Johannes Burgerhof - Academia.edu (original) (raw)
Papers by Johannes Burgerhof
Medical Science Monitor International Medical Journal of Experimental and Clinical Research, May 1, 2009
Journal of psychosomatic research, 2015
Measures of frailty (Groningen Frailty Indicator, GFI) and case complexity (INTERMED for the Elde... more Measures of frailty (Groningen Frailty Indicator, GFI) and case complexity (INTERMED for the Elderly, IM-E-SA) may assist healthcare professionals to allocate healthcare resources. Both instruments have been evaluated with good psychometric properties. Limited evidence has been published about their predictive validity. Thus, our aim is to evaluate the predictive validity of both instruments on healthcare costs. Multivariate linear regression models were developed to estimate associations between the predictors frailty (GFI) and/or case complexity (IM-E-SA) and the healthcare costs (in € log transformed) in the following year. All models were adjusted for demographics and the presence of morbidity. In the multivariate regression analyses the continuous scores of the GFI and IM-E-SA remained significant predictors for total healthcare costs. Adjusted βs for GFI and IM-E-SA were respectively 0.14 (95% CI 0.10-0.18) and 0.06 (95% CI 0.04-0.07). The corresponding explained variance (R(2...
The Journal of clinical endocrinology and metabolism, Jan 19, 2015
Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment w... more Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment with thyroidectomy, radioiodine, and TSH suppression. However, treatment is associated with long-term cardiovascular toxicity. The aim of this study was to evaluate whether there is an increased risk of atrial fibrillation (AF) in DTC patients and whether AF occurrence is related to DTC treatment. Incident AF was compared between 518 DTC patients and 1563 matched controls. A cumulative incidence curve was plotted, and competing risk regression analyses with adjustment for all-cause mortality were performed. Within the DTC cohort, associations between time-varying DTC treatment variables and incident AF were analyzed. For both cohorts, the mean age was 48.6 years (75% of subjects were women). The AF incidence rate was 6.2/1000 person-years for DTC patients and 2.7/1000 person-years for controls. DTC patients had a 2.25-fold (95% confidence interval [CI], 1.40-3.63) and 2.47-fold (95% CI, 1...
The Journal of Clinical Endocrinology & Metabolism, 2015
Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment w... more Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment with thyroidectomy, radioiodine, and TSH suppression. However, treatment is associated with long-term cardiovascular toxicity. The aim of this study was to evaluate whether there is an increased risk of atrial fibrillation (AF) in DTC patients and whether AF occurrence is related to DTC treatment. Incident AF was compared between 518 DTC patients and 1563 matched controls. A cumulative incidence curve was plotted, and competing risk regression analyses with adjustment for all-cause mortality were performed. Within the DTC cohort, associations between time-varying DTC treatment variables and incident AF were analyzed. For both cohorts, the mean age was 48.6 years (75% of subjects were women). The AF incidence rate was 6.2/1000 person-years for DTC patients and 2.7/1000 person-years for controls. DTC patients had a 2.25-fold (95% confidence interval [CI], 1.40-3.63) and 2.47-fold (95% CI, 1.55-3.95) increased AF risk in crude and fully adjusted analyses, respectively. Within the DTC cohort, the TSH level (which was suppressed in 85.7% of patients) was not associated with AF, whereas a higher cumulative radioiodine dose slightly increased AF risk: subdistribution hazard ratio, 1.04 (95% CI, 1.01-1.08) per 50 mCi (1.85 GBq) increase, after adjustment. Patients with DTC have an increased AF risk, independent from established AF risk factors. We could not demonstrate a relation between TSH and AF, whereas cumulative radioiodine dose slightly increased AF risk. Electrocardiogram screening for AF may be warranted during follow-up of DTC patients to allow early diagnosis and treatment of AF and to prevent its complications.
Annals of the Rheumatic Diseases
Background Immunoglobulin free light chains (FLCs) are short-lived products of B lymphocytes and ... more Background Immunoglobulin free light chains (FLCs) are short-lived products of B lymphocytes and possess a wide range of immunological properties as signaling effectors or anti-inflammatory molecules. There is an upcoming interest in the role of circulating FLCs in the pathophysiology and monitoring of disease activity in a variety of autoimmune diseases like rheumatoid arthritis, systemic lupus erythematosus and Sjögren’s syndrome. Objectives To assess whether serum FLC changes upon rituximab (anti-CD20) therapy in primary Sjögren’s syndrome (pSS) patients compared to a placebo group correlate with changes in disease activity. Methods At baseline, serum of 30 pSS patients and 40 random, age and sex matched healthy blood donors was collected. Subsequently, in a randomized, double-blind, placebo-controlled design, 20 pSS patients were treated with rituximab (1000 mg) and 10 patients were treated with placebo infusions on days 1 and 15. FLC kappa and lambda concentrations were measure...
Experimental gerontology
The primary objective of the present study was to evaluate the validity of the Groningen Frailty ... more 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. By December 2012, 5,712 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. The GFI discriminated between subgroups: statistical...
Anticancer research
Intravenous administration of amifostine reduces chemotherapy-induced toxicity. Preclinical exper... more Intravenous administration of amifostine reduces chemotherapy-induced toxicity. Preclinical experiments showed a reduction in radiation-induced mucositis after local application of the active metabolite of amifostine (WR-1065). This study evaluated the effect of local application of WR-1065 on chemotherapy-induced oral mucositis. Non-small cell lung cancer patients treated with gemcitabine and epirubicin every 3 weeks for a maximum of five cycles were included. WR-1065 was administered during the second and third cycle as an oral rinse. Oral mucositis evaluation included WHO toxicity grading, a validated oral mucositis assessment scale (OMAS) and a questionnaire. Twenty-four patients were evaluated for at least one control and one rinse cycle. Mucositis scores, pain and feeding difficulties increased from day 1 to day 15, and were not significantly different between the control and rinse cycles. Local application of WR-1065 leads to detectable quantities of WR-1065 in epithelial muc...
Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer, Jan 10, 2015
Malnutrition in childhood cancer patients has been associated with lower health-related quality o... more Malnutrition in childhood cancer patients has been associated with lower health-related quality of life (HRQOL). However, this association has never actually been tested. Therefore, we aimed to determine the association between nutritional status and HRQOL in children with cancer. In 104 children, aged 2-18 years and diagnosed with hematological, solid, or brain malignancies, nutritional status and HRQOL were assessed at diagnosis and at 3, 6, and 12 months using the child- and parent-report versions of the PedsQL 4.0 Generic scale and the PedsQL 3.0 Cancer Module. Scores on both scales range from 0 to 100. Undernourished children (body mass index (BMI) or fat-free mass < -2 standard deviation score (SDS)) reported significantly lower PedsQL scores compared with well-nourished children on the domains physical functioning (-13.3), social functioning (-7.0), cancer summary scale (-5.9), and nausea (-14.7). Overnourished children (BMI or fat mass >2 SDS) reported lower scores on ...
Briefings in functional genomics, 2011
Genes can be silenced with short-interfering RNA molecules (siRNA). siRNAs are widely used to ide... more 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 predic...
Critical Care Medicine, 2014
To determine whether tidal volume is associated with mortality in critically ill, mechanically ve... more To determine whether tidal volume is associated with mortality in critically ill, mechanically ventilated children. MEDLINE, EMBASE, and CINAHL databases from inception until July 2013 and bibliographies of included studies without language restrictions. Randomized clinical trials and observational studies reporting mortality in mechanically ventilated PICU patients. Two authors independently selected studies and extracted data on study methodology, quality, and patient outcomes. Meta-analyses were performed using the Mantel-Haenszel random-effects model. Heterogeneity was quantified using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. Out of 142 citations, seven studies met the inclusion criteria, and additional two articles were identified from references of the found articles. One was excluded. These eight studies included 1,756 patients. Mortality rates ranged from 13% to 42%. There was no association between tidal volume and mortality when tidal volume was dichotomized at 7, 8, 10, or 12 mL/kg. Comparing patients ventilated with tidal volume less than 7 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg and tidal volume less than 8 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg also showed no association between tidal volume and mortality. Limiting the analysis to patients with acute lung injury/acute respiratory distress syndrome did not change these results. Heterogeneity was observed in all pooled analyses. A relationship between tidal volume and mortality in mechanically ventilated children could not be identified, irrespective of the severity of disease. The significant heterogeneity observed in the pooled analyses necessitates future studies in well-defined patient populations to understand the effects of tidal volume on patient outcome.
Eurosurveillance, 2013
Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Healt... more Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Health Organization to vaccinate healthcare workers against influenza, vaccine uptake remains low in most European countries. We performed a pragmatic cluster randomised controlled trial in order to assess the effects of implementing a multi-faceted influenza immunisation programme on vaccine coverage in hospital healthcare workers (HCWs) and on in-patient morbidity. We included hospital HCWs of three intervention and three control University Medical Centers (UMCs), and 3,367 patients. An implementation programme was offered to the intervention UMCs to assess the effects on both vaccine uptake among hospital staff and patient morbidity. In 2009/10, the coverage of seasonal, the first and second dose of pandemic influenza vaccine as well as seasonal vaccine in 2010/11 was higher in intervention UMCs than control UMCs (all p<0.05). At the internal medicine departments of the intervention group with higher vaccine coverage compared to the control group, nosocomial influenza and/or pneumonia was recorded in 3.9% and 9.7% of patients of intervention and control UMCs, respectively (p=0.015). Though potential bias could not be completely ruled out, an increase in vaccine coverage was associated with decreased patient in-hospital morbidity from influenza and/or pneumonia.
Knee Surg Sports Traumatol Arthrosc, 2014
Reproductive BioMedicine Online, 2013
Medical Science Monitor International Medical Journal of Experimental and Clinical Research, May 1, 2009
Journal of psychosomatic research, 2015
Measures of frailty (Groningen Frailty Indicator, GFI) and case complexity (INTERMED for the Elde... more Measures of frailty (Groningen Frailty Indicator, GFI) and case complexity (INTERMED for the Elderly, IM-E-SA) may assist healthcare professionals to allocate healthcare resources. Both instruments have been evaluated with good psychometric properties. Limited evidence has been published about their predictive validity. Thus, our aim is to evaluate the predictive validity of both instruments on healthcare costs. Multivariate linear regression models were developed to estimate associations between the predictors frailty (GFI) and/or case complexity (IM-E-SA) and the healthcare costs (in € log transformed) in the following year. All models were adjusted for demographics and the presence of morbidity. In the multivariate regression analyses the continuous scores of the GFI and IM-E-SA remained significant predictors for total healthcare costs. Adjusted βs for GFI and IM-E-SA were respectively 0.14 (95% CI 0.10-0.18) and 0.06 (95% CI 0.04-0.07). The corresponding explained variance (R(2...
The Journal of clinical endocrinology and metabolism, Jan 19, 2015
Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment w... more Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment with thyroidectomy, radioiodine, and TSH suppression. However, treatment is associated with long-term cardiovascular toxicity. The aim of this study was to evaluate whether there is an increased risk of atrial fibrillation (AF) in DTC patients and whether AF occurrence is related to DTC treatment. Incident AF was compared between 518 DTC patients and 1563 matched controls. A cumulative incidence curve was plotted, and competing risk regression analyses with adjustment for all-cause mortality were performed. Within the DTC cohort, associations between time-varying DTC treatment variables and incident AF were analyzed. For both cohorts, the mean age was 48.6 years (75% of subjects were women). The AF incidence rate was 6.2/1000 person-years for DTC patients and 2.7/1000 person-years for controls. DTC patients had a 2.25-fold (95% confidence interval [CI], 1.40-3.63) and 2.47-fold (95% CI, 1...
The Journal of Clinical Endocrinology & Metabolism, 2015
Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment w... more Patients with differentiated thyroid carcinoma (DTC) have a favorable prognosis after treatment with thyroidectomy, radioiodine, and TSH suppression. However, treatment is associated with long-term cardiovascular toxicity. The aim of this study was to evaluate whether there is an increased risk of atrial fibrillation (AF) in DTC patients and whether AF occurrence is related to DTC treatment. Incident AF was compared between 518 DTC patients and 1563 matched controls. A cumulative incidence curve was plotted, and competing risk regression analyses with adjustment for all-cause mortality were performed. Within the DTC cohort, associations between time-varying DTC treatment variables and incident AF were analyzed. For both cohorts, the mean age was 48.6 years (75% of subjects were women). The AF incidence rate was 6.2/1000 person-years for DTC patients and 2.7/1000 person-years for controls. DTC patients had a 2.25-fold (95% confidence interval [CI], 1.40-3.63) and 2.47-fold (95% CI, 1.55-3.95) increased AF risk in crude and fully adjusted analyses, respectively. Within the DTC cohort, the TSH level (which was suppressed in 85.7% of patients) was not associated with AF, whereas a higher cumulative radioiodine dose slightly increased AF risk: subdistribution hazard ratio, 1.04 (95% CI, 1.01-1.08) per 50 mCi (1.85 GBq) increase, after adjustment. Patients with DTC have an increased AF risk, independent from established AF risk factors. We could not demonstrate a relation between TSH and AF, whereas cumulative radioiodine dose slightly increased AF risk. Electrocardiogram screening for AF may be warranted during follow-up of DTC patients to allow early diagnosis and treatment of AF and to prevent its complications.
Annals of the Rheumatic Diseases
Background Immunoglobulin free light chains (FLCs) are short-lived products of B lymphocytes and ... more Background Immunoglobulin free light chains (FLCs) are short-lived products of B lymphocytes and possess a wide range of immunological properties as signaling effectors or anti-inflammatory molecules. There is an upcoming interest in the role of circulating FLCs in the pathophysiology and monitoring of disease activity in a variety of autoimmune diseases like rheumatoid arthritis, systemic lupus erythematosus and Sjögren’s syndrome. Objectives To assess whether serum FLC changes upon rituximab (anti-CD20) therapy in primary Sjögren’s syndrome (pSS) patients compared to a placebo group correlate with changes in disease activity. Methods At baseline, serum of 30 pSS patients and 40 random, age and sex matched healthy blood donors was collected. Subsequently, in a randomized, double-blind, placebo-controlled design, 20 pSS patients were treated with rituximab (1000 mg) and 10 patients were treated with placebo infusions on days 1 and 15. FLC kappa and lambda concentrations were measure...
Experimental gerontology
The primary objective of the present study was to evaluate the validity of the Groningen Frailty ... more 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. By December 2012, 5,712 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. The GFI discriminated between subgroups: statistical...
Anticancer research
Intravenous administration of amifostine reduces chemotherapy-induced toxicity. Preclinical exper... more Intravenous administration of amifostine reduces chemotherapy-induced toxicity. Preclinical experiments showed a reduction in radiation-induced mucositis after local application of the active metabolite of amifostine (WR-1065). This study evaluated the effect of local application of WR-1065 on chemotherapy-induced oral mucositis. Non-small cell lung cancer patients treated with gemcitabine and epirubicin every 3 weeks for a maximum of five cycles were included. WR-1065 was administered during the second and third cycle as an oral rinse. Oral mucositis evaluation included WHO toxicity grading, a validated oral mucositis assessment scale (OMAS) and a questionnaire. Twenty-four patients were evaluated for at least one control and one rinse cycle. Mucositis scores, pain and feeding difficulties increased from day 1 to day 15, and were not significantly different between the control and rinse cycles. Local application of WR-1065 leads to detectable quantities of WR-1065 in epithelial muc...
Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer, Jan 10, 2015
Malnutrition in childhood cancer patients has been associated with lower health-related quality o... more Malnutrition in childhood cancer patients has been associated with lower health-related quality of life (HRQOL). However, this association has never actually been tested. Therefore, we aimed to determine the association between nutritional status and HRQOL in children with cancer. In 104 children, aged 2-18 years and diagnosed with hematological, solid, or brain malignancies, nutritional status and HRQOL were assessed at diagnosis and at 3, 6, and 12 months using the child- and parent-report versions of the PedsQL 4.0 Generic scale and the PedsQL 3.0 Cancer Module. Scores on both scales range from 0 to 100. Undernourished children (body mass index (BMI) or fat-free mass < -2 standard deviation score (SDS)) reported significantly lower PedsQL scores compared with well-nourished children on the domains physical functioning (-13.3), social functioning (-7.0), cancer summary scale (-5.9), and nausea (-14.7). Overnourished children (BMI or fat mass >2 SDS) reported lower scores on ...
Briefings in functional genomics, 2011
Genes can be silenced with short-interfering RNA molecules (siRNA). siRNAs are widely used to ide... more 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 predic...
Critical Care Medicine, 2014
To determine whether tidal volume is associated with mortality in critically ill, mechanically ve... more To determine whether tidal volume is associated with mortality in critically ill, mechanically ventilated children. MEDLINE, EMBASE, and CINAHL databases from inception until July 2013 and bibliographies of included studies without language restrictions. Randomized clinical trials and observational studies reporting mortality in mechanically ventilated PICU patients. Two authors independently selected studies and extracted data on study methodology, quality, and patient outcomes. Meta-analyses were performed using the Mantel-Haenszel random-effects model. Heterogeneity was quantified using I. Study quality was assessed using the Newcastle-Ottawa Score for cohort studies. Out of 142 citations, seven studies met the inclusion criteria, and additional two articles were identified from references of the found articles. One was excluded. These eight studies included 1,756 patients. Mortality rates ranged from 13% to 42%. There was no association between tidal volume and mortality when tidal volume was dichotomized at 7, 8, 10, or 12 mL/kg. Comparing patients ventilated with tidal volume less than 7 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg and tidal volume less than 8 mL/kg and greater than 10 mL/kg or greater than 12 mL/kg also showed no association between tidal volume and mortality. Limiting the analysis to patients with acute lung injury/acute respiratory distress syndrome did not change these results. Heterogeneity was observed in all pooled analyses. A relationship between tidal volume and mortality in mechanically ventilated children could not be identified, irrespective of the severity of disease. The significant heterogeneity observed in the pooled analyses necessitates future studies in well-defined patient populations to understand the effects of tidal volume on patient outcome.
Eurosurveillance, 2013
Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Healt... more Nosocomial influenza is a large burden in hospitals. Despite recommendations from the World Health Organization to vaccinate healthcare workers against influenza, vaccine uptake remains low in most European countries. We performed a pragmatic cluster randomised controlled trial in order to assess the effects of implementing a multi-faceted influenza immunisation programme on vaccine coverage in hospital healthcare workers (HCWs) and on in-patient morbidity. We included hospital HCWs of three intervention and three control University Medical Centers (UMCs), and 3,367 patients. An implementation programme was offered to the intervention UMCs to assess the effects on both vaccine uptake among hospital staff and patient morbidity. In 2009/10, the coverage of seasonal, the first and second dose of pandemic influenza vaccine as well as seasonal vaccine in 2010/11 was higher in intervention UMCs than control UMCs (all p<0.05). At the internal medicine departments of the intervention group with higher vaccine coverage compared to the control group, nosocomial influenza and/or pneumonia was recorded in 3.9% and 9.7% of patients of intervention and control UMCs, respectively (p=0.015). Though potential bias could not be completely ruled out, an increase in vaccine coverage was associated with decreased patient in-hospital morbidity from influenza and/or pneumonia.
Knee Surg Sports Traumatol Arthrosc, 2014
Reproductive BioMedicine Online, 2013