Worldwide Secular Trends in Age at Pubertal Onset Assessed by Breast Development Among Girls - A Systematic Review and Meta-analysis
Title: Worldwide Secular Trends in Age at Pubertal Onset Assessed by Breast Development Among Girls
Previously, a decline in age at breast development has been observed in healthy Danish girls. The objective of the present study was to systematically evaluate published data on pubertal timing based on age at thelarche and evaluate the change in pubertal onset in healthy girls not only in Denmark but worldwide. Main findings of the study were that age at pubertal onset, with thelarche assessed by physical or clinical examination of the breast, decreased by a mean of almost 3 months per decade from 1977 to 2013. The study was published in JAMA Pediatrics. More details on the study can be found here.
EDMaRC PhD dissertation defence
January 22nd, 2020 the EDMaRC Ph.D student Lasse Bøllehuus Hansen will defend his dissertation at Panum, Copenhagen University.
Title: The relationship betweenvitamin D, CYP24A1, FGF23-KLOTHO and male reproduction
Supervisors are Professor Anders Juul, Dr. Martin Blomberg Jensen, Professor Beate Lanske and Professor Emeritus Niels Erik Skakkebæk
EDMaRC PhD dissertation defence
May 3rd, 2019 the EDMaRC Ph.D student cand.med. Alexander S. Busch defended his dissertation at Rigshospitalet.
Title: Factors affecting timing and progression of male puberty
The aim of the dissertation was to explore the physiological course of puberty and to investigate the impact of static and dynamic factors in relation to timing of puberty as well as physiological changes during puberty. The dissertation is based on three original publications . Supervisors have been Professor Anders Juul, MD, PhD, DMSc, and Casper Hagen, MD, PhD, DMSc.
EDMaRC research collaborator Professor Jorma Toppari receives the international KFJ prize
This year Professor Jorma Toppari was by Rigshospitalet awarded the prestigious international KFJ prize. The prize was made possible by a generous donation by Kirsten and Freddy Johansen’s Foundation. Jorma Toppari and EDMaRC collaborators from Rigshospitalet have for more than 20 years investigated the differences in testicular function in Finnish and Danish men. Findings from this collaboration has revealed that prenatal exposure to endocrine disrupting chemicals is associated to an impaired testicular function in adult life including impaired semen quality. The purpose of the KFJ prize is to strengthen this unique international collaboration. A video with a description of the research collaboration between Finland and Denmark can be found here.
From left: Freddy Johansen, Jorma Toppari and Kirsten Johansen at the award ceremony at Rigshospitalet.
The Nodal signaling pathway regulate germ cell development in human fetal testis development
Several EDMaRC researchers co-authored a paper, which was published in Cell Reports yesterday. The study investigated the role of Nodal and Activin signaling in human fetal testis development by using ex vivo culture and xenografting approaches to specifically manipulate these signaling pathways. The study provides novel insights into the involvement of Nodal signaling in the establishment of seminiferous cords and in the regulation of germ cell pluripotency factor expression in human fetal testis. This suggest a key role for Nodal signaling in gonocyte differentiation, which has implications for the understanding of how testicular cancer precursor cells may develop. The study was a collaboration between Danish and Scottish researchers. The full paper can be found here.
EDMaRC Ph.D dissertation defence
November 2nd, 2018 the EDMaRC Ph.D student Malte Stær Nissen will defend his dissertation at Department of Computer Science, University of Copenhagen.
Title: Automatic Motility Analysis of Human Sperm
The aim of the thesis was to investigate and solve problems related to automating sperm quality analyses using new advances within machine learning and computer vision. The dissertation is based on three original publications . Supervisors have been Professor Mads Nielsen, Professor Christian Igel, senior researcher Kristian Almstrup, Professor Anders Juul, CEO Søren Kjærulff and programmer Torben Trindkær Nielsen.
EDMaRC Ph.D dissertation defence
September 21st, 2018 the EDMaRC Ph.D student cand.scient. Lærke Priskorn defended her dissertation at the Panum Institute, University of Copenhagen.
Title: Semen quality in young Danish men – prenatal factors and adult lifestyle
The aim of this dissertation was to elucidate the trends in semen quality and potential prenatal factors and adult lifestyle influencing semen quality in Danish men. The dissertation is based on three original publications . Supervisors have been Professor Katharina Main, MD, PhD Niels Jørgensen, and Professor Tina Kold.
Summary of the dissertation can be found here.
EDMaRC Ph.D dissertation defence
In May 2nd, 2018 the EDMaRC Ph.D student MD Marianna Krause will defend her dissertation at the University of Copenhagen.
Marianna Krause: Exposures and possible endocrine disrupting effects of UV filters on human health
The aim of this dissertation were to map the exposures to UV filters in the assumed most susceptible pouplation groups and to investigate how exposure to UV filters influence development in fetal life. The dissertation is based on three original publications . Supervisors have been Professor Krzysztof Drzewiecki, Professor Niels E Skakkebæk, Senior researcher Anna-Maria Andersson, and Professor Anders Juul.
Abstract from the most recent publication 'Maternal exposure to UV filters: associations with maternal thyroid hormones, IGF-I/IGFBP3 and birth outcomes' can be found here.
The winner of the Danish PhD cup 2018 was EDMaRC PhD student Anders Rehfeld
The Danish PhD cup is an annual recurring event where PhD students are challenged to communicate the main findings from their PhD dissertation in competition with each other. The purpose of the event is to disseminate Danish research to the general public. This year EDMaRC Ph.D student Anders Rehfeld won the PhD cup. Anders Rehfeld's presentation (in Danish) can be found here and the press release (also in Danish) can be found here.
The PhD cup is initiated and developed in collaboration with the Danish newspaper Dagbladet Information, Denmark's largest media enterprise DR (Danish Broadcasting Corporation), and the Lundbeck Foundation. More details on the PhD cup can be found here.
Using the painkiller Ibuprofen affects testosterone production in men
EDMaRC researcher Anders Juul co-authored a paper publised in PNAS this week describing the results of a randomised clinical trial on the effects of ibuprofen use on male reproductive hormone levels. The clinical trial with young men exposed to ibuprofen showed that the analgesic resulted in the clinical condition named “compensated hypogonadism," a condition prevalent among elderly men and associated with reproductive and physical disorders. The study was a collaboration between Danish and French researchers.
Read the abstract here
Mentioning about the study in the press:
Article in Human Reproduction on new method for assessing sperm quality
Danish EDMaRC scientists, led by senior scientist Kristian Almstrup, have developed a new method for assessing sperm quality. The method may be used to predict what kind of fertility treatment childless couples will benefit most from.
Traditionally, semen quality is evaluated in a microscope counting how many sperm cells there are, how well they swim and whether they are malformed or not. However, these parameters are not particularly good at predicting how fertile a man is.
New method of assessing the sperm's ability to fertilize an egg
Researchers from EDMaRC and Department of Growth and Reproduction, Copenhagen University Hospital, have therefore been looking for another method to assess how good sperm cells are to fertilize an egg. To penetrate an egg, sperm cells must pass through a rigid barrier (the egg coat or zona pellucida) surrounding the egg. To facilitate this, sperm cells have an acrosome, which releases enzymes that can break down the barrier. The acrosome can be compared to a hat on top of the sperm head that only can be removed when it meets an egg. The researchers have developed a new method that easily can estimate the number of sperm cells with an intact acrosome, and therefore have the potential to fertilize an egg.
The number of acrosome-intact sperm cells can predict a man's fertility
Examination of semen samples from more than 230 men showed that over half of the sperm cells had already lost their acrosome, just after the samples were made. In other words, less than half of the sperm cells had the ability to fertilize an egg. Indeed, the number of acrosome-intact sperm cells was found to be good in predicting the fertility of men. Men who became fathers by natural intercourse had significantly more sperm cells with an intact acrosome than men in fertility treatment.
Senior researcher Kristian Almstrup, who has been responsible for the study, just published in the journal Human Reproduction, says, "The method allows us to test the fertility of a man in a new way. If a man has few sperm cells with an intact acrosome, then the couple will probably benefit the most from a treatment where a sperm cell is injected directly into the egg. "
Reference: Egeberg Palme DL, Rehfeld A, Bang AK, Nikolova KA, Kjærulff S, Petersen MR, Jeppesen JV, Glensbjerg M, Juul A, Skakkebæk NE, Ziebe S, Jørgensen N, and Almstrup K. Viable acrosome-intact human spermatozoa in the ejaculate as a marker of semen quality and fertility status. Human Reproduction. DOI: 10.1093 / humrep / dex380
Mentioning of the study in the Danish News (in Danish):
EDMaRC research has previously shown that some chemicals, including some chemical UV filters, can affect the processes that regulate the human sperm acrosome reaction (Rehfeld et al. EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner. Endocr Connect. 2018 Jan;7(1):16-25). The new method can also be used to investigate associations between human exposure and premature acrosome reaction in human sperm.
Sperm counts, testicular cancers, and the environment
Editorial published in in British Medical Journal by EDMaRC researcher Niels E Skakkebæk (link to BMJ editorial).
Two EDMaRC Ph.D dissertation defences
In September 2017 two EDMaRC Ph.D students successfully defended their dissertations at the University of Copenhagen.
Anders Rehfeld: Do endocrine disrupting chemicals affect human sperm cell function?
This dissertation on direct effects of environmental chemicals on human sperm cell function in vitro is based on three original publications . A short summary of the dissertations can be read here.
Anders Rehfeld's work has drawn the attention of both national Danish as well as international media including an article on CNN health in 2016.
Loa Nordkap: Are stress and adrenal gland activity associated with semen quality and reproductive hormones in men?
A short summary of the dissertation can be read here.