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1.
J Clin Endocrinol Metab ; 96(9): E1491-5, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21752884

RESUMO

CONTEXT: Many factors influence the concentration of circulating testosterone and its primary binding protein, SHBG. However, little is known about the genetic contribution to their circulating concentrations in women, and their heritability in women is not well established. OBJECTIVE: Our objective was to estimate the heritability of circulating total testosterone (TT), free testosterone (FT), and SHBG in women in families from the Framingham Heart Study. METHODS: Women in the Framingham Heart Study who were not pregnant, had not undergone bilateral oophorectomy, and were not using exogenous hormones were eligible for this investigation. TT was measured using liquid chromatography tandem mass spectrometry and SHBG using an immunofluorometric assay (Delfia-Wallac), and FT was calculated. Heritability estimates were calculated using variance-components methods in Sequential Oligogenic Linkage Analysis Routines (SOLAR) and were adjusted for age, age(2), body mass index (BMI), BMI(2), diabetes, smoking, and menopausal status. Bivariate analyses were done to assess genetic correlation between TT, FT, and SHBG. RESULTS: A total of 2685 women were studied including 868 sister pairs and 688 mother-daughter pairs. Multivariable adjusted heritability estimates were 0.26 ± 0.05 for FT, 0.26 ± 0.05 for TT, and 0.56 ± 0.05 for SHBG (P < 1.0 × 10(-7) for all). TT was genetically correlated with SHBG [genetic correlation coefficient (ρG) = 0.31 ± 0.10] and FT (ρG = 0.54 ± 0.09), whereas SHBG was inversely correlated with FT (ρG = -0.60 ± 0.08). CONCLUSION: Circulating TT, FT, and SHBG concentrations in women are significantly heritable, underscoring the importance of further work to identify the specific genes that contribute significantly to variation in sex steroid concentrations in women. The strong shared genetic component among pairs of TT, FT, and SHBG concentrations suggests potential pleiotropic effects for some of the underlying genes.


Assuntos
Globulina de Ligação a Hormônio Sexual/genética , Testosterona/genética , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Globulina de Ligação a Hormônio Sexual/metabolismo , Testosterona/sangue
2.
Anal Biochem ; 416(1): 126-8, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21569754

RESUMO

We describe limitations in the use of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) to examine unfolding intermediates associated with guanidinium chloride (GuHCl)-induced protein denaturation. Several studies have used alterations in fluorescence emission of bis-ANS to quantify the population of "molten globule" states. Our findings indicate that the observed changes in bis-ANS spectroscopic properties could originate from the interactions of bis-ANS and GuHCl and the aggregation of the dye at higher GuHCl concentrations. We posit that in the absence of additional complementary structural or spectroscopic measurements, the use of bis-ANS emission alone to monitor protein conformations can be misleading.


Assuntos
Naftalenossulfonato de Anilina/química , Guanidina/farmacologia , Proteínas/química , Relação Dose-Resposta a Droga , Guanidina/análise , Conformação Proteica/efeitos dos fármacos , Desnaturação Proteica/efeitos dos fármacos , Desdobramento de Proteína/efeitos dos fármacos , Espectrometria de Fluorescência , Relação Estrutura-Atividade
3.
Br J Radiol ; 77(924): 1027-35, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15569645

RESUMO

Effects of 20 mg/kg body weight of abana (ABE) on radiation-induced sickness and mortality in mice exposed to 7 Gy to 12 Gy of gamma irradiation were studied. Treatment of mice with abana 1 h before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls (double distilled water, DDW). Abana provided protection against both the gastrointestinal and haemopoietic deaths. However, animals of both the ABE+irradiation and DDW+irradiation groups did not survive up to 30 days post-irradiation beyond 11 Gy irradiation. The LD(50/30) was found to be 8.5 Gy for the DDW+irradiation group and 10.3 Gy for ABE+irradiation group. The administration of abana resulted in an increase in radiation tolerance by 1.8 Gy, and the dose modification factor (DMF) was found to be 1.2. The irradiation of animals resulted in a dose dependent elevation in lipid peroxidation, and a reduction in glutathione (GSH) concentration on day 31 post-irradiation. Treatment of mice with abana before irradiation caused a significant depletion in lipid peroxidation followed by a significant elevation in GSH concentration in the liver of mice at day 31 post-irradiation. Abana scavenged (*)OH, DPPH, ABTS(*+) and NO(*) in a concentration dependent manner in vitro. Our results indicate that the radioprotective activity of abana may be due to free radical scavenging and increased GSH level in irradiated mice.


Assuntos
Raios gama/efeitos adversos , Fitoterapia/métodos , Extratos Vegetais/uso terapêutico , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Irradiação Corporal Total , Animais , Antioxidantes/metabolismo , Compostos de Bifenilo/metabolismo , Relação Dose-Resposta à Radiação , Sequestradores de Radicais Livres/metabolismo , Glutationa/metabolismo , Hidrazinas/metabolismo , Peroxidação de Lipídeos , Camundongos , Óxido Nítrico/metabolismo , Picratos , Extratos Vegetais/química , Protetores contra Radiação/química
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