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Biomedical subjects

J W M van der Meer

Publications and source records attributed to J W M van der Meer.

At least 19 recordsLinked to original sources
PubMed2006

[Views on the financing of biomedical scientific research; the report 'Erop of eronder' (Sink or swim) from the KNAW (Royal Netherlands Academy of Arts and Sciences)].

In a recent report, entitled 'Erop of eronder. Financiering van (bio)medisch wetenschappelijk onderzoek' [Sink or swim. The financing of (bio)medical scientific research], the Royal Netherlands Academy of Arts and Sciences has reviewed various aspects of the current financing system. The recommendations concern a funding process with emphasis on open programmes focusing on researcher-initiated research, creating an earmarked budget for matching obligations, creating technology transfer centres offering broad expertise for the validation ofthe scientific results, and giving priority to the establishment of a European Research Council that encourages excellence in fundamental research within the European research area.

Biomedical Research↗
PubMed2006

Pathophysiology of in-vitro induced filaments, spheroplasts and rod-shaped bacteria in neutropenic mice.

This study compared the in-vitro properties and in-vivo effects of Escherichia coli filaments, spheroplasts and normal cells in a murine thigh infection model. E. coli was exposed to ceftazidime, meropenem or saline to obtain filaments, spheroplasts or normal bacilli, which were then injected into neutropenic mice. After 24 h, morphology, CFUs, local and circulating endotoxin levels, cytokine levels and mortality were recorded, and correlations between bacterial and host parameters of infection were investigated. Filaments and spheroplasts contained more endotoxin/CFU than controls. Histological studies showed that morphologically altered bacteria changed into rod-shaped cells in the absence of antibiotics. Bacterial spread to the liver was significantly higher in mice challenged with rod-shaped cells, compared with antibiotic-exposed bacteria (p 0.007). Muscle endotoxin levels correlated significantly with circulating interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha, and both pro-inflammatory cytokines were correlated significantly (p 0.011). Despite a tendency toward higher local and systemic concentrations of endotoxin in the filament group, inflammatory responses and survival did not differ between groups. It was concluded that morphologically altered bacteria contain more endotoxin and can regain a rod shape after withdrawal of antibiotics, while non-antibiotic-exposed bacteria show greater spread to the liver. There was a clear intra-individual relationship between local endotoxin, systemic endotoxin, TNF-alpha and IL-6 production, but these parameters did not differ among groups.

Animals↗
PubMed2006

Public health implications of using various case definitions in The Netherlands during the worldwide SARS outbreak.

This study analysed the consequences of deviation from the WHO case definition for the assessment of patients with suspected severe acute respiratory syndrome (SARS) in The Netherlands during 2003. Between 17 March and 7 July 2003, as a result of dilemmas in balancing sensitivity and specificity, five different case definitions were used. The patients referred for SARS assessment were analysed from a public health perspective. None of the patients referred had SARS, based on serological and virological criteria. Nevertheless, all 72 patients required thorough assessment and, depending on the results of the assessment, institution of appropriate prevention and control measures. Changing case definitions caused confusion in classifying cases. A centralised assessment of the reported cases by a team with clinical and public health expertise (epidemiological and geographical risk assessment) is a practical solution for addressing differences in applying case definitions. The burden of managing non-cases is an important issue when allocating public health resources, and should be taken into account during the preparation phase, rather than during an outbreak. This applies not only to SARS, but also to other public health threats, such as pandemic influenza or a bioterrorist episode.

Antibodies, Viral↗
PubMed2006

Extranodal marginal zone (MALT) lymphoma in common variable immunodeficiency.

We describe two patients with common variable immunodeficiency (CVID) who developed extranodal marginal zone lymphoma (formerly described as mucosa-associated lymphoid tissue lymphoma or MALT lymphoma). One patient, with documented pernicious anaemia and chronic atrophic gastritis with metaplasia, developed a Helicobacter pylori-positive extranodal marginal zone lymphoma in the stomach. Three triple regimens of antibiotics were necessary to eliminate the H. pylori, after which the lymphoma completely regressed. Patient B had an H. pylori-negative extranodal marginal zone lymphoma of the parotid gland, which remarkably regressed after treatment with clarithromycin. Reviewing the literature, we found eight cases of extranodal marginal zone lymphoma complicating CVID, but probably many more cases labelled as non-Hodgkin's lymphoma are hidden in the literature. Until more data are available on the predictive value of noninvasive screening for pathology of the stomach, we recommend endoscopy to assess the gastric status in CVID patients in order to detect these malignancies at an early stage. Elimination of H. pylori infection is the treatment of choice in Helicobacter-positive extranodal marginal zone lymphoma. The possibility of elimination failure, most probably due to frequent and prolonged exposure to antibiotics in this patient group, should be taken into account. Treatment with antibiotics in Helicobacter-negative extranodal marginal zone lymphoma must be considered.

Adult↗
PubMed2006

Diabetes mellitus is strongly associated with tuberculosis in Indonesia.

SETTING: Diabetes mellitus is a known risk factor for tuberculosis (TB), but no studies have been reported from South-East Asia, which has a high burden of TB and a rapidly growing prevalence of diabetes. OBJECTIVE: To examine if and to what extent diabetes is associated with an increased risk of TB in an urban setting in Indonesia. DESIGN: Case-control study comparing the prevalence of diabetes mellitus (fasting blood glucose level >126 mg/dl) among newly diagnosed pulmonary TB patients and matched neighbourhood controls. RESULTS: Patients and control subjects had a similar age (median 30 years) and sex distribution (52% male), but malnutrition was more common among TB patients (median body mass index 17.7 vs. 21.5 kg/m2). HIV infection was uncommon (1.5% of patients). Diabetes mellitus was present in 60 of 454 TB patients (13.2%) and 18 of 556 (3.2%) control subjects (OR 4.7; 95%CI 2.7-8.1). Adjustment for possible confounding factors did not reduce the risk estimates. Following anti-tuberculosis treatment, hyperglycaemia reverted in a minority (3.7%) of TB patients. CONCLUSION: Diabetes mellitus is strongly associated with TB in young and non-obese subjects in an urban setting in Indonesia. This may have implications for TB control and patient care in this region.

Adult↗
PubMed2005

Approach to genetic analysis in the diagnosis of hereditary autoinflammatory syndromes.

OBJECTIVE: Hereditary autoinflammatory syndromes are characterized by recurrent episodes of fever and inflammation. Seven subtypes have been described, caused by mutations in four different genes. Apart from a common phenotype of lifelong recurrent inflammatory attacks, all subtypes have distinct features and specific therapeutic options, which emphasizes the need for a specific diagnosis in each case. Our aim was to examine whether genetic screening would allow classification of previously unclassified patients, and whether individual patients suffering from an autoinflammatory syndrome carry additional mutations in one of the other autoinflammatory genes. METHODS: We included 60 patients with an unclassified autoinflammatory syndrome, 87 patients diagnosed with either hyper-IgD syndrome, familial Mediterranean fever (FMF) or tumour necrosis factor (TNF)-receptor-associated periodic syndrome and 50 healthy controls. Deoxyribonucleic acid samples were screened for the most prevalent mutations in the MEFV, TNFRSF1A, MVK and CIAS1 genes. RESULTS: We found only one possible diagnosis of FMF in the 60 previously unclassified patients. Two low-penetrance mutations were found in equal numbers in the groups of patients and controls. CONCLUSIONS: Screening of highly prevalent mutations in known genes involved in these disorders does not yield additional relevant information. Differential diagnosis of hereditary autoinflammatory syndromes can be made by thorough clinical examination followed by targeted genetic analysis of the one or two most likely syndromes. High-prevalence low-penetrant mutations from autoinflammatory genes do not occur more frequently in patients with hereditary autoinflammatory syndromes compared with the general population.

Adolescent↗
PubMed2005

Beneficial response to anakinra and thalidomide in Schnitzler's syndrome.

BACKGROUND: Schnitzler's syndrome is an inflammatory disorder characterised by chronic urticarial rash and monoclonal gammopathy, accompanied by periodic fever, arthralgia or arthritis, and bone pain. The cause and treatment are still unknown. OBJECTIVE: To assess treatment with thalidomide and an interleukin 1 receptor antagonist, anakinra, in Schnitzler's syndrome. CASE REPORTS: Three patients with Schnitzler's syndrome are described, one with IgM gammopathy, two with IgG type. In one patient, thalidomide induced complete remission, but was stopped because of polyneuropathy. Anakinra 100 mg daily in all three patients led to disappearance of fever and skin lesions within 24 hours. After a follow up of 6-18 months, all patients are free of symptoms. CONCLUSION: Anakinra proved to be effective in three patients with Schnitzler's syndrome. This treatment is preferable to thalidomide, which induced a complete remission in one of our patients, as it has fewer side effects.

Antirheumatic Agents↗
PubMed2005

Quality of antibiotic use for lower respiratory tract infections at hospitals: (how) can we measure it?

BACKGROUND: To assess and improve the quality of antibiotic use in patients with community-acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis or chronic obstructive pulmonary disease (AECB), a valid set of quality indicators is required. This set should also be applicable in practice. METHODS: Guidelines and literature were reviewed to derive potential indicators for quality of antibiotic use in treating hospitalized patients with lower respiratory tract infection (LRTI). To assess the evidence base of each indicator, a literature review was performed. Grade A recommendations were considered valid. For grade B-D recommendations, an expert panel performed a consensus procedure on the indicator's relevance to patient health, reduction of antimicrobial resistance, and cost containment. To test applicability in practice, feasibility, opportunity for improvement, reliability, and case-mix stability were determined for a data set of 899 hospitalized patients with LRTI. RESULTS: None of the potential indicators from guidelines and literature were supported by grade A evidence. Nineteen indicators were selected by consensus procedure (12 indicators for CAP and 7 indicators for AECB). Lack of feasibility and of opportunity for improvement led to the exclusion of 4 indicators. A final set of 15 indicators was defined (9 indicators for CAP and 6 indicators for AECB). CONCLUSIONS: A valid set of quality indicators for antibiotic use in hospitalized patients with LRTI was developed by combining evidence and expert opinion in a carefully planned procedure. Subjecting indicators to an applicability test is essential before using them in quality-improvement projects. In our demonstration setting, 4 of the 19 indicators were inapplicable in practice.

Anti-Bacterial Agents↗
PubMed2005

Markers of inflammation are negatively correlated with serum leptin in rheumatoid arthritis.

BACKGROUND: Leptin regulates food intake and modulates immunity and inflammation. A positive feedback mechanism has been described between tumour necrosis factor (TNF) and leptin, and it has been suggested that leptin potentiates inflammation in patients with rheumatoid arthritis (RA). OBJECTIVE: To assess whether inflammation correlates with leptin concentrations in patients with RA, and whether anti-TNF treatment modulates leptin concentrations in these patients. METHODS: Leptin, IL6 and CRP were measured (at baseline and after 2 weeks of treatment) in the blood of 31 patients with RA starting either anti-TNF treatment or placebo, and in 18 healthy controls. RESULTS: In patients with RA, plasma leptin concentrations at baseline correlated inversely with the degree of inflammation as assessed by C reactive protein (CRP; r(s)(2) = 0.21, p<0.01) or interleukin (IL) 6 concentrations (r(s)(2) = 0.22, p<0.008). Mean (SD) leptin concentrations did not differ between patients with RA and controls (6.0 (4.6) v 4.2 (2.8) ng/ml in men; 15.1 (7.9) v 13.4 (5.2) ng/ml in women). Short course anti-TNF treatment for 2 weeks did not modify leptin concentrations, despite significant reduction of CRP and IL6. CONCLUSION: A significant inverse correlation between inflammation and leptin concentrations was found in patients with active RA, although plasma leptin concentrations did not significantly differ from those in healthy controls. This suggests that active chronic inflammation may lower plasma leptin concentrations. Two weeks' treatment with anti-TNF did not change plasma leptin concentrations and longer treatment may be needed to see an effect on leptin.

Adalimumab↗
PubMed2005

Low plasma selenium concentrations, high plasma human immunodeficiency virus load and high interleukin-6 concentrations are risk factors associated with anemia in adults presenting with pulmonary tuberculosis in Zomba district, Malawi.

BACKGROUND: Although anemia is common among adults with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection in sub-Saharan Africa, the factors contributing to its pathogenesis have not been well characterized. OBJECTIVE: To characterize the antioxidant micronutrient status, interleukin-6 (IL-6) concentrations, and HIV load in relationship with anemia in adults with pulmonary tuberculosis. SETTING: Zomba district, Malawi. METHODS: Erythropoietin, IL-6, plasma HIV load, and markers of micronutrient status (hemoglobin (Hb), plasma concentrations of retinol, alpha-tocopherol, carotenoids, ferritin, zinc, and selenium) were measured in 500 adults who presented with pulmonary tuberculosis in Zomba Central Hospital, Malawi. RESULTS: Among 370 HIV-positive and 130 HIV-negative adults, the prevalence of anemia was 88 and 77%, respectively (P = 0.002), and moderate to severe anemia (Hb < 80 g/l) occurred in 30 and 15%, respectively (P = 0.001). Geometric mean IL-6 concentration was 21.1 pg/ml, with no difference between HIV-positive and -negative adults. The erythropoietin response to anemia was not different between adults with elevated IL-6 and those with lower IL-6 concentrations. In a multivariate logistic regression model, HIV load, and lower plasma selenium concentrations were associated with moderate to severe anemia. In a final multivariate linear regression model, IL-6, plasma HIV load, and plasma selenium concentrations were associated with Hb concentrations. CONCLUSION: This study suggests that low selenium concentrations, high HIV load, and high IL-6 concentrations are associated with anemia in adults with pulmonary tuberculosis in sub-Saharan Africa.

Adult↗
PubMed2005

Serum amyloid A serum concentrations and genotype do not explain low incidence of amyloidosis in Hyper-IgD syndrome.

BACKGROUND: Hyper-IgD and periodic fever syndrome (HIDS) is an autosomal recessively inherited disorder characterized by recurrent episodes of fever and inflammation. Unlike other chronic inflammatory conditions, amyloidosis is very rare in HIDS. For deposition of amyloid of the AA type, high concentrations of SAA are a prerequisite, together with certain SAA1 gene polymorphisms. The SAA1.1 genotype predisposes for amyloidosis, while SAA1.5 genotype exerts a protective effect. AIM OF THE STUDY: To determine if SAA concentrations and SAA1 gene polymorphisms could explain the virtual absence of amyloidosis in HIDS patients. METHODS: We measured SAA and CRP concentrations in serum of 20 HIDS patients during an attack and during the asymptomatic phase. Genotype of SAA1 gene was determined in 60 HIDS patients. RESULTS: SAA serum concentrations during attacks were very high (median 205 mg/l; range 75-520 mg/l, normal <3.1 mg/l). During attack-free periods 45% of patients still had elevated SAA concentrations. The distribution of the genotype of SAA1 gene in HIDS was similar to healthy controls (SAA1.1 0.41 vs. 0.50 p=0.32). CONCLUSION: Patients with HIDS have high SAA during attacks and show sub-clinical inflammation when asymptomatic. The low incidence of amyloidosis cannot be explained by a predominance of non amyloidogenic SAA related genotypes.

Amyloidosis↗
PubMed2005

Severely impaired IL-12/IL-18/IFNgamma axis in patients with hyper IgE syndrome.

BACKGROUND: Hyperimmunoglobulin E syndrome (HIES) is an inborn disorder characterized by recurrent skin and respiratory tract infections, skeletal abnormalities, chronic eczema and elevated serum IgE. The nature of the host defence defect has yet to be established. The aim of this study was to investigate whether activation of the interleukin-12/interleukin-18/interferon-gamma axis, known to be crucial for the activation of cellular immune responses, is impaired in patients with HIES. MATERIALS AND METHODS: Cytokine production capacity of seven HIES patients and seven healthy controls was investigated in whole-blood cultures stimulated with heat-killed Staphylococcus aureus, Candida albicans, or a combination of interleukin (IL)-12/IL-18. RESULTS: Interferon (IFN)gamma production, in addition to IFNgamma/IL-10 ratios, was 10-30-fold lower in the HIES patients compared with the healthy volunteers. In contrast TNF, IL-1beta and IL-8 production was normal. CONCLUSIONS: These data revealed a severe dysbalance towards a Th2 phenotype in HIES patients which is likely to contribute to the specific pattern of infection susceptibility characteristic to HIES.

Adult↗
PubMed2005

Cognitive behaviour group therapy for chronic fatigue syndrome: a non-randomised waiting list controlled study.

BACKGROUND: It has been demonstrated that individual cognitive behaviour therapy is an effective treatment for chronic fatigue syndrome (CFS). The aim of the present study was to investigate the effectiveness of cognitive behaviour group therapy (CBGT) in an unselected group of CFS patients. Additionally, pretreatment characteristics of CFS patients who improve after CBGT were explored. METHODS: In a non-randomised waiting list controlled design, 31 patients were allocated to CBGT and 36 to the waiting list condition. CBGT consisted of 12 two-hour sessions during 6 months. Main outcome measures were fatigue (Checklist Individual Strength) and functional impairment (Sickness Impact Profile). RESULTS: A moderate effect on fatigue in favour of CBGT was found. For functional impairment, the effect was opposite to what was expected. Patients who improved after CBGT had less complaints at baseline compared to patients who did not improve. CONCLUSIONS: An explanation for the moderate effect might be that during CBGT, rest and relaxation were too much emphasised. Furthermore, an unselected group of CFS patients and therapists inexperienced in CB(G)T for CFS participated. Suggestions to improve CBGT for future research are given.

Adult↗
PubMed2005

Antibiotic control measures in Dutch secondary care hospitals.

Control measures for the use of antibiotics are essential because of the potential harmful consequences of side effects. Various methods have been developed to help curb undesirable antibiotic prescription. We performed a survey in Dutch secondary care hospitals (response rate 73%) to make an inventory of these measures and elucidate possible shortcomings. Almost every hospital was using an antibiotic formulary (97%), sometimes supported by extra restrictions in antibiotic choice (55%). Local practice guidelines (95%) were commonly present, but effective implementation, for example using intranet applications, could be improved (21%). National guidelines had received little attention in the composition process of local guidelines (19%). Other measures such as educational programmes for specialists (11%) and feedback on antibiotic prescription (52%) remained largely underused, although their effective implementation may optimise antibiotic prescription in hospitals.

Anti-Bacterial Agents↗
PubMed2005

Clinical outcome of experimental human malaria induced by Plasmodium falciparum-infected mosquitoes.

BACKGROUND: Human experimental malaria infections have been safely carried out previously. The objective of this study was to evaluate infection rates and clinical safety of different protocols for human experimental malaria induced by Plasmodium falciparum-infected mosquitoes. METHODS: Thirty nonimmune volunteers were infected by bites of 1-2 or 4-7 Anopheles stephensi mosquitoes infected with the NF54 strain of P. falciparum. RESULTS: A 100 or 50% infection rate was obtained after bites of 4-7 and 1-2 infected mosquitoes, respectively. Median prepatent period was 8.8 days. The most common symptoms after a median incubation time of eight days were headache, malaise/fatigue and fever. There was no significant difference in clinical and parasitological presentation between groups infected by 4-7 or 1-2 mosquitoes. Delay of treatment by maximally 48 hours after the first positive thick smear was generally well tolerated but fever was higher and more frequently observed. The most prominent laboratory abnormality was uncomplicated thrombocytopenia. Two volunteers with parasitaemia developed psychiatric side effects after chloroquine treatment. CONCLUSION: With stringent inclusion criteria, close monitoring and immediate administration of treatment upon detection of parasitaemia, experimental human malaria challenges can be considered safe and generally well tolerated.

Adolescent↗
PubMed2005

Side effects of anticytokine strategies.

Anticytokine strategies probably represent the most important breakthrough in the treatment of inflammatory diseases in the last decade. However, blocking the bioactivity of proinflammatory cytokines, crucial activators of host defence, has proved to be accompanied by an increased susceptibility to infections, especially with Mycobacteria, Salmonellae and fungal pathogens. Multiple mechanisms for these side effects have been proposed, such as inhibition of gamma-interferon production, decreased expression of pattern-recognition receptors, and leucocyte apoptosis. Caution is therefore warranted when these treatments are given to patients with an increased risk for infections. A range of side effects other than infection have been reported.

Adalimumab↗