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2.
Med Eng Phys ; 31(8): 959-63, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19540146

RESUMO

The bio-impedance technique provides a safe, low-cost and non-invasive alternative for lung fluid level monitoring. Here we have investigated the feasibility of a novel bio-impedance system in measuring pulmonary congestion in elderly patients suffering from congestive heart failure (CHF). The system employed a parametric reconstruction algorithm to assess mean lung resistivity. Fourteen patients were studied before and following treatment to reduce lung congestion. Significant correlation was found between the changes of radiographic scores and resistivity values following treatment (R=0.57, p<0.04). A significant difference in resistivity values between patients having low and high congestion degrees was also demonstrated (p<0.01). Moreover, the bio-impedance technique successfully diagnosed an improvement of congestion level in 10 out of 14 patients, while the radiographic score indicated such an improvement in only 5 out of the 14 patients. These results, along with our previous validation studies, suggest that the bio-impedance technique is a feasible bedside system for monitoring of pulmonary congested patients, thus facilitating effective treatment strategies.


Assuntos
Pneumopatias/diagnóstico , Idoso , Impedância Elétrica , Eletrodos , Feminino , Insuficiência Cardíaca/complicações , Humanos , Pneumopatias/complicações , Pneumopatias/diagnóstico por imagem , Pneumopatias/fisiopatologia , Masculino , Radiografia , Reprodutibilidade dos Testes
3.
J Clin Endocrinol Metab ; 90(2): 855-63, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15522925

RESUMO

Previous studies of Delta 4-androstene-3,17-dione (4-androstenedione) administration in men have not demonstrated sustained increments in testosterone levels, fat-free mass (FFM), and muscle strength, and failure to demonstrate androstenedione's androgenic/anabolic effects has stifled efforts to regulate its sales. To determine whether 4-androstenedione has androgenic/anabolic properties, we evaluated its association with androgen receptor (AR) and its effects on myogenesis in vitro. Additionally, we studied the effects of a high dose of 4-androstenedione on testosterone levels, FFM, and muscle strength in hypogonadal men. We determined the dissociation constant (K(d)) for 4-androstenedione using fluorescence anisotropy measurement of competitive displacement of fluorescent androgen from AR ligand-binding domain. AR nuclear translocation and myogenic activity of androstenedione were evaluated in mesenchymal, pluripotent C3H10T1/2 cells, in which androgens stimulate myogenesis through an AR pathway. We determined effects of a high dose of androstenedione (500 mg thrice daily) given for 12 wk on FFM, muscle strength, and hormone levels in nine healthy, hypogonadal men. 4-Androstenedione competitively displaced fluorescent androgen from AR ligand-binding domain with a lower affinity than dihydrotestosterone (K(d), 648 +/- 21 and 10 +/- 0.4 nm, respectively). In C3H10T1/2 cells, 4-androstenedione caused nuclear translocation of AR and stimulated myogenesis, as indicated by a dose-dependent increase in myosin heavy chain II+ myotube area and up-regulation of MyoD protein. Stimulatory effects of 4-androstenedione on myosin heavy chain II+ myotubes and myogenic determination factor expression were attenuated by bicalutamide, an AR antagonist. Administration of 1500 mg 4-androstenedione daily to hypogonadal men significantly increased serum androstenedione, total and free testosterone, estradiol, and estrone levels and suppressed SHBG and high-density lipoprotein cholesterol levels. 4-androstenedione administration was associated with significant gains in FFM (+1.7 +/- 0.5 kg; P = 0.012) and muscle strength in bench press (+4.3 +/- 3.1 kg; P = 0.006) and leg press exercises (+18.8 +/- 17.3 kg; P = 0.045). 4-androstenedione is an androgen that binds AR, induces AR nuclear translocation, and promotes myogenesis in vitro, with substantially lower potency than dihydrotestosterone. 4-androstenedione administration in high doses to hypogonadal men increases testosterone levels, FFM, and muscle strength, although at the dose tested, the anabolic effects in hypogonadal men are likely because of its conversion to testosterone.


Assuntos
Androstenodiona/uso terapêutico , Hipogonadismo/fisiopatologia , Músculo Esquelético/fisiopatologia , Receptores Androgênicos/metabolismo , Testosterona/sangue , Células 3T3 , Adulto , Androstenodiona/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Humanos , Hipogonadismo/classificação , Hipogonadismo/tratamento farmacológico , Cinética , Ligantes , Masculino , Camundongos , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Valores de Referência
4.
Am J Physiol Endocrinol Metab ; 284(1): E120-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12388137

RESUMO

To determine whether oxymetholone increases lean body mass (LBM) and skeletal muscle strength in older persons, 31 men 65-80 yr of age were randomized to placebo (group 1) or 50 mg (group 2) or 100 mg (group 3) daily for 12 wk. For the three groups, total LBM increased by 0.0 +/- 0.6, 3.3 +/- 1.2 (P < 0.001), and 4.2 +/- 2.4 kg (P < 0.001), respectively. Trunk fat decreased by 0.2 +/- 0.4, 1.7 +/- 1.0 (P = 0.018), and 2.2 +/- 0.9 kg (P = 0.005) in groups 1, 2, and 3, respectively. Relative increases in 1-repetition maximum (1-RM) strength for biaxial chest press of 8.2 +/- 9.2 and 13.9 +/- 8.1% in the two active treatment groups were significantly different from the change (-0.8 +/- 4.3%) for the placebo group (P < 0.03). For lat pull-down, 1-RM changed by -0.6 +/- 8.3, 8.8 +/- 15.1, and 18.4 +/- 21.0% for the groups, respectively (1-way ANOVA, P = 0.019). The pattern of changes among the groups for LBM and upper-body strength suggested that changes might be related to dose. Alanine aminotransferase increased by 72 +/- 67 U/l in group 3 (P < 0.001), and HDL-cholesterol decreased by -19 +/- 9 and -23 +/- 18 mg/dl in groups 2 and 3, respectively (P = 0.04 and P = 0.008). Thus oxymetholone improved LBM and maximal voluntary muscle strength and decreased fat mass in older men.


Assuntos
Anabolizantes/administração & dosagem , Composição Corporal/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Oximetolona/administração & dosagem , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Glicemia/análise , Método Duplo-Cego , Jejum , Humanos , Insulina/sangue , Lipídeos/sangue , Hormônio Luteinizante/sangue , Masculino , Avaliação Nutricional , Placebos , Globulina de Ligação a Hormônio Sexual/análise , Testosterona/sangue
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