Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Neurobiol Dis ; 177: 105967, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36535550

RESUMO

Epidemiological studies identified alcohol use disorder (AUD) as a risk factor for Alzheimer's disease (AD), yet there is conflicting evidence on how alcohol use promotes AD pathology. In this study, a 10-week moderate two-bottle choice drinking paradigm was used to identify how chronic ethanol exposure alters amyloid-ß (Aß)-related pathology, metabolism, and behavior. Ethanol-exposed APPswe/PSEN1dE9 (APP/PS1) mice showed increased brain atrophy and an increased number of amyloid plaques. Further analysis revealed that ethanol exposure led to a shift in the distribution of plaque size in the cortex and hippocampus. Ethanol-exposed mice developed a greater number of smaller plaques, potentially setting the stage for increased plaque proliferation in later life. Ethanol drinking APP/PS1 mice also exhibited deficits in nest building, a metric of self-care, as well as increased locomotor activity and central zone exploration in an open field test. Ethanol exposure also led to a diurnal shift in feeding behavior which was associated with changes in glucose homeostasis and glucose intolerance. Complementary in vivo microdialysis experiments were used to measure how acute ethanol directly modulates Aß in the hippocampal interstitial fluid (ISF). Acute ethanol transiently increased hippocampal ISF glucose levels, suggesting that ethanol directly affects cerebral metabolism. Acute ethanol also selectively increased ISF Aß40, but not ISF Aß42, levels during withdrawal. Lastly, chronic ethanol drinking increased N-methyl-d-aspartate receptor (NMDAR) and decreased γ-aminobutyric acid type-A receptor (GABAAR) mRNA levels, indicating a potential hyperexcitable shift in the brain's excitatory/inhibitory (E/I) balance. Collectively, these experiments suggest that ethanol may increase Aß deposition by disrupting metabolism and the brain's E/I balance. Furthermore, this study provides evidence that a moderate drinking paradigm culminates in an interaction between alcohol use and AD-related phenotypes with a potentiation of AD-related pathology, behavioral dysfunction, and metabolic impairment.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Modelos Animais de Doenças , Etanol/toxicidade , Glucose/metabolismo , Hipocampo/metabolismo , Camundongos Transgênicos , Placa Amiloide/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo
2.
Faraday Discuss ; 241(0): 341-356, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36254834

RESUMO

Mechanochemical synthesis routes offer a sustainable, simple method for preparing materials. In this work, NiAl2O4 was synthesised by a mechanically activated method using a high-energy planetary mill and a calcination step. This study aims to identify the effect of different milling energies on the phases, chemical environments and surface composition of the material. In addition, it explores the thermal impact on the decomposition and structure of the materials. The materials were characterised by X-ray phosphorescence (XPS), solid-state UV-VIS (SS-UV-VIS), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), high-resolution transmission electron microscopy (HR-TEM) and thermal gravimetry differential scanning calorimetry (TGA-DSC). A co-precipitated material is used as a reference along with the ground reagents which were used as a baseline. From this in-depth analysis of the material, a good understanding of the disordered partially inverse spinel structure is provided. This study has found that with calcination temperatures of 750 °C and 900 °C a mixed NiAl2O4 : NiO phase is produced with a Ni enriched surface. The surface is found to be relatively stable with the increase from 750 °C to 900 °C.

3.
Clin J Sport Med ; 33(5): e145-e151, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35350037

RESUMO

OBJECTIVE: Concussions are common match injuries in elite rugby, and reports exist of reduced cognitive function and long-term health consequences that can interrupt or end a playing career and produce continued ill health. The aim of this study was to investigate the association between elite rugby status and 8 concussion-associated risk polymorphisms. We hypothesized that concussion-associated risk genotypes and alleles would be underrepresented in elite rugby athletes compared with nonathletes. DESIGN: A case-control genetic association study. SETTING: Institutional (university). PARTICIPANTS: Elite White male rugby athletes [n = 668, mean (SD) height 1.85 (0.07) m, mass 102 (12) kg, and age 29 (7) years] and 1015 nonathlete White men and women (48% men). INTERVENTIONS: Genotype was the independent variable, obtained by PCR of genomic DNA using TaqMan probes. MAIN OUTCOME MEASURE: Elite athlete status with groups compared using χ 2 and odds ratio (OR). RESULTS: The COMT rs4680 Met/Met (AA) genotype, Met allele possession, and Met allele frequency were lower in rugby athletes (24.8%, 74.6%, and 49.7%, respectively) than nonathletes (30.2%, 77.6%, and 54.0%; P < 0.05). The Val/Val (GG) genotype was more common in elite rugby athletes than nonathletes (OR 1.39, 95% confidence interval 1.04-1.86). No other polymorphism was associated with elite athlete status. CONCLUSIONS: Elite rugby athlete status is associated with COMT rs4680 genotype that, acting pleiotropically, could affect stress resilience and behavioral traits during competition, concussion risk, and/or recovery from concussion. Consequently, assessing COMT rs4680 genotype might aid future individualized management of concussion risk among athletes.


Assuntos
Concussão Encefálica , Futebol Americano , Humanos , Masculino , Feminino , Adulto , Rugby , Futebol Americano/lesões , Concussão Encefálica/genética , Concussão Encefálica/psicologia , Polimorfismo Genético , Atletas , Catecol O-Metiltransferase/genética
4.
J Sports Sci ; 41(1): 56-62, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37012221

RESUMO

Success in long-distance running relies on multiple factors including oxygen utilisation and lactate metabolism, and genetic associations with athlete status suggest elite competitors are heritably predisposed to superior performance. The Gly allele of the PPARGC1A Gly482Ser rs8192678 polymorphism has been associated with endurance athlete status and favourable aerobic training adaptations. However, the association of this polymorphism with performance amongst long-distance runners remains unclear. Accordingly, this study investigated whether rs8192678 was associated with elite status and competitive performance of long-distance runners. Genomic DNA from 656 Caucasian participants including 288 long-distance runners (201 men, 87 women) and 368 non-athletes (285 men, 83 women) was analysed. Medians of the 10 best UK times (Top10) for 10 km, half-marathon and marathon races were calculated, with all included athletes having personal best (PB) performances within 20% of Top10 (this study's definition of "elite"). Genotype and allele frequencies were compared between athletes and non-athletes, and athlete PB compared between genotypes. There were no differences in genotype frequency between athletes and non-athletes, but athlete Ser allele carriers were 2.5% faster than Gly/Gly homozygotes (p = 0.030). This study demonstrates that performance differences between elite long-distance runners are associated with rs8192678 genotype, with the Ser allele appearing to enhance performance.


Assuntos
Resistência Física , Corrida , Masculino , Humanos , Feminino , Resistência Física/genética , Polimorfismo Genético , Frequência do Gene , Genótipo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética
5.
J Strength Cond Res ; 37(4): 799-805, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36763468

RESUMO

ABSTRACT: Dines, HR, Nixon, J, Lockey, SJ, Herbert, AJ, Kipps, C, Pedlar, CR, Day, SH, Heffernan, SM, Antrobus, MR, Brazier, J, Erskine, RM, Stebbings, GK, Hall, ECR, and Williams, AG. Collagen gene polymorphisms previously associated with resistance to soft-tissue injury are more common in competitive runners than nonathletes. J Strength Cond Res 37(4): 799-805, 2023-Single-nucleotide polymorphisms (SNPs) of collagen genes have been associated with soft-tissue injury and running performance. However, their combined contribution to running performance is unknown. We investigated the association of 2 collagen gene SNPs with athlete status and performance in 1,429 Caucasian subjects, including 597 competitive runners (354 men and 243 women) and 832 nonathletes (490 men and 342 women). Genotyping for COL1A1 rs1800012 (C > A) and COL5A1 rs12722 (C > T) SNPs was performed by a real-time polymerase chain reaction. The numbers of "injury-resistant" alleles from each SNP, based on previous literature (rs1800012 A allele and rs12722 C allele), were combined as an injury-resistance score (RScore, 0-4; higher scores indicate injury resistance). Genotype frequencies, individually and combined as an RScore, were compared between cohorts and investigated for associations with performance using official race times. Runners had 1.34 times greater odds of being rs12722 CC homozygotes than nonathletes (19.7% vs. 15.5%, p = 0.020) with no difference in the rs1800012 genotype distribution ( p = 0.659). Fewer runners had an RScore 0 of (18.5% vs. 24.7%) and more had an RScore of 4 (0.6% vs. 0.3%) than nonathletes ( p < 0.001). Competitive performance was not associated with the COL1A1 genotype ( p = 0.933), COL5A1 genotype ( p = 0.613), or RScore ( p = 0.477). Although not associated directly with running performance among competitive runners, a higher combined frequency of injury-resistant COL1A1 rs1800012 A and COL5A1 rs12722 C alleles in competitive runners than nonathletes suggests these SNPs may be advantageous through a mechanism that supports, but does not directly enhance, running performance.


Assuntos
Corrida , Lesões dos Tecidos Moles , Masculino , Humanos , Feminino , Colágeno Tipo V/genética , Genótipo , Colágeno/genética , Polimorfismo de Nucleotídeo Único
6.
Angew Chem Int Ed Engl ; 60(44): 23878-23884, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34464506

RESUMO

A combination of charge density studies and solid state nuclear magnetic resonance (NMR) 1 JNC coupling measurements supported by periodic density functional theory (DFT) calculations is used to characterise the transition from an n-π* interaction to bond formation between a nucleophilic nitrogen atom and an electrophilic sp2 carbon atom in a series of crystalline peri-substituted naphthalenes. As the N⋅⋅⋅C distance reduces there is a sharp decrease in the Laplacian derived from increasing charge density between the two groups at ca. N⋅⋅⋅C = 1.8 Å, with the periodic DFT calculations predicting, and heteronuclear spin-echo NMR measurements confirming, the 1 JNC couplings of ≈3-6 Hz for long C-N bonds (1.60-1.65 Å), and 1 JNC couplings of <1 Hz for N⋅⋅⋅C >2.1 Å.

7.
Phys Chem Chem Phys ; 22(6): 3400-3413, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31984388

RESUMO

A combined multinuclear solid state NMR and gauge included projected augmented wave, density functional theory (GIPAW DFT) computational approach is evaluated to determine the four heteronuclear 1J(13C,17O) couplings in solid 17O enriched naphthalaldehydic acid. Direct multi-field 17O magic angle spinning (MAS), triple quantum MAS (3QMAS) and double rotation (DOR) experiments are initially utilised to evaluate the accuracy of the DFT approximations used in the calculation of the isotropic chemical shifts (δiso), quadrupole coupling constants (CQ) and asymmetry (ηQ) parameters. These combined approaches give δiso values of 313, 200 and 66 ppm for the carbonyl (C[double bond, length as m-dash]O), ether (-O-) and hydroxyl (-OH) environments, respectively, with the corresponding measured quadrupole products (PQ) being 8.2, 9.0 and 10.6 MHz. The geometry optimised DFT structure derived using the CASTEP code gives firm agreement with the shifts observed for the ether (δiso = 223, PQ = 9.4 MHz) and hydroxyl (δiso = 62, PQ = 10.5 MHz) environments but the unoptimised experimental XRD structure has better agreement for the carbonyl group (δiso = 320, PQ = 8.3 MHz). The determined δiso and ηQ values are shown to be consistent with bond lengths closer to 1.222 Å (experimental length) rather than the geometry optimised length of 1.238 Å. The geometry optimised DFT 1J(13C,17O) coupling to the hydroxyl is calculated as 20 Hz and the couplings to the ether were calculated to be 37 (O-C[double bond, length as m-dash]O) and 32 (O-C-OH) Hz. The scalar coupling parameters for the unoptimised experimental carbonyl group predict a 1J(13C,17O) value of 28 Hz, whilst optimisation gives a value of 27 Hz. These calculated 1J(13C,17O) couplings, together with estimations of the probability of each O environment being isotopically labelled (determined by electrospray ionisation mass spectrometry) and the measured refocussable transverse dephasing (T2') behaviour, are combined to simulate the experimental decay behaviour. Good agreement between the measured and calculated decay behaviour is observed.

8.
J Strength Cond Res ; 34(6): 1790-1801, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30138238

RESUMO

Brazier, J, Antrobus, M, Stebbings, GK, Day, SH, Callus, P, Erskine, RM, Bennett, MA, Kilduff, LP, and Williams, AG. Anthropometric and physiological characteristics of elite male rugby athletes. J Strength Cond Res 34(6): 1790-1801, 2020-This is the first article to review the anthropometric and physiological characteristics required for elite rugby performance within both rugby union (RU) and rugby league (RL). Anthropometric characteristics such as height and body mass, and physiological characteristics such as speed and muscular strength, have previously been advocated as key discriminators of playing level within rugby. This review aimed to identify the key anthropometric and physiological properties required for elite performance in rugby, distinguishing between RU and RL, forwards and backs and competitive levels. There are differences between competitive standards such that, at the elite level, athletes are heaviest (RU forwards ∼111 kg, backs ∼93 kg; RL forwards ∼103 kg, backs ∼90 kg) with lowest % body fat (RU forwards ∼15%, backs ∼12%; RL forwards ∼14%, backs ∼11%), they have most fat-free mass and are strongest (back squat: RU forwards ∼176 kg, backs ∼157 kg; RL forwards ∼188 kg, backs ∼168 kg; bench press: RU forwards ∼131 kg, backs ∼118 kg; RL forwards ∼122 kg, backs ∼113 kg) and fastest (10 m: RU forwards ∼1.87 seconds, backs ∼1.77 seconds; 10 m: RL forwards ∼1.9 seconds, backs ∼1.83 seconds). We also have unpublished data that indicate contemporary RU athletes have less body fat and are stronger and faster than the published data suggest. Regardless, well-developed speed, agility, lower-body power, and strength characteristics are vital for elite performance, probably reflect both environmental (training, diet, etc.) and genetic factors, distinguish between competitive levels, and are therefore important determinants of elite status in rugby.


Assuntos
Pesos e Medidas Corporais , Futebol Americano/fisiologia , Aptidão Física/fisiologia , Atletas , Desempenho Atlético/fisiologia , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia
9.
Eur J Appl Physiol ; 119(1): 29-47, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30377780

RESUMO

Low bone mineral density (BMD) is established as a primary predictor of osteoporotic risk and can also have substantial implications for athlete health and injury risk in the elite sporting environment. BMD is a highly multi-factorial phenotype influenced by diet, hormonal characteristics and physical activity. The interrelationships between such factors, and a strong genetic component, suggested to be around 50-85% at various anatomical sites, determine skeletal health throughout life. Genome-wide association studies and case-control designs have revealed many loci associated with variation in BMD. However, a number of the candidate genes identified at these loci have no known associated biological function or have yet to be replicated in subsequent investigations. Furthermore, few investigations have considered gene-environment interactions-in particular, whether specific genes may be sensitive to mechanical loading from physical activity and the outcome of such an interaction for BMD and potential injury risk. Therefore, this review considers the importance of physical activity on BMD, genetic associations with BMD and how subsequent investigation requires consideration of the interaction between these determinants. Future research using well-defined independent cohorts such as elite athletes, who experience much greater mechanical stress than most, to study such phenotypes, can provide a greater understanding of these factors as well as the biological underpinnings of such a physiologically "extreme" population. Subsequently, modification of training, exercise or rehabilitation programmes based on genetic characteristics could have substantial implications in both the sporting and public health domains once the fundamental research has been conducted successfully.


Assuntos
Traumatismos em Atletas/genética , Densidade Óssea , Exercício Físico , Predisposição Genética para Doença , Atletas , Traumatismos em Atletas/epidemiologia , Humanos
10.
BMC Genomics ; 19(1): 13, 2018 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-29298672

RESUMO

BACKGROUND: Studies investigating associations between ACTN3 R577X and ACE I/D genotypes and endurance athletic status have been limited by small sample sizes from mixed sport disciplines and lack quantitative measures of performance. AIM: To examine the association between ACTN3 R577X and ACE I/D genotypes and best personal running times in a large homogeneous cohort of endurance runners. METHODS: We collected a total of 1064 personal best 1500, 3000, 5000 m and marathon running times of 698 male and female Caucasian endurance athletes from six countries (Australia, Greece, Italy, Poland, Russia and UK). Athletes were genotyped for ACTN3 R577X and ACE ID variants. RESULTS: There was no association between ACTN3 R577X or ACE I/D genotype and running performance at any distance in men or women. Mean (SD) marathon times (in s) were for men: ACTN3 RR 9149 (593), RX 9221 (582), XX 9129 (582) p = 0.94; ACE DD 9182 (665), ID 9214 (549), II 9155 (492) p = 0.85; for women: ACTN3 RR 10796 (818), RX 10667 (695), XX 10675 (553) p = 0.36; ACE DD 10604 (561), ID 10766 (740), II 10771 (708) p = 0.21. Furthermore, there were no associations between these variants and running time for any distance in a sub-analysis of athletes with personal records within 20% of world records. CONCLUSIONS: Thus, consistent with most case-control studies, this multi-cohort quantitative analysis demonstrates it is unlikely that ACTN3 XX genotype provides an advantage in competitive endurance running performance. For ACE II genotype, some prior studies show an association but others do not. Our data indicate it is also unlikely that ACE II genotype provides an advantage in endurance running.


Assuntos
Actinina/genética , Atletas , Peptidil Dipeptidase A/genética , Resistência Física/genética , Polimorfismo Genético , Corrida/fisiologia , Feminino , Genótipo , Humanos , Masculino , População Branca/genética
11.
Chemphyschem ; 19(14): 1722-1732, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29667743

RESUMO

Multinuclear (1 H, 13 C, 25 Mg) solid-state NMR data is reported for a series of magnesium acetate phases Mg(CH3 COO)2 ⋅ nH2 O (n=0 (two polymorphs), 1, 4). The central focus here is 25 Mg as this set of compounds provides an expanded range of local magnesium coordinations compared to what has previously been reported in the literature using NMR. These four compounds provide 10 distinct magnesium sites with varying NMR interaction parameters. One of the anhydrous crystal structures (α) has an MgO7 site which is reported, to the best of our knowledge, for the first time. For those phases with a single crystal structure, a combination of magic angle spinning (MAS) NMR at high magnetic field (20 T) and first principles density functional theory (DFT) calculations demonstrates the value of including 25 Mg in NMR crystallography approaches. For the second anhydrate phase (ß), where no single crystal structure exists, the multinuclear NMR data clearly show the multiplicity of sites for the different elements, with 25 Mg satellite transition (ST) MAS NMR revealing four inequivalent magnesium environments, which is new information constraining future refinement of the structure. This study highlights the sensitivity of 25 Mg NMR to the local environment, an observation important for several sub-disciplines of chemistry where the structural chemistry of magnesium is likely to be crucial.

12.
BMC Genomics ; 18(Suppl 8): 820, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29143592

RESUMO

BACKGROUND: Two common single nucleotide polymorphisms within the COL5A1 gene (SNPs; rs12722 C/T and rs3196378 C/A) have previously been associated with tendon and ligament pathologies. Given the high incidence of tendon and ligament injuries in elite rugby athletes, we hypothesised that both SNPs would be associated with career success. RESULTS: In 1105 participants (RugbyGene project), comprising 460 elite rugby union (RU), 88 elite rugby league athletes and 565 non-athlete controls, DNA was collected and genotyped for the COL5A1 rs12722 and rs3196378 variants using real-time PCR. For rs12722, the injury-protective CC genotype and C allele were more common in all athletes (21% and 47%, respectively) and RU athletes (22% and 48%) than in controls (16% and 41%, P ≤ 0.01). For rs3196378, the CC genotype and C allele were overrepresented in all athletes (23% and 48%) and RU athletes (24% and 49%) compared with controls (16% and 41%, P ≤ 0.02). The CC genotype in particular was overrepresented in the back and centres (24%) compared with controls, with more than twice the odds (OR = 2.25, P = 0.006) of possessing the injury-protective CC genotype. Furthermore, when considering both SNPs simultaneously, the CC-CC SNP-SNP combination and C-C inferred allele combination were higher in all the athlete groups (≥18% and ≥43%) compared with controls (13% and 40%; P = 0.01). However, no genotype differences were identified for either SNP when RU playing positions were compared directly with each other. CONCLUSION: It appears that the C alleles, CC genotypes and resulting combinations of both rs12722 and rs3196378 are beneficial for rugby athletes to achieve elite status and carriage of these variants may impart an inherited resistance against soft tissue injury, despite exposure to the high-risk environment of elite rugby. These data have implications for the management of inter-individual differences in injury risk amongst elite athletes.


Assuntos
Atletas , Colágeno Tipo V/genética , Futebol Americano , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único , Lesões dos Tecidos Moles/genética , Adulto , Alelos , Haplótipos , Humanos , Masculino
13.
Hippocampus ; 27(12): 1264-1274, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28833775

RESUMO

Glucagon-like peptide-1 (GLP-1) is an endogenous gut hormone and a key regulator in maintaining glucose homeostasis by stimulating insulin secretion. Its natural cleavage product GLP-1 (9-36), used to be considered a "bio-inactive" metabolite mainly because of its lack of insulinotropic effects and low affinity for GLP-1 receptors, possesses unique properties such as anti-oxidant and cardiovascular protection. Little is known about the role of GLP-1 (9-36) in central nervous system. Here we report that chronic, systemic application of GLP-1 (9-36) in adult mice facilitated both the induction and maintenance phases of hippocampal long-term potentiation (LTP), a major form of synaptic plasticity. In contrast, spatial learning and memory, as assessed by the Morris water maze test, was not altered by GLP-1 (9-36) administration. At the molecular level, GLP-1 (9-36) reduced protein levels of the potassium channel Kv4.2 in hippocampus, which is linked to elevated dendritic membrane excitability. Moreover, GLP-1(9-36) treatment inhibited phosphorylation of mRNA translational factor eEF2, which is associated with increased capacity for de novo protein synthesis. Finally, we showed that the LTP-enhancing effects by GLP-1 (9-36) treatment in vivo were blunted by application of exendin(9-39)amide [EX(9-39)], the GLP-1 receptor (GLP-1R) antagonist, suggesting its role as a GLP-1R agonist. These findings demonstrate that GLP-1 (9-36), which was considered a "bio-inactive" peptide, clearly exerts physiological effects on neuronal plasticity in the hippocampus, a brain region critical for learning and memory.


Assuntos
Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Hipocampo/metabolismo , Potenciação de Longa Duração/fisiologia , Peptídeos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Canais de Potássio Shal/metabolismo , Animais , Western Blotting , Fármacos do Sistema Nervoso Central/administração & dosagem , Feminino , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Endogâmicos C57BL , Peptídeos/administração & dosagem , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Memória Espacial/efeitos dos fármacos , Memória Espacial/fisiologia , Técnicas de Cultura de Tecidos
14.
Environ Sci Technol ; 49(13): 8228-36, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26038975

RESUMO

Selenium (Se) reservoirs in coal waste rock from the Elk Valley, southeastern British Columbia, the location of Canada's major steelmaking coal mines, were characterized and quantified by analyzing samples collected from the parent rock, freshly blasted waste rock (less than 10 days old), and aged waste rock (deposited between 1982 and 2012). Se is present throughout the waste rock dumps at a mean digestible (SeD) concentration of 3.12 mg/kg. Microprobe analyses show that Se is associated with the primary minerals sphalerite, pyrite, barite, and chalcopyrite and secondary Fe oxyhydroxides. Selenium K-edge X-ray absorption near-edge spectroscopy analyses indicate that, on average, 21% of Se is present as selenide (Se(2-)) in pyrite and sphalerite, 19% of Se is present as selenite (Se(4+)) in barite, 21% of Se is present as exchangeable Fe oxyhydroxide and clay-adsorbed Se(4+), and 39% of Se is present as organoselenium associated with coaly matter. The dominant source minerals for aqueous-phase Se are pyrite and sphalerite. Secondary Fe oxyhydroxide sequesters, on average, 37% of Se released by pyrite oxidation. Measured long-term Se fluxes from a rock drain at the base of a waste dump suggest that at least 20% of Se(2-)-bearing sulfides were oxidized and released from that dump over the past 30 year period; however, the Se mass lost was not evident in SeD analyses.


Assuntos
Carvão Mineral/análise , Sedimentos Geológicos/química , Selênio/análise , Resíduos/análise , Colúmbia Britânica , Geografia , Análise de Componente Principal , Espectroscopia por Absorção de Raios X
15.
Lancet Oncol ; 15(3): 323-32, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24508103

RESUMO

BACKGROUND: In the BRIM-3 trial, vemurafenib was associated with risk reduction versus dacarbazine of both death and progression in patients with advanced BRAF(V600) mutation-positive melanoma. We present an extended follow-up analysis of the total population and in the BRAF(V600E) and BRAF(V600K) mutation subgroups. METHODS: Patients older than 18 years, with treatment-naive metastatic melanoma and whose tumour tissue was positive for BRAF(V600) mutations were eligible. Patients also had to have a life expectancy of at least 3 months, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and adequate haematological, hepatic, and renal function. Patients were randomly assigned by interactive voice recognition system to receive either vemurafenib (960 mg orally twice daily) or dacarbazine (1000 mg/m(2) of body surface area intravenously every 3 weeks). Coprimary endpoints were overall survival and progression-free survival, analysed in the intention-to-treat population (n=675), with data censored at crossover. A sensitivity analysis was done. This trial is registered with ClinicalTrials.gov, NCT01006980. FINDINGS: 675 eligible patients were enrolled from 104 centres in 12 countries between Jan 4, 2010, and Dec 16, 2010. 337 patients were randomly assigned to receive vemurafenib and 338 to receive dacarbazine. Median follow-up was 12·5 months (IQR 7·7-16·0) on vemurafenib and 9·5 months (3·1-14·7) on dacarbazine. 83 (25%) of the 338 patients initially randomly assigned to dacarbazine crossed over from dacarbazine to vemurafenib. Median overall survival was significantly longer in the vemurafenib group than in the dacarbazine group (13·6 months [95% CI 12·0-15·2] vs 9·7 months [7·9-12·8]; hazard ratio [HR] 0·70 [95% CI 0·57-0·87]; p=0·0008), as was median progression-free survival (6·9 months [95% CI 6·1-7·0] vs 1·6 months [1·6-2·1]; HR 0·38 [95% CI 0·32-0·46]; p<0·0001). For the 598 (91%) patients with BRAF(V600E) disease, median overall survival in the vemurafenib group was 13·3 months (95% CI 11·9-14·9) compared with 10·0 months (8·0-14·0) in the dacarbazine group (HR 0·75 [95% CI 0·60-0·93]; p=0·0085); median progression-free survival was 6·9 months (95% CI 6·2-7·0) and 1·6 months (1·6-2·1), respectively (HR 0·39 [95% CI 0·33-0·47]; p<0·0001). For the 57 (9%) patients with BRAF(V600K) disease, median overall survival in the vemurafenib group was 14·5 months (95% CI 11·2-not estimable) compared with 7·6 months (6·1-16·6) in the dacarbazine group (HR 0·43 [95% CI 0·21-0·90]; p=0·024); median progression-free survival was 5·9 months (95% CI 4·4-9·0) and 1·7 months (1·4-2·9), respectively (HR 0·30 [95% CI 0·16-0·56]; p<0·0001). The most frequent grade 3-4 events were cutaneous squamous-cell carcinoma (65 [19%] of 337 patients) and keratoacanthomas (34 [10%]), rash (30 [9%]), and abnormal liver function tests (38 [11%]) in the vemurafenib group and neutropenia (26 [9%] of 287 patients) in the dacarbazine group. Eight (2%) patients in the vemurafenib group and seven (2%) in the dacarbazine group had grade 5 events. INTERPRETATION: Inhibition of BRAF with vemurafenib improves survival in patients with the most common BRAF(V600E) mutation and in patients with the less common BRAF(V600K) mutation. FUNDING: F Hoffmann-La Roche-Genentech.


Assuntos
Indóis/uso terapêutico , Melanoma/tratamento farmacológico , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , Sulfonamidas/uso terapêutico , Adulto , Idoso , Dacarbazina/uso terapêutico , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Indóis/efeitos adversos , Masculino , Melanoma/genética , Melanoma/mortalidade , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sulfonamidas/efeitos adversos , Vemurafenib
16.
Muscle Nerve ; 49(6): 879-86, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24037782

RESUMO

INTRODUCTION: Inter-individual variability in measurements of muscle strength and its determinants was identified to: (1) produce a normative data set describing the normal range and (2) determine whether some measurements are more informative than others when evaluating inter-individual differences. METHODS: Functional and morphological characteristics of the vastus lateralis were measured in 73 healthy, untrained adult men. RESULTS: Inter-individual variability (coefficient of variation) was greater for isometric maximal voluntary contraction (MVC) torque (18.9%) compared with fascicle force (14.6%; P=0.025) and physiological cross-sectional area (PCSA; 17.2%) compared with anatomical cross-sectional area (ACSA, 13.0%; P<0.0005). The relationship between ACSA and isometric MVC torque (r(2) =0.56) was weaker than that between PCSA and fascicle force (r(2) =0.68). CONCLUSIONS: These results provide a normative data set on inter-individual variability in a variety of muscle strength-related measurements and illustrate the benefit of using more stringent measures of muscle properties. Muscle Nerve 49: 879-886, 2014.


Assuntos
Dinamômetro de Força Muscular , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Humanos , Contração Isométrica/fisiologia , Masculino , Contração Muscular/fisiologia , Valores de Referência , Adulto Jovem
17.
Clin J Sport Med ; 23(5): 384-91, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23657122

RESUMO

OBJECTIVE: To compare the effectiveness of a combination of vibration and wobble board training against wobble board training alone in footballers suffering from functional ankle instability (FAI). DESIGN: A 2 × 3 prefactorial-postfactorial design. SETTING: University research laboratory. PARTICIPANTS: Thirty-three male semiprofessional footballers with self-reported unilateral FAI were randomly assigned in 3 groups: vibration and wobble board (mean age 22.2 years), wobble board (mean age 22.7 years), and control (mean age 23.1 years). INTERVENTIONS: Participants in each intervention group performed a 6-week progressive rehabilitation program using a wobble board, either with or without the addition of vibration stimulus. MAIN OUTCOME MEASURES: Absolute center of mass (COM) distribution during single-leg stance, modified star excursion balance test (SEBT) reach distances, and single-leg triple hop for distance (SLTHD) were measured before and after 6-week intervention. RESULTS: Combined vibration and wobble board training resulted in reduced COM distribution [P ≤ 0.001, effect size (ES) = 0.66], increased SEBT reach distances (P ≤ 0.01 and P ≤ 0.002, ES = 0.19 and 0.29, respectively), and increased SLTHD (P ≤ 0.001, ES = 0.33) compared with wobble board training alone during the course of the 6-week training intervention. CONCLUSIONS: Combined vibration and wobble board training improves COM distribution, modified SEBT scores, and SLTHD among footballers suffering FAI compared with wobble board training alone.


Assuntos
Traumatismos do Tornozelo/reabilitação , Traumatismos em Atletas/reabilitação , Futebol Americano/lesões , Instabilidade Articular/reabilitação , Terapia por Exercício , Humanos , Masculino , Vibração , Adulto Jovem
18.
J Low Genit Tract Dis ; 17(1): 51-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22885641

RESUMO

OBJECTIVE: High-risk human papillomavirus (HR-HPV) persistence is thought to be necessary for the development of cervical cancer. Because not all cases of low-grade squamous intraepithelial lesion (LSIL) or higher-grade squamous intraepithelial lesion are associated with HR-HPV, detection of HR-HPV in women with these cervical abnormalities may be clinically useful for management. The aim of this study was to detect HR-HPV in women with LSIL or higher-grade cytology. MATERIALS AND METHODS: In a multicenter, prospective clinical study, residual liquid-based cytological specimens from 3,966 US women were analyzed. Women with LSIL or higher-grade cytology underwent colposcopy and cervical biopsy as clinically indicated. The test was used to detect HR-HPV in women with cytologically diagnosed LSIL or higher, with histological confirmation of cervical intraepithelial neoplasia 2 (CIN 2) or worse by a central review panel. RESULTS: Among subjects with LSIL or higher-grade cytology and complete data sets, 11.8% (41/347) were diagnosed with CIN 2 or worse; 82.1% (285/347) were HR-HPV positive. The prevalence of CIN 2 or worse and CIN 3 or worse was 14.4% (41/285) and 7.0% (20/285), respectively, among subjects who were HR-HPV positive. All subjects diagnosed with CIN 2 or worse (41/41) and CIN 3 or worse (20/20) tested positive for HR-HPV. Sensitivity and negative predictive value calculated for CIN 2 or worse were 100% (95% CI = 91.4%-100.0%) and 100% (95% CI = 94.2%-100.0%), respectively. Specificity and positive predictive value among these subjects were 20.3% (95% CI = 16.1%-25.1%) and 14.4% (95% CI = 10.8%-18.9%), respectively. CONCLUSIONS: Detection of HR-HPV in women with LSIL or higher-grade cytology using the HPV HR test may allow clinicians to further triage women for advanced clinical management.


Assuntos
Carcinoma in Situ/virologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Carcinoma in Situ/patologia , Colposcopia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Estados Unidos , Neoplasias do Colo do Útero/patologia , Adulto Jovem
19.
J Strength Cond Res ; 27(8): 2055-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23222085

RESUMO

Hypoxia-inducible factor-1α (encoded by HIF1A gene) controls a number of genes that are implicated in various cellular functions including glycolysis and cell proliferation and differentiation. The rs11549465 C > T polymorphism in the HIF1A gene, which produces the amino acid substitution Pro582Ser, increases protein stability and transcriptional activity and, therefore, improves glucose metabolism. The aim of our study was to investigate the association between the HIF1A Pro582Ser polymorphism and elite strength athlete status. A total of 208 Russian strength athletes (122 weightlifters and 86 wrestlers) of regional or national competitive standard and 1,413 controls were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. We found that the frequency of the HIF1A 582Ser variant was significantly higher in weightlifters (13.1%, p = 0.0031) and wrestlers (15.7%, p = 0.0002) compared with the controls (7.5%). Additionally, the highest (21.1%, p = 0.0052) frequency of the 582Ser variant was found in a group of elite strength athletes. Thus, our study provides evidence for an association between the HIF1A gene Pro582Ser polymorphism and elite strength athlete status. Although more replication studies are needed, the preliminary data suggest an opportunity to use the analysis of HIF1A polymorphism along with other gene variations and standard phenotypic assessment in sports selection.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Força Muscular/genética , Levantamento de Peso/fisiologia , Luta Romana/fisiologia , Adulto , Desempenho Atlético/fisiologia , Estudos de Casos e Controles , Feminino , Genótipo , Glicólise/genética , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Federação Russa
20.
Eur J Sport Sci ; 23(5): 726-735, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35293840

RESUMO

There is growing evidence of genetic contributions to tendon and ligament pathologies. Given the high incidence and severity of tendon and ligament injuries in elite rugby, we studied whether 13 gene polymorphisms previously associated with tendon/ligament injury were associated with elite athlete status. Participants from the RugbyGene project were 663 elite Caucasian male rugby athletes (RA) (mean (standard deviation) height 1.85 (0.07) m, mass 101 (12) kg, age 29 (7) yr), including 558 rugby union athletes (RU) and 105 rugby league athletes. Non-athletes (NA) were 909 Caucasian men and women (56% female; height 1.70 (0.10) m, mass 72 (13) kg, age 41 (23) yr). Genotypes were determined using TaqMan probes and groups compared using Χ2 and odds ratio (OR). COLGALT1 rs8090 AA genotype was more frequent in RA (27%) than NA (23%; P = 0.006). COL3A1 rs1800255 A allele was more frequent in RA (26%) than NA (23%) due to a greater frequency of GA genotype (39% vs 33%). For MIR608 rs4919510, RA had 1.7 times the odds of carrying the CC genotype compared to NA. MMP3 rs591058 TT genotype was less common in RA (25.1%) than NA (31.2%; P < 0.04). For NID1 rs4660148, RA had 1.6 times the odds of carrying the TT genotype compared to NA. It appears that elite rugby athletes have an inherited advantage that contributes to their elite status, possibly via resistance to soft tissue injury. These data may, in future, assist personalised management of injury risk amongst athletes.Highlights The elite rugby athletes we studied had differing genetic characteristics to non-athletes regarding genetic variants previously associated with soft-tissue injury risk.COLGALT1 rs8090, COL3A1 rs1800255, MIR608 rs4919510, MMP3 rs591058 and NID1 rs4660148 were all associated with elite status in rugby.We propose that elite rugby athletes might possess an inherited resistance to soft tissue injury, which has enabled them to achieve elite status despite exposure to the high-risk environment of elite rugby.


Assuntos
Futebol Americano , MicroRNAs , Lesões dos Tecidos Moles , Humanos , Masculino , Feminino , Adulto , Metaloproteinase 3 da Matriz , Rugby , Alelos , Lesões dos Tecidos Moles/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA