Search

Cerebrovascular reactivity (CVR) is routinely measured as a predictor of stroke in people with a high risk of ischemic attack. Neuroimaging techniques such as emission tomography, magnetic resonance imaging, and transcranial doppler are frequently used to measure CVR even though each technique has its limitations. Functional near-infrared spectroscopy (fNIRS), also based on the principle of neurovascular coupling, is relatively inexpensive, portable, and allows for the quantification of oxy- and deoxy-hemoglobin concentration changes at a high temporal resolution. This study examines the relationship between age and CVR using fNIRS in 45 young healthy adult participants aged 18–41 years (6 females, 26.64 ± 5.49 years) performing a simple breath holding task. Eighteen of the 45 participants were scanned again after a week to evaluate the feasibility of fNIRS in reliably measuring CVR. Results indicate (a) a negative relationship between age and hemodynamic measures of breath holding task in the sensorimotor cortex of 45 individuals and (b) widespread positive coactivation within medial sensorimotor regions and between medial sensorimotor regions with supplementary motor area and prefrontal cortex during breath holding with increasing age. The intraclass correlation coefficient (ICC) indicated only a low to fair/good reliability of the breath hold hemodynamic measures from sensorimotor and prefrontal cortices. However, the average hemodynamic response to breath holding from the two sessions were found to be temporally and spatially in correspondence. Future improvements in the sensitivity and reliability of fNIRS metrics could facilitate fNIRS-based assessment of cerebrovascular function as a potential clinical tool.

March 2020 marked the beginning of a global pandemic caused by SARSCoV- 2. With the development, production and distribution of several vaccines there are hopes to an end in sight. However, with the emergence of several mutated viral strains concerns are mounting as to the effectiveness of the current treatments and preventative measures against the new strains. Herein we analyzed and compared the interaction of the SARS-CoV-2 Spike (S) protein and its variants with human Angiotensin Converting Enzyme (ACE-2) and the binding affinities of several possible S-protein inhibitors with these variants via in silico molecular docking studies. The binding affinities of all the variants to ACE- 2 are less than that of SARS-CoV-2, indicating they are less potent than SARSCoV- 2. The inhibitors, however, showed decreased binding affinity to most of the mutant S-proteins than SARS-CoV-2, indicating it is more difficult to treat COVID using the therapeutic approach targeting the S-protein.

Resting state fMRI (rs-fMRI) is a neuroimaging modality where individuals are scanned in a rested, but wakeful state, and has been widely used to assess brain functionality in healthy and neurologically diseased populations. It has gained attention in the pediatric imaging community due to its ease of use, since motor ability is not required, in comparison to task-based fMRI. Yet despite the advancements in rs-fMRI in pediatric imaging, limitations also exist in scanning children at rest, especially in terms of head motion. In this review, a range of pediatric disorders including ADHD, ASD, type 1 diabetes, Fetal Alcohol Syndrome (FAS), Tourette’s Syndrome, and premature birth is briefly covered. Additionally, commonly used rs-fMRI preprocessing techniques and resting state functional connectivity (RSFC) analysis methods are discussed. One main difference in the rs-fMRI preprocessing procedure between pediatric and adult brains is the choice of brain template, due to structural differences between the two groups. With robust rs-fMRI techniques, we can study the pediatric brain’s functional connectome, allowing for better understanding, diagnosis, and treatment of pediatric brain disorders.