Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Eur J Appl Physiol ; 124(4): 1239-1252, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37987923

RESUMO

PURPOSE: The systolic blood pressure/workload (SBP/MET) slope was recently reported to be a reliable parameter to identify an exaggerated blood pressure response (eBPR) in the normal population and in athletes. However, it is unclear whether an eBPR correlates with central blood pressure (CBP) and vascular function in elite athletes. METHODS: We examined 618 healthy male elite athletes (age 25.8 ± 5.1 years) of mixed sports with a standardized maximum exercise test. CBP and vascular function were measured non-invasively with a validated oscillometric device. The SBP/MET slope was calculated and the threshold for an eBPR was set at > 6.2 mmHg/MET. Two groups were defined according to ≤ 6.2 and > 6.2 mmHg/MET, and associations of CBP and vascular function with the SBP/MET slope were compared for each group. RESULTS: Athletes with an eBPR (n = 180, 29%) displayed a significantly higher systolic CBP (102.9 ± 7.5 vs. 100 ± 7.7 mmHg, p = 0.001) but a lower absolute (295 ± 58 vs. 384 ± 68 W, p < 0.001) and relative workload (3.14 ± 0.54 vs. 4.27 ± 1.1 W/kg, p < 0.001) compared with athletes with a normal SBP/MET slope (n = 438, 71%). Systolic CBP was positively associated with the SBP/MET slope (r = 0.243, p < 0.001). In multiple logistic regression analyses, systolic CBP (odds ratio [OR] 1.099, 95% confidence interval [CI] 1.045-1.155, p < 0.001) and left atrial volume index (LAVI) (OR 1.282, CI 1.095-1.501, p = 0.002) were independent predictors of an eBPR. CONCLUSION: Systolic CBP and LAVI were independent predictors of an eBPR. An eBPR was further associated with a lower performance level, highlighting the influence of vascular function on the BPR and performance of male elite athletes.


Assuntos
Hipertensão , Esportes , Humanos , Masculino , Adulto Jovem , Adulto , Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Atletas , Esportes/fisiologia , Teste de Esforço
2.
Eur J Appl Physiol ; 124(5): 1487-1497, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38133663

RESUMO

PURPOSE: Physical exercise is crucial for healthy aging and plays a decisive role in the prevention of atherosclerotic cardiovascular disease (ASCVD). A higher level of cardiorespiratory fitness (CRF) in the elderly is associated with lower cardiovascular and all-cause mortality. This study investigated the association of CRF level with vascular function and cardiovascular risk factors in the elderly. METHODS: We examined 79 apparently healthy and physically active subjects aged > 55 years (64 ± 4 years). Cardiovascular functional parameters assessed included brachial and central blood pressure (BP), pulse wave velocity (PWV), augmentation index (Aix), and ankle-brachial index. Sonography of the common carotid artery was performed. CRF level was determined by a cardiopulmonary exercise test, and everyday activity was quantified with an accelerometer. RESULTS: All participants had a higher CRF level than the reported age-specific normative values. Twenty-nine subjects had subclinical atherosclerosis of the common carotid artery. Compared with participants without atherosclerosis, they were older (p = 0.007), displayed higher brachial systolic BP (p = 0.006), and higher central systolic BP (p = 0.014). Lower brachial (p = 0.036) and central (p = 0.003) systolic BP, lower PWV (p = 0.004), lower Aix (p < 0.001), lower body fat percentage (< 0.001), and lower LDL cholesterol (p = 0.005) were associated with a higher CRF level. CONCLUSIONS: In this cohort of healthy and physically active individuals, subjects with subclinical atherosclerosis displayed higher systolic brachial and central BP. A higher CRF level was associated with enhanced vascular function, consistent with an influence of CRF on both BP and vascular function in the elderly.


Assuntos
Aterosclerose , Aptidão Cardiorrespiratória , Humanos , Masculino , Feminino , Aptidão Cardiorrespiratória/fisiologia , Pessoa de Meia-Idade , Aterosclerose/fisiopatologia , Idoso , Pressão Sanguínea/fisiologia , Análise de Onda de Pulso , Índice Tornozelo-Braço , Rigidez Vascular/fisiologia
3.
Biointerphases ; 18(6)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38063476

RESUMO

Protein adsorption behavior can play a critical role in defining the outcome of a material by affecting the subsequent in vivo response to it. To date, the effect of surface properties on protein adsorption behavior has been mainly focused on surface chemistry, but research on the effect of nanoscale surface topography remains limited. In this study, the adsorption behavior of human serum albumin, immunoglobulin G, and fibrinogen in terms of the adsorbed amount and conformational changes were investigated on bare and anodized titanium (Ti) samples (40 and 60 V applied voltages). While the surface chemistry, RMS surface roughness, and arithmetic surface roughness of the anodized samples were similar, they had distinctly different nanomorphologies identified by atomic force microscopy and scanning electron microscopy, and the surface statistical parameters, surface skewness Ssk and kurtosis Sku. The Feret pore size distribution was more uniform on the 60 V sample, and surface nanostructures were more symmetrical with higher peaks and deeper pores. On the other hand, the 40 V sample surface presented a nonuniform pore size distribution and asymmetrical surface nanostructures with lower peaks and shallower pores. The amount of surface-adsorbed protein increased on the sample surfaces in the order of Ti < 40 V < 60 V with the predominant factor affecting the amount of surface-adsorbed protein being the increased surface area attained by pore formation. The secondary structure of all adsorbed proteins deviated from that of their native counterparts. While comparing the secondary structure components of proteins on anodized surfaces, it was observed that all three proteins retained more of their secondary structure composition on the surface with more uniform and symmetrical nanofeatures than the surface having asymmetrical nanostructures. Our results suggest that the nanomorphology of the peaks and outer walls of the nanotubes can significantly influence the conformation of adsorbed serum proteins, even for surfaces having similar roughness values.

4.
Mater Sci Eng C Mater Biol Appl ; 131: 112474, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34857260

RESUMO

Plasma-based strategies offer several advantages for developing antibacterial biomaterials and can be used directly or combined with other surface modification techniques. Direct plasma strategies can be classified as plasma surface modifications that derive antibacterial property by tailoring surface topography or surface chemistry. Nano patterns induced by plasma modification can exhibit antibacterial property and promote the adhesion and proliferation of mammalian cells, creating antibacterial and biocompatible surfaces. Antibacterial effect by tailoring surface chemistry via plasma can be attained by either creating bacteriostatic surfaces or bactericidal surfaces. Plasma-assisted strategies incorporate plasma processes in combination with other surface modification techniques. Plasma coating can serve as a drug-eluting reservoir and diffusion barrier. The plasma-functionalized surface can serve as a platform for grafting antibacterial agents, and plasma surface activation can improve the adhesion of polymeric layers with antibacterial properties. This article critically reviews plasma-based strategies reported in the recent literature for the development of antibacterial biomaterial surfaces. Studies using both atmospheric and low-pressure plasmas are included in this review. The findings are discussed in terms of the trends in material and precursor selection, modification stability, antibacterial efficacy, the choice of bacterial strains tested, cell culture findings, critical aspects of in vitro performance testing and in vivo experimental design.


Assuntos
Antibacterianos , Preparações Farmacêuticas , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Polímeros , Propriedades de Superfície
5.
Sports Med Int Open ; 5(2): E45-E52, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33889714

RESUMO

Workload-indexed blood pressure response (wiBPR) to exercise has been shown to be superior to peak systolic blood pressure (SBP) in predicting mortality in healthy men. Thus far, however, markers of wiBPR have not been evaluated for athletes and the association with vascular function is unclear. We examined 95 male professional athletes (26±5 y) and 30 male controls (26±4 y). We assessed vascular functional parameters at rest and wiBPR with a graded bicycle ergometer test and compared values for athletes with those of controls. Athletes had a lower pulse wave velocity (6.4±0.9 vs. 7.2±1.5 m/s, p=0.001) compared to controls. SBP/Watt slope (0.34±0.13 vs. 0.44±0.12 mmHg/W), SBP/MET slope (6.2±1.8 vs. 7.85±1.8 mmHg/MET) and peak SBP/Watt ratio (0.61±0.12 vs. 0.95±0.17 mmHg/W) were lower in athletes than in controls (p<0.001). The SBP/Watt and SBP/MET slope in athletes were comparable to the reference values, whereas the peak SBP/Watt-ratio was lower. All vascular functional parameters measured were not significantly correlated to the wiBPR in either athletes or controls. In conclusion, our findings indicate the potential use of the SBP/Watt and SBP/MET slope in pre-participation screening of athletes. Further, vascular functional parameters, measured at rest, were unrelated to the wiBPR in athletes and controls.

6.
Colloids Surf B Biointerfaces ; 89: 289-94, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21962854

RESUMO

Amphoteric surfaces were generated on silicone substrates via plasma polymerization technique using a single monomer; diethyl allyl phosphate (DAP). Surface characterization was performed by the means of contact angle titration and Fourier transform infrared (FTIR) spectroscopy. The surface of silicone was found to be slightly basic with an apparent basicity of 0.12 µmol/m(2) while plasma surface modification made the surfaces amphoteric with the surface acid/base concentration adjustable by varying plasma parameters. The adsorption of model protein; bovine serum albumin (BSA) on the surfaces was found to be correlated to the surface acid/base ratio. Percent reduction on modified surfaces compared to bare silicone surface was 32, 59 and 92% for 20 W 5 min, 60 W 5 min and 100 W 5 min modified surfaces respectively. Conformational change of BSA upon adsorption to the surfaces was investigated with FTIR-ATR spectroscopy. It has been shown that BSA preserves more of its secondary structure upon adsorption to plasma modified surfaces than the bare silicone surface. It has been concluded that DAP modified surfaces reduces the amount of protein adsorption on the surfaces due to the modified surfaces amphoteric nature and the ability of modified surfaces to preserve the secondary structure of adsorbed protein better than the bare silicone surface.


Assuntos
Soroalbumina Bovina/química , Propriedades de Superfície , Adsorção , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA