Tag: 10/1/23

Categories : Gender Metabolic DisordersTags :

Why Obesity’s Health Impacts are Worse for Males

On By ModernMedia
Toilet sign male and female
Photo by Tim Mossholder on Unsplash

A newly published study in iScience sheds light on the biological underpinnings in sex differences in obesity-related disease, with researchers observing “striking” differences in the cells that build blood vessels in the fatty tissue of male versus female mice.

Men are more likely than women to develop conditions associated with obesity such as cardiovascular disease, insulin resistance and diabetes, says study leader Professor Tara Haas at York University.

“People have used rodent models to study obesity, and the diseases that are associated with obesity – like diabetes – but they’ve typically always studied male rodents, because females are resistant to developing the same kinds of diseases,” says Haas. “We were really interested in exploring that difference because, to us, it spoke of something really fascinating happening in females that protects them.”

In earlier work, Haas and her team saw that when mice become obese, females grow a lot of new blood vessels to supply the expanding fat tissue with oxygen and nutrients, whereas males grow a lot less. For this study, Haas and her co-authors focused on differences in the endothelial cells that make up the building blocks of these blood vessels in fat tissue.

The team used software to help sift through thousands of genes to zero in on the ones that would be associated with blood vessel growth. They discovered that processes associated with the proliferation of new blood vessels were high in the female mice, whereas the males had a high level of processes associated with inflammation.

“It was very striking the extent of inflammation-associated processes that were prevalent in the males,” Haas recalls. “Other studies have shown that when endothelial cells have that kind of inflammatory response, they’re very dysfunctional, and they don’t respond to stimuli properly.”

York PhD student Alexandra Pislaru, who works in Haas’ lab and is a co-first author of the study, participated in this project as part of her dissertation.

“It is exciting to observe the continuing resilience that female endothelial cells display even when stressed by a long-term high-fat diet,” Pislaru says. “The findings from our study can help researchers to get a better understanding of why obesity manifests differently in men and women.”

The researchers also examined the behaviour of the endothelial cells when they were taken out of the body and studied in petri dishes.

“Even when we take them out of the body where they don’t have the circulating sex hormones or other kinds of factors, male and female endothelial cells still behave very differently from each other,” Haas explains.

Female endothelial cells replicated faster, while male endothelial cells displayed greater sensitivity to an inflammatory stimulus. By comparing with previously published data sets, the researchers found endothelial cells from aged male mice also displayed a more inflammatory profile compared to female cells.

“You can’t make the assumption that both sexes are going to respond to the same series of events the same way,” says Haas. “This isn’t just an obesity related issue – I think it’s a much broader conceptual problem that also encompasses healthy aging. One implication of our findings is that there will be situations where the treatment that is ideal for men is not going to be ideal for women and vice-versa.”

While humans and mice have different genes that may be turned up or down, Haas believes the general findings would likely apply and is interested studying the same cells in humans in future research.

Source: York University

Categories : Ethics and Law General InterestTags :

People Always Strive to See the Good in Villainous Characters

On By ModernMedia
Photo by Stormseeker on Unsplash

From Shakespeare’s Macbeth to Star Wars’ Darth Vader, people love fictional villains. No matter how despicable they may be, audiences are still drawn to the dark side. In fact, according to a new behavioural experiment published in the journal Cognition, both adults and children more often reported that villains were inwardly good than that heroes were inwardly bad.

“In other words, people believe there is a mismatch between a villain’s outward behaviours and their inner, true self, and this is a bigger gap for villains than for heroes,” said study lead author Valerie Umscheid, University of Michigan psychology doctoral student.

Inside, villains are a little less evil than they outwardly seem while heroes are fully good guys inside and out.

Umscheid and colleagues conducted three studies with 434 children (ages 4–12) and 277 adults to determine how individuals make sense of antisocial acts committed by evil-doers. They focused on participants’ judgments of both familiar and novel fictional villains and heroes, such as Disney’s Ursula from The Little Mermaid and Pixar’s Woody from Toy Story.

Study 1 established that children viewed villains’ actions and emotions as overwhelmingly negative. This suggests that children’s well-documented tendency to judge people as good does not prevent their appreciation of extreme forms of villainy.

Studies 2 and 3 assessed children’s and adults’ beliefs regarding heroes’ and villains’ moral character and true selves, using an array of converging evidence, including how a character felt inside, whether a character’s actions reflected their true self and whether a character’s true self could change over time.

Across these measures, the research indicated that both children and adults consistently evaluated villains’ true selves to be overwhelmingly evil and much more negative than heroes’. At the same time, researchers also detected an asymmetry in the judgments, wherein villains were more likely than heroes to have a true self that differed from their outward behaviour.

Both children and adults believed characters like Ursula had some inner goodness, despite the bad/immoral actions they regularly engage in, Umscheid said.

Source: University of Michigan

Categories : COVID VaccinesTags :

Increase in Global Willingness to Accept COVID Vaccines

On By ModernMedia
Vaccine injection
Image source: NCI on Unsplash

Global COVID vaccine acceptance increased from 75.2% in 2021 to 79.1% in 2022, according to a new survey of 23 countries accounting for more than 60% of the world’s population, published today in Nature Medicine. It was not all good news, though: vaccine hesitancy increased in eight countries including South Africa, and nearly one in eight vaccinated respondents were hesitant about receiving a booster dose.

This third annual study reveals a wide variability between countries and suggests a need to tailor communication strategies to effectively address vaccine hesitancy.

“The pandemic is not over, and authorities must urgently address vaccine hesitancy and resistance as part of their COVID prevention and mitigation strategy,” says CUNY Graduate School of Public Health and Health Policy (CUNY SPH) Senior Scholar Jeffrey V. Lazarus. “But to do so effectively, policymakers need solid data on vaccine hesitancy trends and drivers.”

To provide these data, an international collaboration led by Lazarus and CUNY SPH Dean Ayman El-Mohandes performed a series of surveys starting in 2020 in 23 countries which were impacted significantly by the pandemic, including the United States as well as South Africa and Brazil.

Of the 23 000 respondents (1000 per country surveyed), 79.1% were willing to accept vaccination, up 5.2% from June 2021. The willingness of parents to vaccinate their children also increased slightly, from 67.6% in 2021 to 69.5% in 2022. However, eight countries saw an increase in hesitancy (from 1.0% in the UK to 21.1% in South Africa). Worryingly, almost one in eight (12.1%) vaccinated respondents were hesitant about booster doses, and booster hesitancy was higher among the 18–29 age groups.

“We must remain vigilant in tracking this data, containing COVID variants and addressing hesitancy, which may challenge future routine COVID immunisation programs,” says Dean El-Mohandes, the study’s senior author.

The survey also provides new information on COVID treatments received. Globally, ivermectin was used as frequently as other approved medications, despite the fact that it is not recommended by the WHO or other agencies to prevent or treat COVID  

Also of note, almost 40% of respondents reported paying less attention to new COVID information than before, and there was less support for vaccine mandates. 

In some countries, vaccine hesitancy was associated with being female (for example in China, Poland, Russia), having no university degree (in France, Poland, South Africa, Sweden, or the US), or lower income (in Canada, Germany, Turkey or the UK). Also, the profile of people paying less attention to the pandemic varied between countries.

“Our results show that public health strategies to enhance booster coverage will need to be more sophisticated and adaptable for each setting and target population,” says Lazarus, also head of the Health Systems Research Group at ISGlobal. “Strategies to enhance vaccine acceptance should include messages that emphasise compassion over fear and use trusted messengers, particularly healthcare workers.”

The data provided by these surveys may offer insight to policymakers and public health officials in addressing COVID vaccine hesitancy. The study follows on the heels of a global consensus statement on ending COVID as a public health threat that Lazarus, El-Mohandes and 364 co-authors from 112 countries published in Nature in November.

Source: CUNY SPH

Categories : Injury & Trauma Regenerative MedicineTags :

Transplanted Hair Follicles Successfully Reduced Scars

On By ModernMedia
Photo by Diana Polekhina on Unsplash

By treating skin scars in three volunteers with hair follicle transplants, researchers found that the scarred skin began to behave more like uninjured skin. According to the results published in Nature Regenerative Medicine, the scarred skin harboured new cells and blood vessels, remodelled collagen to restore healthy patterns, and even expressed genes found in healthy unscarred skin.

The findings could lead to better treatments for scarring both on the skin and inside the body, leading to hope for patients with extensive scarring, which can impair organ function and cause disability.

Lead author Dr Claire Higgins, of Imperial’s Department of Bioengineering, said: “After scarring, the skin never truly regains its pre-wound functions, and until now all efforts to remodel scars have yielded poor results. Our findings lay the foundation for exciting new therapies that can rejuvenate even mature scars and restore the function of healthy skin.”

Hope in hair

Scar tissue in the skin lacks hair, sweat glands, blood vessels and nerves, impairing temperature regulation and sensation. Scarring can also hinder movement as well as potentially causing discomfort and emotional distress.

Compared to scar tissue, healthy skin undergoes constant remodelling by the hair follicle. Hairy skin heals faster and scars less than non-hairy skin- and hair transplants had previously been shown to aid wound healing. Inspired by this, the researchers hypothesised that transplanting growing hair follicles into scar tissue might induce scars to remodel themselves.

To test their hypothesis, Imperial researchers worked with Dr Francisco Jiménez, lead hair transplant surgeon at the Mediteknia Clinic and Associate Research Professor at University Fernando Pessoa Canarias, in Gran Canaria, Spain. They transplanted hair follicles into the mature scars on the scalp of three participants in 2017. The researchers selected the most common type of scar, called normotrophic scars, which usually form after surgery.

They took and microscope imaged 3mm-thick biopsies of the scars just before transplantation, and then again at two, four, and six months afterwards.

The researchers found that the follicles inspired profound architectural and genetic shifts in the scars towards a profile of healthy, uninjured skin.

Dr Jiménez said: “Around 100 million people per year acquire scars in high-income countries alone, primarily as a result of surgeries. The global incidence of scars is much higher and includes extensive scarring formed after burn and traumatic injuries. Our work opens new avenues for treating scars and could even change our approach to preventing them.”

Architects of skin

After transplantation, the follicles continued to produce hair and induced restoration across skin layers.

Scarring causes the epidermis to thin out, leaving it vulnerable to tears. At six months post-transplant, the epidermis had doubled in thickness alongside increased cell growth, bringing it to around the same thickness as uninjured skin.

The next skin layer down, the dermis, is populated with connective tissue, blood vessels, sweat glands, nerves, and hair follicles. Scar maturation leaves the dermis with fewer cells and blood vessels, but after transplantation the number of cells had doubled at six months, and the number of vessels had reached nearly healthy-skin levels by four months. This demonstrated that the follicles inspired the growth of new cells and blood vessels in the scars, which are unable to do this unaided.

Scarring also increases the density of collagen fibres, causing them to align and make the scar stiffer. The hair transplants reduced the fibre density, allowing them to form a healthier, ‘basket weave’ pattern, which reduced stiffness – a key factor in tears and discomfort.

The authors also found that after transplantation, the scars expressed 719 genes differently to before. Genes that promote cell and blood vessel growth were expressed more, while genes that promote scar-forming processes were expressed less.

Underling mechanism still unknown

It is not known how exactly the transplants brought about the change. Having of a hair follicle in the scar was cosmetically acceptable for the participants as the scars were on the scalp. The researchers are now working to uncover the underlying mechanisms so they can develop therapies that remodel scar tissue towards healthy skin, without the hair follicle transplant. They can then test their findings on non-hairy skin, or on organs like the heart, which can suffer scarring after heart attacks, and the liver, which can suffer scarring through fatty liver disease and cirrhosis.

Dr Higgins said: “This work has obvious applications in restoring people’s confidence, but our approach goes beyond the cosmetic as scar tissue can cause problems in all our organs.

“While current treatments for scars like growth factors focus on single contributors to scarring, our new approach tackles multiple aspects, as the hair follicle likely delivers multiple growth factors all at once that remodel scar tissue. This lends further support to the use of treatments like hair transplantation that alter the very architecture and genetic expression of scars to restore function.”

Source: Imperial College London