Day: October 31, 2023

Categories : Mental Health NeurologyTags :

Fear is in the Eye of the Beholder, Researchers Find

On By ModernMedia
Photo by Stormseeker on Unsplash

Looking away from something frightening may be due to a specific cluster of neurons in a visual region of the brain, according to new research at the University of Tokyo. Researchers found that, in fruit fly brains, these neurons release a chemical called tachykinin which appears to control the fly’s movement to avoid facing a potential threat. Fruit fly brains can offer a useful analogy for larger mammals, so this study, published in Nature Communications, may help studies of human reactions to fearful situations and phobias.

“We discovered a neuronal mechanism by which fear regulates visual aversion in the brains of Drosophila (fruit flies). It appears that a single cluster of 20-30 neurons regulates vision when in a state of fear. Since fear affects vision across animal species, including humans, the mechanism we found may be active in humans as well,” explained Assistant Professor Masato Tsuji from the Department of Biological Sciences at the University of Tokyo.

The team used puffs of air to simulate a physical threat and found that the flies’ walking speed increased after being puffed at. The flies also would choose a puff-free route if offered, showing that they perceived the puffs as a threat (or at least preferred to avoid them). Next the researchers placed a small black object, roughly the size of a spider, 60 degrees to the right or left of the fly. On its own the object didn’t cause a change in behavior, but when placed following puffs of air, the flies avoided looking at the object and moved so that it was positioned behind them.

To understand the molecular mechanism underlying this aversion behavior, the team then used mutated flies in which they altered the activity of certain neurons. While the mutated flies kept their visual and motor functions, and would still avoid the air puffs, they did not respond in the same fearful manner to visually avoid the object.

“This suggested that the cluster of neurons which releases the chemical tachykinin was necessary for activating visual aversion,” said Tsuji. “When monitoring the flies’ neuronal activity, we were surprised to find that it occurred through an oscillatory pattern, ie, the activity went up and down similar to a wave. Neurons typically function by just increasing their activity levels, and reports of oscillating activity are particularly rare in fruit flies because up until recently the technology to detect this at such a small and fast scale didn’t exist.”

By giving the flies genetically encoded calcium indicators, the researchers could make the flies’ neurons shine brightly when activated. Thanks to the latest imaging techniques, they then saw the changing, wavelike pattern of light being emitted, which was previously averaged out and missed.

Next, the team wants to figure out how these neurons fit into the broader circuitry of the brain. Although the neurons exist in a known visual region of the brain, the researchers do not yet know from where the neurons are receiving inputs and to where they are transmitting them, to regulate visual escape from objects perceived as dangerous.

“Our next goal is to uncover how visual information is transmitted within the brain, so that we can ultimately draw a complete circuit diagram of how fear regulates vision,” said Tsuji. “One day, our discovery might perhaps provide a clue to help with the treatment of psychiatric disorders stemming from exaggerated fear, such as anxiety disorders and phobias.”

Source: University of Tokyo

Categories : Environmental EffectsTags :

Selenium Reduces Health Impact of Pollutant Mixtures

On By ModernMedia
Photo by Bill Oxford on Unsplash

A study in mice conducted by the University of Cordoba proves that exposure to mixtures of metals and drug residue exacerbates health impacts, and evaluates the positive effects of a diet enriched in selenium to reduce this harm.

People are exposed daily, through the environment and their diets, to external substances that can be harmful to their health. Metals and the residue of pharmaceuticals, for example, in high doses, contaminate water and food, creating mixtures where they can interact, with this increasing their individual toxicity.

Analysing the effects of environmental pollution on organisms is essential to develop regulations establishing maximum doses of these pollutants for people. But mixtures of pollutants pose unknown challenges as they may interact with each other.

To understand the health effects of exposure to these ‘cocktails of contaminants’, a team at the University of Cordoba, evaluated, in mice, the toxicity of a mixture of contaminants that is very common in the environment and that accumulates along the food chain: a combination of metals (arsenic, cadmium, mercury) and drugs (diclofenac, flumequine).

In order to determine how these compounds interacted with each other, “we studied the controlled exposure of mice to this mixture and analysed how it affects the proteins in the liver; that is, how their liver proteostasis changes when ingesting these mixtures of contaminants for two weeks,” explained Professor Nieves Abril, senior author of the paper published in Science of the Total Environment.

Their conclusion is negative: the cocktail effect synergises these compounds, doing increased damage to health when the compounds act together.

“We used a massive protein detection technique (shotgun proteomic), which allowed us to compare how the proteins of the group exposed to the mixture of contaminants were altered compared to the control group,” April explained.

Of the proteins affected, they selected 275 as sentinels to verify what was changing and, after computer analysis, they were able to determine the metabolic pathways that were altered and their consequences for health. These analyses revealed a disproportionate defence response having a contrary and harmful effect on the system.

The researcher stressed that “although these pollutants generated oxidation in the cells separately too, when they acted together we found that the oxidation was so intense that all the antioxidant defence responses were activated continuously, without deactivating them, which ends up doing damage and causing many proteins to stop working.” The analyses showed a sustained expression of the response mediated by NRF2, which is the regulator that sets in motion a good part of the antioxidant defences, which caused a reducing stress.

Selenium as hope

It’s not all bad news in the study, as selenium could be a way to reduce the damage caused by exposure to these pollutants. A third group of mice were given doses of selenium, a mineral often found in vitamin supplements found in pharmacies, and proteomic analyses showed relief from the molecular damage done by the pollutants.

Selenium itself is an oxidant, but in low doses it activates responses in a controlled manner, predisposing the body to better defence.

Source: University of Córdoba

Categories : Medical IndustryTags :

GEMS Hosts its 14th Annual Symposium, Bringing Together Key Healthcare Industry Stakeholders and Policymakers

On By ModernMedia

The Government Employees Medical Scheme (GEMS) will, on November 2nd, 2023, host its 14th annual GEMS Symposium under the theme: “Advancing Health Equity by Addressing the Social Determinants of Health”. Experts, thought leaders and specialists in healthcare will engage in discussions towards a better understanding of the societal determinants of health in South Africa. 

For this hybrid event, delegates will attend both in person at Sandton and virtually.

Dr Moloabi states that the “Symposium is an important event on the GEMS calendar, providing a platform for academic, clinical, government and business minds to discuss what social issues are at play in determining the nation’s health status and how to improvements in health equity can be realized”. Moreover, he also highlights the need to remove practical obstacles that make us an unequal society if we are to achieve collaborative and cohesive solutions to our healthcare challenges.”

Speakers will include: 

  • Dr Ingrid Pooe – Chief Operations Officer, Government Employees Medical Scheme (GEMS),
  • Dr Sebayitseng Millicent Hlatshwayo – Chairperson, Government Employees Medical Scheme (GEMS),
  • Dr Chana Pilane-Majake – Deputy Minister of Public Service and Administration (DPSA),
  • Professor Mcebisi Ndletyana – Professor of Political Science, Department of Politics and International Relations, University of Johannesburg,
  • Dr Selaelo Mametja – Chief Research Officer, Government Employees Medical Scheme (GEMS),
  • Mr Barry Childs – Joint Chief Executive Officer Insight Actuaries & Consultants,
  • Dr Vuyo Gqola – Chief Healthcare Officer, Government Employees Medical Scheme (GEMS),
  • Mr Louis Botha – Chief Executive Officer, Health Quality Assessment (HQA),
  • Ms Yoliswa Makhasi – Director General, Department of Public Service and Administration (DPSA),
  • Mr Frikkie de Bruin- General Secretary, Public Service Coordinating Bargaining Council (PSCBC),
  • Dr Pali Lehohla – Director of Economic Modelling Academy (EMA), 
  • and
  • GEMS Principal Officer Dr Stanley Moloabi.

Dr Pilane-Majake, the Deputy Minister for the Department of Public Service and Administration (DPSA) will deliver the keynote address, elucidating, amongst other insights, the crucial relationship between the DPSA as employer and GEMS as an implementor of a mandate to ensure access to health and wellness by government employees and thus contributing towards the attainment of the ideals of Universal Healthcare Coverage.

Media personality Ms. Faith Mangope will facilitate conversations as the panel covers key discussion points, including:

  • Achieving the Sustainable Development Agenda 2030.
  • Beyond Healthcare: Addressing health equity and social determinants of health.
  • Policy Interventions for Addressing Social Determinants of Health: Lessons and best practices.
  • Value-Based Care and Social Determinants of Health: Integrating social context into healthcare delivery.
  • Advancing health equity by addressing social determinants of health; and
  • Exploring the interplay between healthcare quality and social determinants.

At GEMS, we are dedicated to fulfilling our responsibilities towards our members and the people of South Africa. The Symposium is a testament to our commitment to Universal Healthcare Coverage, and we are eagerly anticipating a productive outcome that will be memorable and provide an insightful experience for all involved, Dr. Moloabi” concludes. 

To learn more about the GEMS Symposium, visit www.symposium.gems.gov.za. 

Categories : COVID General InterestTags :

World-renowned Vaccinologist Shabir Madhi Awarded CBE

On By ModernMedia

Professor Shabir Madhi has been appointed as an honorary Commander of the Most Excellent Order of the British Empire (CBE) by King Charles III.

Wits Professor of  Vaccinology Shabir Madhi led the Oxford University sponsored Oxford/AstraZeneca Covid-19 vaccine clinical trials in South Africa

Wits University and the University of Oxford contributed scientifically to informing the public health response to the Covid-19 pandemic in South Africa and globally.

Madhi receives the Order in recognition of his services to science and public health in a global pandemic.

Madhi led South Africa and the continent’s first Covid-19 vaccine trials in 2020/2021 as founder and Director of the South African Medical Research Council (SAMRC) Wits Vaccines and Infectious Diseases Analytics (Wits VIDA) Research Unit.

An internationally recognised leader in his field, the National Research Foundation A-rated scientist was involved in multiple clinical and serology epidemiology studies on Covid-19, in addition to his research on vaccines against other life-threatening diseases.

The first of (subsequently two) Wits University-led South African Covid-19 vaccine trials, Madhi led the Oxford/AstraZeneca Covid-19 vaccine clinical trials in South Africa, in association with the University of Oxford.

Professor Sir Andrew Pollard, Director of the Oxford Vaccine Group, University of Oxford, and Madhi’s UK counterpart in these Covid-19 vaccine trials, says of Madhi’s CBE appointment: “I am delighted that Professor Shabir Madhi CBE has been honoured by King Charles for his remarkable contributions to global public health and particularly for his extraordinary leadership in the midst of a global pandemic. It has been a huge privilege for me to work alongside him and his team on the development of the globally impactful Oxford-AstraZeneca vaccine.”

Over the course of the pandemic (2020-2022), Madhi had been an outspoken, articulate, and ardent advocate of Covid-19 vaccination as well as for increased access to these and other vaccines in Africa.

On his appointment as CBE, Madhi says: “The privilege of being conferred this honour is credit to the tremendous effort of the incredible Wits VIDA research team that I have the privilege of leading at Wits University – before, during and beyond the Covid-19 pandemic. As a collective, and together with colleagues at the University of Oxford and in South Africa, we are proud to have contributed scientifically to informing the public health response to the Covid-19 pandemic in South Africa and globally.”

Source: Wits University

Categories : General Interest GeneticsTags :

Genetic Analysis Reveals Secrets of Vlad Dracula the Impaler

On By ModernMedia

Mediaeval tyrant and inspiration for vampires, protein analysis reveals health secrets about Vlad the Impaler

New research analysing ancient protein residues left in letters written by the sadistic 15th century tyrant – and vampire inspiration – Vlad Dracula the Impaler suggests that he suffered from a number of health conditions. One of these conditions seemingly confirms one of the more outlandish tales about him – that he cried tears of blood.

Vlad the Impaler got his nickname because he impaled thousands of people on stakes: enemies (mainly the Ottoman Empire), criminals and anyone suspected of conspiring against his rule. He was eventually defeated in 1460, but the newly invented printing press spread the tale of his gruesome deeds all over Europe. Tales surrounding him may have inspired the iconic character of Bram Stoker’s Count Dracula in 1897. Nevertheless, more modern vampire stories such as Netflix’s ‘Castlevania’ make use of Vlad as inspiration.

This terrifying reputation made him an interesting topic for a bit of genetic archaeology in a paper published in Analytical Chemistry. Using sophisticated proteomic techniques, scientists analysed three letters written in 1457 and 1475 by the voivode of Wallachia, Vlad III, also known as Vlad the Impaler, or Vlad Dracula. This allowed them to tease out information about the man who wrote the letters as well as general information about the environmental conditions of 15th century Wallachia, a place of regional trade and conflict as well as disease transmission.

While centuries-old paper is unlikely to hold entire DNA strands, scientists were still able to piece together genetic information about the writer. The technique depends on the notion that a person’s writing hand will tend to rest on the paper being written upon, rubbing off a surprising amount of organic molecules in the process. They applied ethylene vinyl acetate to the papers, and with mass spectrometry, they discovered over 500 peptides – short chains of amino acids – with about 100 being of human origin, which they looked up in database searches.

Figure 1. (a) First letter (archive catalog number is II 365), dated August 4, 1475, here investigated, also showing the positions of the EVA strips (brownish rectangles) applied to its surface for capturing biological material; (b) mapping of the fluorescence of phenylalanine, tyrosine, and tryptophan under flash UV illumination (see the original article). Anal. Chem. 2023, 95, 34, 12732-12744

The researchers noted that while many mediaeval people may have handled these papers, it is also presumable that the most prominent ancient proteins can be attributed to the one who wrote and signed them – Prince Vlad the Impaler.

First, they discovered proteins pointing to ciliopathy, which affects the cellular cilia or the cilia anchoring structures, the basal bodies or ciliary function. This can manifest in a wide range of disorders, ranging from cerebral malformation to liver disease and intellectual disability.

They also uncovered signs of an undetermined inflammatory disease which likely involved his skin and respiratory tract.

Proteomics data also suggests that, according to some stories, he might also have suffered from a pathological condition called haemolacria – he could shed tears admixed with blood. This appears to confirm what some stories said about Vlad – that he sometimes cried tears of blood. While it is a known medical condition, it would have no doubt been terrifying for superstitious mediaeval people to behold when seen in someone with a reputation like Vlad the Impaler’s.

Non-human peptides also proved to be a window into the conditions of the time, hinting at common foods, pests and diseases. Database searches of the identified, as potential endogenous original components, 3 proteins from bacteria, 24 from viruses, 4 from fungi, 17 from insects (suggesting fruit flies), and 5 from plants (including rice, wheat and thale cress). Of the bacteria, they noted that some peptides related to Enterobacterales are specific to Yersinia pestis, the pathogenic bacterium causing plague, whereas another group is specific to E. coli.