Medical Bulletin 20/November/2023

Here are the top medical news of the day:

Children’s brains shaped by their time on tech devices

Time spent watching television or playing computer games has measurable and long-term effects on children’s brain function, according to a review of 23 years of neuroimaging research, which while showing negative impacts also demonstrates some positive effects.

However, the researchers stop short of advocating limits on screen time, which they say can lead to confrontation. Instead, they urge policymakers to help parents navigate the digital world by promoting programs which support positive brain development.

The evidence review, published today in the peer-reviewed journal Early Education and Development, is an analysis of 33 studies which use neuroimaging technology to measure the impact of digital technology on the brains of children under the age of 12. In total, more than 30,000 participants are included.

In particular, the research finds screen time leads to changes in the pre-frontal cortex of the brain, which is the base of executive functions such as working memory and the ability to plan or to respond flexibly to situations. It also finds impacts on the parietal lobe, which helps us to process touch, pressure, heat, cold, and pain;the temporal lobe, which is important for memory, hearing and language; and the occipital lobe, which helps us to interpret visual information.

Reference: Children’s brains shaped by their time on tech devices, research to-date shows; Early Education and Development, DOI: 10.1080/10409289.2023.2278117.

hemoglobin in the epidermis

Researchers have shown for the first time that hemoglobin, a protein found in red blood cells where it binds oxygen, is also present in the epidermis, our skin's outermost body tissue. The study, which appears in the Journal of Investigative Dermatology, published by Elsevier, provides important insights into the properties of our skin's protective external layer.

This research was driven by a curiosity about how the epidermis protects our delicate body from the environment and what unexpected molecules are expressed in the epidermis. Researchers discovered the hemoglobin α protein in keratinocytes of the epidermis and in hair follicles. This unexpected evidence adds a new facet to the understanding of the workings of our skin's defense mechanisms.

Hemoglobin binds gases such as oxygen, carbon dioxide, and nitric oxide, and it is an iron carrier via the heme complex. These properties make epidermal hemoglobin a prime candidate for antioxidant activity and potentially other roles in barrier function.

Professor Amagai concludes: "Our study showed that epidermal hemoglobin was upregulated by oxidative stress and inhibited the production of reactive oxygen species in human keratinocyte cell cultures. Our findings suggest that hemoglobin α protects keratinocytes from oxidative stress derived from external or internal sources such as UV irradiation and impaired mitochondrial function, respectively. Therefore, the expression of hemoglobin by keratinocytes represents an endogenous defense mechanism against skin aging and skin cancer."

Reference: Discovery of hemoglobin in the epidermis sheds new light on our skin's protective properties; Journal of Investigative Dermatology, DOI:10.1016/j.jid.2023.08.008.

Cerebral microstructural reorganization in children following mild TBI

A new study published in the peer-reviewed Journal of Neurotrauma shows that children with persistent symptoms following mild traumatic brain injury had evidence of ongoing cerebral microstructural change.

Researchers used brain MRI-based orientation dispersion index (ODI) metrics to study the microstructural damage in the brains of pediatric patients following “mild” TBI. The investigators studied children with persistent symptoms after injury and children displaying clinical recovery at 1 and 2-3 months post-TBI compared to healthy controls. Whole-brain ODI was significantly increased in symptomatic individuals compared to healthy controls at both 1- and 2-months post-injury. Symptomatic individuals had the highest ODI in all regions of interest. The ODI was lower in asymptomatic individuals, and healthy controls had the lowest ODI in all regions of interest. ODI progressively decreased over time alongside clinical recovery.

“Our results show evidence of ongoing microstructural reorganization or neuroinflammation between 1- and 2-3 months post-injury, further supporting delayed return to play in children who remain symptomatic,” stated the investigators.

“This study is an important contribution to the field. In addition to revealing key insights into the pathophysiological correlates of symptomatic mild TBI in children, it identifies an objective imaging metric in this population which could be further developed as a clinical tool.” They ended.

Reference: Evidence of ongoing cerebral microstructural reorganization in children with persisting symptoms following mild traumatic brain injury: a NODDI DTI analysis; Journal of Neurotrauma; DOI:10.1089/neu.2023.0196.