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Biomedical subjects

J C de Jongste

Publications and source records attributed to J C de Jongste.

At least 19 recordsLinked to original sources
PubMed2003

Mattress encasings and mite allergen levels in the Prevention and Incidence of Asthma and Mite Allergy study.

BACKGROUND: Reduction of allergen exposure from birth may reduce sensitization and subsequent allergic disease. OBJECTIVE: To measure the influence of mite allergen-impermeable mattress encasings and cotton placebo encasings on the amount of dust and mite allergen in beds. METHODS: A total of 810 children with allergic mothers took part in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Allergen-impermeable and placebo mattress encasings were applied to the childrens' and the parents' beds before birth. Dust samples were taken from the beds of children and their parents before birth and 3 and 12 months after birth. Extracts of dust samples were analysed for mite allergens (Der p 1 and Der f 1). RESULTS: Active mattress encasings were significantly more effective in reducing dust and mite allergen levels than placebo encasings. Mite allergen levels were low in general and the treatment effect was modest. Twelve months after birth, mattresses with active mattress encasings had about half the amount of Der 1 (Der p 1 + Der f 1)/m2, compared to mattresses with placebo encasings, for the child's and the parental mattress. CONCLUSION: This study shows that mite-impermeable mattress encasings have a significant but modest effect on dust and mite allergen levels of mattresses with low initial mite allergen levels, compared to placebo.

Allergens↗
PubMed2003

Bronchodilation in infants with malacia or recurrent wheeze.

BACKGROUND: Controversy remains regarding the effectiveness of bronchodilators in wheezy infants. AIMS: To assess the effect of inhaled beta(2) agonists on lung function in infants with malacia or recurrent wheeze, and to determine whether a negative effect of beta(2) agonists on forced expiratory flow (V'(maxFRC)) is more pronounced in infants with airway malacia, compared to infants with wheeze. METHODS: We retrospectively analysed lung function data of 27 infants: eight with malacia, 19 with recurrent wheeze. Mean (SD) age was 51 (18) weeks. Mean V'(maxFRC) (in Z score) was assessed before and after inhalation of beta(2) agonists. RESULTS: Baseline V'(maxFRC) was below reference values for both groups. Following inhalation of beta(2) agonists the mean (95% CI) change in mean V'(maxFRC) in Z scores was -0.10 (-0.26 to 0.05) and -0.33 (-0.55 to -0.11) for the malacia and wheeze group, respectively. CONCLUSIONS: In infants with wheeze, inhaled beta(2) agonists caused a significant reduction in mean V'(maxFRC). Infants with malacia were not more likely to worsen after beta(2) agonists than were infants with recurrent wheeze.

Administration, Oral↗
PubMed2003

Association of consumption of products containing milk fat with reduced asthma risk in pre-school children: the PIAMA birth cohort study.

BACKGROUND: Environment and lifestyle contribute to the development of asthma in children. Understanding the relevant factors in this relationship may provide methods of prevention. The role of diet in the development of asthma in pre-school children was investigated. METHODS: Data from 2978 children participating in a prospective birth cohort study were used. Food frequency data were collected at the age of 2 years and related to asthma symptoms reported at the age of 3 years. RESULTS: The prevalence of recent asthma at age 3 was lower in children who consumed (at age 2) full cream milk daily (3.4%) than in those who did not (5.6%) and in those who consumed butter daily (1.5%) than in those who did not (5.1%). The prevalence of recent wheeze was lower in children who consumed milk products daily (13.7%) than in those who did not (18.4%) and in children who consumed butter daily (7.7%) than in those who did not (15.4%). These effects remained in a logistic regression model including different foods and confounders (adjusted odds ratio (CI) for recent asthma: full cream milk daily v rarely 0.59 (0.40 to 0.88), butter daily v rarely 0.28 (0.09 to 0.88)). Daily consumption of brown bread was also associated with lower rates of asthma and wheeze, whereas no associations were observed with the consumption of fruits, vegetables, margarine, and fish. CONCLUSIONS: In pre-school children, frequent consumption of products containing milk fat is associated with a reduced risk of asthma symptoms.

Animals↗
PubMed2002

[Negative effects of passive smoking on the (unborn) child].

The negative effects of passive smoking on the health of the foetus or child continue to receive little attention, despite the large volume of research in this area. Passive smoking during pregnancy is associated with low birth weight, a reduction in head circumference at birth, and a far higher incidence of sudden infant death syndrome. Exposure to cigarette smoke also leads to a decreased lung function, an increased risk of severe infections, including respiratory syncytial virus bronchiolitis, meningococcal disease and middle ear infections. There is no association between passive smoking and the development of allergic asthma, but passive smoking does cause an increase in the prevalence of respiratory symptoms in children with or without asthma. Finally, there is a relation between passive smoking and behavioural disorders including attention deficit/hyperactivity disorder (ADHD). Passive smoking before birth seems even more harmful than after birth. A causal relationship is suggested in most studies, or has been proven by animal experiments. A decreased birth weight in general increases the risk of developing chronic diseases as an adult, such as hypertension, cardiovascular disease and type 2 diabetes mellitus. This extensive knowledge about the adverse health effects of smoke exposure in (unborn) children deserves greater attention in the counselling of pregnant women, and in anti-smoking campaigns.

Attention Deficit Disorder with Hyperactivity↗
PubMed2002

Effectiveness of pharmacotherapy in asthmatic preschool children.

The term "effectiveness" relates to the question of whether or not a certain treatment works in practice. Usually, such a treatment was first evaluated under tightly controlled conditions in selected patient populations, and the potential benefits were shown. There is, however, a great difference between the efficacy of a given treatment, indicating its optimal therapeutic action in controlled trials, and its effectiveness when applied to a less well-defined population of patients in daily practice. This is especially relevant for asthma in young children, where many factors are responsible for the difference. Among these are, first of all, the heterogeneity of the wheezing phenotype. Other factors include the compliance with prescribed treatments, as determined by the attitude of doctors and parents towards such treatment, the ease of administration and the perceived effects and side effects. Also, the performance of different inhaler devices may be insufficient for a good, reliable dose deposition in young children in daily life. As a result, the current treatment guidelines for preschool children with recurrent wheeze are probably too optimistic in assuming that inhaled treatment is most effective and feasible at all ages. We propose careful re-evaluation of such recommendations in a first-line setting resembling daily life as closely as possible, and consideration of oral treatments as well. Also, we need methods to separate the different phenotypes within the group of recurrently wheezing preschool children to optimize targeting of asthma treatment to those who have ongoing airway inflammation.

Anti-Asthmatic Agents↗
PubMed2002

Annual lung function changes in young patients with chronic lung disease.

Reference equations for ventilatory function that use different statistical models may introduce artifacts that affect the estimated change of lung function during growth in young subjects. The effect of differently modelled reference equations on the estimated annual change of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in young patients with chronic lung disease was assessed. Four frequently used reference equations were used to describe the longitudinal changes of FEV1 and FVC in 52 patients (23 females) with cystic fibrosis (CF) during a mean follow-up of 3.9 yrs. Choice of reference equations directly affected value and, most importantly, estimated annual change of FVC and FEV1. Mean+/-SD annual change of FEV1 varied from 2.2+/-6.2 to -2.2+/-3.6% of predicted. For two reference equations the estimated individual changes of FEV1 and FVC in CF were positively correlated with mean individual age. This probably reflects underestimation of deteriorating lung function. Variability of annual change was independent of age only when reference equations that were designed to accurately predict lung function during the pubertal growth spurt were used. These findings have implications for patient care and clinical research.

Adolescent↗
PubMed2002

Measurement of exhaled nitric oxide in children, 2001.

Measurement of fractional exhaled nitric oxide in exhaled air is an exciting innovative technique that gives new insights in to the pathophysiology of lung disease and asthma in particular, with many potential clinical applications. Careful standardisation of measurement techniques will facilitate the use of this new measurement in paediatric respiratory medicine: this Task Force was set up for this purpose. Methodologies, for use in all age groups, are already available and there are abundant questions relating to interpretation and application of fractional exhaled nitric oxide waiting to be addressed. Noninvasiveness and instantaneous results potentially make it a suitable monitoring instrument for use in children. Exhaled nitric oxide measurement has definitely found its way into clinical research in paediatric respiratory medicine. Evidence for clinically-useful applications is accumulating, and the merits of this new technique must now be demonstrated in larger studies, using standardised methodology in an appropriate setting.

Adolescent↗
PubMed2002

Measurements of interrupter resistance: reference values for children 3-13 yrs of age.

The interrupter technique is a convenient and sensitive technique for studying airway function in subjects who cannot actively participate in (forced) ventilatory function tests. Reference values for preschool children exist but are lacking for children >7 yrs. Reference values were obtained for expiratory interrupter resistance (R(int,e)) in 208 healthy Dutch Caucasian children 3-13 yrs of age. A curvilinear relationship between R(int,e) and height was observed, similar to published airways resistance data measured by plethysmography. No significant differences in cross-sectional trend or level of R(int,e) were observed according to sex. It was found that Z-scores could be used to express individual R(int,e) values and to describe intra- and interindividual differences based on the reference equation: 10logR(int,e)=0.645-0.00668x standing height (cm) kPa x L(-1) x s(-1) and residual SD (0.093 kPa x L(-1) x s(-1)). Expiratory interrupter resistance provides a tool for clinical and epidemiological assessment of airway function in a large age range.

Adolescent↗
PubMed2002

Exhaled nitric oxide measurements with dynamic flow restriction in children aged 4-8 yrs.

Fractional exhaled nitric oxide concentration (FENO) depends on exhalation flow; however, children often are unable to perform controlled flow procedures. Therefore, a device was developed for off-line FENO sampling, with dynamic flow restriction (DFR). The authors compared off-line with on-line FENO, assessed feasibility, and obtained normal values for FENO in children aged 4-8 yrs. Subjects inhaled nitric oxide (NO)-free air and exhaled into the device, where DFR kept exhalation flow constant at 50 mL x s(-1). Dead space air was discarded. Exhaled air was collected in a 150 mL mylar balloon. On-line measurements were performed and values compared with off-line FENO in 19 adult volunteers. Seventy-nine children performed off-line sampling. All samples were analysed with a chemiluminescence NO-analyser. Normal values were obtained in 34 healthy children. There was an excellent correlation between on- and off-line values. Bland and Altman plots showed good agreement between on- and off-line FENO. Seventy-four out of 79 children were able to perform a correct off-line procedure. Geometric mean+/-SEM FENO in healthy children was 4.9+/-1.2 parts per billion (ppb) for male children and 7.6+/-1.1 ppb for female children. It can be concluded that off-line fraction of exhaled nitric oxide measurements with dynamic flow restriction are feasible in young children and correspond to on-line values.

Adult↗
PubMed2001

Airway inflammation is present during clinical remission of atopic asthma.

Symptoms of atopic asthma often disappear at puberty. However, asthmatic subjects in clinical remission will frequently have a relapse later in life. The aim of this study was to investigate whether subjects in clinical remission of atopic asthma have persistent airway inflammation and/or airway remodeling. Bronchial biopsies were obtained from subjects in clinical remission, asthmatic subjects, and healthy control subjects. The presence and/or activation state of eosinophils, mast cells, macrophages, T lymphocytes, interleukin (IL)-5, eotaxin, and inducible nitric oxide synthase (iNOS) were analyzed. Results were compared with less invasive indicators of airway inflammation. Also aspects of airway remodeling were determined. Eosinophils, T cells, mast cells, and IL-5 were significantly elevated in the airway mucosa of subjects in remission compared with control subjects. Also, blood eosinophil cell counts were significantly higher in subjects in clinical remission. Blood eosinophil cell counts, exhaled nitric oxide (eNO) levels, and bronchial response to adenosine-5'-monophosphate correlated significantly with the quantity of tissue eosinophils. Significant airway remodeling was found in subjects in clinical remission. Our study has shown ongoing airway inflammation and airway remodeling in adolescents in clinical remission of atopic asthma. Subclinical airway inflammation may well determine the risk of an asthma relapse later in life.

Adenosine Monophosphate↗
PubMed2001

['Inflammometry' with nitric oxide in exhaled air: a new test for lung diseases].

The gas nitric oxide (NO) is produced in increased amounts in certain types of inflammatory responses and its presence in exhaled air can be demonstrated. The nitric oxide fraction in exhaled air (FeNO) is elevated in patients with asthma and lowered in the case of several other lung diseases such as cystic fibrosis and primary ciliary dyskinesia. The FeNO can be quickly measured in a non-invasive and reproducible manner: on-line if the patient (adult or child), having taken a deep breath in, breathes out with a low flow rate into the NO measuring device or off-line if the expired air is collected in an NO inert reservoir. Confounding factors are contamination of inhaled air with ambient NO and contamination of exhaled air with NO that has been produced in the paranasal sinuses and the nose. The possible applications of FeNO measurement as a new lung function test include diagnostic tests for chronic respiratory symptoms and the possible guidance of anti-inflammatory therapy for asthma and, perhaps, other respiratory disorders.

Breath Tests↗
PubMed2001

Definition of respiratory symptoms and disease in early childhood in large prospective birth cohort studies that predict the development of asthma.

We have reviewed the prospective value of early respiratory symptoms for determining the risk of development of asthma later in life by using data from studies based on the general population, hospital population, and general practices. Although "wheezing" in infancy generally has a good prognosis, it is an important risk factor for the development of asthma later in life. The prognostic value of "coughing" and "shortness of breath" in infancy for the later development of asthma is less clear. Despite the fact that no internationally accepted criteria for the definition of asthma in early childhood are available, many studies have been performed on this topic. We also investigated the outcome variables that were used to describe respiratory symptoms and disease in early childhood in the publications of nine large prospective birth cohort studies on the development of asthma. From seven of these studies, we reviewed the original questionnaires. We found that various studies used different outcome variables, but the data actually collected were similar. This is an important observation because it implies that comparisons between studies can be markedly improved by data sharing among investigators.

Asthma↗
PubMed2001

Hydrogen peroxide in breath condensate during a common cold.

BACKGROUND: Hydrogen peroxide (H2O2) in exhaled air condensate is elevated in inflammatory disorders of the lower respiratory tract. It is unknown whether viral colds contribute to exhaled H2O2. AIM: To assess exhaled H2O2 during and after a common cold. METHODS: We examined H2O2 in the breath condensate of 20 normal subjects with acute symptoms of a common cold and after recovery 2 weeks later and, similarly, in 10 subjects without infection. H2O2 was measured with a fluorimetric assay. RESULTS: At the time of infection exhaled H2O2 (median, ranges) was 0.20 microM (0.03-1.2 microM), and this decreased to 0.09 microM (< 0.01-0.40 microM) after recovery (p = 0.006). There was no significant difference in lung function (forced vital capacity and forced expiratory volume in 1 sec) during and after colds. In the controls, exhaled H2O2 did not change over a 2-week period. CONCLUSIONS: H2O2 in exhaled air condensate is elevated during a common cold, and returns to normal within 2 weeks of recovery in healthy subjects. Hence, symptomatic upper respiratory tract infection may act as a confounder in studies of H2O2 as a marker of chronic lower airway inflammation.

Adult↗
PubMed2001

Pro-inflammatory cytokines induce c-fos expression followed by IL-6 release in human airway smooth muscle cells.

BACKGROUND: Airway smooth muscle (ASM) is considered to be a target for mediators released during airway inflammation. AIMS: To investigate the expression of c-fos, a constituent of the transcription factor activator protein-1, in human ASM cells. In addition, to measure the release of interleukin (IL)-6 into the conditioned medium of stimulated ASM cells, as well as DNA biosynthesis and changes in cell number. METHODS: Serum-deprived human ASM cells in the G0/G1 phase were stimulated with the pro-inflammatory cytokines; tumour necrosis factor-alpha, IL-1beta, IL-5 and IL-6. The expression of mRNA encoding the proto-oncogene c-fos was measured by Northern blot analysis. Cell proliferation was assessed by [3H]-thymidine incorporation assays and cell counting, and IL-6 levels in cell-conditioned medium were measured by enzyme-linked immunosorbent assay. RESULTS: All of the cytokines investigated induced a rapid (within 1 h) and transient increase in the expression of mRNA encoding c-fos, followed by the expression and enhanced release of IL-6. Cell proliferation remained unchanged in cytokine-stimulated cells. CONCLUSIONS: Cytokine-induced c-fos expression in human ASM cells could be described as a marker of cell 'activation'. The possible association of these results with airway inflammation, through secondary intracellular mechanisms such as cytokine production, is discussed.

Bronchi↗
PubMed2001

The Sophia Anatomical Infant Nose-Throat (Saint) model: a valuable tool to study aerosol deposition in infants.

Relatively little is known about the variables that influence lung deposition of inhaled aerosols in children. A model of the upper airways of an infant could be a useful tool to study these variables in vitro. The objective of this study was to construct an anatomically correct model of the upper airways of a young child. A routine three-dimensional (3D) CT scan of the skull and neck of a child was selected that included the airway from the nasal cavity down to the subglottic region. The CT scan was edited to obtain an anatomically correct distinction between air and mucosa. Next, a model was constructed with a stereolithographic technique using a UV-sensitive resin. To validate the model, a 3D CT scan of the model was made and compared to the anatomy of the original image. To study aerosol deposition, the model was connected to a breathing simulator. Medical aerosols were delivered to the model by MDI/spacer during stimulated breathing. An upper airway model was made of a 9-month-old child that needed reconstructive surgery for a skull deformity and with normal anatomy of the upper airways. The nasal airway of the model was open for air passage and the oral airway was closed. The CT scan of the model matched the original in vivo CT scan closely. Aerosol deposition measurements showed that dose passing the model, or lung dose, was comparable with in vivo lung deposition data. We have constructed an anatomically correct model of the upper airways of a child, using a stereolithographic method for in vitro studies of aerosol deposition in young children. This model will be used to obtain insight in aerosol treatment that cannot be obtained in vivo.

Aerosols↗
PubMed2001

Randomised controlled study of clinical efficacy of spacer therapy in asthma with regard to electrostatic charge.

BACKGROUND: Inhalation therapy using a pressured metered dose inhaler (pMDI) and a spacer is frequently used in the treatment of airway disease in children. Several laboratory studies found a clear negative influence of electrostatic charge (ESC) on plastic spacers on the delivery of aerosol. AIMS: To investigate whether ESC on plastic spacers could diminish bronchodilating responses to salbutamol. METHODS: Ninety asthmatic children (aged 4-8 years) were randomised into three groups: metal Nebuchamber, plastic Volumatic, and plastic Aerochamber. The bronchodilating response was measured by the change in peak expiratory flow rate (PEF) after 100 microgram and 400 microgram salbutamol. Within the Volumatic and Aerochamber groups, a crossover comparison was made between electrostatic and non-electrostatic spacers. RESULTS: We found no significant effect of ESC on the bronchodilating response to salbutamol with any of the doses in the Aerochamber and Volumatic groups. For the plastic spacers, the mean difference of the change in PEF after 100 microgram salbutamol between non-electrostatic and electrostatic spacers was only +1.7% (95% CI -1.3% to 4.7%). After 400 microgram salbutamol this was +1.9% (95% CI -1.4% to 5.1%). A comparable efficacy was found for the Nebuchamber, the Aerochamber, and Volumatic with respect to the change in PEF after 100 and 400 microgram salbutamol. CONCLUSION: This study showed no negative influence of ESC on plastic spacers with regard to clinical efficacy of a beta(2) agonist (salbutamol) in children with asthma. The metal Nebuchamber, plastic Aerochamber, and plastic Volumatic were equally effective.

Administration, Inhalation↗