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1.
Hum Reprod ; 36(9): 2443-2451, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34223605

RESUMO

STUDY QUESTION: Is anogenital distance (AGD) shorter in testicular cancer (TC) survivors than in men from the general population, and is AGD affected by testosterone replacement therapy in adulthood? SUMMARY ANSWER: AGD, measured as distance from anus to scrotum (AGDas), is shorter in TC survivors and does not change as a result of testosterone replacement therapy. WHAT IS KNOWN ALREADY: Animal studies have shown that AGD is a postnatal 'read-out' of foetal androgen action, and short AGD in male offspring is considered a sign of feminization caused by in utero disruption of the reproductive system. Likewise, measurement of AGD in human studies has suggested AGD to be part of the testicular dysgenesis syndrome hypothesis, which proposes that male reproductive disorders, such as hypospadias, cryptorchidism, some cases of impaired semen quality and TC, all share a common foetal origin. STUDY DESIGN, SIZE, DURATION: The aim was to assess AGD in men with a history of TC and controls, and furthermore to examine AGD during testosterone replacement therapy in adulthood. Study participants were TC survivors with a mild Leydig cell insufficiency who participated in a randomized double-blind study of testosterone replacement therapy versus placebo for 52 weeks (N = 69). Men from the general population were prospectively included from a study on testicular function as controls (N = 67). PARTICIPANTS/MATERIALS, SETTING, METHODS: We measured two variants of AGD; as our primary outcome the anoscrotal distance (AGDas) measured from the centre of the anus to the posterior base of the scrotum, and secondarily the anopenile distance (AGDap) measured from the anus to the cephalad insertion of the penis. Using multiple regression analysis, the mean difference in AGD between TC survivors and men from the general population was assessed, adjusted for height, BMI and examiner. Next, AGD was measured before and after 52 weeks of treatment with testosterone or placebo, and with covariance analysis differences between the two groups at follow-up was assessed after adjustment for baseline AGD, examiner, BMI and change in BMI during treatment. MAIN RESULTS AND THE ROLE OF CHANCE: TC survivors had a shorter AGDas (-0.84 cm, 95% CI: -1.31; -0.37) compared to men from the general population, and AGDas did not differ between the testosterone and placebo treated group at follow-up (0.11 cm, 95% CI: -0.22; 0.44). In contrast, AGDap was not shorter in TC survivors after adjustment (0.05 cm, 95% CI: -0.30; 0.39), and was 0.48 cm longer (95% CI: 0.13; 0.82) at follow-up in the testosterone treated compared to the placebo-treated group. LIMITATIONS, REASONS FOR CAUTION: A limitation of the study is that the number of included men was limited, and results need confirmation in a larger study. Furthermore, TC survivors were significantly older than controls. For the comparison of AGD in TC survivors and controls, it was not possible to conduct the examinations with the examiner being blinded to which group he was examining, and it cannot be excluded that this can cause a bias. WIDER IMPLICATIONS OF THE FINDINGS: The shorter AGDas in TC survivors compared to controls, which did not change upon adult testosterone replacement therapy, supports the hypothesis that reduced AGD is part of the testicular dysgenesis syndrome and may be a marker of disrupted foetal testicular development. By contrast, AGDap was not shorter in TC survivors and might be modestly sensitive to adult testosterone treatment, and thus inferior to AGDas as a constant postnatal marker of the foetal androgen environment. STUDY FUNDING/COMPETING INTEREST(S): Expenses were paid by the Department of Oncology, Copenhagen University Hospital, Rigshospitalet. Kiowa Kirin International covered expenses for Tostran and placebo. The Danish Cancer Society, The Danish Cancer Research Foundation, the Preben & Anna Simonsen Foundation, and Rigshospitalet have supported the study. L.P. was financed by the Research Fund of the Capital Region of Denmark. The authors have no competing interests. TRIAL REGISTRATION NUMBER: Part of the study is based on men participating in a randomized controlled trial registered at ClinicalTrials.gov, NCT02991209, 25 November 2016.


Assuntos
Neoplasias Testiculares , Adulto , Canal Anal , Animais , Humanos , Masculino , Estudos Prospectivos , Análise do Sêmen , Sobreviventes , Testosterona
2.
Stud Mycol ; 96: 155-184, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32774511

RESUMO

Typhuloid fungi are a very poorly known group of tiny clavarioid homobasidiomycetes. The phylogenetic position and family classification of the genera targeted here, Ceratellopsis, Macrotyphula, Pterula sensu lato and Typhula, are controversial and based on unresolved phylogenies. Our six-gene phylogeny with an expanded taxon sampling shows that typhuloid fungi evolved at least twice in the Agaricales (Pleurotineae, Clavariineae) and once in the Hymenochaetales. Macrotyphula, Pterulicium and Typhula are nested within the Pleurotineae. The type of Typhula (1818) and Sclerotium (1790), T. phacorrhiza and S. complanatum (synonym T. phacorrhiza), are encompassed in the Macrotyphula clade that is distantly related to a monophyletic group formed by species usually assigned to Typhula. Thus, the correct name for Macrotyphula (1972) and Typhula is Sclerotium and all Typhula species but those in the T. phacorrhiza group need to be transferred to Pistillaria (1821). To avoid undesirable nomenclatural changes, we suggest to conserve Typhula with T. incarnata as type. Clavariaceae is supported as a separate, early diverging lineage within Agaricales, with Hygrophoraceae as a successive sister taxon to the rest of the Agaricales. Ceratellopsis s. auct. is polyphyletic because C. acuminata nests in Clavariaceae and C. sagittiformis in the Hymenochaetales. Ceratellopsis is found to be an earlier name for Pterulicium, because the type, C. queletii, represents Pterulicium gracile (synonym Pterula gracilis), deeply nested in the Pterulicium clade. To avoid re-combining a large number of names in Ceratellopsis we suggest to conserve it with C. acuminata as type. The new genus Bryopistillaria is created to include C. sagittiformis. The families Sarcomyxaceae and Phyllotopsidaceae, and the suborder Clavariineae, are described as new. Six new combinations are proposed and 15 names typified.

3.
Soc Psychiatry Psychiatr Epidemiol ; 55(11): 1457-1468, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32409884

RESUMO

PURPOSE: To investigate the psychiatric healthcare utilisation of refugees vis-à-vis their peers in Denmark during the ages 15-22. METHODS: This paper utilises comprehensive full-population registry data from 1995 to 2016 to explore the psychiatric healthcare utilisation during the transition from childhood to adulthood for refugees (N = 13,027), a comparison group of children of labour migrants from Morocco, Pakistan, and Turkey (N = 13,413), and the majority population (N = 693,043) in Denmark. To test for population differences in types of admission for particular types of disorders, odds ratios for a first contact during ages 15-22 were calculated using logistic regression. For those with at least one diagnosis-specific hospital contact, differences in the amount and type of treatment were tested using negative binomial regression to estimate means ratios of days hospitalised, days in outpatient care, number of outpatient contacts, consultations with psychiatrists in private practice, and prescribed medicine purchases. RESULTS: Refugees and the comparison group were generally less likely than the majority population to have a first contact for most disorders (adjusted ORs 0.03-0.88), but not for schizophrenia for boys (adjusted ORs 0.92-2.13). Among those who did have a first contact, youths from the ethnic minority groups tended to have more or similar inpatient and emergency room contacts (MRs 0.89-2.10), hospitalisations of refugee girls being an exception (MR 0.46; CI [0.23-0.94]), but fewer outpatient contacts, consultations with psychiatrists in private practice, and prescribed medicine purchases (MRs 0.23-0.94). CONCLUSIONS: The results suggest that refugee and other ethnic minority groups may face barriers both to initial contact and to completing adequate treatment beyond the first contact.


Assuntos
Serviços de Saúde Mental , Refugiados , Adolescente , Adulto , Criança , Dinamarca/epidemiologia , Etnicidade , Feminino , Humanos , Masculino , Grupos Minoritários , Marrocos , Paquistão , Refugiados/psicologia , Turquia , Adulto Jovem
4.
Hum Reprod ; 33(11): 1963-1974, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30247578

RESUMO

STUDY QUESTION: Are infertile men with reduced semen quality at risk of a further decrease in testicular function? SUMMARY ANSWER: Infertile men with severely reduced semen quality risk further deterioration of semen quality 15 years after treatment for infertility, and a lower baseline sperm concentration was associated with a more pronounced increase in LH and decrease in testosterone/LH ratio at follow-up. WHAT IS KNOWN ALREADY: Male factors account for up to 50% of human infertility. The most common finding is spermatogenic failure (SgF) yet the life course of semen quality and testosterone production in such men has not been described. STUDY DESIGN, SIZE, DURATION: A follow-up study of men with SgF was performed 15 years after the initial infertility assessment between January 1995 and December 2000. PARTICIPANTS/MATERIALS, SETTING, METHODS: Hospital records were used to identify potential participants in the study. A total of 137 men with primary male infertility due to SgF and 70 controls with good semen quality from couples with female factor infertility who attended a tertiary referral centre were included: the participation rate was 31% and 26%, respectively. The men provided semen samples and underwent a physical examination. Blood samples were taken to measure levels of reproductive hormones (FSH, LH, testosterone, sex hormone-binding globulin, estradiol and inhibin B). Current results were compared with results from the initial assessments. MAIN RESULTS AND THE ROLE OF CHANCE: At the time of follow up the SgF men had significantly lower Leydig cell capacity than the control group as well as much lower semen quality. For the SgF men, between baseline sampling and follow up, the median sperm concentration decreased from 1.9 to 0.6 mill/ml and total sperm count from 7.7 to 2.0 million (P = 0.019 and 0.012, respectively), and 10% developed azoospermia. Calculated free testosterone (cFT), but not total testosterone (tT) decreased in the SgF group by ~0.6% (95% CI 0.1-1.2%) per year. In the SgF group, LH increased by 1.6% (CI 0.9-2.3%) annually, and consequently tT/LH and cFT/LH ratios had decreased by 1.3% (CI 0.5-2.1) and 2.1% (CI 1.2-3.0%), respectively. The increase in LH and the decreases in tT/LH and cFT/LH ratios were more pronounced in men with lower baseline sperm concentrations. LIMITATIONS, REASONS FOR CAUTION: We consider the case group as representative of infertile men not in need of testosterone treatment at baseline investigation, but do not have information on those that chose not to participate in the follow-up study. There were alterations in some hormone analysis methods during the follow-up period that may introduce uncertainty in interpretation of long-term changes in hormone levels despite rigorous quality control. The validity of the control group suffers from a lack of hormone values at baseline. Also, at follow-up, for practical reasons only one semen sample could be obtained, which makes the effect estimate more uncertain and there is a risk of non-differential misclassification. WIDER IMPLICATIONS OF THE FINDINGS: Without being able to predict individual outcomes, it is prudent to consider sperm cryopreservation or advise not to postpone fertility treatment when men present with infertility due to impaired semen quality. Whether partly compensated Leydig cell insufficiency in men with SgF will eventually develop into overt testosterone deficiency cannot be determined from our study. STUDY FUNDING/COMPETING INTEREST(s): Aase and Einar Danielsen (Grant no. 10-001053), Nordic Research Committee (Grant no. 5109), The Kirsten and Freddie Johansen Fund, and Rigshospitalet's Research Fund (grant no. R24-A812). There are no competing interests.


Assuntos
Infertilidade Masculina/sangue , Células Intersticiais do Testículo/fisiologia , Contagem de Espermatozoides/estatística & dados numéricos , Motilidade dos Espermatozoides/fisiologia , Adulto , Estudos de Casos e Controles , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Infertilidade Masculina/fisiopatologia , Estudos Longitudinais , Hormônio Luteinizante/sangue , Masculino , Testosterona/sangue
5.
Diabet Med ; 34(6): 800-803, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28326618

RESUMO

AIM: To compare HbA1c and fasting plasma glucose assessment, with the 2-h oral glucose tolerance test as reference, in screening for diabetes in people with turberculosis. METHODS: Individuals (N=268) with newly diagnosed smear-positive tuberculosis were screened for diabetes at a tertiary hospital in Lahore, Pakistan. Diabetes diagnosis was based on WHO criteria: thresholds were ≥48 mmol/mol (≥6.5%) for HbA1c and ≥7.0mmol/l for fasting plasma glucose. RESULTS: The proportion of participants diagnosed with diabetes was 4.9% (n =13) by oral glucose tolerance test, while 11.9% (n =32) and 14.6% (n =39) were diagnosed with diabetes using HbA1c and fasting plasma glucose criteria, respectively. The area under the receiver-operating characteristic curve was 0.79 (95% CI 0.64 to 0.94) for HbA1c and 0.61 (95% CI 0.50 to 0.73) for fasting plasma glucose, with a borderline significant difference between the two tests (P=0.07). CONCLUSIONS: HbA1c and fasting plasma glucose performed equally in terms of diagnosing new diabetes cases in individuals with tuberculosis, but the proportion of participants falsely classified as positive was higher for fasting plasma glucose. This may be explained by acute blood glucose fluctuations when using fasting plasma glucose. HbA1c may be a more reliable test in individuals with transient hyperglycaemia.


Assuntos
Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Jejum/sangue , Hemoglobinas Glicadas/análise , Programas de Rastreamento/métodos , Tuberculose/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Diabetes Mellitus Tipo 2/complicações , Reações Falso-Positivas , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Paquistão , Tuberculose/complicações
6.
Hum Reprod ; 31(5): 947-57, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26936886

RESUMO

STUDY QUESTION: Is the Leydig cell function of young European men associated with semen quality? SUMMARY ANSWER: Compensated reduction in Leydig cell function, defined as increased LH concentration combined with adequate testosterone production is associated with lower semen quality. WHAT IS ALREADY KNOWN: Semen quality of young European men shows a heterogeneous pattern. Many have sperm counts below and in the lower WHO reference where there nevertheless is a significant risk of subfecundity. Little is known about differences in Leydig cell function between men with semen quality below and within the WHO reference range. STUDY DESIGN, SIZE AND DURATION: A coordinated, cross-sectional population-based study of 8182 men undertaken in 1996-2010. PARTICIPANTS, SETTING AND METHOD: Young men (median age 19.1 years) were investigated in centres in Denmark, Estonia, Finland, Germany Latvia, Lithuania, and Spain. The men originated from the general populations, all were young, almost all were unaware of their fecundity and each provided a semen and blood sample. Associations between semen parameters and serum levels of testosterone and luteinising hormone (LH), calculated free testosterone, and ratios between serum testosterone and LH were determined. MAIN RESULT AND ROLE OF CHANCE: Serum testosterone levels were not associated with sperm concentrations, total sperm counts, or percentage of motile or morphologically normal spermatozoa. There was an inverse association between the semen parameters and serum LH levels, and accordingly a positive association to testosterone/LH ratio and calculated-free-testosterone/LH ratio. LIMITATIONS, REASON FOR CAUTION: The size of the study mitigates the intra-individual variability concern. The distinction between different sub-categories of sperm motility and sperm morphology is subjective despite training. However, inter-observer variation would tend towards non-differential misclassification and would decrease the likelihood of detecting associations between reproductive hormone levels and semen variables, suggesting that the presented associations might in reality be even stronger than shown. Although we adjusted for confounders, we cannot of course exclude that our results can be skewed by selection bias or residual confounding. WIDER IMPLICATIONS OF THE FINDINGS: Compensated reduction in Leydig cell function, defined as increased LH concentration combined with adequate testosterone production is associated with lower semen quality. This is apparent even within the WHO reference range of semen quality. It is unknown whether impaired Leydig cell function in young men may confer an increased risk of acquired testosterone deficiency later in life. STUDY FUNDING/COMPETING INTERESTS: Support from The Research Fund of Rigshospitalet (grant no. R42-A1326) to N.J. made this study possible. The background studies of young men have been supported economically by several grants. ITALIC! Denmark: The European Union (contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT-2002-00603 and most recently FP7/2007-2013, DEER Grant agreement no. 212844), The Danish Research Council (grants nos. 9700833 2107-05-0006), The Danish Agency for Science, Technology and Innovation (Grant no. 271070678), Rigshospitalet (Grant no. 961506336), The University of Copenhagen (Grant no. 211-0357/07-3012), The Danish Ministry of Health and the Danish Environmental Protection Agency, A.P. Møller and wife Chastine McKinney Møllers foundation, and Svend Andersens Foundation. ITALIC! Finland: European Union (contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT- 2002-00603 and most recently FP7/2008-2012, DEER Grant agreement no. 212844), The Academy of Finland, Turku University Hospital Funds, Sigrid Juselius Foundation. ITALIC! Estonia, Latvia and Lithuania: European Union (QLRT-2001-02911), the Estonian Science Foundation, grant number 2991, Lithuanian Foundation for Research, Organon Agencies B.V. and the Danish Research Council, grant no. 9700833. ITALIC! Germany: European Union (contract numbers QLK4-CT-2002-00603). ITALIC! Spain: European Commission QLK4-1999-01422. M.F. received support from the Spanish Ministry of Science and Innovation (Program Ramon y Cajal). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. None of the authors have any competing interests to declare.


Assuntos
Células Intersticiais do Testículo/fisiologia , Análise do Sêmen , Adulto , Estudos Transversais , Europa (Continente) , Fertilidade , Humanos , Hormônio Luteinizante/sangue , Masculino , Estudos Prospectivos , Valores de Referência , Testosterona/sangue
7.
Ultrasound Obstet Gynecol ; 46(3): 312-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25580809

RESUMO

OBJECTIVE: To study the effect of initial simulation-based transvaginal sonography (TVS) training compared with clinical training only, on the clinical performance of residents in obstetrics and gynecology (Ob-Gyn), assessed 2 months into their residency. METHODS: In a randomized study, new Ob-Gyn residents (n = 33) with no prior ultrasound experience were recruited from three teaching hospitals. Participants were allocated to either simulation-based training followed by clinical training (intervention group; n = 18) or clinical training only (control group; n = 15). The simulation-based training was performed using a virtual-reality TVS simulator until an expert performance level was attained, and was followed by training on a pelvic mannequin. After 2 months of clinical training, one TVS examination was recorded for assessment of each resident's clinical performance (n = 26). Two ultrasound experts blinded to group allocation rated the scans using the Objective Structured Assessment of Ultrasound Skills (OSAUS) scale. RESULTS: During the 2 months of clinical training, participants in the intervention and control groups completed an average ± SD of 58 ± 41 and 63 ± 47 scans, respectively (P = 0.67). In the subsequent clinical performance test, the intervention group achieved higher OSAUS scores than did the control group (mean score, 59.1% vs 37.6%, respectively; P < 0.001). A greater proportion of the intervention group passed a pre-established pass/fail level than did controls (85.7% vs 8.3%, respectively; P < 0.001). CONCLUSION: Simulation-based ultrasound training leads to substantial improvement in clinical performance that is sustained after 2 months of clinical training. © 2015 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Competência Clínica , Ginecologia/educação , Internato e Residência , Obstetrícia/educação , Treinamento por Simulação , Ultrassonografia Pré-Natal , Adulto , Dinamarca , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Gravidez , Método Simples-Cego
8.
Hum Reprod ; 27(10): 3074-84, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22791754

RESUMO

STUDY QUESTION: Is it possible to define an optimal dose of hCG in combination with rFSH from the first day of stimulation in the GnRH agonist protocol applied to IVF? SUMMARY ANSWER: Supplementation with hCG from the first day of stimulation may increase the number of top-quality embryos per patient. Daily doses of hCG up to 150 IU are compatible with good live birth rates. A ceiling level of estradiol (E(2)) was reached with hCG doses above 100 IU/day. A positive dose-response was seen for pre-ovulatory progesterone, but concentrations remained below values for which an impairment of endometrial receptivity has been previously reported. We suggest a large clinical trial to be proceeded with a group given 100 IU hCG daily versus a control group. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: Prospective multicentre studies have indicated increased live birth rates and increased number of top-quality embryos when low doses of hCG were associated with FSH. We analysed the clinical, embryological and endocrine aspects of adding increasing doses of hCG to rFSH from the first day of stimulation for IVF. DESIGN: A prospective randomized, controlled, open-label dose-response pilot study was conducted between February 2009 and June 2010 at Copenhagen University Hospital, Rigshospitalet, Denmark. Adequate allocation concealment was assured from sequentially numbered, opaque, sealed envelopes prepared from a computer-generated list. Scoring of the embryos was done in an assessor-blinded way. PARTICIPANTS AND SETTING: Endocrinologically normal IVF patients aged 25-37 years, BMI 18-30 kg/m(2), regular cycles and FSH <12 IU/l, were treated with a fixed dose of rFSH 150 IU/day and randomized to daily hCG dose of 0, 50, 100 or 150 IU from Day 1 of stimulation. Primary end-point was the total number of top-quality embryos on Day 3. DATA ANALYSIS METHOD: Data were analysed by analysis of variance, Kruskal-Wallis test, chi-squared test or Poisson distribution count. MAIN FINDINGS: A total of 62 patients were randomized into four hCG dose groups: Dose 0 (D0; n= 16), Dose 50 (D50; n= 15), Dose 100 (D100; n= 16) and Dose 150 (D150; n= 15). Two patients in D150 were withdrawn after randomization because of major (10- to 30-fold) hCG dosing errors, leaving 13 patients in this group. Thus, the results are based on the per protocol population. The mean numbers of top-quality embryos per patient were D0: 0.8 ± 1.2, D50: 0.5 ± 0.7, D100: 1.2 ± 1.7 and D150: 1.5 ± 1.7 (P= 0.04). All pregnancies were singleton gestations, and the live birth rates per started cycle were D0: 25%, D50: 27%, D100: 25% and D150: 31% (P= 0.98). Steady state level of serum (s)-hCG was reached on Day 6 of stimulation. S-hCG levels (IU/l) on the day of hCG administration were D0: <0.1, D50: 3.1 (2.6-3.6), D100: 5.5 (4.1-7.4) and D150: 11.0 (8.9-13.6) (P< 0.01). The patients receiving hCG supplementation were stratified by 33 and 66% percentiles into three groups according to the concentration of s-hCG on Day 6 of stimulation: 0.5-3.5 IU/l (n= 16), 3.5-8.0 IU/l (n= 14) and 8.0-21.1 IU/l (n= 14). The mean numbers of top-quality embryos in the three groups were 0.5 ± 0.9, 1.1 ± 1.8 and 1.5 ± 1.5, respectively (P= 0.03). The progesterone increments from stimulation Day 1 to the day of hCG triggering were D0 = 49%, D50 = 79%, D100 = 110% and D150 = 160% (P= 0.02). S-androstenedione level was highest in D150 (P< 0.01). S-E(2) was 2-fold higher in the D100 and D 150 compared with D0 (P= 0.09). BIAS, LIMITATION, GENERALISABILITY: Our study has a limited sample size. Supplementation with daily hCG dose up to 150 IU throughout stimulation has never been used before. Hence, this had to be tested in a small study before conducting a larger trial. STUDY FUNDING/COMPETING INTERESTS: Ferring Pharmaceuticals, Research and Development, provided funds for the endocrine measurements. CLINICALTRIAL.GOV REGISTRATION: NCT00844311.


Assuntos
Gonadotropina Coriônica/administração & dosagem , Hormônio Foliculoestimulante/administração & dosagem , Indução da Ovulação/métodos , Proteínas Recombinantes de Fusão/administração & dosagem , Substâncias para o Controle da Reprodução/administração & dosagem , Adulto , Gonadotropina Coriônica/efeitos adversos , Gonadotropina Coriônica/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Fertilização in vitro , Hormônio Foliculoestimulante/efeitos adversos , Hormônio Foliculoestimulante/uso terapêutico , Humanos , Recuperação de Oócitos , Projetos Piloto , Gravidez , Resultado da Gravidez , Proteínas Recombinantes de Fusão/efeitos adversos , Proteínas Recombinantes de Fusão/uso terapêutico , Substâncias para o Controle da Reprodução/efeitos adversos , Substâncias para o Controle da Reprodução/uso terapêutico
9.
Int J Androl ; 35(3): 216-26, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22428786

RESUMO

Phthalates are a group of chemicals present in numerous consumer products. They have anti-androgenic properties in experimental studies and are suspected to be involved in human male reproductive health problems. A few studies have shown associations between phthalate exposure and changes in pubertal timing among girls, although controversies exist. We determined the concentration of 12 phthalate metabolites in first morning urine samples from 725 healthy Danish girls (aged 5.6-19.1 years) in relation to age, pubertal development (breast and pubic hair stage) and reproductive hormone levels (luteinizing hormone, oestradiol and testosterone). Furthermore, urinary phthalates were determined in 25 girls with precocious puberty (PP). In general, the youngest girls with less advanced pubertal development had the highest first morning urinary concentration of the monobutyl phthalate isoforms (∑MBP((i+n))), monobenzyl phthalate (MBzP), metabolites of di-(2-ethylhexyl) phthalate (∑DEHPm) and of di-iso-nonyl phthalate (∑DINPm). After stratification of the urinary phthalate excretion into quartiles, we found that the age at pubarche was increasing with increasing phthalate metabolite quartiles (except for MEP). This trend was statistically significant when all phthalate metabolites (except MEP) were summarized and expressed as quartiles. No association between phthalates and breast development was observed. In addition, there were no differences in urinary phthalate metabolite levels between girls with PP and controls. We demonstrated that delayed pubarche, but not thelarche, was associated with high phthalate excretion in urine samples from 725 healthy school girls, which may suggest anti-androgenic actions of phthalates in our study group of girls.


Assuntos
Ácidos Ftálicos/urina , Puberdade/efeitos dos fármacos , Adolescente , Mama/efeitos dos fármacos , Mama/crescimento & desenvolvimento , Criança , Pré-Escolar , Dinamarca , Poluentes Ambientais/farmacologia , Poluentes Ambientais/urina , Feminino , Cabelo/crescimento & desenvolvimento , Humanos , Puberdade Precoce/induzido quimicamente , Puberdade Precoce/urina , População Branca , Adulto Jovem
10.
Int J Androl ; 35(4): 499-510, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22404291

RESUMO

Vitamin D (VD) is important for male reproduction in mammals and the VD receptor (VDR) and VD-metabolizing enzymes are expressed in human spermatozoa. The VD-inactivating enzyme CYP24A1 titrates the cellular responsiveness to VD, is transcriptionally regulated by VD, and has a distinct expression at the sperm annulus. Here, we investigated if CYP24A1 expression serves as a marker for VD metabolism in spermatozoa, and whether CYP24A1 expression was associated with semen quality. We included 130 men (53 healthy young volunteers and 77 subfertile men) for semen analysis and immunocytochemical (ICC) detection of CYP24A1. Another 40 men (22 young, 18 subfertile) were tested for in vitro effects of 1,25(OH)(2)D(3) on intracellular calcium concentration ([Ca(2+)](i)) and sperm motility. Double ICC staining showed that CYP24A1 and VDR were either concomitantly expressed or absent in 80% of the spermatozoa from young men. The median number of CYP24A1-expressing spermatozoa was 1% in subfertile men and thus significantly (p < 0.0005) lower than 25% in spermatozoa from young men. Moreover, CYP24A1 expression correlated positively with total sperm count, -concentration, -motility and -morphology (all p < 0.004), and the percentage of CYP24A1-positive spermatozoa increased (15 vs. 41%, p < 0.0005) after percoll-gradient-centrifugation. We noticed that the presence of >3% CYP24A1-positive spermatozoa distinguished young men from subfertile men with a sensitivity of 66.0%, a specificity of 77.9% and a positive predictive value of 98.3%. Functional studies revealed that 1,25(OH)(2)D(3) increased [Ca(2+)](i) and sperm motility in young healthy men, while 1,25(OH)(2)D(3) was unable to increase motility in subfertile patients. In conclusion, we suggest that CYP24A1 expression at the annulus may serve as a novel marker of semen quality and an objective proxy for sperm function.


Assuntos
Infertilidade Masculina/diagnóstico , Análise do Sêmen/métodos , Espermatozoides/enzimologia , Esteroide Hidroxilases/biossíntese , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/biossíntese , Adulto , Biomarcadores , Cálcio , Colestanotriol 26-Mono-Oxigenase/biossíntese , Família 2 do Citocromo P450 , Humanos , Masculino , Receptores de Calcitriol/metabolismo , Contagem de Espermatozoides , Motilidade dos Espermatozoides/fisiologia , Espermatozoides/metabolismo , Vitamina D/metabolismo , Vitamina D3 24-Hidroxilase , Adulto Jovem
11.
Trop Med Int Health ; 17(2): 223-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22032340

RESUMO

OBJECTIVES: Refugees and immigrants are likely to be vulnerable to mortality from infectious diseases as a result of high prevalences in their countries of origin and barriers in access to healthcare in the recipient countries. Consequently, we aimed to compare and investigate differences in mortality from infectious diseases among refugees and immigrants and native Danes. METHODS: A register-based, historical prospective cohort design. All refugees (n=29139) and family-reunited immigrants (n=27134) who, between 1 January1993 and 31 December1999, were granted the right to reside in Denmark were included and matched 1:4 on age and sex with native Danes. Civil registration numbers were cross-linked to the Register of Causes of Death, and fatalities owing to infectious diseases (based on ICD-10 diagnosis) were identified. Mortality ratios were estimated separately for men and women by migrant status and region of birth; adjusting for age and income; using a Cox regression model, after a mean follow-up of 10-12years after arrival. RESULTS: Female [hazard ratio (HR)=4.15; 95% CI: 2.38, 7.25] and male (HR=2.05; 95% CI: 1.27, 3.33) refugees experienced significantly higher mortality risks from infectious diseases than did native Danes, as was the case for male immigrants (HR=2.39; 95% CI: 1.20, 4.76) but less so for female immigrants (HR=1.23; 95% CI: 0. 50-3.01). Mortality by region of origin was notably higher for individuals from North Africa and sub-Saharan Africa. CONCLUSIONS: Higher mortality among refugees and immigrants than among the native population should lead to reflections on medical reception systems in recipient countries and subsequent possibilities of access to specialised diagnostic and curative healthcare.


Assuntos
Doenças Transmissíveis/mortalidade , Emigrantes e Imigrantes , Acessibilidade aos Serviços de Saúde , Refugiados , Adulto , África Subsaariana/etnologia , África do Norte/etnologia , Causas de Morte , Estudos de Coortes , Dinamarca/epidemiologia , Feminino , Seguimentos , História do Século XX , Humanos , Masculino , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores Sexuais , Adulto Jovem
12.
Andrology ; 8(2): 315-322, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31373436

RESUMO

BACKGROUND: Lower semen quality is associated with increased mortality and morbidity, which may include osteoporosis. OBJECTIVE: To assess whether infertile men have a lower bone mineral density (BMD) compared with fertile men at the time of fertility workup. METHODS: A total of 146 men from infertile couples with unexplained impaired semen quality, characterized by sperm concentration < 20 million/mL, progressive motility < 50% or < 12% morphologically normal spermatozoa. Men with infertility due to a genetic etiology or a condition that could cause testicular damage were excluded. A total of 271 men from couples with an ongoing naturally conceived pregnancy served as a control group. Lumbar, femoral, and total body BMD were measured by dual X-ray absorptiometry. RESULTS: Infertile men had similar BMD compared with fertile men (Beta coefficient (g/cm2 ) and 95% confidence interval for the difference between the two groups: -0.02 (-0.05; 0.01) for lumbar BMD, -0.02 (-0.05; 0.01) for femoral neck BMD, -0.01 (-0.04; 0.02) for total femur BMD, and -0.01 (-0.03; 0.01) for total body BMD). Semen parameters were not associated with BMD measurements. Furthermore, BMD did not differ between infertile men with the lowest semen quality vs. infertile men with better semen quality nor between infertile men with low testosterone vs. fertile men with normal testosterone levels. CONCLUSION: Bone mineral density is preserved in men with unexplained infertility at the time of fertility workup.


Assuntos
Densidade Óssea , Infertilidade Masculina , Adulto , Estudos de Casos e Controles , Humanos , Masculino
13.
Ann Oncol ; 19(11): 1910-4, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18632724

RESUMO

BACKGROUND: A possible association between the polymorphic CAG repeat in the DNA polymerase gamma (POLG) gene and the risk of testicular germ-cell tumours (TGCT) was investigated in this study. The hypothesis was prompted by an earlier preliminary study proposing an association of the absence of the common 10-CAG-long POLG allele with testicular cancer as well as previously reported in some European populations' association with male subfertility, which is a condition carrying an increased risk of TGCT. PATIENTS AND METHODS: The number of CAG repeats in both POLG alleles was established in 243 patients with TGCT and in 869 controls by the analysis of the genomic DNA fragment. RESULTS: A significantly higher proportion of men homozygous allele of other than the common 10 CAG repeats was found among the patients with TGCT in comparison to the controls (4.9% versus 1.3%, respectively, P = 0.001). The vast majority of the homozygous patients had a seminoma (11 of 12; 97%), despite that only about half (55%) of the studied patients had this tumour type. CONCLUSIONS: The findings indicate that the POLG polymorphism may be a contributing factor in the pathogenesis of TGCT particularly in seminoma, but the mechanisms remain to be elucidated.


Assuntos
DNA Polimerase Dirigida por DNA/genética , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Testiculares/genética , Repetições de Trinucleotídeos , Adulto , Alelos , Estudos de Casos e Controles , DNA Polimerase gama , Genótipo , Humanos , Masculino , Estadiamento de Neoplasias , Neoplasias Embrionárias de Células Germinativas/enzimologia , Neoplasias Embrionárias de Células Germinativas/patologia , Polimorfismo Genético , Neoplasias Testiculares/enzimologia , Neoplasias Testiculares/patologia
14.
Andrology ; 6(2): 286-292, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29266868

RESUMO

Impaired semen quality is frequent in Western countries and is the main reason or contributing reason in up to 50% of cases of couple infertility. Male factor infertility is mainly determined by examination of semen samples according to the World Health Organization's 2010 guidelines. AMH has both autocrine and paracrine properties through a direct effect via the AMH type II receptor and is therefore thought to be involved in spermatogenesis. We aimed to study the association between the serum concentration of AMH and semen quality in a cross-sectional study including 970 young Danish men from the general population. All participants provided a semen sample, had a blood sample drawn, underwent a physical examination, and answered a questionnaire including information on lifestyle and medical history. Serum concentrations of reproductive hormones [AMH, luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), calculated free T, oestradiol (E2) and inhibin B] and semen parameters (semen volume, sperm concentration, and percentages of motile and morphologically normal spermatozoa) were determined. We found no association between serum AMH and semen quality, except for a significant (p = 0.011) trend for lower percentage of normal morphology with higher AMH. AMH quartile was positively associated with serum inhibin B (p < 0.001), inhibin B/FSH ratio (p < 0.001) and T/E2 ratio (0.016), and negatively associated with FSH (p = 0.004), LH (p = 0.005) and E2 (p = 0.028). There was no association between AMH quartile and T, calculated free T or total T/LH ratio. In conclusion, serum AMH is not useful as a marker of semen quality, and semen analysis using WHO criteria is still the golden standard in the evaluation of the infertile man.


Assuntos
Hormônio Antimülleriano/sangue , Sêmen/fisiologia , Adolescente , Estudos de Coortes , Estudos Transversais , Fertilidade , Humanos , Células Intersticiais do Testículo/fisiologia , Masculino , Análise do Sêmen , Espermatogênese , Adulto Jovem
15.
Endocr Connect ; 7(1): 16-25, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28874401

RESUMO

Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca2+ influx into human sperm cells via the CatSper Ca2+-channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca2+ influx through CatSper, thus mimicking the effect of progesterone on Ca2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on sperm function. We examined 29 UV filters allowed in sunscreens in the US and/or EU for their ability to affect acrosome reaction, penetration, hyperactivation and viability in human sperm cells. We found that, similar to progesterone, the UV filters 4-MBC, 3-BC, Meradimate, Octisalate, BCSA, HMS and OD-PABA induced acrosome reaction and 3-BC increased sperm penetration into a viscous medium. The capacity of the UV filters to induce acrosome reaction and increase sperm penetration was positively associated with the ability of the UV filters to induce a Ca2+ influx. None of the UV filters induced significant changes in the proportion of hyperactivated cells. In conclusion, chemical UV filters that mimic the effect of progesterone on Ca2+ signaling in human sperm cells can similarly mimic the effect of progesterone on acrosome reaction and sperm penetration. Human exposure to these chemical UV filters may impair fertility by interfering with sperm function, e.g. through induction of premature acrosome reaction. Further studies are needed to confirm the results in vivo.

16.
Endocr Connect ; 7(2): 334-346, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29362228

RESUMO

BACKGROUND: Several chemical UV filters/absorbers ('UV filters' hereafter) have endocrine-disrupting properties in vitro and in vivo. Exposure to these chemicals, especially during prenatal development, is of concern. OBJECTIVES: To examine maternal exposure to UV filters, associations with maternal thyroid hormone, with growth factor concentrations as well as to birth outcomes. METHODS: Prospective study of 183 pregnant women with 2nd trimester serum and urine samples available. Maternal concentrations of the chemical UV filters benzophenone-1 (BP-1) and benzophenone-3 (BP-3) in urine and 4-hydroxy-benzophenone (4-HBP) in serum were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The relationships between 2nd trimester maternal concentrations of the three chemical UV filters and maternal serum concentrations of thyroid hormones and growth factors, as well as birth outcomes (weight, height, and head and abdominal circumferences) were examined. RESULTS: Positive associations between maternal serum concentrations of 4-HBP and triiodothyronine (T3), thyroxine (T4), insulin-like growth factor I (IGF-I) and its binding protein IGFBP3 were observed in mothers carrying male fetuses. Male infants of mothers in the middle 4-HBP exposure group had statistically significantly lower weight and shorter head and abdominal circumferences at birth compared to the low exposure group. CONCLUSIONS: Widespread exposure of pregnant women to chemical UV filters and the possible impact on maternal thyroid hormones and growth factors, and on fetal growth, calls for further studies on possible long-term consequences of the exposure to UV filters on fetal development and children's health.

17.
Andrology ; 5(6): 1105-1114, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28992366

RESUMO

Perceived stress has been associated with decreased semen quality but the mechanisms have not been elucidated. It is not known whether cortisol, the major stress hormone in humans, can act directly via receptors in the testis, and whether variants in the gene encoding the glucocorticoid receptor (NR3C1) can possibly modulate the effect. To address these questions, we investigated the expression of the glucocorticoid receptor in human testicular tissue, including adult and fetal samples (n = 20) by immunohistochemical staining, and in silico analysis of publicly available datasets. In the adult testis NR3C1 protein was detected in peritubular cells, a subset of Leydig cells, Sertoli cells (weak), and spermatogonia, but not in spermatids. The NR3C1 expression pattern in fetal testis samples differed by a notably stronger reaction in Sertoli cells, lack of staining in gonocytes but the presence in a subset of pro-spermatogonia, and the almost absent reaction in nascent peritubular cells. In parallel, we explored the association between adult testicular function and three single nucleotide NR3C1 polymorphisms (BcII [rs41423247], 9ß [rs6198], and Tth111I [rs10052957]) affecting glucocorticoid sensitivity. Testicular function was determined by semen analysis and reproductive hormone profiling in 893 men from the general population. The NR3C1 SNP BclI was associated with semen quality in an over-dominant manner with heterozygotes having better semen parameters compared to both homozygote constellations, and with sperm motility showing the strongest association. This association was supported by a higher inhibin B and inhibin B/FSH ratio, as well as a lower FSH in BclI heterozygotes. The SNPs 9ß and Tth111I were not associated with semen parameters. Although the clinical impact of the findings is limited, the results substantiate a suggested link between stress and testicular function. Hence this investigation should be regarded as a discovery study generating hypotheses for future studies.


Assuntos
Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Análise do Sêmen , Testículo/metabolismo , Adolescente , Adulto , Feto , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Adulto Jovem
18.
J Clin Endocrinol Metab ; 91(3): 820-6, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16394092

RESUMO

CONTEXT: Many aspects of hormonal regulation and mechanisms of normal infancy growth are poorly understood. OBJECTIVE: The objective of this study was to establish the determinants of serum growth factor levels in infancy and their association with growth. DESIGN: A prospective, longitudinal, population-based birth cohort between 1997-2001 was studied. PARTICIPANTS: Study participants were 942 healthy appropriate weight for gestational age (AGA) infants (538 boys and 404 girls) and 49 small for gestational age (SGA) children (29 boys and 20 girls). INTERVENTIONS: INTERVENTIONS were anthropometrical measurements (0, 3, 18, and 36 months) and serum samples (3 months). MAIN OUTCOME MEASURES: Height, weight, and serum IGF-I and IGF-binding protein-3 (IGFBP-3) were the main outcome measures. RESULTS: IGF-I levels showed no gender difference [boys, 92 ng/ml (confidence interval, 49, 162); girls, 91 ng/ml (47, 149); P = 0.50]. IGFBP-3 levels were significantly higher in females [2174 ng/ml (1295, 3330)] than in males [2103 ng/ml (1266, 3143); P = 0.04]. Infants receiving breast milk had lower IGF-I levels [90 ng/ml (48, 154)] than infants receiving formula [n = 62; 97 ng/ml (58, 165)] or both [n = 123; 94 ng/ml (48, 169); P < 0.001]. IGF-I and IGFBP-3 levels were positively associated with weight gain and height gain from birth to 3 months of age in AGA, but not in SGA, children. SGA children had significantly lower IGF-I [88.0 ng/ml (28, 145); P = 0.05] and IGFBP-3 [1835 ng/ml (1180, 2793); P < 0.001] levels than AGA children. CONCLUSION: We found a significant, but weak, association between IGF-I and IGFBP-3 levels at 3 months and postnatal growth in AGA, but not SGA, children. Factors other than IGF-I must contribute to the regulation of normal postnatal growth, and these may differ between AGA and SGA children. IGFBP-3, but not IGF-I, showed a gender difference, which may reflect an influence of the postnatal activation of the pituitary-gonadal axis on binding protein levels.


Assuntos
Aleitamento Materno , Crescimento/fisiologia , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , Peso ao Nascer , Estudos de Coortes , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Valores de Referência , Caracteres Sexuais
19.
Clin Chim Acta ; 454: 82-8, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26765096

RESUMO

We report reference ranges based on LC-MS/MS for testosterone (T), free testosterone (FT) and its precursors, i.e. 17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEAS) and androstenedione (Adione), in relation to different health markers and lifestyle factors. The study was based on 304 healthy men aged 30-61 years participating in a population-based cross-sectional study (Health2008). Examination program consisted of a clinical examination, completion of a self-administered questionnaire and blood sampling. Steroid metabolites were measured by a validated and sensitive LC-MS/MS method. Older age-groups were significantly associated with decreased concentrations of DHEA, DHEAS, Adione, and FT, while no significant associations with age were shown for 17-OHP or T. Participants with BMI≥30 kg/m(2) had lower age-related steroid metabolite z-scores compared to participants with BMI<30 kg/m(2), i.e. 17-OHP: -0.51 vs. 0.08 (p<0.001); DHEA: -0.27 vs. 0.09 (p=0.014); Adione: -0.29 vs. 0.09 (p=0.012); T: -0.99 vs. 0.14 (p<0.001); and FT -0.55 vs. 0.05 (p<0.001), respectively. In conclusion, this large study on serum steroid metabolites and concomitant assessment of health markers in healthy men provides age-related reference ranges, and furthermore evaluates the impact of lifestyle factors and metabolic syndrome on androgen metabolite levels.


Assuntos
17-alfa-Hidroxiprogesterona/sangue , Androstenodiona/sangue , Análise Química do Sangue , Desidroepiandrosterona/sangue , Sulfatos/sangue , Testosterona/sangue , Adulto , Biomarcadores/sangue , Cromatografia Líquida , Estudos Transversais , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem
20.
J Clin Endocrinol Metab ; 82(12): 3976-81, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9398699

RESUMO

Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, testosterone, and estradiol all increased significantly between stages I and II of puberty. From stage II of puberty the inhibin B level was relatively constant, whereas the FSH level continued to increase between stages II and III. From stage III of puberty the FSH level was also relatively constant, although there was a nonsignificant trend of slightly decreased FSH levels at pubertal stage V compared to stage IV. The levels of serum LH, testosterone, and estradiol increased progressively throughout puberty. In prepubertal boys younger than 9 yr, there were no correlation between inhibin B and the other three hormones. In prepubertal boys older than 9 yr, a significant positive correlation was observed between inhibin B and FSH, LH, and testosterone. However, at this pubertal stage, each hormone correlated strongly with age, and when the effect of age was taken into account, only the partial correlation between inhibin B and LH/testosterone remained statistically significant. At stage II of puberty, the positive partial correlation between inhibin B and LH/testosterone was still present. At stage III of puberty, an negative partial correlation between inhibin B and FSH, LH, and estradiol was present, whereas no correlation between inhibin B and testosterone could be observed from stage III onward. The negative correlation between inhibin B and FSH persisted from stage III of puberty onward, whereas the correlation between inhibin B and LH and between inhibin B and estradiol was nonsignificant at stages IV and V of puberty. In conclusion, in boys, serum inhibin B levels increase early in puberty; by pubertal stage II the adult level of inhibin B has been reached. The correlation of inhibin B to FSH, LH, and testosterone changes during pubertal development. Early puberty is characterized by a positive correlation between inhibin B and LH/testosterone, but no correlation to FSH. Late puberty (from stage III) is characterized by a negative correlation between inhibin B and FSH (which is maintained in adult men), a diminishing negative correlation between inhibin B and LH, and no correlation between inhibin B and testosterone, suggesting that developmental and maturational processes in the hypothalamic-pituitary-gonadal axis take place, leading to the establishment of the closed loop feedback regulation system operating in adult men. The positive correlation between inhibin B and LH/ testosterone at the time when serum inhibin B levels rise early in puberty suggests that Leydig cell factors may play an important role in the maturation and stimulation of Sertoli cells in the beginning of pubertal development.


Assuntos
Adolescente/fisiologia , Envelhecimento/sangue , Hormônios/sangue , Inibinas/sangue , Puberdade/sangue , Adulto , Criança , Estudos Transversais , Estradiol/sangue , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Valores de Referência , Testosterona/sangue
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