Johannes Burgerhof

Sodium intake affects urinary albumin excretion especially in overweight subjects

Objectives.  To examine the relationship between sodium intake and urinary albumin excretion, being an established risk marker for later cardiovascular morbidity and mortality.

Cardiovascular Risk Factors Are Differently Associated with Urinary Albumin Excretion in Men and Women

Cardiovascular morbidity and mortality is not equally distributed among genders, men being more affected than women. It is not clear whether this is only related to a higher prevalence of the cardiovascular risk factors or to a similar prevalence of the risk factors as in women but a greater vascular susceptibility to these risk factors in men. This was tested by studying the association between various cardiovascular risk factors and urinary albumin excretion (UAE) in a large cohort of male and female subjects. While the prevalence of smoking and hypercholesterolemia was comparable between the genders, obesity was more common in women, and diabetes and hypertension were more frequent in men. The prevalence of microalbuminuria was about twofold higher in men. Interestingly, for a given level of any risk factor, UAE was higher in men than in women. On multivariate analysis with UAE as the dependent variable, an interaction with gender was found for the risk factors age, body mass index, and plasma glucose. Thus, for a higher age, body mass index, and glucose, the UAE is significantly increased in men when compared with women. It is concluded that gender differences exist in the association between cardiovascular risk factors and UAE. This is consistent with a larger vascular susceptibility to these risk factors in men as compared with women.

Neurological soft signs discriminating mood disorders from first episode schizophrenia

Objective:  To investigate the specificity of neurological soft signs (NSS) for first episode schizophrenia compared with mood disorders.

A comparison of carboplatin and paclitaxel with cisplatinum and 5-fluorouracil in definitive chemoradiation in esophageal cancer patients

BACKGROUND In esophageal cancer (EC) patients who are not eligible for surgery, definitive chemoradiation (dCRT) with curative intent using cisplatinum with 5-fluorouracil (5-FU) is the standard chemotherapy regimen. Nowadays carboplatin/paclitaxel is also often used. In this study, we compared survival and toxicity rates between both regimens. PATIENTS AND METHODS This multicenter study included 102 patients treated in five centers in the Northeast Netherlands from 1996 till 2008. Forty-seven patients received cisplatinum/5-FU (75 mg/m(2) and 1 g/m(2)) and 55 patients carboplatin/paclitaxel (AUC2 and 50 mg/m(2)). RESULTS Overall survival (OS) was not different between the cisplatinum/5-FU and carboplatin/paclitaxel group {[P = 0.879, hazard ratio (HR) 0.97 [confidence interval (CI) 0.62-1.51]}, with a median survival of 16.1 (CI 11.8-20.5) and 13.8 months (CI 10.8-16.9). Median disease-free survival (DFS) was comparable [P = 0.760, HR 0.93 (CI 0.60-1.45)] between the cisplatinum/5-FU group [11.1 months (CI 6.9-15.3)] and the carboplatin/paclitaxel group [9.7 months (CI 5.1-14.4)]. Groups were comparable except clinical T stage was higher in the carboplatin/paclitaxel group (P = 0.008). High clinical T stage (cT4) was not related to OS and DFS in a univariate analysis (P = 0.250 and P = 0.201). A higher percentage of patients completed the carboplatin/paclitaxel regimen (82% versus 57%, P = 0.010). Hematological and nonhematological toxicity (≥grade 3) in the carboplatin/paclitaxel group (4% and 18%) was significantly lower than in the cisplatinum/5-FU (19% and 38%, P = 0.001). CONCLUSIONS In this study, we showed comparable outcome, in terms of DFS and OS for carboplatin/paclitaxel compared with cisplatinum/5-FU as dCRT treatment in EC patients. Toxicity rates were lower in the carboplatin/paclitaxel group together with higher treatment compliance. Carboplatin/paclitaxel as an alternative treatment of cisplatinum/5-FU is a good candidate regimen for further evaluation.BACKGROUND In esophageal cancer (EC) patients who are not eligible for surgery, definitive chemoradiation (dCRT) with curative intent using cisplatinum with 5-fluorouracil (5-FU) is the standard chemotherapy regimen. Nowadays carboplatin/paclitaxel is also often used. In this study, we compared survival and toxicity rates between both regimens. PATIENTS AND METHODS This multicenter study included 102 patients treated in five centers in the Northeast Netherlands from 1996 till 2008. Forty-seven patients received cisplatinum/5-FU (75 mg/m2 and 1 g/m2) and 55 patients carboplatin/paclitaxel (AUC2 and 50 mg/m2). RESULTS Overall survival (OS) was not different between the cisplatinum/5-FU and carboplatin/paclitaxel group {[P = 0.879, hazard ratio (HR) 0.97 [confidence interval (CI) 0.62-1.51]}, with a median survival of 16.1 (CI 11.8-20.5) and 13.8 months (CI 10.8-16.9). Median disease-free survival (DFS) was comparable [P = 0.760, HR 0.93 (CI 0.60-1.45)] between the cisplatinum/5-FU group [11.1 months (CI 6.9-15.3)] and the carboplatin/paclitaxel group [9.7 months (CI 5.1-14.4)]. Groups were comparable except clinical T stage was higher in the carboplatin/paclitaxel group (P = 0.008). High clinical T stage (cT4) was not related to OS and DFS in a univariate analysis (P = 0.250 and P = 0.201). A higher percentage of patients completed the carboplatin/paclitaxel regimen (82% versus 57%, P = 0.010). Hematological and nonhematological toxicity (≥grade 3) in the carboplatin/paclitaxel group (4% and 18%) was significantly lower than in the cisplatinum/5-FU (19% and 38%, P = 0.001). CONCLUSIONS In this study, we showed comparable outcome, in terms of DFS and OS for carboplatin/paclitaxel compared with cisplatinum/5-FU as dCRT treatment in EC patients. Toxicity rates were lower in the carboplatin/paclitaxel group together with higher treatment compliance. Carboplatin/paclitaxel as an alternative treatment of cisplatinum/5-FU is a good candidate regimen for further evaluation.

Validation and Modification of a Prediction Model for Acute Cardiac Events in Patients With Breast Cancer Treated With Radiotherapy Based on Three-Dimensional Dose Distributions to Cardiac Substructures

Purpose A relationship between mean heart dose (MHD) and acute coronary event (ACE) rate was reported in a study of patients with breast cancer (BC). The main objective of our cohort study was to validate this relationship and investigate if other dose-distribution parameters are better predictors for ACEs than MHD. Patients and Methods The cohort consisted of 910 consecutive female patients with BC treated with radiotherapy (RT) after breast-conserving surgery. The primary end point was cumulative incidence of ACEs within 9 years of follow-up. Both MHD and various dose-distribution parameters of the cardiac substructures were collected from three-dimensional computed tomography planning data. Results The median MHD was 2.37 Gy (range, 0.51 to 15.25 Gy). The median follow-up time was 7.6 years (range, 0.1 to 10.1 years), during which 30 patients experienced an ACE. The cumulative incidence of ACE increased by 16.5% per Gy (95% CI, 0.6 to 35.0; P = .042). Analysis showed that the volume of the left ventricle receiving 5 Gy (LV-V5) was the most important prognostic dose-volume parameter. The most optimal multivariable normal tissue complication probability model for ACEs consisted of LV-V5, age, and weighted ACE risk score per patient (c-statistic, 0.83; 95% CI, 0.75 to 0.91). Conclusion A significant dose-effect relationship was found for ACEs within 9 years after RT. Using MHD, the relative increase per Gy was similar to that reported in the previous study. In addition, LV-V5 seemed to be a better predictor for ACEs than MHD. This study confirms the importance of reducing exposure of the heart to radiation to avoid excess risk of ACEs after radiotherapy for BC.

Pediatric Differentiated Thyroid Carcinoma in The Netherlands: A Nationwide Follow-Up Study

INTRODUCTION Treatment for differentiated thyroid carcinoma (DTC) in pediatric patients is based mainly on evidence from adult series due to lack of data from pediatric cohorts. Our objective was to evaluate presentation, treatment-related complications, and long-term outcome in patients with pediatric DTC in The Netherlands. PATIENTS AND METHODS In this nationwide study, presentation, complications, and outcome of patients with pediatric DTC (age at diagnosis ≤18 y) treated in The Netherlands between 1970 and 2013 were assessed using medical records. RESULTS We identified 170 patients. Overall survival was 99.4% after a median follow-up of 13.5 years (range 0.3-44.7 y). Extensive follow-up data were available for 105 patients (83.8% women), treated in 39 hospitals. Median age at diagnosis was 15.6 years (range 5.8-18.9 y). At initial diagnosis, 43.8% of the patients had cervical lymph node metastases; 13.3% had distant metastases. All patients underwent total thyroidectomy. Radioiodine was administered to 97.1%, with a median cumulative activity of 5.66 GBq (range 0.74-35.15 GBq). Life-long postoperative complications (permanent hypoparathyroidism and/or recurrent laryngeal nerve injury) were present in 32.4% of the patients. At last known follow-up, 8.6% of the patients had persistent disease and 7.6% experienced a recurrence. TSH suppression was not associated with recurrences (odds ratio 2.00, 95% confidence interval 0.78-5.17, P = .152). CONCLUSIONS Survival of pediatric DTC is excellent. Therefore, minimizing treatment-related morbidity takes major priority. Our study shows a frequent occurrence of life-long postoperative complications. Adverse effects may be reduced by the centralization of care, which is crucial for children with DTC.

RNAi Experiments in D. melanogaster : Solutions to the Overlooked Problem of Off-Targets Shared by Independent dsRNAs

Background RNAi technology is widely used to downregulate specific gene products. Investigating the phenotype induced by downregulation of gene products provides essential information about the function of the specific gene of interest. When RNAi is applied in Drosophila melanogaster or Caenorhabditis elegans, often large dsRNAs are used. One of the drawbacks of RNAi technology is that unwanted gene products with sequence similarity to the gene of interest can be down regulated too. To verify the outcome of an RNAi experiment and to avoid these unwanted off-target effects, an additional non-overlapping dsRNA can be used to down-regulate the same gene. However it has never been tested whether this approach is sufficient to reduce the risk of off-targets. Methodology We created a novel tool to analyse the occurance of off-target effects in Drosophila and we analyzed 99 randomly chosen genes. Principal Findings Here we show that nearly all genes contain non-overlapping internal sequences that do show overlap in a common off-target gene. Conclusion Based on our in silico findings, off-target effects should not be ignored and our presented on-line tool enables the identification of two RNA interference constructs, free of overlapping off-targets, from any gene of interest.

RNAi-induced off-target effects in Drosophila melanogaster: frequencies and solutions

Genes can be silenced with short-interfering RNA molecules (siRNA). siRNAs are widely used to identify gene functions and have high potential for therapeutic treatments. It is critical that the siRNA specifically targets the expression of the gene of interest but has no off-target effects on other genes. Although siRNAs were initially considered to be exclusively active on mature mRNAs in the cytoplasm, additional studies have shown that siRNAs are present in the nucleus as well, suggesting that pre-mRNA sequences containing introns and other untranslated regions can also be targeted. In this study, we investigated the extent to which off-targets may occur in Drosophila melanogaster by looking at mature mRNA sequences and pre-mature RNA sequences separately. First, an in silico approach revealed that, based on sequence similarity, numerous off-targets are predicted to occur in RNAi experiments. Second, existing microarray data were used to investigate a possible effect of the predicted off-targets based on analysis of in vitro data. We found that the occurrence of off-targets in both mature and pre-mature RNA sequences in RNAi experiments can be extensive and significant. Possibilities are discussed how to minimize off-target effects.

Construct validity of the Groningen Frailty Indicator established in a large sample of home-dwelling elderly persons: Evidence of stability across age and gender.

BACKGROUND The primary objective of the present study was to evaluate the validity of the Groningen Frailty Indicator (GFI) in a sample of Dutch elderly persons participating in LifeLines, a large population-based cohort study. Additional aims were to assess differences between frail and non-frail elderly and examine which individual characteristics were associated with frailty. METHODS By December 2012, 5712 elderly persons were enrolled in LifeLines and complied with the inclusion criteria of the present study. Mann-Whitney U or Kruskal-Wallis tests were used to assess the variability of GFI-scores among elderly subgroups that differed in demographic characteristics, morbidity, obesity, and healthcare utilization. Within subgroups Kruskal-Wallis tests were also used to examine differences in GFI-scores across age groups. Multivariate logistic regression analyses were performed to assess associations between individual characteristics and frailty. RESULTS The GFI discriminated between subgroups: statistically significantly higher GFI-median scores (interquartile range) were found in e.g. males (1 [0-2]), the oldest old (2 [1-3]), in elderly who were single (1 [0-2]), with lower socio economic status (1 [0-3]), with increasing co-morbidity (2 [1-3]), who were obese (2 [1-3]), and used more healthcare (2 [1-4]). Overall age had an independent and statistically significant association with GFI scores. Compared with the non-frail, frail elderly persons experienced statistically significantly more chronic stress and more social/psychological related problems. In the multivariate logistic regression model, psychological morbidity had the strongest association with frailty. CONCLUSION The present study supports the construct validity of the GFI and provides an insight in the characteristics of (non)frail community-dwelling elderly persons participating in LifeLines.

Effectiveness of indometacin to prevent ovulation in modified natural-cycle IVF: A randomized controlled trial

Modified natural-cycle IVF has a lower pregnancy rate per started cycle as compared with IVF with ovarian stimulation due to, for example, premature ovulation. Indometacin administered before ovulation prevents follicle rupture. Therefore, addition of indometacin may improve the effectiveness of modified natural-cycle IVF. This double-blind, randomized, placebo-controlled trial with indometacin or placebo in 120 women aged 27-36 years compared the number of patients without premature ovulation as compared with the number of patients with one or more ovulations in a maximum of six cycles. Indometacin had no significant influence on the probability of a premature ovulation in patients during the six cycles (OR 2.38, 95% CI 0.94-6.04). A subgroup analysis showed a significant influence of indometacin in decreasing the probability of a premature ovulation in cycles without LH surge at the day of human chorionic gonadotrophin administration (OR 8.29, 95% CI 1.63-42.3, P=0.009). Although this study could not detect a significantly lower ovulation rate in the indometacin group versus the placebo group, the data suggest that a subgroup of patients without LH surge prior to oocyte retrieval might benefit from indometacin in modified natural-cycle IVF.