Tag: PLOS

Categories : Mental Health NeurologyTags :

What Happens in the Brain When a Person with Schizophrenia ‘Hears Voices’?

On By ModernMedia
Source: Pixabay

Auditory hallucinations are likely the result of abnormalities in two brain processes: a “broken” corollary discharge that fails to suppress self-generated sounds, and a “noisy” efference copy that makes the brain hear these sounds more intensely than it should. That is the conclusion of a new study published October 3rd in the open-access journal PLOS Biology by Xing Tian, of New York University Shanghai, China, and colleagues.

Patients with certain mental disorders, including schizophrenia, often hear voices in the absence of sound.

Patients may fail to distinguish between their own thoughts and external voices, resulting in a reduced ability to recognise thoughts as self-generated.

In the new study, researchers carried out electroencephalogram (EEG) experiments measuring the brain waves of twenty patients diagnosed with schizophrenia with auditory hallucinations and twenty patients diagnosed with schizophrenia who had never experienced such hallucinations.

In general, when people are preparing to speak, their brains send a signal known as “corollary discharge” that suppresses the sound of their own voice.

However, the new study showed that when patients with auditory hallucinations were preparing to speak a syllable, their brains not only failed to suppress these internal sounds, but had an enhanced “efference copy” response to internal sounds other than the planned syllable.

The authors conclude that impairments in these two processes likely contribute to auditory hallucinations and that targeting them in the future could lead to new treatments for such hallucinations.

The authors add, “People who suffer from auditory hallucinations can ‘hear’ sounds without external stimuli. A new study suggests that impaired functional connections between motor and auditory systems in the brain mediate the loss of ability to distinguish fancy from reality.”

Provided by PLOS

Categories : AntibioticsTags :

Treatment with a Mixture of Antimicrobial Peptides can Impede Antibiotic Resistance

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Pseudomonas exposed to mixtures instead of single peptides did not gain resistance

A common infection-causing bacteria was much less likely to evolve antibiotic resistance when treated with a mixture of antimicrobial peptides rather than a single peptide, making these mixtures a viable strategy for developing new antibiotic treatments. Jens Rolff of the Freie Universitat Berlin, Germany, and colleagues report these findings in a new study publishing July 2nd in the open-access journal PLOS Biology.

Antibiotic-resistant bacteria have become a major threat to public health. The World Health Organization estimates that 1.27 million people died directly from drug-resistant strains in 2019 and these strains contributed to 4.95 million deaths. While bacteria naturally evolve resistance to antibiotics, misuse and overuse of these drugs has accelerated the problem, rendering many antibiotics ineffective. One emerging strategy to combat antibiotic resistance is the use of antimicrobial peptides, which are chains of amino acids that function as broad-spectrum antimicrobial compounds and are key components of the innate immune system in animals, fungi and plants.

In the new study, researchers investigated whether antimicrobial peptide mixtures synthesised in the lab could reduce the risk of the pathogen Pseudomonas aeruginosa from evolving antimicrobial resistance, compared to exposure to a single antimicrobial peptide. They found that using antimicrobial peptide mixtures carried a much lower risk of the bacteria developing resistance. The mixtures also helped prevent the bacteria from developing cross-resistance to other antimicrobial drugs, while maintaining – or even improving – drug sensitivity.

Overall, the findings suggest that the use of antimicrobial peptide mixtures is a strategy worth pursuing in the search for new, longer-lasting treatments for bacteria. The researchers suspect that using a cocktail of multiple antimicrobial peptides creates a larger set of challenges for bacteria to overcome, which can potentially delay the evolution of resistance, compared to traditional antibiotics. Furthermore, these cocktails can be synthesized affordably, and previous studies have shown them to be non-toxic in mice.

Lead author Bernardo Antunes adds, “Even after four weeks of exposure, a usual treatment duration for Pseudomonas infections, we could not find resistance against our new random peptide, but against other antimicrobials.”

Provided by PLOS

Categories : HospitalsTags :

Evidence-based Design or Feng Shui in Hospital Rooms might Benefit Patients

On By ModernMedia

Image-based online study shows no benefits, however, of virtual room designs incorporating the golden ratio

In an online study, virtual hospital rooms designed according to the principles of evidence-based design or the principles of Feng Shui were associated with greater potential benefit for viewers than virtual representations of standard hospital rooms. Emma Zijlstra of Hanze University of Applied Sciences in the Netherlands and colleagues present these findings in the open-access journal PLOS ONE on June 5.

Hospital designers might consider employing specific design principles in an effort to improve patients’ experiences. Growing evidence suggests there are beneficial outcomes from an approach known as evidence-based design. For instance, exposure to more daylight in hospitals is associated with lower stress and pain. Other well-known design approaches include Feng Shui, a Chinese system based on hypothetical energy flow, and the use of proportions following the golden ratio.

Despite these well-known options, experimental evidence on their relative benefits in hospitals is lacking. To help clarify, Zijlstra and colleagues randomly assigned each of 558 study participants to view online representations and information about a virtual hospital room designed with one of four approaches: Feng Shui, the golden ratio, evidence-based design or, as a control, a standard design from a real-life hospital. Only people who had previously been hospitalized at some point in their lives were invited to participate.

After experiencing the virtual rooms, participants completed a questionnaire that included standard measures of anxiety and other outcomes. Statistical analysis of their answers showed that, compared to participants who viewed the standard rooms, those who viewed rooms with evidence-based design reported less anxiety and greater senses of control, social support, distraction from negative thoughts, and pleasantness of the room.

Feng Shui design was not directly associated with lower anxiety, but participants who viewed the Feng Shui rooms did have greater senses of social support, positive distraction, and pleasantness of the room. There was no evidence for any benefits of golden ratio-based design.

On the basis of their findings, the authors suggest that rooms designed according to the principles of evidence-based design or Feng Shui might benefit patients. They note similarities between the two approaches, such as incorporation of greenery. However, they caution, it is unclear how well these online findings might translate to real-life hospital settings.

The authors add: “To our knowledge, this is the first and largest randomized controlled trial linking design principles, partly ancient and world-renowned, directly to anxiety in hospital rooms. This study showed that both Feng Shui and Evidence-Based Design are capable in effecting anxiety and it is important that large follow-up studies are conducted to examine the effect of specific design features.”

Provided by PLOS