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Biomedical subjects

J van der Laag

Publications and source records attributed to J van der Laag.

At least 19 recordsLinked to original sources
PubMed2003

Moyamoya and extracranial vascular involvement: fibromuscular dysplasia? A report of two children.

We present two patients with moyamoya syndrome and the unusual involvement of extracranial vessels. The first case illustrates the rare association between moyamoya and primary pulmonary hypertension. In the second patient, moyamoya was complicated by stenoses of vertebral, renal, and mesenteric arteries. In both cases, a systemic intima-proliferative disease, such as fibromuscular dysplasia (FMD), was suspected to be the cause of both intracranial and extracranial arterial disease.

Child↗
PubMed2003

Spirometry in young children: should computer-animation programs be used during testing?

Currently, computer-animation programs are frequently used to instruct and stimulate young children in performing maximal expiratory flow/volume (MEFV) curves. The reproducibility and maximal performance of MEFV manoeuvres with and without the use of two computer-animation programs (the "candles" and the "balloon" programs) were evaluated. Eighty-eight children, aged 4-8 yrs, were randomly assigned to one of the two animation programs. All children performed two series of at least three technically acceptable curves, one series with the incentive and one without, in random order. With the use of computer-animation programs, a lower proportion of children were able to fulfil international criteria for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) reproducibility. The use of incentives improved reproducibility and performance of peak expiratory flow (PEF). Performance of FVC decreased significantly in 6-8-yr-old children using the animation programs. Training with a program for a short period of time before the formal lung-function test may be valuable. According to the results, however, the use of these programs during tests under the guidance of an experienced lung-function technician cannot be routinely recommended because of possible deteriorating effects on reproducibility and performance of forced expiratory manoeuvres.

Child↗
PubMed2002

Treatment of children with cystic fibrosis: central, local or both?

UNLABELLED: Owing to a lack of longitudinal studies, the effect of centralization of care on pulmonary function and survival remains unclear. Three different levels of involvement of centralized care in the treatment of paediatric cystic fibrosis patients were compared with regard to longitudinal pulmonary function and nutritional and microbiological status in a 3-y period, and the literature was reviewed on the possible advantages and disadvantages of centralized care. The study included 105 paediatric patients attending the Cystic Fibrosis Centre between January 1997 and January 2001. Twenty-three patients were treated by local paediatricians according to the protocol of the Centre and were seen only once a year at the Centre, for an annual check-up (local care). Forty-one patients were treated at the Centre only (centralized care). The remaining 41 patients were treated in close cooperation between the Centre and local hospitals, with patients visiting the doctors alternately (shared care). The mean annual changes in pulmonary function and body mass index from all patients, as well as a microbiological survey, were reviewed. No significant differences were found between the three groups for annual changes in FEV1, FVC and body mass index, nor did the review of microbial colonization show any significant differences between the groups. Because the groups in this study were relatively small, the results might have been influenced by lack of power. CONCLUSION: In this relatively small group, no differences in pulmonary function, nutritional status or microbiological colonization between the three levels of involvement of centralized care could be found. This could signify that local paediatricians have a special role in the care for patients with cystic fibrosis, in close cooperation with the specialists at the Centre.

Analysis of Variance↗
PubMed2001

Attitudes towards reproductive issues and carrier testing among adult patients and parents of children with cystic fibrosis (CF).

Assessing the reproductive choices of parents of children with cystic fibrosis (CF) is important in getting a greater insight into the possible needs for counselling of carrier couples in the reproductive decision-making process. Also, parents' reproductive attitudes might indicate critical issues for discussion with regard to introducing general population screening programmes. Data were available from two groups of subjects: 287 adult patients with CF (mean age 27.5 years) and 288 parents of a child with CF (mean age of child 7.7 years) who participated in a Dutch national survey. Attitudes towards reproductive issues and carrier screening and parents' reproductive behaviour were analysed in terms of responses to questionnaires. To avoid having another child with CF, most parents decided against further pregnancies or used other reproductive options. Prenatal diagnosis was used by 72% of parents, whereas 76% of parents planning more children intended using this option. Intention to use prenatal diagnosis was associated with the strength of religious conviction, and was not associated with perceived severity of CF, health of the child, or future therapeutic possibilities. Respondents demonstrated difficulties in deciding to abort for CF. A majority of parents and adult patients supported carrier couple identification within CF families. The results suggest that those most closely involved with CF will accept the reproductive choices of carrier couples identified in population screening programmes.

Abortion, Induced↗
PubMed2001

Insulin-like growth factors and leucine kinetics during exercise training in children with cystic fibrosis.

BACKGROUND: Little is known about the metabolic effects of exercise training in children with cystic fibrosis. The hypothesis for the current study was that in patients with declining clinical status, exercise increases circulating insulin-like growth factors (IGFs) and improves protein kinetics. METHODS: This was a prospective intervention study in 10 children with cystic fibrosis who participated in a structured isoenergetic exercise (cycling) training program for 3 months. Measurements of IGFs, protein kinetics (using intravenous [13C]-1-leucine tracer infusions) and nutritional balance studies were conducted at baseline and after 3 months. RESULTS: Standard deviation scores of plasma IGF-I, IGF-II, and IGF binding protein (BP)-3 were all decreased at baseline (mean +/- SE: -2.0+/-0.2, -2.0+/-0.2. -0.6+/-0.2, respectively). IGF-I and IGF-II concentrations were significantly higher after exercise training (standard deviation scores -1.4+/-0.3 and -1.3 +/-0. 1, respectively; compared with baseline: one-tailed t-test P = 0.03 and 0.002). The standard deviation score of the IGF-I/IGF BP-3 ratio, an indicator of free IGF-I in the circulation, normalized during exercise training (0.0+/-0.6 vs. -1.3+/-0.2 SD units at baseline, one-tailed t-test P = 0.04). There was no significant difference in protein intake and fasting protein breakdown, oxidation, and protein synthesis or in energy balance and fat absorption. CONCLUSIONS: These results show that isoenergetic exercise training can be safely recommended to patients with cystic fibrosis. It provides a positive anabolic stimulus to IGF status but is not sufficient to adequately augment protein accretion in patients with diminished nutritional status.

Adolescent↗
PubMed1996

Tidal breathing analysis as a measure of airway obstruction in children three years of age and older.

This study was designed to evaluate the value and applicability of tidal breathing pattern analysis to assess airflow obstruction in young children. The time needed to reach maximal tidal expiratory flow (TME) divided by total expiratory time (TE) was measured in 228 healthy children 3 to 11 yr of age, 64 patients with asthma, and 12 children with cystic fibrosis. In 70 patients both TME/TE and forced maximal expiratory flow volume (MEFV) parameters were measured. The mean TME/TE in healthy subjects was 43.0 +/- 7.6%. The within-subject reproducibility was high (repeatability index, 5.3%). In the asthmatic patients the mean TME/TE was significantly lower (30.0 +/- 8.2%, p < 0.001), and it increased to 36.5 +/- 7.9% after bronchodilation (n = 44, p < 0.001). The TME/TE level of the subgroup of patients with asthma and FEV1/FVC > or = 0.80 was lower when compared with age-matched normal subjects (30.9 +/- 8.5, p < 0.0001), but it was in a higher range when compared with asthmatics with FEV1/FVC < 0.80 (25.9 +/- 7.9, p < 0.001). In the cystic fibrosis group the mean TME/TE was 27.4 +/- 10.7% without a significant change after bronchodilation. TME/TE correlated significantly with MEFV parameters. Tidal breathing analysis proved easy to perform in children older than 3 yr of age. The TME/TE ratio may be a reliable and simple indicator for airway obstruction.

Airway Resistance↗
PubMed1995

Risk of cross-colonization and infection by Pseudomonas aeruginosa in a holiday camp for cystic fibrosis patients.

The risk of cross-colonization and subsequent infection by Pseudomonas aeruginosa in holiday camps for cystic fibrosis patients was studied in 91 children by culturing sputum at their arrival, at their departure, 2 months later, and at regular intervals thereafter. The isolated strains were subjected to serotyping, phage typing, pyocin typing, and genotyping by random amplified polymorphic DNA fingerprinting-PCR. It was concluded from random amplified polymorphic DNA fingerprinting-PCR typing that the Pseudomonas flora was not constant in most children. Some children harbored one genotype, whereas some harbored two or more different genotypes simultaneously. Most culture-positive children easily acquired a strain of another genotype which replaced the former one or coexisted with the original one. The incidence of sputum conversion was 7.7% in previously negative children; the incidence of permanent colonization and infection was 1.9%. This risk was comparable with that observed in the community. We conclude that the risk of cross-infection is trivial compared with the obvious joy and social benefit derived from a holiday camp.

Adolescent↗
PubMed1995

Efficiency of oxidative work performance of skeletal muscle in patients with cystic fibrosis.

BACKGROUND: Exercise intolerance in patients with cystic fibrosis is commonly attributed to reduced pulmonary and nutritional status. The possible role of diminished efficiency of mitochondrial oxidative phosphorylation in relation to skeletal muscle performance was investigated in patients with cystic fibrosis. METHODS: In vivo synthesis of ATP in skeletal muscle during submaximal exercise was studied in eight patients with cystic fibrosis aged 12-17 years, and in 19 healthy control subjects aged 8-36 years. The intracellular pH and concentrations of phosphate compounds were calculated at four steady states from phosphorus-31 labelled nuclear magnetic resonance spectroscopy measurements in the forearm muscle during bulb squeezing in an exercise protocol. Normalised power output, expressed as percentage maximal voluntary contraction (Y, in %MVC), was related to the energy force of ATP hydrolysis (X = ln [ATP]/[ADP][Pi]). This relationship provides an in vivo measure of efficiency of oxidative work performance of skeletal muscle. RESULTS: During all workloads (but not at rest) intracellular pH was higher in the patients with cystic fibrosis than in the controls. The linear least square fit for Y = a-bX showed high correlations in both groups; the slope b was 19% lower in the patients than in the controls (11.8% v 14.5% MVC/ln M; 95% confidence interval for difference 0.3 to 5.0). CONCLUSIONS: In patients with cystic fibrosis oxidative work performance of skeletal muscle is reduced. This may be related to secondary pathophysiological changes in skeletal muscle in cystic fibrosis.

Adolescent↗
PubMed1995

Pulmonary hemosiderosis and immune complex glomerulonephritis.

Two children with a syndrome of pulmonary hemorrhage and immune complex nephritis are reported. Clinical history suggests that pulmonary lesions precede renal abnormalities. Necrotizing glomerulonephritis with granular immune deposits along the glomerular basement membrane was found. Although the etiology of this disease complex is still unknown, the clinical and pathological findings in these patients suggest that immune complex glomerulonephritis is an unusual complication of idiopathic pulmonary hemosiderosis.

Anti-Glomerular Basement Membrane Disease↗
PubMed1992

Impaired diluting segment chloride reabsorption in patients with cystic fibrosis.

Clearance studies were performed in 12 patients with cystic fibrosis (CF) during maximum water diuresis. The fractional diluting segment reabsorption was calculated from chloride clearance (CCl) and maximum free water clearance (CH2O) as 'CH2O/CCl+CH2O'. Fractional delivery to the diluting segment and from the proximal tubules was estimated by maximum urine flow during water diuresis (Vmax/GFR) and lithium clearance (CLi/GFR), respectively. The data were compared with results obtained in young healthy subjects. To estimate free water generation beyond the medullary diluting segment, CH2O/GFR was also measured during acute furosemide administration in 5 patients. Values for the term CH2O/CCl+CH2O were significantly lower in patients with CF (79.1 +/- 5.1%) as compared with healthy controls (89.4 +/- 4.4%). This was also true for the terms Vmax/GFR (CF: 9.5 +/- 1.6%; control subjects: 13.8 +/- 2.5%) and CLi/GFR (CF: 22.2 +/- 4.1%; control subjects: 30.7 +/- 5.1%). Compared to data derived from the literature, the solute-free water generation during administration of furosemide (CH2O/GFR) was significantly reduced in patients with CF (6.8 +/- 1.5%) as compared with healthy subjects (13.3 +/- 6.1%). We conclude that reabsorption in the diluting segment is impaired in patients with CF, perhaps at a site beyond the thick ascending limb of Henle's loop. Enhanced proximal reabsorption, suggested by reductions in Vmax/GFR and CLi/GFR, appears to be a compensatory phenomenon to maintain sodium and chloride balance.

Absorption↗