Publications by authors named "H J Kloosterboer"

Certain steroidal compounds have an antioxidant effect in humans. Our aim was to test whether the synthetic steroid tibolone and its metabolites are also able to display such a property. For this, granulocytes from healthy men and women were incubated for two hours with different concentrations (10(-7), 10(-8), 10(-9 )M) of either estradiol, tibolone, 3α-hydroxytibolone, 3β-hydroxytibolone, Δ(4)-tibolone, 3α-sulfated-tibolone, 3α-17β-disulfated-tibolone, 3β-sulfated-tibolone or 3β-17β-disulfated-tibolone.

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Damage to peripheral nerves caused during a surgical intervention often results in function loss. Fluorescence imaging has the potential to improve intraoperative identification and preservation of these structures. However, only very few nerve targeting agents are available.

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Background: Estetrol (E4) is a pregnancy-specific estrogenic steroid hormone produced by the human fetal liver in both male and female fetuses. During pregnancy, E4 plasma values increase exponentially until parturition and decrease thereafter. The synthesis of E4 in the liver of a newborn ceases during the first weeks after birth.

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Human ketosteroid reductases of the aldo-keto reductase (AKR) superfamily, i.e. AKR1C1-4, are implicated in the biotransformation of synthetic steroid hormones.

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Risk assessment of future breast cancer risk through exposure to sex steroids currently relies on clinical scorings such as mammographic density. Knowledge about the gene expression patterns in existing breast cancer tumors may be used to identify risk factors in the breast tissue of women still free of cancer. The differential effects of estradiol, estradiol together with gestagens, or tibolone on breast cancer-related gene expression in normal breast tissue samples taken from postmenopausal women may be used to identify gene expression profiles associated with a higher breast cancer risk.

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