in yeast helps us to seek a more achievable way to improve healthy ageing though diet compared to sustained and severe calorie restriction, although more research is needed.

Source: Babraham Institute