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AIM: In postmenopause, ovarian decline along with sedentary lifestyle could contribute to the loss of lean body mass (LBM) and muscle strength. This study aimed to verify whether exercise and isoflavones could have additive effects on muscle quality, muscle mass index, relative strength and physical capacity in overweight sedentary postmenopausal women. METHOD: We recruited 70 overweight-to-obese (body mass index 32.2±4.8 kg/m(2)) postmenopausal women (59±5 years old) to participate in a 6-month clinical study combining isoflavones (70 mg/day) and exercise (resistance and aerobic training) treatments. Subjects were divided into four groups: (1) placebo (n =15), (2) isoflavones (n =15), (3) exercise and placebo (n =20), and (4) exercise and isoflavone (n =20). Principal outcome variables included maximal muscle strength (1RM) at the leg press and the bench press, muscle mass index, muscle quality in the legs and relative strength. RESULTS: After 6 months of training, exercise produced 49% and 23% increases, respectively, in leg press and bench press 1RM (p ≤0.01). Leg relative strength and muscle quality increased by more than 50% (both p <0.01), while muscle mass index increased by 7% (p <0.05) in both exercise groups only. CONCLUSION: Exercise training can improve muscle tissue strength, function and quality in sedentary postmenopausal women. Isoflavones, irrespective of exercise, did not produce changes in these variables. From a clinical perspective, these results suggest that overweight women could reduce the risks of mobility impairments, even in the absence of weight loss, by following a sound exercise intervention that includes both resistance and aerobic training at a high intensity.
Assuntos
Ciclismo/fisiologia , Isoflavonas/administração & dosagem , Aptidão Física , Fitoestrógenos/administração & dosagem , Pós-Menopausa/fisiologia , Treinamento Resistido , Tolerância ao Exercício , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular/efeitos dos fármacos , Músculo Esquelético/fisiologia , Sobrepeso/terapia , Comportamento Sedentário , Glycine maxRESUMO
BACKGROUND: Postmenopausal women seem to favor alternative therapies such as exercise and phytoestrogens as a substitute for potentially harmful hormone replacement therapy. Based on previous research, we hypothesized that phytoestrogens combined with exercise could have a synergic effect on women's health. OBJECTIVE: To verify whether phytoestrogens enhance the response to mixed training regarding menopausal symptoms and quality of life in postmenopausal women. METHODS: From a pool of women participating in a 6-month randomized, controlled exercise study, 21 received a placebo (mean age 58.3 ± 5.4 years, body mass index 29.8 ± 5.1 kg/m(2)) and 19 received phytoestrogen supplements (mean age 60.1 ± 3.4 years; body mass index 30.3 ± 4.6 kg/m(2)). Body weight, fat mass and lean body mass (dual-energy X-ray absorptiometry) were assessed. Quality of life was estimated by the Short Form-36 (SF-36) and Perceived Stress Scale-10 (PSS-10) questionnaires, and menopausal symptoms by the Kupperman index. All measurements were performed before and after the intervention. RESULTS: Although the Kupperman index and PSS-10 remained unchanged in both groups, the SF-36 Physical Component Summary and almost all the SF-36 subscales (except for role-emotional and mental health) increased only in the exercise group taking phytoestrogens (0.001 < p < 0.04). CONCLUSION: While phytoestrogens combined with mixed exercise were not sufficient to improve menopausal symptoms, it seemed to be a better strategy than exercise alone to improve the general quality of life in postmenopausal women.
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Exercício Físico , Obesidade/complicações , Fitoestrógenos/administração & dosagem , Pós-Menopausa , Qualidade de Vida , Índice de Massa Corporal , Suplementos Nutricionais , Feminino , Fogachos/epidemiologia , Fogachos/terapia , Humanos , Pessoa de Meia-Idade , Sobrepeso/complicações , PlacebosRESUMO
This cross-sectional study proposes two relative strength indexes in order to evaluate the risks of lower mobility in healthy older adults: 1) handgrip strength on body mass index and 2) quadriceps strength on body weight. Nine hundred and four men and women aged between 67-84 years old were tested for body composition, muscle strength and mobility function. Individuals in the lowest and middle tertiles of relative handgrip strength were respectively 2.2 (1.3-3.7) and 4.4 (2.6-7.6) more likely to have a lower mobility score. As for relative quadriceps strength, odd ratios for lowest and middle tertiles were respectively 2.8 (1.6-4.9) and 6.9 (3.9-12.1). Relative strength indexes, either using handgrip strength or quadriceps strength, are convenient to use in large scale studies and clinical practice.
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Envelhecimento/fisiologia , Índice de Massa Corporal , Avaliação Geriátrica/métodos , Força da Mão , Limitação da Mobilidade , Força Muscular , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Razão de Chances , Músculo Quadríceps/fisiologia , RiscoRESUMO
Capillary electrophoresis (CE) was used to monitor the laser-induced conversion of supercoiled pKOL8UV5 plasmid DNA into nicked conformers. The plasmid samples (0.1 mg/ml) were incubated in the absence or presence of 110 mumol/l ethidium bromide (EB) and then exposed to 100 J of argon laser radiation (488 nm). The nicked, open circular conformers were separated from the supercoiled DNA by a 15% increase in retention time. Approximately 90% of the control DNA was in the supercoiled form. Laser radiation in the presence of EB caused complete conversion of the supercoiled plasmid DNA into nicked conformers. Laser-induced fluorescence CE (LIF-CE) was about 100-fold more sensitive than UV-CE in the detection of these conformers. Agarose gel electrophoresis confirmed these findings and showed the presence of the nicked plasmid conformers. Based on these comparisons, CE is an efficient analytical tool for the identification of laser-induced conformational changes in plasmid DNA.
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DNA Recombinante/efeitos da radiação , Eletroforese Capilar/métodos , Dano ao DNA , DNA Recombinante/metabolismo , Lasers , Fotólise , Espectrofotometria UltravioletaRESUMO
Planar optical waveguides are an attractive tool for use in analytical chemistry and spectroscopy. Although similar to fiber optics, planar waveguides have been slow to be commercially accepted due to the difficulty of coupling light into the guide. Generally, prism coupling is the method of choice in the laboratory, as efficiencies approaching 80% can be reached. However, prisms are impractical for routine use for several reasons: expensive positioning equipment is required, coupled power is sensitive to environmental fluctuations, and prism coupling prohibits the fabrication of a truly planar device. The use of thin gratings on the surface of the waveguide allows for a two-dimensional structure to be maintained, while providing enough efficiency to be useful as a sensor. Our research efforts focus on developing a technique to make inexpensive, reproducible gratings that are easy to fabricate. By chemically modifying the surface of a commercial grating with a suitable release agent, it is possible to emboss replica gratings onto a variety of waveguide types. The fabrication of embossed gratings will be described, and their performance on glass, ion-diffused, polymer, and semiconductor waveguides will be presented.
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A solid-phase competitive immunoassay is performed in flow injection analysis for the measurement of the hormone 17-beta-estradiol. The flow injection analysis system incorporates a column-type reactor packed with solid silica particles onto which we have covalently immobilized the antigen 17-beta-estradiol. Anti-estradiol is noncovalently conjugated to the liposome through a streptavidin-biotin linkage. When mixed with a sample containing the antigen, the antibody binding sites on the liposomes are complexed which reduces the binding of liposomes to the solid support in a concentration-dependent manner. Sequential immunoassays are performed on-column following a simple regeneration step.
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The use of liposomes as detectable reagents in solid-phase immunoassays has been explored in a flow injection immunoanalysis (FIIA) system. Model calculations are presented for FIIA based on the competitive binding of univalent analyte and multivalent liposomes to immobilized antibodies. Parameters such as binding constants, concentrations of liposomes and antibody, and steric hindrance are considered for their relative effects on detectable liposome signal response to analyte concentrations. Qualitative comparisons of the model with the experimental data are made.