Eef Lentjes
Utrecht University
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Featured researches published by Eef Lentjes.
Psychoneuroendocrinology | 2007
C.S. de Kloet; Eric Vermetten; Cobi J. Heijnen; Elbert Geuze; Eef Lentjes; Herman G.M. Westenberg
BACKGROUND While enhanced cortisol suppression in response to dexamethasone is one of the most consistent biological findings in posttraumatic stress disorder (PTSD), the relative contribution of trauma exposure to this finding remains unclear. METHODS Assessment of diurnal salivary cortisol levels and 1600 h salivary cortisol before and after oral administration of 0.5mg dexamethasone in veterans with PTSD, veterans without PTSD (trauma controls) and healthy controls. Assessment of 1600 h plasma cortisol, ACTH and corticotrophin binding globulin (CBG) in response to dexamethasone in PTSD patients and trauma controls. RESULTS Both PTSD patients and trauma controls demonstrated significantly more salivary cortisol suppression compared to healthy controls. Salivary cortisol, plasma cortisol and ACTH suppression as well as CBG levels did not differ between PTSD patients and trauma controls. PTSD patients showed a reduced awakening cortisol response (ACR) compared to healthy controls that correlated significantly with PTSD symptoms. No significant differences were observed in ACR between PTSD patients and trauma controls. CONCLUSIONS These data suggest that enhanced cortisol suppression to dexamethasone is related to trauma exposure and not specifically to PTSD. The correlation between the ACR and PTSD severity suggests that a flattened ACR may be a result of clinical symptoms.
Human Reproduction | 2009
Carolien M. Boomsma; Annemieke Kavelaars; Marinus J.C. Eijkemans; Eef Lentjes; Bart C.J.M. Fauser; Cobi J. Heijnen; Nick S. Macklon
BACKGROUND The study of human endometrial-embryonic interactions is complicated by the disruptive impact of endometrial sample collection on the process of implantation itself. Endometrial secretion analysis is a novel technique, non-disruptive to implantation. The primary aim of this prospective cohort study was to explore whether a cytokine profile predictive of implantation and clinical pregnancy can be identified in endometrial secretions aspirated immediately prior to embryo transfer following IVF. METHODS Endometrial secretions, aspirated immediately prior to embryo transfer from 210 women undergoing IVF, were analyzed using a multiplex immunoassay for 17 soluble regulators of implantation, namely interleukin (IL)-1beta, IL-5, IL-6, IL-10, IL-12, IL-15, IL-17, IL-18, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, macrophage migration inhibitory factor, eotaxin, IFN-gamma-inducible 10 kDa protein (IP-10), monocyte chemo-attractant protein-1 (MCP-1), Dickkopf homolog 1, heparin-binding epidermal growth factor and vascular endothelial growth factor (VEGF). In order to detect implantation, daily urine samples were collected after embryo transfer, and human Chorionic Gonadotropin (hCG) concentrations were analyzed by an immunoassay. RESULTS Multivariable logistic regression analysis revealed significant associations (negative and positive association, respectively) between MCP-1 (P = 0.005) and IP-10 (P = 0.037) levels and implantation, and between IL-1beta (P = 0.047) and TNF-alpha (P = 0.023) levels and clinical pregnancy. The predictive value for pregnancy of IL-1beta and TNF-alpha was observed to be equivalent and additive to that of embryo quality. CONCLUSIONS Endometrial secretion cytokine profiling offers a novel, non-disruptive approach to study the role of the endometrium in human embryo implantation and identifies a profile which appears to be conducive to clinical pregnancy. CLINICAL TRIAL REGISTRATION www.clinicaltrials.gov (nCT00264992).
Progress in Brain Research | 2007
C.S. de Kloet; Eric Vermetten; Elbert Geuze; Eef Lentjes; Cobi J. Heijnen; G.K. Stalla; Herman G.M. Westenberg
Posttraumatic stress disorder (PTSD) is associated with alterations in corticotrophin-releasing hormone (CRH) secretion. Plasma CRH levels, which are easily acquired, might serve as a predictor of hypothalamic CRH levels. Assessment of plasma CRH, adrenocorticotrophin hormone (ACTH), and cortisol levels in 31 veterans with PTSD, 30 traumatized veterans without PTSD matched on age, year, and region of deployment (traumacontrols), and 28 age-matched healthy controls (HCs) was carried out. Plasma CRH levels were higher in PTSD patients compared to both HCs (p=0.005) and traumacontrols (p=0.007). This led to our conclusion, that elevated plasma CRH levels are specifically related to PTSD and not to exposure to traumatic stress during deployment.
Psychoneuroendocrinology | 2008
Carien S. de Kloet; Eric Vermetten; Eef Lentjes; Elbert Geuze; Johannes van Pelt; Remy Manuel; Cobi J. Heijnen; Herman G.M. Westenberg
BACKGROUND Neuroendocrine studies have shown profound alterations in HPA-axis regulation in posttraumatic stress disorder (PTSD). Based on baseline assessments and the response to dexamethasone, a hypothalamic overdrive with enhanced glucocorticoid feedback inhibition has been suggested. The dexamethasone-corticotrophin releasing hormone (DEX-CRH) test has shown to be a more sensitive test to assess HPA-axis dysregulation in major depression and therefore may provide a useful test tool to probe HPA-axis regulation in PTSD. METHODS To evaluate the effect of PTSD on HPA-axis regulation, we compared the response to a DEX-CRH test between male veterans with PTSD (n=26) and male veterans, who had been exposed to similar traumatic events during their deployment, without PTSD (n=23). Patients and controls were matched on age, year and region of deployment. Additionally, we compared the response of PTSD patients with (n=13) and without co-morbid major depressive disorder (MDD) (n=13). RESULTS No significant differences were observed in ACTH and cortisol response to the DEX-CRH test between patients and controls. PTSD patients with co-morbid MDD showed a significantly lower ACTH response compared to patients without co-morbid MDD. The response to the DEX-CRH test did not correlate with PTSD or depressive symptoms. CONCLUSION The DEX-CRH test did not reveal HPA-axis abnormalities in PTSD patients as compared to trauma controls. PTSD patients with a co-morbid MDD showed an attenuated ACTH response compared to PTSD patients without co-morbid MDD, suggesting the presence of subgroups with different HPA-axis regulation within the PTSD group. Altered sensitivity of the CRH receptors at the pituitary or differences in AVP secretion might explain these differences in response.
European Journal of Endocrinology | 2011
Femi Janse; M.J. Eijkemans; Angelique J. Goverde; Eef Lentjes; Annemieke Hoek; C.B. Lambalk; Theresa E. Hickey; Bart C.J.M. Fauser; Robert J. Norman
OBJECTIVE The measurement of serum testosterone in women is challenging due to lack of trueness, precision, and sensitivity of various available testosterone assays. Accurate assessment of testosterone in women is crucial especially in conditions associated with alleged over- or under-production of testosterone, such as in polycystic ovary syndrome (PCOS) or primary ovarian insufficiency (POI). The aim of this study was to measure and compare androgen concentrations in women with PCOS, POI, and female controls and to evaluate the performance of extraction RIA and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in these women. DESIGN Cross-sectional study. METHODS Carefully phenotyped women with POI (n=208) or PCOS (n=200) and 45 healthy, regularly cyclic female controls were included. Method comparison analyses were performed for total testosterone, androstenedione (AD), and DHEA, as measured by LC-MS/MS and extraction RIA. RESULTS All androgen levels were significantly elevated in women with PCOS compared with POI patients (P<0.05) and controls (P<0.05). Women with POI presented with similar androgen concentrations as controls, except for AD. Compared with measurements by extraction RIA, testosterone, DHEA, and AD concentrations measured by LC-MS/MS were systematically lower. However, using extraction RIA and LC-MS/MS, testosterone, DHEA, and AD measurements were shown to have good agreement as assessed by Bland-Altman analysis and intraclass correlation coefficient: 0.95 (95% confidence interval 0.94-0.91), 0.83 (0.79-0.86), and 0.96 (0.95-0.97) respectively. CONCLUSIONS LC-MS/MS, compared with a labor-intensive extraction RIA, shows good precision, sensitivity, and high accuracy for measuring female testosterone, DHEA, and AD concentrations under various clinical conditions. LC-MS/MS, therefore, represents a convenient and reliable assay for both clinical and research purposes, where androgen measurement in women is required.
Annals of Clinical Biochemistry | 2003
Cornelis J. M. Lips; Eef Lentjes; Jo W.M. Höppener
Carcinoids are neuroendocrine tumours of the gut which may also be found in the bronchus, pancreatic islets and retroperitoneum. They probably arise from gastrointestinal or bronchopulmonary pluripotential stem cells. Carcinoid tumours derived from these cells are potentially malignant; the strength of the tendency for aggressive growth correlates with the site of origin, depth of local penetration and the size of the tumour. Carcinoids occur sporadically or result from specific hereditary tumour syndromes. Mutations and/or aberrant expression of specific genes induce and promote tumour growth. Clinical features include local symptoms due to angulation or obstruction and hepatomegaly due to liver metastases. The carcinoid syndrome commonly involves flushing, diarrhoea, bronchospasm and hypotension. Other distinct syndromes may be caused by tumour release of products that may also be used as biochemical markers in diagnosis and follow-up. Scanning using radiolabelled octreotide, an analogue of somatostatin, sensitively identifies occult primary and metastatic deposits. Localized carcinoid tumours should be resected. Some patients benefit from hepatic resection. Palliation of symptoms is best achieved with octreotide. Hepatic artery chemoembolization may produce long-acting palliation. Further genetic characterization of the different types and stages of carcinoid development as well as assessment of gene expression profiles may improve differential diagnosis, prognosis and treatment.
Psychoneuroendocrinology | 2007
Carolina de Weerth; J.A. Jansen; Mariska H. Vos; Inge Maitimu; Eef Lentjes
Saliva for measurement of cortisol is generally sampled by swabbing the mouth with a cotton roll, but this method has drawbacks. In the present study, we evaluated the use of an eye sponge as an oral collection device for saliva cortisol. The eye sponge was compared with commercial cotton rolls, and tested for use in infants as well as adults. Our results show that the eye sponge has adequate cortisol recoveries, even after samples have been kept at 4-8 degrees C for up to a week. In adults, volumes of 200-250 microl are obtained without problem; although smaller volumes are obtained in young infants, they are sufficient for assays requiring only 50-100 microl of saliva. In conclusion, the eye sponge is a valid and adequate collection device for saliva cortisol. Additional advantages as compared to cotton rolls are: more comfortable sampling, tastelessness, no need to manipulate the absorbing material, and the ease with which the untrained eye can determine that enough saliva has been collected.
Psychoneuroendocrinology | 2011
Saskia van Liempt; Eric Vermetten; Eef Lentjes; Johan Arends; Herman G.M. Westenberg
BACKGROUND Healthy sleep facilitates the consolidation of newly acquired memories. Although patients with posttraumatic stress disorder (PTSD) often complain of sleep disturbances and memory deficits, the interrelatedness of these symptoms is not well understood. Sleep may be disturbed in PTSD by increased awakenings during sleep, which has been associated with decreased growth hormone (GH) secretion. We conducted a controlled study in which we assessed sleep fragmentation, nocturnal secretion of GH, and memory consolidation in patients with PTSD. METHODS While sleep EEG was being monitored, 13 veterans with PTSD, 15 trauma controls (TC) and 15 healthy controls (HC) slept with an iv catheter, through which blood was collected every 20 min from 23:00 h to 08:00 h. Declarative memory encoding was assessed with the 15 word task before sleep, and consolidation was assessed the next morning by a free recall. RESULTS Sleep was more fragmented in patients with PTSD, with more awakenings in the first half of the night (p<0.05). Plasma levels of GH during the night were significantly decreased in PTSD compared with HC (p<0.05). Furthermore, GH secretion and awakenings were independent predictors for delayed recall, which was lower in PTSD compared to HC (p<0.05). CONCLUSIONS These data show that PTSD is associated with increased awakenings during sleep and decreased nocturnal GH secretion. Furthermore, decreased GH secretion may be related to sleep fragmentation and both variables may exert a negative effect on sleep dependent memory consolidation.
Molecular Psychiatry | 2014
Jurjen J. Luykx; Steven C. Bakker; Eef Lentjes; M Neeleman; Eric Strengman; L Mentink; Joseph DeYoung; S. de Jong; Jae Hoon Sul; Eleazar Eskin; K.R. van Eijk; J van Setten; Jacobine E. Buizer-Voskamp; Rita M. Cantor; Ake Tzu-Hui Lu; M van Amerongen; E P A van Dongen; Peter Keijzers; Teus H. Kappen; P Borgdorff; Peter Bruins; Eske M. Derks; R.S. Kahn; Roel A. Ophoff
Studying genetic determinants of intermediate phenotypes is a powerful tool to increase our understanding of genotype–phenotype correlations. Metabolic traits pertinent to the central nervous system (CNS) constitute a potentially informative target for genetic studies of intermediate phenotypes as their genetic underpinnings may elucidate etiological mechanisms. We therefore conducted a genome-wide association study (GWAS) of monoamine metabolite (MM) levels in cerebrospinal fluid (CSF) of 414 human subjects from the general population. In a linear model correcting for covariates, we identified one locus associated with MMs at a genome-wide significant level (standardized β=0.32, P=4.92 × 10−8), located 20 kb from SSTR1, a gene involved with brain signal transduction and glutamate receptor signaling. By subsequent whole-genome expression quantitative trait locus (eQTL) analysis, we provide evidence that this variant controls expression of PDE9A (β=0.21; Punadjusted=5.6 × 10−7; Pcorrected=0.014), a gene previously implicated in monoaminergic transmission, major depressive disorder and antidepressant response. A post hoc analysis of loci significantly associated with psychiatric disorders suggested that genetic variation at CSMD1, a schizophrenia susceptibility locus, plays a role in the ratio between dopamine and serotonin metabolites in CSF. The presented DNA and mRNA analyses yielded genome-wide and suggestive associations in biologically plausible genes, two of which encode proteins involved with glutamate receptor functionality. These findings will hopefully contribute to an exploration of the functional impact of the highlighted genes on monoaminergic transmission and neuropsychiatric phenotypes.
Psychoneuroendocrinology | 2012
Kim van Rooij; Jos Bloemers; Leo de Leede; Irwin Goldstein; Eef Lentjes; H. P. F. Koppeschaar; Berend Olivier; Adriaan Tuiten
CONTEXT Sublingual testosterone is a single-dose treatment often used in studies regarding social, cognitive and sexual behavior. It is hypothesized that an increase in the ratio of free to total testosterone (free fraction) is indirectly, via genomic effects, responsible for the behavioral effects after sublingual testosterone administration. OBJECTIVE To characterize the pharmacokinetics of three doses sublingual testosterone in premenopausal women. Also, to investigate the SHBG saturation threshold influencing the free level and free fraction of testosterone. DESIGN We conducted an investigator-blind, randomized, cross-over placebo controlled study. SETTING This study was undertaken at the research and development department of a scientific company for research regarding female sexual dysfunction. PARTICIPANTS 16 healthy premenopausal women (mean age 27.3±5.3 years). INTERVENTIONS Sublingual testosterone solution; 0.25, 0.50 and 0.75 mg. MAIN OUTCOMES MEASURE The pharmacokinetics of three single doses sublingual testosterone solution; the influence of SHBG levels on free and total levels of testosterone. RESULTS After sublingual testosterone administration, serum free and total testosterone levels peaked at 15 min and reached baseline levels within 150 min. The AUCs and C(max) of free and total testosterone differed significantly between the three doses (p<0.0001) and increased dose-dependently. A dose-dependent increase in free fraction of testosterone was found in women with low SHBG levels, but not in women with high SHBG levels. CONCLUSIONS The three doses sublingual testosterone are rapidly absorbed and quickly metabolized in premenopausal women. These data demonstrate the influence of SHBG levels on the treatment induced alterations in plasma free testosterone.