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Starts and Stops of Rhythmic and Discrete Movements: Modulation in the Excitability of the Corticomotor Tract During Transition to a Different Type of Movement

Lim et al. | Aug 27, 2018

Starts and Stops of Rhythmic and Discrete Movements: Modulation in the Excitability of the Corticomotor Tract During Transition to a Different Type of Movement

Control of voluntary and involuntary movements is one of the most important aspects of human neurological function, but the mechanisms of motor control are not completely understood. In this study, the authors use transcranial magnetic stimulation (TMS) to stimulate a portion of the motor cortex while subjects performed either discrete (e.g. throwing) or rhythmic (e.g. walking) movements. By recording electrical activity in the muscles during this process, the authors showed that motor evoked potentials (MEPs) measured in the muscles during TMS stimulation are larger in amplitude for discrete movements than for rhythmic movements. Interestingly, they also found that MEPs during transitions between rhythmic and discrete movements were nearly identical and larger in amplitude than those recorded during either rhythmic or discrete movements. This research provides important insights into the mechanisms of neurological control of movement and will serve as the foundation for future studies to learn more about temporal variability in neural activity during different movement types.

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Developing anticholinergic drugs for the treatment of asthma with improved efficacy

Wong et al. | Jul 05, 2023

Developing anticholinergic drugs for the treatment of asthma with improved efficacy
Image credit: Wong et al.

Anticholinergics are used in treating asthma, a chronic inflammation of the airways. These drugs block human M1 and M2 muscarinic acetylcholine receptors, inhibiting bronchoconstriction. However, studies have reported complications of anticholinergic usage, such as exacerbated eosinophil production and worsened urinary retention. Modification of known anticholinergics using bioisosteric replacements to increase efficacy could potentially minimize these complications. The present study focuses on identifying viable analogs of anticholinergics to improve binding energy to the receptors compared to current treatment options. Glycopyrrolate (G), ipratropium (IB), and tiotropium bromide (TB) were chosen as parent drugs of interest, due to the presence of common functional groups within the molecules, specifically esters and alcohols. Docking score analysis via AutoDock Vina was used to evaluate the binding energy between drug analogs and the muscarinic acetylcholine receptors. The final results suggest that G-A3, IB-A3, and TB-A1 are the most viable analogs, as binding energy was improved when compared to the parent drug. G-A4, IB-A4, IB-A5, TB-A3, and TB-A4 are also potential candidates, although there were slight regressions in binding energy to both muscarinic receptors for these analogs. By researching the effects of bioisosteric replacements of current anticholinergics, it is evident that there is a potential to provide asthmatics with more effective treatment options.

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Investigation of unknown causes of uveal melanoma uncovers seven recurrent genetic mutations

Nanda et al. | Aug 25, 2022

Investigation of unknown causes of uveal melanoma uncovers seven recurrent genetic mutations

Uveal melanoma (UM) is a rare subtype of melanoma but the most frequent primary cancer of the eye in adults. The goal of this study was to research the genetic causes of UM through a comprehensive frequency analysis of base-pair mismatches in patient genomes. Results showed a total of 130 genetic mutations, including seven recurrent mutations, with most mutations occurring in chromosomes 3 and X. Recurrent mutations varied from 8.7% to 17.39% occurrence in the UM patient sample, with all mutations identified as missense. These findings suggest that UM is a recessive heterogeneous disease with selective homozygous mutations. Notably, this study has potential wider significance because the seven genes targeted by recurrent mutations are also involved in other cancers.

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Geographic Distribution of Scripps National Spelling Bee Spellers Resembles Geographic Distribution of Child Population in US States upon Implementation of the RSVBee “Wildcard” Program

Kannankeril et al. | Aug 17, 2020

Geographic Distribution of Scripps National Spelling Bee Spellers Resembles Geographic Distribution of Child Population in US States upon Implementation of the RSVBee “Wildcard” Program

The Scripps National Spelling Bee (SNSB) is an iconic academic competition for United States (US) schoolchildren, held annually since 1925. However, the sizes and geographic distributions of sponsored regions are uneven. One state may send more than twice as many spellers as another state, despite similar numbers in child population. In 2018, the SNSB introduced a wildcard program known as RSVBee, which allowed students to apply to compete as a national finalist, even if they did not win their regional spelling bee. In this study, the authors tested the hypothesis that the geographic distribution of SNSB national finalists more closely matched the child population of the US after RSVBee was implemented.

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An Analysis on Exoplanets and How They are Affected by Different Factors in Their Star Systems

Selph et al. | Dec 06, 2018

An Analysis on Exoplanets and How They are Affected by Different Factors in Their Star Systems

In this article, the authors systematically study whether the type of a star is correlated with the number of planets it can support. Their study shows that medium-sized stars are likely to support more than one planet, just like the case in our solar system. They predict that, of the hundreds of planets beyond our solar system, 6% might be habitable. As humans work to travel further and further into space, some of those might truly be suited for human life.

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Music's Effect on Dogs' Heart Rates

Aubin et al. | Oct 03, 2017

Music's Effect on Dogs' Heart Rates

Music can affect the behavior of humans and other animals. In this study, the authors studied five types of music with different tempos and demonstrated how each one affected dogs' heart rates.

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Impact of gadodiamide (Omniscan) on a beef liver catalase ex vivo model

Hirsch et al. | Mar 10, 2023

Impact of gadodiamide (Omniscan) on a beef liver catalase <em>ex vivo</em> model
Image credit: Marcelo Leal

Here, seeking to better understand the effects of gadolinium-based contrast agents, dyes typically used for MRI scans, the authors evaluated the activity of catalase found in beef liver both with and without gadodiamide when exposed to hydrogen peroxide. They found that gadioamide did not significantly inhibit catalase's activity, attributing this lack of effects to the chelating agent found in gadodiamide.

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Evaluation of Tea Extract as an Inhibitor of Oxidative Stress in Prostate Cells

Zhang et al. | Jan 22, 2019

Evaluation of Tea Extract as an Inhibitor of Oxidative Stress in Prostate Cells

One important factor that contributes to human cancers is accumulated damage to cells' DNA due to the oxidative stress caused by free radicals. In this study, the authors investigate the effects of several different tea leaf extracts on oxidative stress in cultured human prostate cells to see if antioxidants in the tea leaves could help protect cells from this type of DNA damage. They found that all four types of tea extract (as well as direct application of the antioxidant EGCG) improved the outcomes for the cultured cells, with white tea extract having the strongest effect. This research suggests that tea extracts and the antioxidants that they contain may have applications in the treatment of the many diseases associated with cellular DNA damage, including cancer.

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