Acute effects of exogenous melatonin have been widely reported to promote sleep or induce drowsiness in human. However, testing of the hypnotic effects of melatonin in nocturnal rodents has... Show moreAcute effects of exogenous melatonin have been widely reported to promote sleep or induce drowsiness in human. However, testing of the hypnotic effects of melatonin in nocturnal rodents has yielded contradictory results. The latter may be associated with differences in concentration, lighting conditions, time of administration of melatonin, and possibly the type of analysis. In this study, electroencephalogram (EEG) and electromyogram were recorded in pigmented male Brown Norway rats under both light-dark (LD) and constant dark (DD) conditions. Melatonin was administered intraperitoneally at a moderate dose of 3 mg/kg, at either 1 h after lights on under LD condition or 1 h after the activity offset under DD condition. The dosage is known to be able to entrain nocturnal rodents in DD conditions, but does not change sleep in rodents in LD. Only the rats under DD conditions showed a significant reduction in nonrapid eye movement (NREM) sleep latency, while the NREM sleep power spectrum remained unaffected. Under LD condition, melatonin did not alter NREM and rapid eye movement (REM) sleep latency, and had only minor effects on the NREM sleep EEG. Regardless of lighting conditions, melatonin administration resulted in less, but longer episodes for all vigilance states suggesting increased vigilance state consolidation. In the discussion, we compare our results with a summary of previously published data concerning the hypnotic effects of melatonin in polysomnographic/EEG-confirmed sleep in humans and nocturnal rodents. In conclusion, the hypnotic effect of exogenous melatonin in nocturnal rodents not only depends on the time of day, and concentration, but is also influenced by the lighting conditions. Regardless of inducing sleep or not, melatonin may consolidate sleep and through that enhance sleep quality. Show less
Wang, Y.M.; Boog, P. van der; Hemmelder, M.H.; Dekker, F.W.; Vries, A. de; Meuleman, Y. 2023
The purpose of our article is to investigate the impact of symptom experience on health related quality of life (HRQOL) in kidney transplant recipients (KTRs) and whether illness perceptions... Show moreThe purpose of our article is to investigate the impact of symptom experience on health related quality of life (HRQOL) in kidney transplant recipients (KTRs) and whether illness perceptions mediated this impact. Symptom experience, illness perceptions, and HRQOL were measured at transplantation and 6 weeks after transplantation in KTRs in an ongoing Dutch cohort study. Multivariable linear regression models were used for the analysis. 90 KTRs were analyzed. Fatigue and lack of energy were the most prevalent and burdensome symptoms at transplantation. Mental HRQOL at 6 weeks after transplantation was comparable to that of the general Dutch population (mean [standard deviation, SD]: 49.9 [10.7]) versus 50.2 [9.2]), while physical HRQOL was significantly lower (38.9 [9.1] versus 50.6 [9.2]). Experiencing more symptoms was associated with lower physical and mental HRQOL, and the corresponding HRQOL reduced by -0.15 (95%CI, -0.31; 0.02) and -0.23 (95%CI, -0.42; -0.04) with each additional symptom. The identified mediation effect suggests that worse symptom experiences could cause more unhelpful illness perceptions and consequently lead to lower HRQOL. Illness perceptions may explain the negative impact of symptom experience on HRQOL. Future studies at later stages after kidney transplantation are needed to further explore the mediation effect of illness perceptions and guide clinical practice to improve HRQOL. Show less
Wang, Y.M.; Melgers, M.; Meijer, J.H.; Deboer, T. 2023
Ketamine is known for its antidepressant effects, but the mechanism underlying this effect remains largely unclear. In contrast to most antidepressant drugs, the action of ketamine is rapid,... Show moreKetamine is known for its antidepressant effects, but the mechanism underlying this effect remains largely unclear. In contrast to most antidepressant drugs, the action of ketamine is rapid, suggesting a different mode of action. A rapid antidepressant effect is also observed following sleep deprivation (SD). In the present study, we aimed to evaluate the effect of a 6-h SD and acute ketamine treatment on vigilance states, locomotor activity, and electroencephalogram (EEG) power density spectra in Brown Norway rats under constant condition over 2 recording days. After SD and after the initial waking period induced by ketamine, both treatments induced a similar increase in non-rapid eye movement (NREM) sleep and EEG slow-wave activity (SWA) in NREM sleep. Rapid eye movement (REM) sleep was reduced immediately after both treatments but was recovered later only after the SD. The effects on the waking EEG differed between the treatments, with a faster theta peak during and after SD, and no change in the waking spectrum after ketamine. In conclusion, SD and ketamine both lead to an acute increment in NREM sleep SWA as well as in a reduction in REM sleep. The results suggest that selective suppression of REM sleep, combined with enhancement of SWA during NREM may be effective in the treatment of depression. Show less
Veltkamp, D.M.J.; Wang, Y.M.; Meuleman, Y.; Dekker, F.W.; Michels, W.M.; Boog, P.J.M. van der; Vries, A.P.J. de 2023
Background Health-related quality of life (HRQOL) is an increasingly important patient-reported outcome in kidney transplant recipients (KTRs). This study explored relationships between symptom... Show moreBackground Health-related quality of life (HRQOL) is an increasingly important patient-reported outcome in kidney transplant recipients (KTRs). This study explored relationships between symptom prevalence and burden with HRQOL, and age and gender differences in symptom experience. Methods Eligible Dutch KTRs transplanted in Leiden University Medical Center were invited for this cross-sectional study. HRQOL, and occurrence and burden of 62 symptoms were measured using validated questionnaires. Univariate and multivariate regression analysis were used for investigating the associations of symptom experience with mental and physical HRQOL, and differences in symptom experience between genders and KTRs of diverse age groups. Results A total of 631 KTRs were analyzed; the mean (standard deviation) age was 61.3 (11.3) years, and 62% were male. The median (interquartile range) number of symptoms was 14 (7-22), with a burden of 20 (8-37; range 0-244). Per extra symptom, physical and mental HRQOL decreased [-0.41 (-0.50; -0.31) and -0.51 (-0.59; -0.42), respectively, P < .001]. Most occurring symptoms were bruises, tiredness, lack of energy, urge to urinate at night and dry skin. Sexual problems were considered most burdensome. Female KTRs reported more symptoms than men. Amongst others, younger KTRs experienced more (18-50 > 50-65 >= 65 years) feelings of depression and both female and younger KTRs reported higher symptom prevalence concerning changes in physical appearance. Conclusion KRTs' symptom experience differed depending on gender and age, highlighting the need to develop tailored treatment strategies to reduce symptom experience and subsequently improve HRQOL. Show less
Background: Caffeine is a central nervous system stimulant that influences both the sleep-wake cycle and the circadian clock and is known to influence neuronal activity in the lateral hypothalamus,... Show moreBackground: Caffeine is a central nervous system stimulant that influences both the sleep-wake cycle and the circadian clock and is known to influence neuronal activity in the lateral hypothalamus, an important area involved in sleep-wake regulation. Light is a strong zeitgeber and it is known to interact with the effect of caffeine on the sleep-wake cycle. We therefore wanted to investigate the long-term effects of a single dose of caffeine under constant dark conditions. Methods: We performed long-term (2 days) electroencephalogram (EEG)/electromyogram recordings combined with multi-unit neuronal activity recordings in the peduncular part of the lateral hypothalamus (PLH) under constant darkness in Brown Norway rats, and investigated the effect of a single caffeine treatment (15 mg/kg) or saline control given 1 h after the onset of the endogenous rest phase. Results: After a reduction in sleep and an increase in waking and activity in the first hours after administration, also on the second recording day after caffeine administration, rapid eye movement (REM) sleep was still reduced. Analysis of the EEG showed that power density in the theta range during waking and REM sleep was increased for at least two days. Neuronal activity in PLH was also increased for two days after the treatment, particularly during non-rapid eye movement sleep. Conclusion: Surprisingly, the data reveal long-term effects of a single dose of caffeine on vigilance states, EEG, and neuronal activity in the PLH. The absence of a light-dark cycle may have enabled the expression of these long-term changes. It therefore may be that caffeine, or its metabolites, have a stronger and longer lasting influence, particularly on the expression of REM sleep, than acknowledged until now. Show less
Wang, Y.M.; Zanden, S.Y. van der; Leerdam, S. van; Tersteeg, M.M.H.; Kastelein, A.; Michel, S.; ... ; Deboer, T. 2022
Simple Summary: Cancer-related fatigue (CRF) is a devastating side effect of cancer treatment, affecting the quality of life of many patients for years after treatment. This long-term side effect... Show moreSimple Summary: Cancer-related fatigue (CRF) is a devastating side effect of cancer treatment, affecting the quality of life of many patients for years after treatment. This long-term side effect often results in loss of social functioning and even job loss. The cause of CRF is unknown, and consequently, CRF is often considered a 'psychological problem', much to the frustration of the patients. Here, we show in an animal model that the severity of CRF depends on the working mechanism of the treatment. In addition, the data show that the CRF is probably caused by a dysfunctioning circadian clock and thus has a physiological basis, as this effect depends on the anticancer drug. Therefore, the findings may have implications for the selection of chemotherapy and thus strongly improve the quality of life of future cancer survivors. Cancer-related fatigue (CRF) is the most devastating long-term side effect of many cancer survivors that confounds the quality of life for months to years after treatment. However, the cause of CRF is poorly understood. As a result, cancer survivors, at best, receive psychological support. Chemotherapy has been shown to increase the risk of CRF. Here, we study therapy-induced fatigue in a non-tumor-bearing mouse model with three different topoisomerase II-poisoning cancer drugs. These drugs either induce DNA damage and/or chromatin damage. Shortly before and several weeks after treatment, running wheel activity and electroencephalographic sleep were recorded. We show that doxorubicin, combining DNA damage with chromatin damage, unlike aclarubicin or etoposide, induces sustained CRF in this model. Surprisingly, this was not related to changes in sleep. In contrast, our data indicate that the therapy-induced CRF is associated with a disrupted circadian clock. The data suggest that CRF is probably a circadian clock disorder that influences the quality of waking and that the development of CRF depends on the type of chemotherapy provided. These findings could have implications for selecting and improving chemotherapy for the treatment of cancer in order to prevent the development of CRF. Show less
Wang, Y.M.; Veltkamp, D.M.J.; Boog, P.J.M. van der; Hemmelder, M.H.; Dekker, F.W.; Vries, A.P.J. de; Meuleman, Y. 2022
Background: Medication nonadherence to immunosuppressants is a well-known risk factor for suboptimal health outcomes in kidney transplant recipients (KTRs). This study examined the relationship... Show moreBackground: Medication nonadherence to immunosuppressants is a well-known risk factor for suboptimal health outcomes in kidney transplant recipients (KTRs). This study examined the relationship between illness perceptions and medication nonadherence in prevalent Dutch KTRs and whether this relationship depended on post-transplant time.Methods: Eligible KTRs transplanted in Leiden University Medical Center were invited for this cross-sectional study. The illness perceptions and medication nonadherence were measured via validated questionnaires. Associations between illness perceptions and medication nonadherence were investigated using multivariable logistic regression models.Results: For the study, 627 participating KTRs were analyzed. 203 (32.4%) KTRs were considered nonadherent to their immunosuppressants with "taking medication more than 2 h from the prescribed dosing time" as the most prevalent nonadherent behaviour (n = 171; 27.3%). Three illness perceptions were significantly associated with medication nonadherence: illness identity (adjusted odds ratio [ORadj] = 1.07; 95% confidence interval [CI], 1.00-1.14), concern (ORadj = 1.07; 95%CI,1.00-1.14), and illness coherence (ORadj = 1.11; 95%CI,1.01-1.22). The relationships between illness perceptions and medication nonadherence did not differ depending on post-transplant time (p-values ranged from 0.48 to 0.96).Conclusion: Stronger negative illness perceptions are associated with medication nonadherence to immunosuppressants. Targeting negative illness perceptions by means of psychoeducational interventions could optimize medication adherence and consequently improve health outcomes in KTRs. Show less
GCTB is an osteolytic, locally-aggressive, rarely-metastasizing tumour, characterized by abundance of osteoclastlike giant cells, induced by neoplastic mononuclear cells expressing high-levels of... Show moreGCTB is an osteolytic, locally-aggressive, rarely-metastasizing tumour, characterized by abundance of osteoclastlike giant cells, induced by neoplastic mononuclear cells expressing high-levels of the receptor activator of nuclear factor Kappa-B ligand (RANKL), a mediator of osteoclast activation. Although the mainstay of treatment is complete tumour removal with preservation of bone, therapy with denosumab, an inhibitor of RANKL, has been introduced for selected cases. Objectives: Denosumab-treated GCTB (DT-GCTB) was reported to show a wide spectrum of histological changes such as depletion of osteoclast-like giant cells and intralesional bone deposition, which may lead to diagnostic difficulties. We investigated clinicopathologic and molecular features of DT-GCTB, matched with pre-therapy samples. Participants: 21 cases were included (13 females, 8 males), aged 15 to 64 (median, 30 years). Results: DT-GCTB showed development of sclerotic neocortex and varying degrees of osteosclerosis radiographically. Marked depletion of giant cells, different degree of ossification, fibrosis, and proliferation of mononuclear cells was observed. Staining for H3.3G34W was positive in mononuclear cells in 19 cases (90.5%), while one negative case was positive for H3.3G34V. H3F3A G34W mutation was confirmed in 17 of 19 cases (89.5%), corresponding to nuclear staining with H3.3 G34W antibody. G34L mutation was detected in one G34W negative case, in which H3.3 G34V nuclear positive staining was observed, possibly due to cross-reaction. Conclusions: Post-therapy tumours still exhibit a similar mutation profile, while significantly differing from classic GCTB morphologically. Correlation with history of denosumab administration, awareness of features of DT-GCTB, IHC and molecular studies for histone H3 mutations are important in its assessment. Show less
Background. Health-related quality of life (HRQOL) is becoming an increasingly important outcome in kidney transplantation (KT). To describe HRQOL in kidney transplant recipients (KTRs), this... Show moreBackground. Health-related quality of life (HRQOL) is becoming an increasingly important outcome in kidney transplantation (KT). To describe HRQOL in kidney transplant recipients (KTRs), this systematic review summarizes literature that compared HRQOL among KTRs and other relevant populations [i.e. patients receiving dialysis, patients on the waiting list (WL) for KT, patients with chronic kidney disease (CKD) not receiving renal replacement therapy (RRT), the general population (GP) and healthy controls (HCs)] and themselves before KT.Methods. The literature search was conducted in PubMed, Embase, Web of Science and the Cochrane Library. Eligible studies published between January 2000 and October 2020 were included.Results. Forty-four studies comprising 6929 KTRs were included in this systematic review. Despite the study heterogeneity, KTRs reported a higher HRQOL after KT compared with pre-transplantation and compared with patients receiving dialysis with or without being on the WL, especially in disease-specific domains (i.e. burden and effects of kidney disease). Additionally, KTRs had similar to marginally higher HRQOL compared with patients with CKD Stages 3-5 not receiving RRT. When compared with HCs or the GP, KTRs reported similar HRQOL in the first 1 or 2 years after KT and lower physical HRQOL and lower to comparable mental HRQOL in studies with longer post-transplant time.Conclusions. The available evidence suggests that HRQOL improves after KT and can be restored to but not always maintained at pre-CKD HRQOL levels. Future studies investigating intervention targets to improve or maintain post-transplant HRQOL are needed. Show less
Wang, Y.M.; Snoep, J.D.; Hemmelder, M.H.; Bogt, K.E.A. van der; Bos, W.J.W.; Boog, P.J.M. van der; ... ; Meuleman, Y. 2021
Graft function and patient survival are traditionally the most used parameters to assess the objective benefits of kidney transplantation. Monitoring graft function, along with therapeutic drug... Show moreGraft function and patient survival are traditionally the most used parameters to assess the objective benefits of kidney transplantation. Monitoring graft function, along with therapeutic drug concentrations and transplant complications, comprises the essence of outpatient management in kidney transplant recipients (KTRs). However, the patient's perspective is not always included in this process. Patients' perspectives on their health after kidney transplantation, albeit subjective, are increasingly acknowledged as valuable healthcare outcomes and should be considered in order to provide patient-centred healthcare. Such outcomes are known as patient-reported outcomes (PROs; e.g. health-related quality of life and symptom burden) and are captured using PRO measures (PROMS). So far, PROMS have not been routinely used in clinical care for KTRs. In this review we will introduce PROMS and their potential application and value in the field of kidney transplantation, describe commonly used PROMS in KTRs and discuss structural PROMS implementation into kidney transplantation care. Show less
Background Hospital readmission after transplantation is common in kidney transplant recipients (KTRs). In this study, we aim to compare the risk of 3-month hospital readmission after kidney... Show moreBackground Hospital readmission after transplantation is common in kidney transplant recipients (KTRs). In this study, we aim to compare the risk of 3-month hospital readmission after kidney transplantation with different donor types in the overall population and in both young (< 65 years) and elderly (>= 65 years) KTRs. Methods We included all first-time adult KTRs from 2016 to 2018 in the Netherlands Organ Transplant Registry. Multivariable logistic regression models were used to estimate the effect while adjusting for baseline confounders. Results Among 1917 KTRs, 615 (32.1%) had at least one hospital readmission. Living donor kidney transplantation (LDKT) recipients had an adjusted OR of 0.76 (95%CI, 0.61 to 0.96; p = 0.02) for hospital readmission compared to deceased donor kidney transplantation (DDKT) recipients. In the young and elderly, the adjusted ORs were 0.69 (95%CI, 0.52 to 0.90, p = 0.01) and 0.93 (95%CI, 0.62 to 1.39, p = 0.73) and did not differ significantly from each other (p-value for interaction = 0.38). In DDKT, the risk of hospital readmission is similar between recipients with donation after cardiac death (DCD) or brain death (DBD) and the risk was similar between the young and elderly. Conclusion A lower risk of post-transplant 3-month hospital readmission was found in recipients after LDKT compared to DDKT, and this benefit of LDKT might be less dominant in elderly patients. In DDKT, having either DCD or DBD donors is not associated with post-transplant 3-month hospital readmission, regardless of age. Tailored patient management is needed for recipients with DDKT and elderly KTRs. Show less
Objective. The development of effective cancer treatments depends on the availability of cell lines that faithfully recapitulate the cancer in question. This study definitively re-assigns the... Show moreObjective. The development of effective cancer treatments depends on the availability of cell lines that faithfully recapitulate the cancer in question. This study definitively re-assigns the histologic identities of two ovarian cancer cell lines, COV434 (originally described as a granulosa cell tumour) and TOV-112D (originally described as grade 3 endometrioid carcinoma), both of which were recently suggested to represent small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), based on their shared gene expression profiles and sensitivity to EZH2 inhibitors. Methods. For COV434 and TOV-112D, we re-reviewed the original pathology slides and obtained clinical followup on the patients, when available, and performed immunohistochemistry for SMARCA4, SMARCA2 and additional diagnostic markers on the original formalin-fixed, paraffin-embedded (FFPE) clinical material, when available. For COV434, we further performed whole exome sequencing and validated SMARCA4 mutations by Sanger sequencing. We studied the growth of the cell lines at baseline and upon re-expression of SMARCA4 in vitro for both cell lines and evaluated the serum calcium levels in vivo upon injection into immunodeficient mice for COV434 cells.Results. The available morphological, immunohistochemical, genetic, and clinical features indicate COV434 is derived from SCCOHT, and TOV-112D is a dedifferentiated carcinoma. Transplantation of COV434 into mice leads to increased serum calcium level. Re-expression of SMARCA4 in either COV434 and TOV-112D cells suppressed their growth dramatically. Conclusions. COV434 represents a bona fide SCCOHT cell line. TOV-112D is a dedifferentiated ovarian carcinoma cell line.(c) 2020 Elsevier Inc. All rights reserved. Show less
