RESUMO
The effects of gender-affirming hormone therapy on the skeletal integrity and fracture risk in transitioning adolescent trans girls are unknown. To address this knowledge gap, we developed a mouse model to simulate male-to-female transition in human adolescents in whom puberty is first arrested by using gonadotrophin-releasing hormone analogs with subsequent estradiol treatment. Puberty was suppressed by orchidectomy in male mice at 5 weeks of age. At 3 weeks post-surgery, male-to-female mice were treated with a high dose of estradiol (~0.85 mg) by intraperitoneal silastic implantation for 12 weeks. Controls included intact and orchidectomized males at 3 weeks post-surgery, vehicle-treated intact males, intact females and orchidectomized males at 12 weeks post-treatment. Compared to male controls, orchidectomized males exhibited decreased peak bone mass accrual and a decreased maximal force the bone could withstand prior to fracture. Estradiol treatment in orchidectomized male-to-female mice compared to mice in all control groups was associated with an increased cortical thickness in the mid-diaphysis, while the periosteal circumference increased to a level that was intermediate between intact male and female controls, resulting in increased maximal force and stiffness. In trabecular bone, estradiol treatment increased newly formed trabeculae arising from the growth plate as well as mineralizing surface/bone surface and bone formation rate, consistent with the anabolic action of estradiol on osteoblast proliferation. These data support the concept that skeletal integrity can be preserved and that long-term fractures may be prevented in trans girls treated with GnRHa and a sufficiently high dose of GAHT. Further study is needed to identify an optimal dose of estradiol that protects the bone without adverse side effects.
Assuntos
Osso Esponjoso , Estradiol , Adolescente , Masculino , Humanos , Feminino , Camundongos , Animais , Estradiol/farmacologia , Osso e Ossos , Identidade de Gênero , Modelos Animais de DoençasRESUMO
The high sensitivity of antidoping detection tests creates the possibility of inadvertent doping due to an athlete's unknowing ingestion of contaminated environmental sources such as dietary supplements, food, or drinks. Recently, athletes denying use of a prohibited substance have claimed that the positive antidoping tests was due to exchange of bodily fluids with a nonathlete partner using a prohibited substance. Measurement of drugs in semen is largely limited to one or very few samples due to the inaccessibility of sufficiently frequent semen samples for detailed pharmacokinetics. An emerging issue in semen drug measurements is that semen samples may contain residual urine from ejaculation left in the urethra; however, the urine content in semen samples has not been studied. In the present study, we employed concurrent creatinine measurements in urine and seminal plasma to determine the urine content of semen samples.
Assuntos
Dopagem Esportivo , Atletas , Suplementos Nutricionais , Contaminação de Medicamentos , Humanos , Masculino , SêmenRESUMO
Recent studies have highlighted the potential role of 11oxygenated (keto or hydroxy) androgens in human reproductive function with 11keto androgens circulating at concentrations comparable with testosterone in women and children. However, the intrinsic androgenic bioactivities of 11 keto and hydroxy androgens are not fully characterized. We therefore investigated the full androgen dose-response curves using complementary in vitro yeast and mammalian (HEK293) host cell bioassays of 11 keto and hydroxy derivatives of the potent androgens, testosterone (T) and dihydrotestosterone (DHT), compared with their parent non-11 oxygenated steroids together with the pro-androgen precursor (androstenedione (A4)) and metabolites (androstanedione, androsterone). For potent androgens, the mammalian HEK293 host cell bioassay was 22-138 times more sensitive than the yeast host cell bioassay. In both androgen bioassays, 11keto derivatives displayed androgenic bioactivity but significantly lower molar potency than their parent non-keto steroids. By contrast, the 11hydroxy derivatives had minimal or no androgenic bioactivity. In both bioassays 5α-reduction increased androgenic potency. These findings confirm that that 11keto androgens may contribute directly to androgen status in women, children, and other conditions apart from healthy eugonadal men whereas 11hydroxy androgens have negligible androgenic potency although it cannot be excluded that they may be converted to more potent androgens in vivo.
Assuntos
Androgênios , Saccharomyces cerevisiae , Androgênios/metabolismo , Androstenodiona/metabolismo , Animais , Criança , Di-Hidrotestosterona/metabolismo , Di-Hidrotestosterona/farmacologia , Feminino , Células HEK293 , Humanos , Masculino , Mamíferos/metabolismo , Saccharomyces cerevisiae/metabolismo , Esteroides/metabolismo , Testosterona/metabolismoRESUMO
CONTEXT: Vitamin D status is conventionally defined by measurement of unconjugated circulating 25-hydroxyvitamin D (25OHD), but it remains uncertain whether this isolated analysis gives sufficient weight to vitamin D's diverse metabolic pathways and bioactivity. Emerging evidence has shown that phase II endocrine metabolites are important excretory or storage forms; however, the clinical significance of circulating phase II vitamin D metabolites remains uncertain. OBJECTIVE: In this study we analyzed the contribution of sulfate and glucuronide vitamin D metabolites relative to unconjugated levels in human serum. METHODS: An optimized enzyme hydrolysis method using recombinant arylsulfatase (Pseudomonas aeruginosa) and beta-glucuronidase (Escherichia coli) was combined with liquid chromatography mass spectrometry (LC-MS/MS) analysis to measure conjugated and unconjugated vitamin D metabolites 25OHD3, 25OHD2, 3-epi-25OHD3, and 24,25(OH)2D3. The method was applied to the analysis of 170 human serum samples from community-dwelling men aged over 70 years, categorized by vitamin D supplementation status, to evaluate the proportions of each conjugated and unconjugated fraction. RESULTS: As a proportion of total circulating vitamin D metabolites, sulfate conjugates (ranging between 18% and 53%) were a higher proportion than glucuronide conjugates (ranging between 2.7% and 11%). The proportion of conjugated 25OHD3 (48 ± 9%) was higher than 25OHD2 conjugates (29.1 ± 10%) across all supplementation groups. Conjugated metabolites correlated with their unconjugated forms for all 4 vitamin D metabolites (r = 0.85 to 0.97). CONCLUSION: Sulfated conjugates form a high proportion of circulating vitamin D metabolites, whereas glucuronide conjugates constitute a smaller fraction. Our findings principally in older men highlight the differences in abundance between metabolites and suggest a combination of both conjugated and unconjugated measurements may provide a more accurate assessment of vitamin D status.
Assuntos
Espectrometria de Massas em Tandem/métodos , Vitamina D/isolamento & purificação , Idoso , Calibragem , Cromatografia Líquida de Alta Pressão/métodos , Suplementos Nutricionais , Glucuronídeos/metabolismo , Humanos , Limite de Detecção , Masculino , Sulfatos/metabolismo , Vitamina D/administração & dosagem , Vitamina D/sangue , Vitamina D/metabolismoRESUMO
BACKGROUND AND AIMS: The role of antioxidant intake in cardiovascular disease remains inconclusive. This study evaluates the association between antioxidant intake and the risk of major adverse cardiovascular events (MACE) among older Australian men. METHODS AND RESULTS: 794 men aged ≥75 years participated in the 3rd wave of the Concord Health and Ageing in Men Project. Dietary adequacy of antioxidant intake was assessed by comparing participants' intake of vitamins A, E, C and zinc to the Nutrient Reference Values (NRV) for Australia. Attainment of NRVs of antioxidants was categorised into a dichotomised variable 'inadequate' (meeting≤2 of 4 antioxidants) or 'adequate' (meeting≥3 of 4 antioxidants). The usage of antioxidant supplements was assessed. The outcome measure was MACE. The composite MACE endpoint was defined as having one of the following: death, myocardial infarction, ischemic stroke, congestive cardiac failure (CCF), and revascularization during the period of observation. There was no significant association between dietary (HR: 1.03, 95% CI: 0.71, 1.48) or supplemental antioxidant intake (HR: 1.10, 95% CI: 0.75, 1.63) and overall MACE. However, a significant association was observed between inadequate antioxidant intake and CCF (HR: 1.32; 95% CI: 1.16, 1.50). The lowest quartile of zinc intake (<11.00 mg/d) was significantly associated with CCF (HR 2.36; 95% CI: 1.04, 5.34). None of the other antioxidants were significantly associated with CCF or other MACE components. CONCLUSION: Inadequate dietary antioxidant intake, particularly zinc, is associated with increased risk of CCF in older Australian men but not associated with overall MACE.
Assuntos
Antioxidantes/administração & dosagem , Doenças Cardiovasculares/prevenção & controle , Dieta Saudável , Suplementos Nutricionais , Envelhecimento Saudável , Saúde do Homem , Comportamento de Redução do Risco , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , New South Wales/epidemiologia , Estado Nutricional , Prognóstico , Estudos Prospectivos , Fatores de Proteção , Recomendações Nutricionais , Medição de Risco , Fatores Sexuais , Fatores de Tempo , Zinco/administração & dosagemAssuntos
Kisspeptinas , Testosterona , Animais , Suplementos Nutricionais , Masculino , Camundongos , Camundongos Knockout , Puberdade , Espermatogênese , EspermatozoidesRESUMO
BACKGROUND: The objective of the study is to evaluate the prospective associations between antioxidant intake and incident frailty among older Australian men aged ≥75 years. METHODS: Seven hundred and ninety-four men participated in a detailed diet history interview at the Concord Health and Ageing in Men Project (CHAMP) study third wave (considered baseline nutrition here) and 781 men participated at the fourth wave (considered 3-year follow-up here). The main outcome measurement was incident frailty at 3-year follow-up, using the Cardiovascular Health Study definition. Dietary adequacy of antioxidant intake was assessed by comparing participants' median intakes of four dietary antioxidants (vitamin A, E, C, and zinc) to the nutrient reference values (NRVs). Attainment of the NRVs was incorporated into a dichotomized variable "poor" (meeting ≤2 antioxidants) or "good" (meeting ≥3 antioxidants) as the independent variable using the cut-point method. Also, intakes of each individual dietary antioxidant at baseline nutrition were categorized into quartiles. Analyses were performed using multinomial logistic regression. RESULTS: Incidence of pre-frailty was 53.0% and frailty was 6.4% at 3-year follow-up. Poor dietary antioxidant intake (meeting ≤2) at baseline nutrition was associated with incident frailty at 3-year follow-up in unadjusted (OR: 2.59 [95% CI: 1.47, 4.59, p = .001]) and adjusted (OR: 2.46 [95% CI: 1.10, 5.51, p = .03]) analyses. The lowest quartile of vitamin E intake (<7.08 mg/d) was significantly associated with incident frailty (OR: 2.46 [95% CI: 1.01, 6.00, p = .05]). CONCLUSIONS: Poor antioxidant intake, particularly vitamin E, is a plausible factor associated with incident frailty among older men. This supports the need for clinical trials of diets rich in antioxidants or possibly low-dose antioxidant supplements, for prevention of frailty.
Assuntos
Antioxidantes/administração & dosagem , Idoso Fragilizado , Fragilidade/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Avaliação Geriátrica , Humanos , Incidência , Estudos Longitudinais , Masculino , Estudos Prospectivos , Inquéritos e QuestionáriosRESUMO
BACKGROUND: To explore the associations between serum 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D) levels at baseline and incidence of sarcopenia over time in older Australian community-dwelling older men. METHODS: Of the 1,705 men aged ≥70 years (2005-2007) participating in the Concord Health and Ageing in Men Project, those without sarcopenia at baseline (n = 1,312 for 25D and n = 1,231 for 1,25D), 2 years (n = 1,024 for 25D and n = 956 for 1,25D), and 5-year follow-up (n = 709 for 25D and n = 663 for 1,25D) were included in the study. The main outcome measurement was the incidence of sarcopenia defined as appendicular lean mass adjusted for body mass index <0.789 and grip strength <26.0 kg. Serum 25D and 1,25D levels were measured at baseline by radioimmunoassay (Diasorin, Stillwater, MN) and categorized into quartiles as predictor variables. Covariates included age, income, season of blood collection, physical activity, vitamin D supplement and medication use, measures of health, serum parathyroid hormone (PTH), estimated glomerular filtration rate (eGFR), albumin, and white blood cell count. RESULTS: In this study, incidence of sarcopenia was 3.9% in men at the 2-year follow-up and 8.6% at the 5-year follow-up. In adjusted analysis, men with vitamin D levels in the lowest quartiles (25D <40nmol/L; 1,25D <62 pmol/L) showed significant associations with increased odds of incident sarcopenia compared to those with vitamin D levels in the highest quartiles over 5 years. [25D: odds ratio (OR) 2.53 (95% confidence interval (CI) 1.14, 5.64) p = .02; 1,25D: OR 2.67 (95% CI 1.28, 5.60) p = .01]. After further adjustments for the respective other serum vitamin D measure, (either 25D or 1,25D), the association remained significant [25D: OR 2.40 (95% CI 1.02, 5.64) p = .04; 1,25D: OR 2.23 (95% CI 1.04, 4.80) p = .04]. CONCLUSION: Low serum 1,25D and 25D concentrations at baseline are independently associated with the incidence of sarcopenia over the subsequent 5 years. Although our data do not prove any causal relationship, it is conceivable that maintaining vitamin D sufficiency may reduce the incidence of sarcopenia in ageing men.
Assuntos
Envelhecimento/sangue , Atividade Motora/fisiologia , Músculo Esquelético/fisiopatologia , Hormônio Paratireóideo/sangue , Sarcopenia/sangue , Vitamina D/análogos & derivados , Idoso , Austrália/epidemiologia , Biomarcadores/sangue , Índice de Massa Corporal , Estudos Transversais , Suplementos Nutricionais , Seguimentos , Humanos , Incidência , Masculino , Força Muscular/fisiologia , Prognóstico , Radioimunoensaio , Estudos Retrospectivos , Sarcopenia/epidemiologia , Sarcopenia/fisiopatologia , Fatores de Tempo , Vitamina D/sangueRESUMO
Sport supplements containing steroids never approved for therapeutic use have the potential for abuse by athletes. Most are marketed online and may contain undisclosed steroids yet are readily available despite lacking toxicological or pharmacological evaluation. In this study, 18 supplements purchased online underwent organic solvent extraction to isolate any steroids they contained. From the 18 supplements, 19 steroids were identified and for each, its intrinsic androgenic potency was determined by a yeast cell (Saccharomyces cerevisiae) androgen bioassay and its potential androgenic potency was determined by a liver (HuH7) cell androgen bioassay. The yeast bioassay showed that of the 19 steroids tested, 6 demonstrated strong intrinsic bioactivity, with 4 metabolically activated to even stronger androgens. Moreover, 4 steroids with moderate and 1 with intrinsically weak androgenic bioactivity were activated to more potent androgens. Finally, 8 steroids were metabolically inactivated or deactivated into weaker androgens. Our results show that Internet-sourced sport supplements may contain intrinsically strong androgens, or precursors that can be metabolized to them. These potentially potent pharmacologically active steroids are being used without regulatory control or consumer awareness of their potential adverse effects. Copyright © 2016 John Wiley & Sons, Ltd.
Assuntos
Androgênios/análise , Androgênios/farmacologia , Suplementos Nutricionais/análise , Animais , Linhagem Celular , Dopagem Esportivo , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Internet , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Esteroides/análise , Esteroides/farmacologiaRESUMO
OBJECTIVES: To examine the associations between serum 25-hydroxyvitamin D (25OHD) levels and the active vitamin D metabolite, 1,25-hydroxyvitamin D (1,25OHD), with type 2 diabetes mellitus (DM) in community-living men aged 70 and older. DESIGN: Cross-sectional. SETTING: A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007. PARTICIPANTS: Community dwelling men aged 70 and older taking part in CHAMP (N = 1,659). MEASUREMENTS: Serum 25OHD and 1,25OHD levels, presence of DM, age, country of birth, season of blood collection, sun exposure, body mass index, vitamin D supplement use, statin use, income, measures of health, depression, activity of daily living disabilities, parathyroid hormone, estimated glomerular filtration rate, phosphate, and calcium. RESULTS: The prevalence of DM was 20.0%. There was a significant association between low 25OHD and 1,25OHD levels and DM that remained after adjustment for a wide range of confounders and covariates of clinical significance such as comorbidity, renal function, calciotropic hormones, and medications. CONCLUSION: 25OHD and 1,25OHD levels were associated with DM. The independent association between serum 25OHD and 1,25OHD concentrations and DM raises the question of whether each of the two vitamin D metabolites may influence DM through different biological mechanisms and pathways.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Modelos Logísticos , Masculino , Vitamina D/sangueRESUMO
The aim of this population-based, prospective, observational study was to examine the relationship between serum levels of 25-hydroxyvitamin D (25OHD) and fracture risk in a cohort of 1662 community-dwelling men aged 70 to 97 years followed for a mean of 4.3 years. Data about mobility, muscle strength, balance, medication use, cognition, medical history, lifestyle factors, renal function, and serum 25OHD were collected at baseline. Data on radiologically verified fractures were collected every 4 months. The relationship between fractures and serum 25OHD levels was analyzed using Cox's proportional hazard regression. We accounted for bone mineral density, falls, physical activity, sun exposure, and season of blood draw, in addition to anthropometric and lifestyle factors, medical history, muscle strength, balance, and medication and supplement use. There were 123 first-incident fragility fractures. The relationship between baseline 25OHD and fracture risk was U-shaped, with increased fracture risk in men with either low or high serum 25OHD levels. In multivariate analysis, the risk of fracture was greatest in men with 25OHD levels in the lowest quintile (25OHD ≤36 nmol/L; hazard ratio [HR] = 3.5; 95% confidence interval [CI] 1.7-7.0) and in men in the highest quintile (25OHD >72 nmol/L; HR = 2.7; 95% CI 1.4-5.4) compared with men in the 4th quintile (25OHD ≥60 to ≤72 nmol/L). These associations were not explained by lower BMD, increased physical activity, fall risk, or other lifestyle or anthropomorphic factors. In community-dwelling older men, there appears to be a healthy target range for serum 25OHD concentrations. Thus, serum 25OHD levels too high and too low may be harmful in regard to fracture risk.
Assuntos
Fraturas Ósseas/sangue , Fraturas Ósseas/epidemiologia , Vitamina D/análogos & derivados , Idoso , Envelhecimento/patologia , Austrália/epidemiologia , Humanos , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Vitamina D/sangueRESUMO
Homozygous androgen receptor (AR)-knockout (ARKO) female mice are subfertile due to both intra- and extraovarian (neuroendocrine) defects as defined by ovary transplantation. Using ARKO mice, this study set out to reveal the precise AR-regulated pathways required for optimal androgen-regulated ovulation and fertility. ARKO females exhibit deficient neuroendocrine negative feedback, with a reduced serum luteinizing hormone (LH) response to ovariectomy (OVX) (P < 0.01). Positive feedback is also altered as intact ARKO females, at late proestrus, exhibit an often mistimed endogenous ovulatory LH surge. Furthermore, at late proestrus, intact ARKO females display diminished preovulatory serum estradiol (E2; P < 0.01) and LH (P < 0.05) surge levels and reduced Kiss1 mRNA expression in the anteroventral periventricular nucleus (P < 0.01) compared with controls. However, this reduced ovulatory LH response in intact ARKO females can be rescued by OVX and E2 priming or treatment with endogenous GnRH. These findings reveal that AR regulates the negative feedback response to E2, E2-positive feedback is compromised in ARKO mice, and AR-regulated negative and positive steroidal feedback pathways impact on intrahypothalamic control of the kisspeptin/GnRH/LH cascade. In addition, intraovarian AR-regulated pathways controlling antral to preovulatory follicle dynamics are disrupted because adult ARKO ovaries collected at proestrus have small antral follicles with reduced oocyte/follicle diameter ratios (P < 0.01) and increased proportions of unhealthy large antral follicles (P < 0.05) compared with controls. As a consequence of aberrant follicular growth patterns, proestrus ARKO ovaries also exhibit fewer preovulatory follicle (P < 0.05) and corpora lutea numbers (P < 0.01). However, embryo development to the blastocyst stage is unchanged in ARKO females, and hence, the subfertility is a consequence of reduced ovulations and not altered embryo quality. These findings reveal that the AR has a functional role in neuroendocrine regulation and timing of the ovulatory LH surge as well as antral/preovulatory follicle development.
Assuntos
Hipotálamo/metabolismo , Infertilidade Feminina/metabolismo , Ovário/metabolismo , Ovulação/metabolismo , Receptores Androgênicos/metabolismo , Animais , Corpo Lúteo/metabolismo , Estradiol/sangue , Ciclo Estral/sangue , Ciclo Estral/genética , Ciclo Estral/metabolismo , Feminino , Hipotálamo/fisiopatologia , Infertilidade Feminina/genética , Infertilidade Feminina/fisiopatologia , Kisspeptinas/genética , Kisspeptinas/metabolismo , Hormônio Luteinizante/sangue , Hormônio Luteinizante/metabolismo , Camundongos , Camundongos Knockout , Folículo Ovariano/metabolismo , Ovário/fisiopatologia , Ovulação/sangue , Ovulação/genética , Receptores Androgênicos/genéticaRESUMO
BACKGROUND: Poor vitamin D status and frailty are common in older people and associated with adverse health outcomes. The aim of this study was to examine the associations between serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels and frailty and components of frailty in older Australian men. METHODS: Cross-sectional analysis of the Concord Health and Ageing in Men Project, a large epidemiological study conducted in Sydney, Australia, between January 2005 and May 2007. Participants included 1,659 community-dwelling men. Main outcome measurements were frailty (assessed using the Cardiovascular Health Study), frailty criteria comprising five core components: weight loss; reduced muscular strength/weakness; slow walking speed; exhaustion; and low activity level, and the separate components of frailty. Covariates included serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels measured by radioimmunoassay, age, country of birth, season of blood collection, sun exposure, body mass index, vitamin D supplement use, income, measures of health, parathyroid hormone, estimated glomerular function. RESULTS: Frailty was present in 9.2% of the sample. Low serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels were independently associated with frailty and with four of the five components of frailty (except weight loss). CONCLUSIONS: 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D levels were independently associated with frailty in older men. This suggests that there might be a number of different biological mechanisms for how low vitamin D status might contribute to the frailty syndrome. In addition, the possibility that improving vitamin D status may specifically influence the incidence and progression of frailty needs to be explored.
Assuntos
Envelhecimento/sangue , Envelhecimento/fisiologia , Idoso Fragilizado , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Fadiga/sangue , Idoso Fragilizado/estatística & dados numéricos , Humanos , Modelos Logísticos , Masculino , Atividade Motora/fisiologia , Debilidade Muscular/sangue , New South Wales/epidemiologia , Fatores de Risco , Vitamina D/sangue , Caminhada/fisiologia , Redução de Peso/fisiologiaRESUMO
Androgenic steroids marketed online as nutraceuticals are a growing concern in sport doping. The inability of conventional mass spectrometry (MS)-based techniques to detect structurally novel androgens has led to the development of in vitro androgen bioassays to identify such designer androgens by their bioactivity. The objective of this study was to determine the androgenic bioactivity of novel steroidal compounds isolated from nutraceuticals using both yeast and mammalian cell-based androgen bioassays. We developed two new in vitro androgen bioassays by stably transfecting HEK293 and HuH7 cells with the human androgen receptor (hAR) expression plasmid together with a novel reporter gene vector (enhancer/ARE/SEAP). The yeast ß-galactosidase androgen bioassay was used for comparison. Our new bioassay featuring the enhancer/ARE/SEAP construct (-S) displayed simpler assay format and higher specificity with lower sensitivity compared with the commonly used mouse mammary tumour virus (MMTV)-luciferase. The relative potencies (RP), defined as [EC(50)] of testosterone/[EC(50)] of steroid, of nutraceutical extracts in the yeast, HEK293-S, and HuH7-S, were 34, 333, and 80,000 for Hemapolin; 208, 250, and 80 for Furazadrol; 0.38, 10, and 106 for Oxyguno; 2.7, 0.28, and 15 for Trena; and 4.5, 0.1, and 0.4 for Formadrol, respectively. The wide discrepancies in rank RP of these compounds was reconciled into a consistent potency ranking when the cells were treated with meclofenamic acid, a nonselective inhibitor of steroid metabolizing enzymes. These findings indicate that steroids extracted from nutraceuticals can be converted in vitro into more or less potent androgens in mammalian but not in yeast cells. We conclude that the putative androgenic bioactivity of a new compound may depend on the bioassay cellular format and that mammalian cell bioassays may have an added benefit in screening for proandrogens but sacrifice specificity for sensitivity in quantitation.
Assuntos
Androgênios/química , Androgênios/farmacologia , Bioensaio/métodos , Suplementos Nutricionais , Saccharomyces cerevisiae/citologia , Esteroides/química , Esteroides/farmacologia , Células HEK293 , Humanos , Receptores Androgênicos/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismoRESUMO
OBJECTIVE: To determine the proportion of older Australian men who meet the Pharmaceutical Benefits Scheme (PBS) criteria for osteoporosis treatment and are receiving effective treatment. DESIGN AND SETTING: A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study focusing on the health of older men. Data were collected through questionnaires and clinical assessments. Bone mineral density (BMD) of the hip and spine was measured by dual x-ray absorptiometry (DXA). Vertebral deformities were identified from DXA lateral vertebral fracture assessment images. The study was conducted at Concord Hospital, Sydney, between January 2005 and May 2007. PARTICIPANTS: 1705 community-dwelling men aged 70 years or over from a defined geographical region around Concord Hospital. MAIN OUTCOME MEASURES: Prevalence of vertebral deformities; previous minimal trauma fractures; BMD T-scores ≤ - 3; falls in the previous 12 months; use of bisphosphonates and calcium and vitamin D supplements. RESULTS: Of the 1705 men seen at baseline, 1626 completed all DXA scans and 401 (25%) met one or more of the PBS criteria for osteoporosis treatment. Ninety per cent of the men who met the PBS criteria were unaware they had osteoporosis. Of the men eligible for PBS-subsidised treatment, 39 (10%) reported use of a bisphosphonate, 56 (14%) had taken calcium supplements, and 28 (7%) had taken vitamin D supplements. Only three men had taken calcium, vitamin D and bisphosphonates in combination. CONCLUSIONS: Despite a high prevalence of osteoporosis in elderly Australian men, awareness, diagnosis and treatment of the condition remain very low.
Assuntos
Osteoporose/tratamento farmacológico , Osteoporose/epidemiologia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Densidade Óssea , Cálcio/uso terapêutico , Estudos Transversais , Difosfonatos/uso terapêutico , Humanos , Masculino , Prevalência , Vitamina D/uso terapêuticoRESUMO
BACKGROUND: Clinically important rapid bone loss occurs within 3 to 6 months after liver transplantation and may be associated with osteoporotic fractures. OBJECTIVE: To determine whether bisphosphonate treatment with zoledronic acid reduces transplant-related bone loss more than placebo in adults having liver transplantation for chronic liver disease. DESIGN: 12-month randomized, double-blind, placebo-controlled trial. SETTING: 2 large liver transplantation centers in Australia. PATIENTS: 62 adults having liver transplantation for chronic liver disease. INTERVENTIONS: Infusions of zoledronic acid, 4 mg (n = 32), or saline (n = 30) were given within 7 days of transplantation and again at months 1, 3, 6, and 9 after transplantation. All patients received supplementation with calcium carbonate, 600 mg/d, and ergocalciferol, 1000 U/d. MEASUREMENTS: The primary outcome was bone mineral density (BMD) measured by dual x-ray absorptiometry before transplantation and 3, 6, and 12 months later. Secondary outcomes included bone turnover markers that were measured before transplantation and 1, 3, 6, 9, and 12 months later. RESULTS: There were statistically significant interactions between treatment effects and time for BMD measurements at the lumbar spine (P = 0.002), femoral neck (P = 0.001), and total hip (P < 0.001). Differences in acute bone loss 3 months after transplantation favored zoledronic acid over placebo. Differences between groups in percentage change from baseline adjusted for baseline weight and serum parathyroid hormone (PTH) level were 4.0% (95% CI, 1.1% to 7.0%) for the lumbar spine, 4.7% (CI, 1.9% to 7.6%) for the femoral neck, and 3.8% (CI, 1.7% to 6.0%) for the total hip. At 12 months after transplantation, the difference in percentage change from baseline between the 2 groups adjusted for baseline weight and serum PTH level was 1.1% (CI, -2.1% to 4.4%) for the lumbar spine, 2.7% (CI, 0.0% to 5.4%) for the femoral neck, and 2.4% (CI, 0.1% to 4.7%) for the total hip. Treatment with zoledronic acid induced temporary secondary hyperparathyroidism and postinfusion hypocalcemia statistically significantly more often than did placebo. LIMITATIONS: The trial was not powered to assess fractures, and 10 of 62 (16%) patients were not included in adjusted analyses because of missing weight or serum PTH measurements. CONCLUSION: Treatment with zoledronic acid can prevent bone loss within the first year after liver transplantation.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Imidazóis/uso terapêutico , Transplante de Fígado/efeitos adversos , Osteoporose/prevenção & controle , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/efeitos adversos , Doença Crônica , Difosfonatos/efeitos adversos , Método Duplo-Cego , Seguimentos , Humanos , Hidroxicolecalciferóis/sangue , Hiperparatireoidismo Secundário/induzido quimicamente , Hipocalcemia/induzido quimicamente , Imidazóis/efeitos adversos , Infusões Intravenosas , Falência Hepática/complicações , Falência Hepática/cirurgia , Osteoporose/etiologia , Hormônio Paratireóideo/sangue , Ácido ZoledrônicoRESUMO
OBJECTIVES: This study investigated the effects of androgens on gene expression in male- and female-donor macrophages. BACKGROUND: Men have more severe coronary disease than women. Androgen exposure increases foam cell formation in male but not female macrophages, and male macrophages express >4-fold more androgen receptor messenger ribonucleic acid than female macrophages. Therefore, androgen exposure may have gender-specific and potentially pro-atherogenic effects in macrophages. METHODS: Utilizing complementary deoxyribonucleic acid arrays, we studied the effects of a pure androgen (dihydrotestosterone, 40 nmol/l) on human monocyte-derived macrophages from healthy male and female donors (n = 4 hybridizations; 2 men, 2 women). Differential expression of atherosclerosis-related genes was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR) in five male and five female donors. Functional corroboration of foam cell formation-related findings was undertaken by experiments using (125)I-acetylated low-density lipoprotein (AcLDL). RESULTS: In male macrophages, androgen treatment produced differential up-regulation of 27 genes concentrated in five functional classes: 1) lipoprotein processing; 2) cell-surface adhesion; 3) extracellular signaling; 4) coagulation and fibrinolysis; and 5) transport protein genes. By contrast, none of 588 genes were up-regulated in female macrophages. By RT-PCR, we confirmed the gender-specific up-regulation of six of these atherosclerosis-related genes: acyl coenzyme A:cholesterol acyl transferase I, lysosomal acid lipase (LAL), caveolin-2, CD40, vascular endothelial growth factor-165 receptor, and tissue factor pathway inhibitor. Functionally, androgen-treated male macrophages showed increased rates of lysosomal AcLDL degradation, by 45% to 75% after 15 to 20 h of (125)I-AcLDL incubation (p = 0.001), consistent with increased LAL activity. CONCLUSIONS: Androgens increase expression of atherosclerosis-related genes in male but not female macrophages, with functional consequences. These findings may contribute to the male predisposition to atherosclerosis.