Genetic testing for talent identification and development
Silvia Camporesi, Mike McNamee in Bioethics, Genetics and Sport, 2018
Direct-to-consumer (DTC) testing that provides analysis of genes in association with sports performance and sports talent is primarily based around the angiotensin I-converting enzyme (ACE) and the gene for α-actinin-3 (ACTN3). The ACE gene was the first to be widely recognised for its association with performance; in particular it was demonstrated to have an association with skeleto-muscle formation and function. In 2003 Yang and colleagues found that both male and female elite sprinters have a significantly higher frequency of the functional 477R genotype, where R stands in place of the amino acid arginine ‘R’ rather than a stop codon in the ACTN3 gene (Yang et al. 2003). Alfa-actinin belongs to a large family of actin-binding proteins, where actin is a fundamental component of the contractile unit of muscle fibres. Polymorphisms in ACTN3 are thought to contribute to the heritability of fibre-type distribution in muscle, where Type I muscle fibres are slow-twitch fibres that use aerobic metabolism and are used in endurance races, while Type II muscle fibres are fast-twitch fibres, which use anaerobic metabolism to create energy and are used in activities requiring short intense effort such as sprints or basketball, football and hockey (Berman and North 2010). Subsequent research has consistently supported the view that the genotypes of ACE and ACTN3 influence human performance in relation to sprint/power or endurance events. Although many genes and allelic variants have been tentatively associated with performance-related traits, these associations have not reached a conclusive level.
Magnesium in obstetrics
Kupetsky A. Erine in Magnesium, 2019
Regardless of the larger question of whether or not tocolysis is beneficial, intravenous magnesium is not itself a tocolytic in that it does not alter term or preterm labor in any meaningful clinical context. This is somewhat counterintuitive with regards to the known understanding of myometrial contractility and available in vitro studies. Like all smooth muscles, myometrial contractions are triggered by an increase in intracellular calcium which in turn activates myosin light chain kinase (MLKC). MLKC, in turn, phosphorylates myosin leading to its activation and interaction with actin which ultimately generates the contraction of the entire muscle cell. Thus, one could inhibit myometrial contractions by antagonizing calcium on a cellular level, and likewise, one of the other commonly used categories of tocolytic agents are calcium channel blockers (CCB), such as nifedipine.34 Likewise, in vitro myometrial samples exposed to high concentrations of magnesium will demonstrate impaired contractility in conjunction with decreased intracellular concentrations of calcium.35
Nutrigenomics for Sport and Exercise Performance
Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse in The Routledge Handbook on Biochemistry of Exercise, 2020
The ACTN3 (rs1815739) gene encodes the alpha-actin 3 protein, which plays a key role in the contraction of fast-twitch or power-type muscle fibres during short bursts of intense activities, such as sprinting or lifting heavy objects (154). Genetic variation in ACTN3 affects the expression of the resulting protein in fast-twitch fibres, and individuals who carry at least one copy of the T variant produce a lower-functioning ACTN3 protein that has been linked to increased risk of muscle damage (52). For example, a recent study showed that experienced endurance athletes with the T variant had higher levels of markers of muscle damage after a competitive marathon (38) compared to individuals with the CC variant. A similar trend was observed in a study where healthy young men performed knee extension exercises, working the quadriceps, in a laboratory setting (39).
Cyclo-VEGI inhibits bronchial artery remodeling in a murine model of chronic asthma
Published in Experimental Lung Research, 2021
Kyung Hoon Kim, Jung Hur, Hwa Young Lee, Eung Gu Lee, Sook Young Lee
Six-micrometer-thick sections of lung tissues from each paraffin block were deparaffinized in xylene and rehydrated in ethanol. The sections were subjected to immunohistochemical staining for alpha-smooth muscle actin (α-SMA) to assess changes involving α-SMA area. The lung sections were incubated overnight at 4 °C with primary mouse monoclonal antibodies (Dako, High Wycombe, UK) directed against α-SMA. Immunoreactivity was detected by sequentially incubating the lung sections with a biotinylated secondary antibody, followed by peroxidase reagent (Vector Laboratories, Burlingame, CA, USA) and diaminobenzidine chromogen (Invitrogen, Carlsbad, CA, USA). Immunostained areas of α-SMA were estimated from the α-SMA-positive areas using an image processing software (Pannoramic MIDI; 3 D Histech, Budapest, Hungary). The results were expressed as the immunostained area per micrometer length of the basement membrane of the bronchioles (internal diameter, 150−200 μm) and bronchial arteries. The immunostained areas of the bronchial arteries and bronchi were measured separately using an image analysis system attached to a light microscope (BX50, Olympus, Tokyo, Japan).
Changes of hippocampus proteomic profiles after blueberry extracts supplementation in APP/PS1 transgenic mice
Published in Nutritional Neuroscience, 2020
Hai-qiang Li, Long Tan, Hong-peng Yang, Wei Pang, Tong Xu, Yu-gang Jiang
β-actin and γ-actin are the major actin isoforms in non-muscle cells.39 Actin, found in both neurons and glial cells, is a core subunit of microfilaments. Actin microfilaments are particularly concentrated in presynaptic terminals, dendritic spines, and growth cones. Actin microfilaments play a role in the neuronal membrane cytoskeleton by maintaining the distribution of membrane proteins and segregating axonal an dendritic proteins.40 Actin was also found to be a target of Aβ1–42-mediated protein oxidation. Both β-actin and γ-actin were found to be oxidized in synaptosomes treated with Aβ1–42, however, only β-actin was found to be significantly modified, which was consistent with its reported oxidation in AD brain.41 In this study, β-actin was down-regulated in AD+BB mice, consistent with the previous reasoning.
Sudden cardiac arrest as the initial presentation for left ventricular noncompaction cardiomyopathy
Published in Baylor University Medical Center Proceedings, 2019
Avaneesh Jakkoju, Rakesh Jakkoju, Vishnupriya Kuchana, Pedro R. Cox-Alomar, Frank W. Smart, D. Luke Glancy
Although LVNC had been described in patients with other congenital cardiac malformations and in a variety of muscular dystrophies, isolated LVNCC was initially described in eight patients by Chin et al in 1990.3 LVNC with or without LV dysfunction has been found in 0.14% to 0.26% of patients referred for echocardiography.4,5 Both sporadic and familial mutations have been described for LVNC. Familial mutations are most often autosomal dominant, and in rare cases inheritance has been X linked.6 Several familial mutations have been reported in genes responsible for sarcomeric and mitochondrial proteins. Beta myosin heavy chain (MYH7), alpha-cardiac actin (ACTC), cardiac troponin T (TNNT2), troponin I (TNN13), SCN5A, and G4.5 are some of the familial mutations that have been described.6,7 Murphy et al screened asymptomatic first-degree family members with echocardiography and found 25% of the screened population to have echocardiographic abnormalities, which included LVNC, enlarged LV diameter, and noncompaction of posterior wall that did not meet criteria for LVNC.8
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