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Biomedical subjects

G Wennergren

Publications and source records attributed to G Wennergren.

At least 19 recordsLinked to original sources
PubMed1998

Sociodemographic risk factors for sudden infant death syndrome: associations with other risk factors. The Nordic Epidemiological SIDS Study.

The aim of this study was to investigate associations between sudden infant death syndrome (SIDS) and social factors in the Nordic countries. A case-control study was conducted in Denmark, Norway and Sweden: The Nordic Epidemiological SIDS Study. Parents of 244 SIDS infants and 869 control infants matched on gender, age at death and place of birth filled in questionnaires. The dataset was analysed by conditional logistic regression. In univariate analysis, the following sociodemographic factors were associated with an increased risk of SIDS: low maternal age [odds ratio (OR) 7.8; 2.8-21.5], high birth order (OR 4.4; 2.5-7.5), single motherhood (OR 2.9; 1.7-5.0), low maternal education (OR 4.5; 2.8-7.1), low paternal education (OR 3.0; 1.9-4.7), maternal unemployment (OR 2.4; 1.8-3.4) and paternal unemployment (OR 4.0; 2.7-5.9). In a multivariate analysis where maternal smoking was also included, only paternal unemployment, young maternal age and high birth order remained significantly associated with SIDS. Housing conditions were not associated with SIDS. However, the risk of SIDS was high if the family had lived in their present home for only a few years (OR 2.3; 1.3-4.1). Sociodemographic differences remain a major concern in SIDS in a low-incidence situation and even in an affluent population with adequate health services.

Case-Control Studies↗
PubMed1998

Prevalence of allergy in children in relation to prior BCG vaccination and infection with atypical mycobacteria.

By influence on the Th1/Th2 cell balance, infectious agents may affect the development of atopic allergy. In this study, we investigated whether previous BCG vaccination or infection with atypical mycobacteria might be related to the development of atopic disease. The study, which involved skin testing with mycobacteria and answers to a questionnaire for more than 6000 children in Sweden, revealed a low prevalence of allergy among BCG-vaccinated children who were immigrants or adopted from other countries. Vaccinated children born in Sweden, however, did not have significantly lower allergy prevalence than age-matched, unvaccinated children. Furthermore, the overall frequencies of skin-test reactivity to the atypical mycobacteria M. avium and M. scrofulaceum were higher rather than lower in allergic than in nonallergic children. By contrast, there was a tendency toward a lower frequency of more strongly positive skin reactions (> or = 10 mm) to mycobacteria in allergic than in nonallergic children. These findings do not support the hypothesis that early mycobacterial infections have a suppressive effect on the development of atopic disease. Earlier findings of an apparent association between atopy and lack of previous mycobacterial infection may possibly be explained by a relatively decreased ability of atopic patients to mount strong Th1 cell-mediated immune responses.

BCG Vaccine↗
PubMed1998

A case-control study of smoking and sudden infant death syndrome in the Scandinavian countries, 1992 to 1995. The Nordic Epidemiological SIDS Study.

AIM: To establish whether smoking is an independent risk factor for sudden infant death syndrome (SIDS), if the effect is mainly due to prenatal or postnatal smoking, and the effect of smoking cessation. METHODS: The analyses were based on data from the Nordic epidemiological SIDS study, a case-control study with 244 cases and 869 controls. Odds ratios were computed by conditional logistic regression analysis. RESULTS: Smoking emerged as an independent risk factor for SIDS, and the effect was mainly mediated through maternal smoking in pregnancy (crude odds ratio 4.0 (95% confidence interval 2.9 to 5.6)). Maternal smoking showed a marked dose-response relation. There was no effect of paternal smoking if the mother did not smoke. Stopping or even reducing smoking was beneficial. SIDS cases exposed to tobacco smoke were breast fed for a shorter time than non-exposed cases, and feeding difficulties were also more common. CONCLUSIONS: Smoking is an independent risk factor for SIDS and is mainly mediated through maternal smoking during pregnancy. Stopping smoking or smoking less may be beneficial in reducing the risk of SIDS.

Breast Feeding↗
PubMed1998

Short- and long-term efficacy. Childhood asthma.

In clinical studies of asthma, great attention should be focused on the choice and validation of outcome measures. The outcome parameters to be used when evaluating efficacy of early intervention in childhood asthma treatment must be closely linked to the aims of the intervention and considered in the design of the study. In an interventional study, possible adverse consequences should also be considered as outcome measures when designing the study. The appropriate time span for assessing different types of interventions may vary from days to several decades, depending on the character of the intervention. Not only outcome parameters, such as improvement in symptom score and improvement of lung function, but also those that measure reduction in frequency and severity of acute exacerbations, reduction in morbidity and improvement in quality of life should be used. For some purposes, a more detailed approach to symptom severity is needed, such as separation of acute from chronic symptoms. Other outcome measures that need to be considered are: cost-effectiveness, normalization of inflammatory changes in the airways, control of airway hyperresponsiveness, airway growth and prevention of airway remodelling and importantly, whether an intervention against asthma can alter the natural course, or cure, the disease. Interventions should be evaluated to see to what extent such aims have been met.

Asthma↗
PubMed1997

Cytokines in nasal fluids from school children with seasonal allergic rhinitis.

Allergic rhinitis is a particularly good model for studies of cytokine production in vivo. In this study the occurrence of the cytokines IL-4, IL-5, IL-10 and IFN-gamma as well as the soluble receptor for IL-4 in nasal lavage fluids were assayed in 38 school children, with seasonal allergic rhinitis, and 19 healthy age-matched, non-atopic controls, using highly sensitive enzyme immunoassays. IL-4 levels in patients with seasonal allergic rhinitis were markedly increased in comparison with those in non-atopic controls or in atopic patients before the start of the pollen season. In controls, but not in the atopic patients, levels of IFN-gamma and IL-5 were significantly higher in specimens obtained during the pollen season than in those obtained outside the season. The IL-4/IFN-gamma ratios were significantly higher in atopic than in non-atopic subjects and further increased in atopic patients during the season. In addition to IL-4, elevated levels of IL-10 were observed in association with seasonal rhinitis. Following treatment with a topical steroid (budesonide) there was a statistically significant increase of the levels of soluble IL-4 receptor. These findings indicate that nonatopic and atopic individuals react to pollen exposure with distinct cytokine patterns in agreement with the Th1/Th2 concept. Topical steroids may possibly decrease inflammation by increasing the formation of soluble IL-4 receptor.

Adolescent↗
PubMed1997

Wheezing bronchitis reinvestigated at the age of 10 years.

We have reinvestigated 92/101 children aged 10, who before the age of 2 years were admitted to a paediatric ward due to wheezing bronchitis. At the present time, 70% are symptom-free without medication, 20% have mild asthma, 8% moderate and 2% severe asthma. Persistent asthma correlated significantly to the presence of some other atopic disease in recent years, to early start of wheezing during infancy and to intense obstructive disease as a young child, while initial respiratory syncytial virus infection did not. A clear-cut relationship between smoking in the home in infancy and persistent asthma emerged (not visible at a preschool follow-up). The histamine challenge results correlated to the clinical picture. A normal histamine challenge was seen in 63%, mild hyperresponsiveness in 19%, moderate in 12% and pronounced hyperresponsiveness in 6%. The figures for persistent asthma and bronchial hyperresponsiveness are high compared with the prevalence of asthma in the overall population of schoolchildren.

Asthma↗
PubMed1997

The decline in the incidence of SIDS in Scandinavia and its relation to risk-intervention campaigns. Nordic Epidemiological SIDS Study.

A prospective case-control study of sudden infant death syndrome (SIDS) in Norway, Denmark and Sweden between September 1, 1992 and August 31, 1995 comprised 244 cases and 869 matched controls. After the introduction of risk-intervention campaigns, the SIDS incidence decreased from 2.3/1000 live births in Norway, 1.6 in Denmark and 1.0 in Sweden to 0.6/1000 or fewer in all the Scandinavian countries in 1995. The decrease paralleled a decline in the prone sleeping position and there was an accompanying parallel fall in total postneonatal mortality in all three countries. Thus, the risk-reducing campaigns for SIDS have been successful not only in Norway and Denmark, starting from relatively high incidences, but also in Sweden, starting from a low incidence. During the study period, a gradual increase was observed for the effects of prone sleeping, smoking and bottle-feeding as risk factors for SIDS.

Case-Control Studies↗
PubMed1997

Combined effects of sleeping position and prenatal risk factors in sudden infant death syndrome: the Nordic Epidemiological SIDS Study.

OBJECTIVE: Prone sleeping is a strong risk factor for sudden infant death syndrome (SIDS). We investigated whether the combined effect of prone sleeping position and prenatal risk factors further increased the SIDS risk. METHODS: In the Nordic Epidemiological SIDS Study, parents of SIDS victims in Denmark, Norway, and Sweden completed a questionnaire on potential risk factors for SIDS. Forensic pathologists verified the SIDS diagnosis. Four controls of the same gender, age, and place of birth were selected. This matched case-control study, which included 244 SIDS cases and 869 controls from 1992 to 1995, was analyzed by conditional logistic regression. RESULTS: Odds ratios (ORs) for prone and side sleeping compared with supine sleeping for the last sleep were 13.9 (95% confidence interval 8.2-24) and 3.5 (2.1-5.7). Infants 13 to 24 weeks old had particularly high risk in prone and side sleeping, at 28.5 (7.9-107) and 5.9 (1.6-22). OR for prone sleeping was higher in girls, at 30.4 (11-88), than in boys, 10.3 (5.5-19). We found strong combined effects of sleeping position and prenatal risk factors (more than multiplicative). The OR for prone and side sleeping was increased for infants with birth weight <2500 g, at 83 (25-276) and 36.6 (13-107); for preterm infants, at 48.8 (19-128) and 40.5 (14-115); and for intrauterine growth retarded, at 38.8 (14-108) and 9.6 (4.3-22), compared with supine position in infants without these prenatal factors. The combined effect of nonsupine positions and intrauterine growth retarded was highest among 13- to 24-week-old infants. Effects of combined presence of nonsupine sleeping positions and each of the factors of smoking in pregnancy, young maternal age, higher parity, low level of maternal education, and single motherhood were more than additive. Attributable fractions in the population for prone and side sleeping were 18.5% and 26.0%. CONCLUSIONS: Both prone and side sleeping increased the risk of SIDS. The risk was increased further in low birth weight infants, preterm infants, and infants at the age of 13 to 24 weeks, suggesting that SIDS may be triggered by nonsupine sleeping in infants with prenatal risk factors during a vulnerable period of postnatal development.

Age Factors↗
PubMed1996

Urinary eosinophil protein X in children with atopic asthma: a useful marker of antiinflammatory treatment.

BACKGROUND: Bronchial asthma is associated with elevated serum levels of eosinophil products, such as eosinophil protein X (EPX), but the occurrence in urine of this substance in patients with asthma has not previously been studied. OBJECTIVE: This study was performed to clarify whether increased amounts of eosinophil granulocyte proteins in urine and serum reflect ongoing asthmatic inflammation and whether decreasing values reflect successful treatment. METHODS: Twelve children with a median age of 12.5 years who had mild or moderate atopic asthma were studied for 3 months. At the time of inclusion in the study, treatment with inhaled budesonide was initiated. Nine children of the same age without atopic disease served as control subjects. Levels of EPX, eosinophil cationic protein (ECP), and myeloperoxidase in serum and in urine (urinary EPX) were determined at inclusion and then after 3 months of treatment. Spirometry was performed on the same occasions. RESULTS: At the time of inclusion, urinary EPX and serum ECP were significantly higher in children with atopic asthma than in the control subjects (mean, 116.4 vs 43.0 micrograms/mmol creatinine [p = 0.004] and 37.0 vs 14.8 micrograms/L [p = 0.004]). In the asthma group urinary EPX, as well as serum ECP, decreased significantly after 3 months of treatment with budesonide (116.4 to 68.4 micrograms/mmol creatinine [p = 0.005] and 37.0 to 24.0 micrograms/L [p = 0.04]). At the same time, peak expiratory flow values increased significantly in the children with asthma (76.0% to 87.8% of predicted value [p = 0.005]) but not in the control subjects (87.0% to 90.1%). In the asthma group the levels of myeloperoxidase were similar to those in the control group, both at inclusion and after 3 months. CONCLUSION: Increased urinary EPX and serum ECP levels seem to reflect active atopic asthma, whereas decreased levels after antiinflammatory treatment probably reflect normalization of airway inflammation, and indirectly, improved lung function.

Adolescent↗
PubMed1996

Decrease in hospitalization for treatment of childhood asthma with increased use of antiinflammatory treatment, despite an increase in prevalence of asthma.

BACKGROUND: During the past 15 years, the prevalence of asthma in children in Sweden has doubled. However, since 1985, antiinflammatory treatment with inhaled steroids has increased continuously. OBJECTIVE: The aim of this study was to analyze the net effect of these changes in terms of hospitalization of children for treatment of asthma. METHODS: The numbers of hospital days, admissions, and individual patients admitted to the Children's Hospital in Göteborg because of acute asthma were recorded from 1985 through 1993. all the in-patient treatment of children is centralized at this hospital (i.e., the study was population-based). Göteborg has half a million inhabitants. Hospitalization policies were not altered during the study period. RESULTS: In children aged 2 to 18 years, the number of hospital days per year gradually decreased to less than a third (r = 0.9; p less than 0.001), and admissions decreased by 45% (r = 0.7; p less than 0.05). The decrease in hospitalization was most marked in the group older than the age of 5 years in which hospital days were reduced to one fifth (r = 0.9; p less than 0.0001) and admissions were halved (r = 0.8; p less than 0.05). A decreasing trend in number of hospital days was also seen in the 2- to 5-year-old group. The number of individual patients admitted did not show a statistically significant decreasing trend. In children under the age of 2 years, the number of hospital days fluctuated, and there was no clear-cut change with time. CONCLUSION: Although increased concentration on the education of parents and patients may have been a contributing factor, the major reason for the decrease in hospitalization in the group of children aged 2 to 18 years is most probably antiinflammatory treatment with inhaled steroids. The results suggest that this is a very cost-effective therapeutic approach.

Administration, Inhalation↗
PubMed1996

Nebulized budesonide for the treatment of moderate to severe asthma in infants and toddlers.

Maintenance treatment with nebulized budesonide was studied in young children with asthma not controlled without steroids. In a blind parallel-group study for 18 weeks, 102 children, mean age 22 (5- 47) months, were randomized for treatment starting with 0.25 or 1 mg b.i.d. The patients were reviewed every 3 weeks, and if symptom control had been achieved the dose was reduced, otherwise it was kept. The clinical effect was very good with both dose regimens. The median time to 7 consecutive days without any asthma symptoms was about 1 month with both, highlighting the importance of the duration of therapy rather than the benefits of a high starting dose. In 18 of 24 children who attained the placebo stage, symptoms had reappeared at the last visit. Although an overall minimal effective maintenance dose could not be demonstrated, 47% achieved symptom control on 0.25 mg b.i.d., i.e. fulfilled criteria for further dose reduction. No significant side effects were seen. On average, 25% of the nominal dose reached the patients.

Administration, Inhalation↗
PubMed1996

Inflammatory markers in childhood asthma.

The importance of airway inflammation in the pathogenesis of asthma is clearly established. Studies in adults as well as in children have led to the concept that asthma is a chronic inflammatory disease. Airway inflammation is found even in mild asthma. Bronchoconstriction and hyper-reactivity appear to be secondary to the release of inflammatory mediators. The changed view of the pathogenesis of asthma and current emphasis on anti-inflammatory treatment have raised a need for markers that reflect the inflammatory status in the airways. This is of special importance in paediatric practice because lung function tests are less easily performed in young children, and it is preferable to keep steroid doses as low as possible. The eosinophil granulocyte has a multitude of proinflammatory functions and plays a key role in the asthmatic inflammation. It secretes toxic proteins and produces cytokines, which have important roles in airway inflammation. Use of eosinophil granula proteins to monitor inflammation is now finding its place. Measurement of eosinophil cationic protein (ECP) seems to be a valuable complement to the recording of lung function. For paediatric use, measurement of urinary eosinophil protein X (EPX) is promising because it does not require blood sampling.

Asthma↗
PubMed1995

Leukotriene B4 and C4 generation by human leukocytes after ex vivo stimulation with Ca-ionophore and opsonized zymosan in children with atopic asthma.

The ex vivo release of leukotriene B4 (LTB4) and leukotriene C4 (LTC4) from leukocytes was evaluated after stimulation with both Ca-ionophore (Ca-I) and opsonized zymosan (OZ) in children with atopic asthma. Twenty-seven patients with asthma of varying severity were evaluated and divided into three groups: 1) moderate to severe asthma using inhaled steroids and symptom-free for the last 3 weeks (n = 8), 2) mild asthma with sporadic symptoms, only using inhaled beta 2-agonists < 3 times/week (n = 8), and 3) acute asthmatic attacks admitted to hospital (n = 11). A group of children without atopic disease or any other known disease served as controls (n = 15). Total serum IgE levels were significantly increased in the children with asthma compared with the control group. LTC4 production was only significantly increased in the group of children with moderate to severe asthma after stimulation with Ca-I, when compared with controls. In the same group, a trend towards increased LTC4 production after stimulation with OZ was found. LTB4 was not significantly increased in any patient group compared with the control group. A significant correlation between LTC4 production after stimulation with Ca-I, but not OZ, and the relative blood eosinophil count was found in all subjects. LTC4 generation per eosinophilic cell after stimulation with Ca-I or OZ was not statistically different in any patient group compared with the controls. We conclude that the increased leukotriene (LT) levels found after the stimulation of peripheral white blood cells sampled from atopic children with asthma are mainly the result of increased numbers of LT-producing cells, rather than due to increased releasability from these cells.

Adolescent↗
PubMed1994

Inhibitory effects of theophylline, terbutaline, and hydrocortisone on leukotriene B4 and C4 generation by human leukocytes in vitro.

Leukotriene B4 (LTB4) and leukotriene C4 (LTC4) are considered to be important mediators in the pathophysiology of asthma. Theophylline, terbutaline, and hydrocortisone are drugs commonly used in the treatment of asthma. In the present study we have investigated the in vitro inhibitory effects of theophylline, terbutaline, and hydrocortisone on LTB4 and LTC4 generation from human leukocytes. After preincubation in the presence of these drugs, the cells were stimulated with the calcium ionophore A 23187 and the supernatants were analyzed for their LTB4 and LTC4 content using reverse-phase high-performance liquid chromatography (HPLC). Total leukotriene (LT) production (the combined amounts of LTB4 and LTC4) was dose-dependently inhibited by pretreatment with theophylline, terbutaline or hydrocortisone. Therapeutic levels of hydrocortisone (5 x 10(-6) M) plus theophylline (5 x 10(-5) M) inhibited LTB4 and LTC4 production in an additive way, as did the combination of hydrocortisone plus terbutaline (5 x 10(-8) M). A statistically significant effect of diminished LTB4 generation was obtained after preincubation with therapeutic levels of theophylline plus terbutaline, but no such effect was seen for LTC4 levels. The in vitro inhibitory effects on LTB4 and LTC4 generation from human leukocytes by theophylline, terbutaline, and hydrocortisone, as well as the additive effect of hydrocortisone plus theophylline or terbutaline, add to our understanding of the therapeutic effects of these drugs in the treatment of bronchopulmonary obstruction.

Calcimycin↗
PubMed1994

Leukotriene B4 and C4 generation by blood leukocytes after ex vivo stimulation by Ca-ionophore and opsonized zymosan in children with atopic dermatitis.

The ex vivo release of leukotrienes B4 (LTB4) and C4 (LTC4) from the leukocytes of children with atopic dermatitis (AD) was evaluated after stimulation with Ca-ionophore and opsonized zymosan and compared with that of control children of similar ages. The blood eosinophil counts and total serum IgE levels in AD children were significantly higher than those in control children. The production of LTC4, but not LTB4, was significantly higher in AD children than in control children. There was a significant correlation between the relative blood eosinophil count and LTC4 generation after stimulation with both Ca-ionophore and opsonized zymosan in all subjects. Calculations of the amount of LTC4 produced per eosinophilic cell showed that there was no significant difference between cells from AD children and control children in terms of their ability to produce LTC4. These findings suggest that the enhanced LTC4 generation is due to increased numbers of eosinophils rather than to enhanced releasability of these cells.

Adolescent↗