Menopause, menopausal therapies and asymmetric dimethylarginine, an emerging cardiovascular risk factor

Oestrogenen en asymmetrische dimethylarginine Hart- en vaatziekten (HVZ) vormen de belangrijkste doodsoorzaak in de Westerse wereld. Premenopauzale vrouwen hebben een lager risico op HVZ dan mannen van dezelfde leeftijd, maar na de menopauze neemt de kans op HVZ bij vrouwen snel toe. Door de eierstokken geproduceerde hormonen (oestrogenen en progestagenen) spelen waarschijnlijk een rol bij de bescherming van premenopauzale vrouwen tegen HVZ en mogelijk kan toediening van deze hormonen na de menopauze vrouwen enigszins beschermen tegen de versnelde toename van het risico van HVZ. Asymmetrische dimethylarginine (ADMA) is een stof die door het lichaam zelf wordt gemaakt. Een hoge concentratie van ADMA vermindert een goed functioneren van de bloedvaten en leidt tot een verhoogde kans op HVZ. Of ADMA ook een rol speelt bij de verhoogde kans op HVZ na de menopauze is nog niet eerder onderzocht. Dit proefschrift behandeld het onderzoek naar de relatie tussen oestrogenen en aan oestrogeen verwante stoffen en ADMA bij vrouwen van middelbare leeftijd. Er werd gekeken naar de invloed van de menopauze en naar de effecten van verschillende (hormonale) menopauzale therapieën op ADMA concentraties. De voornaamste bevinding was dat hogere oestrogeen concentraties gepaard gaan met lagere ADMA concentraties. Het ADMA verlagende effect van oestrogeensuppletie was groter bij orale toediening dan bij gebruik van pleisters of spray en bovendien afhankelijk van de gebruikte oestrogeen/progestageen combinatie. Hoewel dit onderzoek laat zien dat vrouwelijke geslachtshormonen ADMA spiegels in gunstige zin beïnvloeden, moeten de klinische consequenties hiervan nog nader onderzocht worden.Kenemans, P. [Promotor]Mooren, M.J. [Copromotor]van der Teerlink, T. [Copromotor

Determination of the morphology of starch granules in cereal endosperm

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Clinical outcomes of uninterrupted embryo culture with or without time-lapse-based embryo selection versus interrupted standard culture (SelecTIMO): a three-armed, multicentre, double-blind, randomised controlled trial.

BACKGROUND: Time-lapse monitoring is increasingly used in fertility laboratories to culture and select embryos for transfer. This method is offered to couples with the promise of improving pregnancy chances, even though there is currently insufficient evidence for superior clinical results. We aimed to evaluate whether a potential improvement by time-lapse monitoring is caused by the time-lapse-based embryo selection method itself or the uninterrupted culture environment that is part of the system. METHODS: In this three-armed, multicentre, double-blind, randomised controlled trial, couples undergoing in-vitro fertilisation or intracytoplasmic sperm injection were recruited from 15 fertility clinics in the Netherlands and randomly assigned using a web-based, computerised randomisation service to one of three groups. Couples and physicians were masked to treatment group, but embryologists and laboratory technicians could not be. The time-lapse early embryo viability assessment (EEVA; TLE) group received embryo selection based on the EEVA time-lapse selection method and uninterrupted culture. The time-lapse routine (TLR) group received routine embryo selection and uninterrupted culture. The control group received routine embryo selection and interrupted culture. The co-primary endpoints were the cumulative ongoing pregnancy rate within 12 months in all women and the ongoing pregnancy rate after fresh single embryo transfer in a good prognosis population. Analysis was by intention to treat. This trial is registered on the ICTRP Search Portal, NTR5423, and is closed to new participants. FINDINGS: 1731 couples were randomly assigned between June 15, 2017, and March 31, 2020 (577 to the TLE group, 579 to the TLR group, and 575 to the control group). The 12-month cumulative ongoing pregnancy rate did not differ significantly between the three groups: 50·8% (293 of 577) in the TLE group, 50·9% (295 of 579) in the TLR group, and 49·4% (284 of 575) in the control group (p=0·85). The ongoing pregnancy rates after fresh single embryo transfer in a good prognosis population were 38·2% (125 of 327) in the TLE group, 36·8% (119 of 323) in the TLR group, and 37·8% (123 of 325) in the control group (p=0·90). Ten serious adverse events were reported (five TLE, four TLR, and one in the control group), which were not related to study procedures. INTERPRETATION: Neither time-lapse-based embryo selection using the EEVA test nor uninterrupted culture conditions in a time-lapse incubator improved clinical outcomes compared with routine methods. Widespread application of time-lapse monitoring for fertility treatments with the promise of improved results should be questioned. FUNDING: Health Care Efficiency Research programme from Netherlands Organisation for Health Research and Development and Merck

ALICE addentum to the Technical Design Report of the time of flight system (TOF)

ALIC