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Biomedical subjects

G Visser

Publications and source records attributed to G Visser.

At least 19 recordsLinked to original sources
PubMed2006

Surveillance of Salmonella spp. and Campylobacter spp. in poultry production flocks in The Netherlands.

In The Netherlands, a national programme for the surveillance of zoonotic bacteria in farm animals has been operative since 1997. We describe the results of the surveillance of Salmonella spp. in flocks of laying hens and broilers and of Campylobacter spp. in broiler flocks in the period 1999-2002. The prevalence of Salmonella spp. in laying-hen flocks has significantly decreased from 21.1% in 1999 to 13.4% in 2002. This decreasing trend might indicate that the control measures taken by the poultry industry were effective. S. Enteritidis was the predominant serovar in laying hens accounting for one third of the positive flocks. Although prevalence estimates for Salmonella spp. in broiler flocks did not yield a significant decreasing trend in 1999-2002, a decrease in Salmonella prevalence to 11% was measured in 2002. During the study period, S. Paratyphi B var. Java emerged in broilers to become the predominant serovar in 2002 accounting for one third of the positive flocks. The prevalence of Campylobacter spp. in broiler flocks did not increase nor decrease continuously between 1999 and 2002, which roughly corresponds with the monitoring results from the poultry industry. In this period, the estimated flock prevalence roughly averaged around 20%, with C. jejuni being the predominant species. The approach of monitoring presented in this paper can serve as a blueprint for monitoring schemes in farm animal populations to be developed in the context of the EC Zoonoses Directive.

Animals↗
PubMed2005

Prolonged exercise testing in two children with a mild Multiple Acyl-CoA-Dehydrogenase deficiency.

BACKGROUND: Multiple Acyl-CoA-Dehydrogenase deficiency (MADD) is an inherited metabolic disorder characterized by impaired oxidation of fatty acids and some amino acids. METHODS: We were interested whether children with MADD could tolerate a prolonged low-intensity exercise test and if this test could have any additional diagnostic value. Therefore, we performed a maximal exercise test and a low-intensity prolonged exercise test in 2 patients with MADD and in 5 control subjects. During a prolonged exercise test the subjects exercised on a cycle ergometer at a constant workload of 30% of their maximum for 90 minutes and heart rate, oxygen uptake, fuel utilization and changes in relevant blood and urinary parameters were monitored. RESULTS: The tests were tolerated well. During the prolonged exercise test the fatty acid oxidation (FAO) was quite low compared to 5 control subjects, while characteristic metabolites of MADD appeared in plasma and urine. CONCLUSION: We suggest that the prolonged exercise test could be of diagnostic importance and might replace the fasting test as a diagnostic procedure in some cases, particularly in patients with anamnestic signs of intolerance for prolonged exercise.

Journal Article↗
PubMed2004

The end of life: informal care for dying older people and its relationship to place of death.

OBJECTIVE: This study examined the features of informal end-of-life care of older people living in the community and the association between informal care characteristics and dying at home. METHODS: Retrospective data were obtained from interviews and self-administered questionnaires of 56 persons who had been primary caregivers of older relatives in the last three months of their lives. RESULTS: Results showed that informal caregivers of terminally ill older people living in the community provided a considerable amount of personal, household, and management care. Secondary informal caregivers and formal caregivers assisted resident primary caregivers less often than nonresident primary caregivers. Primary caregivers who felt less burdened, who gave personal care more intensively, and/or who were assisted by secondary caregivers, were more likely to provide informal end-of-life care at home until the time of death. CONCLUSIONS: Our study showed that informal care at the end of life of older people living in the community is complex, since the care required is considerable and highly varied, and involves assistance from secondary informal caregivers, formal home caregivers as well as institutional care. Burden of informal care is one of the most important factors associated with home death. More attention is needed to help ease the burden on informal caregivers, specifically with regard to resident caregivers and spouses. Since these resident caregivers were disadvantaged in several respects (i.e., health, income, assistance from other carers) compared to nonresident caregivers, interventions by formal caregivers should also be directed towards these persons, enabling them to bear the burden of end-of-life care.

Aged↗
PubMed2003

Characteristic growth pattern in male X-linked phosphorylase-b kinase deficiency (GSD IX).

Growth retardation is one of the clinical characteristics of glycogen storage disease (GSD) type IX. Initial growth retardation has been described in a few case reports, followed by a complete catch-up in growth. This study aimed to determine the growth pattern of patients with GSD IX. Growth charts of 51 male Dutch patients with GSD IX (age 0-33 years, median follow-up time 8.3 years (range 0-30.5 years)) were studied retrospectively and compared with Dutch standard growth charts. Patients had a normal height at birth, significant growth retardation between the ages of 2 and 10 years (mean z-score -1.96), delayed growth spurt in puberty and catch-up towards quite normal final height (mean z-score -0.55). We conclude that GSD IX patients have a specific growth pattern characterized by initial growth retardation, a late growth spurt and complete catch-up in final height. Intervention for growth retardation is therefore in general not warranted. It is speculated that mild hypoglycaemia related to the disorder may cause endocrine changes. Because the glucose need per kg bodyweight decreases with age, the enzyme defect becomes less important with ageing and the effect on growth diminishes.

Adolescent↗
PubMed2003

Bone mineral density in children, adolescents and adults with glycogen storage disease type Ia: a cross-sectional and longitudinal study.

The occurrence of (symptoms related to) osteopenia is a known complication in glycogen storage disease type Ia (GSD Ia) patients. However, only limited information is available about bone mineral density (BMD). Using dual energy x-ray absorptiometry, we studied both cross-sectional and longitudinal lumbar spine areal BMD (BMD(areal) in g/cm2), areal BMD corrected for delayed bone maturation (BMD(bone age) in g/cm2), and volumetric BMD (BMD(vol) in g/cm3). Prepubertal GSD Ia patients (n = 8) had normal BMD (median z-scores BMD(areal) -0.6, BMD(bone age) -0.5 and BMD(vol) -0.5), whereas adolescent patients (n = 12) and adult patients (n = 9) had significantly reduced BMD (BMD(areal) -2.3, BMD(bone age) -1.6, BMD(vol) -2.0, and BMD(areal) -1.9, BMD(vol) -1.5, respectively). Our longitudinal study, showing a stable BMD(areal) but a trend to a decrease in BMD(vol) in prepubertal patients during follow-up, did not clarify whether the difference in BMD between prepubertal and adolescent/adult patients reflects a diminished accretion of BMD during childhood or reflects historical differences in treatment. In adolescent and adult GSD Ia patients, BMD(areal) and BMD(vol) were reduced but stable during follow-up. Especially patients with delayed bone maturation were at risk for reduced BMD. No correlation between parameters of metabolic control and BMD could be detected. Daily calcium intake was within recommended allowances ranges. Abnormal biochemical results included hypomagnesaemia (29%), hypercalciuria (34%) and reduced tubular resorption of phosphate (21%). Although the underlying pathophysiology of reduced BMD in GSD Ia remains unsolved, metabolic control should be optimized to correct as much as possible metabolic and endocrine abnormalities that may influence both bone matrix formation and bone mineral accretion.

Absorptiometry, Photon↗
PubMed2002

Intestinal function in glycogen storage disease type I.

Glycogen storage disease type I (GSD I) (McKusick 232200) is caused by inherited defects of the glucose-6-phosphatase complex. Patients with GSD Ia as well as patients with GSD lb may suffer from intermittent diarrhoea, which seems to worsen with age. The cause of this diarrhoea is unknown. This study describes the results of investigations of intestinal functions and morphology in patients with GSD Ia and GSD lb, which were performed to detect a common cause for chronic diarrhoea in GSD I. The following were investigated: faecal fat excretion, faecal alpha1-antitrypsin and faecal chymotrypsin, expiratory H2 concentrations, persorption of cornstarch in urine and colonic biopsies. With the investigations presented in this study, no common cause for diarrhoea in GSD I was found. In GSD lb loss of mucosal barrier function due to inflammation, documented by increased faecal alpha1-antitrypsin excretion (3.5-9.6 mg/g dry faeces) and inflammation in the colonic biopsies, seems to be the main cause. The inflammation is most likely related to disturbed neutrophil function, which is often found in GSD lb. Whether another cause is involved in GSD Ia and in GSD Ib, related to the disturbed function of glucose-6-phosphatase in the enterocyte, remains to be investigated.

Adolescent↗
PubMed2000

Identification of a novel mutation (867delA) in the glucose-6-phosphatase gene in two siblings with glycogen storage disease type Ia with different phenotypes.

We identified a novel mutation (867delA) in the glucose-6-phosphatase gene of two siblings with glycogen storage disease type Ia. Although both siblings share the same mutations, their phenotype regarding adult height and hepatomegaly differs. In glycogen storage disease type Ia, substantial heterogeneity in phenotype is observed. So far, no evidence for a clear genotype-phenotype correlation has been found. Hum Mutat 15:381, 2000.

Adult↗
PubMed2000

Transient chaos in intracellular dynamics?

Periodogram analyses of the temporal variations of several cellular oscillations occasionally reveal the existence of short duration bands containing a wide range of frequencies. The possibility is considered that these are due to the transient compliance with chaotic conditions.

Animals↗
PubMed2000

3-methylcrotonyl-CoA carboxylase deficiency in an infant with cardiomyopathy, in her brother with developmental delay and in their asymptomatic father.

UNLABELLED: Three affected members of one family, each with a different clinical presentation of isolated biotin-resistant 3-methylcrotonyl-CoA carboxylase (MCC) deficiency are described. The index patient presented at 7 weeks of age with feeding difficulties, sweating and tachypnoea. Echocardiography showed a severely dilated left ventricle with minimal contractility. MCC deficiency was suspected on the basis of elevated urinary excretion of 3-hydroxyisovalerate and 3-methylcrotonylglycine. Deficiency of MCC activity was found in lymphocytes and fibroblasts (ca. 2% of mean normal). Serum carnitine was low (free 10 micromol/l). Some other possible causes of cardiomyopathy were excluded. Cardiomyopathy was not improved by carnitine therapy. The healthy father and a developmentally delayed brother also had MCC deficiency. Both also had decreased serum carnitine concentrations, but without cardiac involvement. Dilatative cardiomyopathy as predominant symptom in isolated MCC deficiency has not been described before, although severe carnitine deficiency is a common finding in MCC deficiency. It is not clear whether this is a coincidental association. CONCLUSION: In order to understand the phenotypic spectrum of this rare disorder, cardiac evaluation should be made in patients with 3-methylcrotonyl-CoA carboxylase deficiency. Biochemical and clinical investigations have also to be performed in their parents and siblings. In addition, 3-methylcrotonyl-CoA carboxylase deficiency should be included in the differential diagnosis of dilatative cardiomyopathy.

Adult↗
PubMed2000

Glycogen storage disease type Ia: recent experience with mutation analysis, a summary of mutations reported in the literature and a newly developed diagnostic flow chart.

UNLABELLED: We studied the glucose-6-phosphatase (G6Pase) gene of 30 unrelated glycogen storage disease type Ia (GSD Ia) patients using single strand conformational polymorphism (SSCP) prior to automated sequencing of exons revealing an aberrant SSCP pattern. In all patients we could identify mutations on both alleles of the G6Pase gene, indicating that this method is a reliable procedure. A total of 14 different mutations were identified. R83C (16/60), 158delC (12/60), Q347X (7/60), R170X (6/60) and deltaF327 (4/60) were found most frequently. Nine other mutations accounted for the other 15 mutant alleles. Two DNA-based prenatal diagnoses were performed successfully. At present, 56 mutations in the G6Pase gene have been reported in 300 unrelated GSD Ia patients and an overview of these mutations is presented. Evidence for a clear genotype-phenotype correlation could be established neither from our data nor from those in the literature. With increased knowledge about the genetic basis of GSD Ia and GSD Ib and the high detection rate of mutations, it is our opinion that the diagnoses GSD Ia and GSD Ib can usually be based on clinical and biochemical abnormalities combined with mutation analysis instead of enzyme assays in liver tissue obtained by biopsy. A newly developed flowchart for the diagnosis of GSD I is presented. CONCLUSION: Increased knowledge of the genetic basis of glycogen storage disease type I provides a DNA-based diagnosis, prenatal DNA-based diagnosis in chorionic villus samples and carrier detection.

Chorionic Villi Sampling↗
PubMed2000

End-stage liver disease as the only consequence of a mitochondrial respiratory chain deficiency: no contra-indication for liver transplantation.

UNLABELLED: The prerequisite for liver transplantation as a therapeutic option for inherited metabolic diseases should be that the enzyme defect, being responsible for the major clinical (hepatic and/or extra-hepatic) abnormalities, is localised in the liver. Furthermore, no adequate dietary or pharmacological treatment should be available or such treatment should have an unacceptable influence on the quality of life. We report an infant, who developed end-stage liver disease with persistent lactic acidaemia in his first months of life. Analysis of the mitochondrial respiratory chain in liver tissue revealed a combined partial complex I and IV deficiency. No extra-hepatic involvement could be demonstrated by careful screening for multiple organ involvement, including analysis of the mitochondrial respiratory chain in muscle tissue and cultured skin fibroblasts. The boy received a reduced size liver graft at the age of 8 months. He recovered successfully. Almost 5 years after transplantation he is in good clinical condition. No clinical or biochemical signs of any organ dysfunction have been demonstrated. The considerations on which basis it was decided that there was no contra-indication to perform liver transplantation in this patient are discussed. CONCLUSION: The possibility of a mitochondrial respiratory chain deficiency should be considered in liver disease of unknown origin prior to liver transplantation. Liver transplantation is a therapeutic option in mitochondrial respiratory chain deficiency-based end-stage liver disease provided that extra-hepatic involvement is carefully excluded.

Child, Preschool↗
PubMed2000

Neutropenia, neutrophil dysfunction, and inflammatory bowel disease in glycogen storage disease type Ib: results of the European Study on Glycogen Storage Disease type I.

OBJECTIVE: To investigate the incidence, the severity, and the course of neutropenia, neutrophil dysfunction, and inflammatory bowel disease (IBD) in glycogen storage disease (GSD) type Ib. METHOD: As part of a collaborative European Study on GSD type I, a retrospective registry was established in 12 European countries that included all patients with GSD-I who were known at the centers and were born from 1960 to 1995. Of a total of 288 patients with GSD-I, 57 who had GSD-Ib form the basis of this study. RESULTS: Neutropenia (defined as an absolute neutrophil count <1 x 10(9)/L) was found in 54 patients. In 64% of the patients neutropenia was documented before the age of 1 year, but in 18% of the patients neutropenia was first noted between the ages of 6 and 9 years. Neutropenia was persistent in 5 patients and intermittent without any clear cyclical course in 45. Neutrophil function was investigated in 18 patients with neutropenia and was abnormal in all. Perioral infections were reported in 37 patients, perianal infections in 27 patients, and protracted diarrhea in 23 patients. Findings on colonoscopy and radiologic studies in 10 of 20 patients suspected to have IBD were abnormal in all. All patients with IBD, perioral infections, and perianal infections had neutropenia. CONCLUSIONS: Intermittent severe neutropenia is frequently found in patients with GSD-Ib. The study also indicates that IBD in GSD-Ib is underdiagnosed; up to 77% of the patients studied had evidence of IBD, all of whom had neutropenia. IBD was not detected in those with normal neutrophil counts. These findings support the notion that neutropenia and/or neutrophil dysfunction in GSD-Ib and IBD are causally related.

Adolescent↗
PubMed1999

[A child with dark discoloration of urine].

In a 3-year-old boy alkaptonuria was diagnosed. From early age on gradual dark discoloration of his urine had been noticed in the diapers, but routine urinalysis had not revealed abnormalities. Alkaptonuria is a rare metabolic disease in which homogentisic acid cannot be metabolised, due to a lack of the enzyme homogentisic acid oxidase. The disease often manifests itself in childhood by darkening of urine on standing. The excretion of homogentisic acid in urine in these patients is increased. The disease leads to serious consequences, such as ochronosis of cartilage and connective tissues with arthritis. It is expected that treatment with ascorbic acid and a dietary restriction of protein (1 g/kg/day) can decrease the late and serious consequences by diminishing the serum concentration of the metabolite benzoquinone acetic acid.

Alkaptonuria↗
PubMed1999

Glycogen storage disease type Ia: four novel mutations (175delGG, R170X, G266V and V338F) identified. Mutations in brief no. 220. Online.

Deficient activity of glucose-6-phosphatase (G6Pase) causes glycogen storage disease type Ia (GSD Ia). We analysed the G6Pase gene of 16 GSD Ia patients using single strand conformation polymorphism (SSCP) analysis prior to automated sequencing of exon(s) revealing an aberrant SSCP pattern. In all GSD Ia patients we were able to identify mutations on both alleles of the G6Pase gene, indicating that this method is a reliable procedure to identify mutations. Four novel mutations (175delGG, R170X, G266V and V338F) were identified.

Amino Acid Substitution↗
PubMed1999

A convenient diagnostic function test of peripheral blood neutrophils in glycogen storage disease type Ib.

Neutrophils from patients suffering from glycogen storage disease type Ib (GSD-Ib) show several defects. one of which is a decreased rate of glucose utilization. In this study, we established experimental conditions to show the stimulation of the neutrophil respiratory burst by extracellular glucose. With phorbol-myristate-acetate as stimulus of the burst, the activity of the NADPH oxidase in GSD-Ib neutrophils hardly increased on addition of glucose. In control and GSD-type Ia neutrophils, a clear increase was observed. The lack of response to extracellular glucose in GSD-Ib neutrophils is correlated with the inability to raise intracellular glucose-6-P levels on glucose addition, thereby limiting the activity of the generation of NADPH in the hexose-monophosphate shunt. Our study shows the usefulness of this test for the diagnosis of neutrophil function abnormality in GSD-Ib patients.

Adenosine Triphosphate↗