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1.
J Endocrinol Invest ; 47(2): 433-442, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37592052

RESUMO

PURPOSE: Trabecular bone score (TBS) is a gray-level textural metric that has shown to correlate with risk of fractures in several forms of osteoporosis. The value of TBS in predicting fractures and the effects of bone-active drugs on TBS in aromatase inhibitors (AIs)-induced osteoporosis are still largely unknown. The primary objective of this retrospective study was to assess the effects of denosumab and bisphosphonates (BPs) on TBS and vertebral fractures (VFs) in women exposed to AIs. METHODS: 241 consecutive women (median age 58 years) with early breast cancer undergoing treatment with AIs were evaluated for TBS, bone mineral density (BMD) and morphometric VFs at baseline and after 18-24 months of follow-up. During the study period, 139 women (57.7%) received denosumab 60 mg every 6 months, 53 (22.0%) BPs, whereas 49 women (20.3%) were not treated with bone-active drugs. RESULTS: Denosumab significantly increased TBS values (from 1.270 to 1.323; P < 0.001) accompanied by a significant decrease in risk of VFs (odds ratio 0.282; P = 0.021). During treatment with BPs, TBS did not significantly change (P = 0.849) and incidence of VFs was not significantly different from women untreated with bone-active drugs (P = 0.427). In the whole population, women with incident VFs showed higher decrease in TBS vs. non-fractured women (P = 0.003), without significant differences in changes of BMD at any skeletal site. CONCLUSIONS: TBS variation predicts fracture risk in AIs treated women. Denosumab is effective to induce early increase of TBS and reduction in risk of VFs.


Assuntos
Fraturas Ósseas , Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Feminino , Humanos , Pessoa de Meia-Idade , Osso Esponjoso , Denosumab/uso terapêutico , Denosumab/farmacologia , Inibidores da Aromatase/efeitos adversos , Estudos Retrospectivos , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Osteoporose/complicações , Densidade Óssea , Fraturas da Coluna Vertebral/complicações , Absorciometria de Fóton , Vértebras Lombares , Fraturas por Osteoporose/induzido quimicamente , Fraturas por Osteoporose/epidemiologia
3.
J Endocrinol Invest ; 46(11): 2195-2211, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37515706

RESUMO

PURPOSE: The clinical significance of metabolic syndrome (MetS) versus its single components in erectile dysfunction (ED) is conflicting. Thus, the purpose is to analyze the available evidence on the relationship between MetS-along with its components-and ED. METHODS: All prospective and retrospective observational studies reporting information on ED and MetS were included. In addition, we here reanalyzed preclinical and clinical data obtained from a previously published animal model of MetS and from a consecutive series of more than 2697 men (mean age: 52.7 ± 12), respectively. RESULTS: Data derived from this meta-analysis showed that MetS was associated with an up to fourfold increased risk of ED when either unadjusted or adjusted data were considered. Meta-regression analysis, performed using unadjusted statistics, showed that the MetS-related risk of ED was closely associated with all the MetS components. These associations were confirmed when unadjusted analyses from clinical models were considered. However, fully adjusted data showed that MetS-associated ED was more often due to morbidities included (or not) in the algorithm than to the MetS diagnostic category itself. MetS is also associated with low testosterone, but its contribution to MetS-associated ED-as derived from preclinical and clinical models-although independent, is marginal. CONCLUSIONS: The results of our analysis suggest that MetS is a useless diagnostic category for studying ED. However, treating the individual MetS components is important, because they play a pivotal role in determining ED.

4.
J Endocrinol Invest ; 46(2): 297-304, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36030302

RESUMO

BACKGROUND: Klinefelter syndrome (KS) frequently causes skeletal fragility characterized by profound alterations in bone microstructure with increased risk of fractures. Increased body fat mass associated with decreased body lean mass are frequent features of KS with possible detrimental effects on skeletal health. In this cross-sectional study, we evaluated the associations between body composition parameters, vertebral fractures (VFs) and trabecular bone score (TBS) in adult subjects with KS. METHODS: Seventy-one adult males (median age 41 years, range 18-64) with 47, XXY KS were consecutively enrolled by two Endocrinology and Andrology Units (IRCCS Humanitas Research Hospital in Milan and ASST Spedali Civili in Brescia). Dual-energy X-ray absorptiometry (DXA) was performed to assess bone mineral density (BMD) at lumbar spine, femoral neck and total hip, TBS and body composition. Prevalence of VFs was assessed by quantitative morphometry on lateral spine X-rays. RESULTS: VFs were detected in 14 patients (19.7%), without significant association with low BMD (p = 0.912). In univariate logistic regression analysis, VFs were significantly associated with truncal/leg fat ratio (OR 2.32 per tertile; 95% CI 1.05-5.15; p = 0.038), whereas impaired TBS (detected in 23.4% of subjects) was associated with older age at study entry (p = 0.001) and at diagnosis of disease (p = 0.015), body mass index (BMI; p = 0.001), waist circumference (p = 0.007), fat mass index (FMI; p < 0.001), FMI/lean mass index (LMI) ratio (p = 0.001). Prevalence of VFs was not significantly different between subjects with impaired TBS as compared to those with normal TBS (26.7 vs. 18.4%; p = 0.485). Skeletal end-points were not significantly associated with duration of testosterone replacement therapy and serum testosterone and 25hydroxyvitamin D values. CONCLUSION: Body composition might influence bone quality and risk of VFs in subjects with KS.


Assuntos
Síndrome de Klinefelter , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Masculino , Adulto , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Osso Esponjoso/diagnóstico por imagem , Síndrome de Klinefelter/complicações , Síndrome de Klinefelter/epidemiologia , Síndrome de Klinefelter/metabolismo , Estudos Transversais , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Densidade Óssea , Absorciometria de Fóton , Colo do Fêmur , Vértebras Lombares/metabolismo , Testosterona/metabolismo , Composição Corporal , Fraturas por Osteoporose/diagnóstico
5.
J Endocrinol Invest ; 46(5): 939-945, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36370325

RESUMO

BACKGROUND: While low testosterone (T) was described as a predictor of unfavorable coronavirus-disease 19 (COVID-19) outcome in men, data concerning the role of T in women with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are scant and limited to small cohorts. This study investigated the relationship between serum T values and outcomes of COVID-19 in a large female hospitalized cohort. METHODS: One-hundred-sixty-eight adult women (median age 77, range 18-100 years; 154 in post-menopause) hospitalized for COVID-19 were assessed for PaO2/Fio2 ratio, serum T and inflammatory parameters. RESULTS: Median duration for hospital stay was 14.2 days (range 1-115) with overall mortality of 26% (n = 44). Subjects who died were significantly older (p < 0.001), had significantly more comorbidities (p = 0.015) and higher serum T (p = 0.040), white blood cells (p = 0.007), c-reactive protein (CRP; p < 0.001), interleukin-6 (IL-6; p < 0.001), procalcitonin (PCT; p < 0.001), lactate dehydrogenase (LDH; p = 0.001), D-dimer (p = 0.035), fibrinogen (p = 0.038) and lower serum free-triiodothyronine (FT3; p < 0.001) and luteinizing hormone (LH; p = 0.024) values. In post-menopausal women, significant associations were observed between T levels and serum CRP (rho: 0.23; p = 0.002), IL-6 (rho: 0.41; p < 0.001), LDH (rho: 0.34; p < 0.001), D-Dimer (rho: 0.21; p = 0.008), PCT (rho: 0.26; p = 0.001) and HDL cholesterol (rho: - 0,22, p = 0.008). In multivariate regression analyses, serum T maintained the significant association with mortality after correction for age, coexistent comorbidities and serum LH and FT3, whereas it was lost after correction for inflammatory parameters. CONCLUSION: In females, high serum T levels might be a mirror of inflammatory phenotype and worse COVID-19 course.


Assuntos
COVID-19 , Humanos , Feminino , SARS-CoV-2 , Interleucina-6 , Inflamação , Testosterona
6.
J Endocrinol Invest ; 45(10): 2007-2017, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35751803

RESUMO

PURPOSE: There is emerging evidence that radiomics analyses can improve detection of skeletal fragility. In this cross-sectional study, we evaluated radiomics features (RFs) on computed tomography (CT) images of the lumbar spine in subjects with or without fragility vertebral fractures (VFs). METHODS: Two-hundred-forty consecutive individuals (mean age 60.4 ± 15.4, 130 males) were evaluated by radiomics analyses on opportunistic lumbar spine CT. VFs were diagnosed in 58 subjects by morphometric approach on CT or XR-ray spine (D4-L4) images. DXA measurement of bone mineral density (BMD) was performed on 17 subjects with VFs. RESULTS: Twenty RFs were used to develop the machine learning model reaching 0.839 and 0.789 of AUROC in the train and test datasets, respectively. After correction for age, VFs were significantly associated with RFs obtained from non-fractured vertebrae indicating altered trabecular microarchitecture, such as low-gray level zone emphasis (LGLZE) [odds ratio (OR) 1.675, 95% confidence interval (CI) 1.215-2.310], gray level non-uniformity (GLN) (OR 1.403, 95% CI 1.023-1.924) and neighboring gray-tone difference matrix (NGTDM) contrast (OR 0.692, 95% CI 0.493-0.971). Noteworthy, no significant differences in LGLZE (p = 0.94), GLN (p = 0.40) and NGDTM contrast (p = 0.54) were found between fractured subjects with BMD T score < - 2.5 SD and those in whom VFs developed in absence of densitometric diagnosis of osteoporosis. CONCLUSIONS: Artificial intelligence-based analyses on spine CT images identified RFs associated with fragility VFs. Future studies are needed to test the predictive value of RFs on opportunistic CT scans in identifying subjects with primary and secondary osteoporosis at high risk of fracture.


Assuntos
Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Absorciometria de Fóton/métodos , Inteligência Artificial , Densidade Óssea , Estudos Transversais , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Osteoporose/complicações , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
7.
J Endocrinol Invest ; 45(12): 2207-2219, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35527294

RESUMO

PURPOSE: The short- and long-term andrological effects of coronavirus disease 2019 (COVID-19) have not been clarified. Our aim is to evaluate the available evidence regarding possible andrological consequences of COVID-19 either on seminal or hormonal parameters. The safety of the COVID-19 vaccines in terms of sperm quality was also investigated. METHODS: All prospective and retrospective observational studies reporting information on severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) mRNA semen and male genitalia tract detection (n = 19), as well as those reporting data on semen analysis (n = 5) and hormonal parameters (n = 11) in infected/recovered patients without any arbitrary restriction were included. RESULTS: Out of 204 retrieved articles, 35 were considered, including 2092 patients and 1138 controls with a mean age of 44.1 ± 12.6 years, and mean follow-up 24.3 ± 18.9 days. SARS-CoV-2 mRNA can be localized in male genitalia tracts during the acute phase of the disease. COVID-19 can result in short-term impaired sperm and T production. Available data cannot clarify long-term andrological effects. Low T observed in the acute phase of the disease is associated with an increased risk of being admitted to the Intensive Care Unit or death. The two available studies showed that the use of mRNA COVID-19 vaccines does not affect sperm quality. CONCLUSIONS: The results of our analysis clearly suggest that each patient recovering from COVID-19 should be monitored to rule out sperm and T abnormalities. The specific contribution of reduced T levels during the acute phase of the infection needs to be better clarified.


Assuntos
COVID-19 , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , SARS-CoV-2 , Vacinas contra COVID-19 , Estudos Prospectivos , Estudos Retrospectivos , Sêmen , RNA Mensageiro
8.
J Endocrinol Invest ; 45(5): 911-926, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35041193

RESUMO

BACKGROUND: The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate. METHODS: All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered. RESULTS: Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies. CONCLUSION: TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.


Assuntos
Reabsorção Óssea , Hipogonadismo , Densidade Óssea , Reabsorção Óssea/complicações , Suplementos Nutricionais , Colo do Fêmur , Terapia de Reposição Hormonal , Humanos , Hipogonadismo/tratamento farmacológico , Vértebras Lombares , Testosterona/farmacologia , Testosterona/uso terapêutico
9.
J Endocrinol Invest ; 45(4): 753-762, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34792796

RESUMO

PURPOSE: Hypogonadism was described in high number of male subjects with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this study, we investigated whether low testosterone (T) values may influence the clinical presentation and outcome of SARS-CoV-2-related pneumonia in a large population of adult males with coronavirus disease 19 (COVID-19). METHODS: Two hundred twenty one adult males hospitalized for COVID-19 at the IRCCS Humanitas Research Hospital, Rozzano-Milan (Italy) were consecutively evaluated for arterial partial pressure oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, serum T and inflammatory parameters at study entry, need of ventilation during hospital stay and in-hospital mortality. RESULTS: Subjects low T values (< 8 nmol/L; 176 cases) were significantly older (P = 0.001) and had higher serum interleukin-6 (P = 0.001), C-reactive protein (P < 0.001), lactate dehydrogenase (P < 0.001), ferritin (P = 0.012), lower P/F ratio (P = 0.001), increased prevalence of low T3 syndrome (P = 0.041), acute respiratory insufficiency (P < 0.001), more frequently need of ventilation (P < 0.001) and higher mortality rate (P = 0.009) compared to subjects with higher T values. In the multivariable regression analyses, T values maintained significant associations with acute respiratory insufficiency (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.79-0.94; P < 0.001 and in-hospital mortality (OR 0.80, 95% CI 0.69-0.95; P = 0.009), independently of age, comorbidities, thyroid function and inflammation. CONCLUSION: Low T levels values are associated with unfavorable outcome of COVID-19. Prospective studies are needed to evaluate the long-term outcomes of hypogonadism related to COVID-19 and the clinical impact of T replacement during and after acute illness.


Assuntos
COVID-19/complicações , Insuficiência Respiratória/etiologia , Testosterona/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , COVID-19/sangue , COVID-19/mortalidade , Hospitalização , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Insuficiência Respiratória/sangue , Insuficiência Respiratória/mortalidade , Taxa de Sobrevida
10.
J Endocrinol Invest ; 44(3): 391-402, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32691371

RESUMO

BACKGROUND: Testicular adrenal rest tumors (TARTs) are benign masses deemed to originate from pluripotent testicular steroidogenic cells that grow under chronic ACTH stimulation. These lesions, occasionally misdiagnosed as Leydig cell tumors (LCTs), are typically described in patients with congenital adrenal hyperplasia (CAH). X-linked adrenoleukodystrophy (X-ALD) is an inherited disorder of beta-oxidation with accumulation of very long chain fatty acids (VLCFAs) in various tissues, and a rare cause of primary adrenal insufficiency (PAI). TARTs have never been associated with X-ALD. CASE 1 DESCRIPTION: A 19-year old male, who had previously undergone bilateral enucleation of presumed LCTs, was referred to our unit. Follow-up scans showed persistent bilateral lesions compatible with TARTs. Biochemical exams revealed PAI but excluded CAH. A serum VLCFAs panel was consistent with X-ALD, with gene testing confirming the diagnosis. Histological revision of the previously resected testicular lesions was compatible with TARTs. Start of glucocorticoid replacement therapy was associated with a reduction of testicular masses. CASE 2 DESCRIPTION: A 26-year old X-ALD male was diagnosed with bilateral testicular lesions compatible with TARTs. These lesions increased after ACTH elevation following switch to modified-release hydrocortisone. Clinical and sonographic findings allowed for a "watchful-waiting" approach, avoiding unnecessary surgery. CONCLUSION: These are the first cases reported of TARTs in patients with X-ALD-associated PAI. Testicular lesions in patients with an early onset of ACTH elevation, regardless of the cause, should always be thoughtfully investigated, as they may reveal themselves as TARTs. We suggest that all patients affected from chronic ACTH elevation of a young age of onset should undergo testicular ultrasound in order to evaluate the presence of these lesions. GRT in these patients might also help preserving fertility.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , Tumor de Resto Suprarrenal/diagnóstico , Adrenoleucodistrofia/diagnóstico , Hipoadrenocorticismo Familiar/diagnóstico , Neoplasias Testiculares/diagnóstico , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Prognóstico , Adulto Jovem
11.
J Endocrinol Invest ; 44(2): 223-231, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32661947

RESUMO

PURPOSE: The COVID-19 pandemic, caused by the SARS-CoV-2, represents an unprecedented challenge for healthcare. COVID-19 features a state of hyperinflammation resulting in a "cytokine storm", which leads to severe complications, such as the development of micro-thrombosis and disseminated intravascular coagulation (DIC). Despite isolation measures, the number of affected patients is growing daily: as of June 12th, over 7.5 million cases have been confirmed worldwide, with more than 420,000 global deaths. Over 3.5 million patients have recovered from COVID-19; although this number is increasing by the day, great attention should be directed towards the possible long-term outcomes of the disease. Despite being a trivial matter for patients in intensive care units (ICUs), erectile dysfunction (ED) is a likely consequence of COVID-19 for survivors, and considering the high transmissibility of the infection and the higher contagion rates among elderly men, a worrying phenomenon for a large part of affected patients. METHODS: A literature research on the possible mechanisms involved in the development of ED in COVID-19 survivors was performed. RESULTS: Endothelial dysfunction, subclinical hypogonadism, psychological distress and impaired pulmonary hemodynamics all contribute to the potential onset of ED. Additionally, COVID-19 might exacerbate cardiovascular conditions; therefore, further increasing the risk of ED. Testicular function in COVID-19 patients requires careful investigation for the unclear association with testosterone deficiency and the possible consequences for reproductive health. Treatment with phosphodiesterase-5 (PDE5) inhibitors might be beneficial for both COVID-19 and ED. CONCLUSION: COVID-19 survivors might develop sexual and reproductive health issues. Andrological assessment and tailored treatments should be considered in the follow-up.


Assuntos
COVID-19 , Saúde Reprodutiva , SARS-CoV-2 , Saúde Sexual , Enzima de Conversão de Angiotensina 2/fisiologia , COVID-19/complicações , COVID-19/fisiopatologia , COVID-19/psicologia , Doenças Cardiovasculares/virologia , Síndrome da Liberação de Citocina/virologia , Disfunção Erétil/sangue , Disfunção Erétil/psicologia , Disfunção Erétil/virologia , Humanos , Hipogonadismo/virologia , Hormônio Luteinizante/sangue , Masculino , SARS-CoV-2/fisiologia , Testículo/enzimologia , Testículo/fisiopatologia , Testículo/virologia , Testosterona/sangue
12.
J Endocrinol Invest ; 43(12): 1675-1687, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32567016

RESUMO

PURPOSE: Low testosterone (T) in Klinefelter's syndrome (KS) can contribute to typical features of the syndrome such as reduced bone mineral density, obesity, metabolic disturbances and increased cardiovascular risk. The aim of the present study is to review and meta-analyze all available information regarding possible differences in metabolic and bone homeostasis profile between T treated (TRT) or untreated KS and age-matched controls. METHODS: We conducted a random effect meta-analysis considering all the available data from observational or randomized controlled studies comparing TRT-treated and untreated KS and age-matched controls. Data were derived from an extensive MEDLINE, Embase, and Cochrane search. RESULTS: Out of 799 retrieved articles, 21 observational and 22 interventional studies were included in the study. Retrieved trials included 1144 KS subjects and 1284 healthy controls. Not-treated KS patients showed worse metabolic profiles (including higher fasting glycemia and HOMA index as well as reduced HDL-cholesterol and higher LDL-cholesterol) and body composition (higher body mass index and waist circumference) and reduced bone mineral density (BMD) when compared to age-matched controls. TRT in hypogonadal KS subjects was able to improve body composition and BMD at spinal levels but it was ineffective in ameliorating lipid and glycemic profile. Accordingly, TRT-treated KS subjects still present worse metabolic parameters when compared to age-matched controls. CONCLUSION: TRT outcomes observed in KS regarding BMD, body composition and glyco-metabolic control, are similar to those observed in male with hypogonadism not related to KS. Moreover, body composition and BMD are better in treated than untreated hypogonadal KS. Larger and longer randomized placebo-controlled trials are advisable to better confirm the present data, mainly derived from observational studies.


Assuntos
Síndrome de Klinefelter/tratamento farmacológico , Testosterona/uso terapêutico , Adulto , Composição Corporal/efeitos dos fármacos , Índice de Massa Corporal , Densidade Óssea/efeitos dos fármacos , Humanos , Hipogonadismo/sangue , Hipogonadismo/tratamento farmacológico , Hipogonadismo/epidemiologia , Hipogonadismo/etiologia , Síndrome de Klinefelter/sangue , Síndrome de Klinefelter/complicações , Síndrome de Klinefelter/epidemiologia , Masculino , Pessoa de Meia-Idade , Testosterona/sangue
13.
J Endocrinol Invest ; 42(9): 1001-1010, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30742257

RESUMO

BACKGROUND: Functional hypothalamic amenorrhea (FHA) is a form of chronic anovulation not due to identifiable organic causes and with adverse health consequences. The identification of women with this disorder or the precocious identification of women at risk is based on the knowledge of lifestyle risk factors or behaviors such as stress, weight loss, and excessive physical exercise that are known to negatively impact gonadal axis activity. METHODS: In this overview, we described the most common forms of FHA, in particular stress-induced amenorrhea and overtraining-induced amenorrhea. In addition, although its mechanisms can differ from those involved in FHA, we reviewed the available literature on drug-induced amenorrhea, highlighting the clear connection between this condition and psychoactive drugs such as antipsychotics, antidepressants and anti-epilectics thus raising concern about the role that the abuse of substances such as opioids or alcohol can possibly have on the growing unexplained infertility of the female population.


Assuntos
Amenorreia/etiologia , Amenorreia/patologia , Doenças Hipotalâmicas/complicações , Psicotrópicos/efeitos adversos , Feminino , Humanos , Prognóstico
14.
Proc Natl Acad Sci U S A ; 114(50): E10622-E10631, 2017 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-29208716

RESUMO

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207-1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems.

15.
Proc Natl Acad Sci U S A ; 112(4): 1001-6, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25583477

RESUMO

Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the surface drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.

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