Biomedical subjects

W Karmaus

Publications and source records attributed to W Karmaus.

At least 55 records · Page 3Linked to original sources

PubMed1996

Shift work and subfecundity: a European multicenter study. European Study Group on Infertility and Subfecundity.

Shift work has been associated with various unfavorable pregnancy outcomes (ie, pregnancy loss, spontaneous abortion, low birth weight, etc). The suggested underlying mechanism is the interference of shift work with the circadian regulation of human metabolism and, in particular, with the temporal pattern of endocrine function. To analyze the effect of shift work on fecundity, the Time of Unprotected Intercourses (TUI) has been measured in couples recruited in the European Studies on Infertility and Subfecundity, which were undertaken in seven European countries. A low (odds ratio < 2.0) but consistent excess risk of subfecundity (TUI > or = 9.4 months) has been observed both in a representative sample of the general population of women in reproductive age and in a sample of pregnant women or women who had just given birth. The excess risk was also consistently evident both in the subsample of the first pregnancies and in the subsample of the most recent pregnancies. Only the exposure of women to shift work seemed to affect a couple's fecundity; men working shift work did not modify the fecundity pattern of their own couples. No specific job title among shift workers concentrated the risk of subfecundity. No association of menstrual disorders with shift work was identified. Even though residual confounding could partly account for the results and the fact that a plausible biological explanation of the claimed effect is still lacking, data from this study are in favor of an association between shift work and prolonged waiting time to pregnancy.

Adult↗

PubMed1995

Effects of inhalative exposure to dioxins in wood preservatives on cell-mediated immunity in day-care center teachers.

The study investigated the effects of chronic inhalative low-level exposure to dioxins in day-care centers containing wood treated with preservatives on (1) the number of peripheral CD4 and CD8 cells and the CD4:CD8 ratio in peripheral blood and (2) the delayed-type hypersensitivity reaction of the skin (Multitest Méreux). The study population consisted of 221 exposed and 189 unexposed employees of day-care centers in or near Hamburg. A status of decreased skin test reagibility was operationalized as hypoergy I (score < 5 mm), hypoergy II (< or = 1 positive reaction), and anergy (no positive reaction). Taking the fading during postexposure time into account, a surrogate for the dioxin burden based on the concentration of dioxins in indoor air (measured using the 2,3,7,8-TCDD TEF followed by the Federal Republic of Germany) was modeled. No effect was found regarding the number of CD4 cells, CD8 cells, and CD4:CD8 ratio. However, some evidence for an increasing dose-response relationship between inhalative exposure to dioxins and the risk of hypoergy and anergy was found, both in the total study population and among subjects with a short postexposure time (< or = 6 months). Subjects with a short postexposure time and a dioxin burden > 0.6 pg/m3 had a significantly higher risk of hypoergy than unexposed subjects (hypoergy I: OR = 9.51, 95% CI = 1.96-42.02; hypoergy II: OR = 2.92, 95% CI = 1.14-7.5). It is concluded that a suppressive effect of inhalative exposure to dioxins in wood preservatives on human cell-mediated immunity cannot be ruled out.

Adolescent↗

PubMed1995

Sensitization to mite allergens is a risk factor for early and late onset of asthma and for persistence of asthmatic signs in children.

BACKGROUND: To describe the natural history of asthma between the ages of 7 and 10 years and to analyze risk factors for prevalences, as well as new onset of asthma-like symptoms, a longitudinal study of 1812 children was conducted. METHODS: In four surveys, each 1 year apart, four asthma-like symptoms and several hypothetical risk factors were ascertained through standardized questionnaires. Sensitization to seven common inhalant allergens was measured by skin prick testing. Exposure to mite allergens (Der p I, Der f I) was assessed by measuring the antigen concentrations in the dust of each child's mattress. Occurrence of more than one asthma-like symptom closely related to the practioner's diagnoses of bronchial asthma and recurrent wheezy bronchitis was used as the outcome variable. RESULTS: After an initial prevalence of 14.5%, new onset of symptoms in children unaffected at the beginning was reported in 7.2% during the 3 years. Of the factors explaining prevalence and persistence of asthma-like symptoms (sensitization to mite allergens and animal danders, history of hay fever and eczema, low gestational age, male gender, parental atopy), only sensitization to mite allergens (odds ratio = 2.3, 95% confidence interval = 1.1-4.7) and parental atopy (odds ratio = 2.1, 95% confidence interval = 1.2-3.7) were also significantly associated with new onset. In a relatively small number of sensitized subjects with new onset of symptoms (n = 31), mite antigen concentration did not appear to be associated with incidence of symptoms. CONCLUSION: Sensitization to mite allergens antedated the onset of asthma-like symptoms, and no strong effect of allergen exposure on clinical development could be found. Thus the primary focus should be on preventing sensitization to mite allergens by implementing avoidance measures in infancy or at early school age in order to reduce the onset of asthma at a later stage.

Allergens↗

PubMed1995

Reduced birthweight and length in the offspring of females exposed to PCDFs, PCP, and lindane.

The objective of this study was to investigate a broad range of adverse health outcomes and their potential association to wood preservative used in daycare centers. This article focuses on reproductive effects. A sample of 221 exposed teachers was provided by the employer's liability insurers. A comparison group (n = 189) insured by the same two organizations was recruited from nonexposed daycare centers. In a face-to-face interview, job history and reproductive history of 398 female teachers were ascertained. Data on exposure were provided, including measurements on concentration of pentachlorophenol (PCP) and lindane in wood panels, and of PCP, lindane, polychlorinated dibenzo-p-dioxins and dibenzofurans in indoor air. An exposure matrix based on individual job history, independent exposure information from each center, and reproductive history was set up with regard to the vulnerable time windows for each pregnancy. Using this approach, 49 exposed and 507 nonexposed pregnancies were identified, including 32 exposed and 386 nonexposed live births. For subgroup analyses the observations were restricted to independent pregnancies, excluding multiple and consecutive births. The data were analyzed with linear regression techniques, taking confounders into account. The crude median difference between exposed and nonexposed was 175 g in birthweight and 2 cm in length. Controlling for confounders, the results show a significantly reduced but weight (p = 0.04) and length (p = 0.02) in exposed pregnancies, even after restricting the data to independent pregnancies and pregnancies for which data could be validated from the mother's health cards. These differences were not explained by differences in gestational age indicating that a toxic effect, which could cause small-for date newborns, might have affected the fetus.

Adult↗

PubMed1994

Relationship between atopy and frequent bronchial response to exercise in school children.

The natural history of a bronchial response to exercise (BRE) was studied in a cohort of primary-school children, who were followed over a 2-year period. In 1,094 children, three free-running tests were performed in 1-year intervals. Children who responded in one of the tests were designated as "infrequent" responders (20.5%), whereas those responding at two or all three occasions were designated as "frequent" responders (7.4%). A frequent positive BRE was closely associated with atopy (defined as skin test positivity to 1 of 7 common aeroallergens) and respiratory symptom status. Compared to atopics without respiratory symptoms, an increased risk for a frequent positive BRE was seen for atopic children who were symptomatic during the whole study period [odds ratio (OR) 25.4; confidence interval (CI) 6.9-94.0], who had gained symptoms (OR, 11.0; CI, 2.8-43.2) or who had symptoms at the beginning of the study but had lost them during follow-up (OR, 4.6; CI, 1.0-20.6). A sensitization to dust mites (OR, 8.0; CI, 4.3-15.0) but not to animal dander (OR, 2.3; CI, 1.0-5.2) or pollen (OR, 0.7; CI, 0.3-1.6) was significantly related to a frequent positive BRE. Our findings support the notion that while "children grow out of asthma," they might maintain their bronchial hyperresponsiveness. Regarding specific sensitization, mite allergy seems to play the predominant role.

Allergens↗

PubMed1994

Effect of moderate NO2 air pollution on the lung function of children with asthmatic symptoms.

In the course of a 2 1/2-year longitudinal study, the influence of outdoor NO2 and of the heating device at home on lung function was investigated in 467 children of school age in the urban area of Freiburg. Data were gathered in three surveys using standardized interviews, lung function measurements, skin prick tests with inhalant allergens, and NO2 measurements from October to April near the child's home. Regarding the lung function of a subpopulation with asthmatic symptoms (n = 106) in the three consecutive surveys, multivariate regression analyses adjusted for confounders indicate negative associations between five dependent variables, FEV1%FVC (P = 0.004), FEV1% (P = 0.02), MEF75% (P = 0.038), MEF50% (P = 0.052), and MEF25% (P = 0.002), on the one hand, and outdoor NO2 for average NO2 concentrations exceeding 40 micrograms/m3 on the other. The use of individual room heaters is associated with decreased lung function and is significant only for FEV1%FVC (P = 0.033). Neither NO2 nor individual room heating is significantly associated with one of the lung function parameters in the subpopulation without asthmatic symptoms (n = 361). In conclusion, children with asthmatic symptoms are identified as being susceptible to having reduced lung function under outdoor air pollution where average NO2 concentrations exceed 40 micrograms/m3.

Air Pollutants↗

PubMed1994

Eosinophils and eosinophil cationic protein in children with and without sensitization to inhalant allergens.

Eosinophil inflammation is a common feature of allergic disorders and particularly in allergic asthma interest has been paid to related markers. In a community-based survey of 10-year-old children, the association of eosinophil count (EC) and serum eosinophil cationic protein (ECP) with allergic sensitization, clinical history and exposure to mite allergen was studied. Relying on the results of skin prick tests, the children were divided to three groups: (1) children showing no sensitization to one of the seven inhalant allergens (n = 16); (2) children with sensitization to at least one of five non-mite allergens (n = 16); and (3) children with sensitization to mite allergens (n = 75). Clinical history of asthma and hay fever was ascertained using standardized questionnaires. EC in peripheral blood and serum ECP were measured on one single occasion. Prior to blood sampling, mite allergen exposure at home had been assessed by taking dust samples and measuring the mite antigen concentration by means of an enzyme immunoassay. Compared to group 1, higher ECs were obvious in group 2 (P = 0.037) and in group 3 (P = 0.0013). Regarding serum ECP, higher levels occurred in group 2 (P = 0.0033) as well as in group 3 (P = 0.0001) when comparing them to the reference group. Sensitized children with neither asthma, nor asthma-like symptoms, nor hay fever (n = 28) did not have significantly lower ECs and serum ECP levels than those with hay fever (n = 15; P = 0.09, P = 0.17) and those with asthma (n = 22; P = 0.69, P = 0.64).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Mite allergen exposure is a risk for the incidence of specific sensitization.

BACKGROUND: Mite allergen exposure is essential for the process of specific allergic sensitization. However, it is not clear whether incidence of specific sensitization at school age depends on the level of mite antigen exposure. Therefore the relationship between mite allergen exposure and incidence of specific sensitization was investigated. METHODS: Eighteen hundred twelve primary school children were enrolled in a population-based 2-year follow-up study. In three consecutive skin prick tests (SPTs), each 12 months apart, sensitization to Dermatophagoides pteronyssinus (Dpt) and six non-Dpt allergens was ascertained. To assess exposure to Der p I between the first and second SPTs (period I) and the second and third SPTs (period II), the amount of antigen per gram of dust (taken from the children's mattresses was measured. By using the SPT reactions to Dpt as a basis, conversions after "no wheal" were classified as doubtful incidence (average yearly incidence = 6.7%) or definite incidence (average yearly incidence = 3.2%). Then, with the use of multiple logistic regression, the risk of exposure to Der p I (medians: 1.4 micrograms/gm in period I, 1.6 micrograms/gm in period II) was analyzed with adjustment being made for gender, low gestational age, parental atopy, and initial sensitization to non-Dpt allergens. RESULTS: Regarding doubtful incidence, the analysis failed to identify a reliable cutoff point of exposure. For definite incidence, the Der p I exposure represents a significant risk in the total population, starting from a concentration of 9 micrograms/gm. This effect is modified by an initial sensitization to non-Dpt allergens: for these children exposure to concentrations above 2 micrograms/gm poses a significant risk, whereas for the population without other initial sensitizations, only an extremely high cutoff limit (> 80 micrograms/gm) gains significance. CONCLUSION: Our data suggest that a concentration limit of 2 micrograms Der p I antigen per gram of dust should be regarded as minimal avoidance level for primary prevention in children with sensitization to other inhalant allergens.

Animals↗

PubMed1994

Natural variation in mite antigen density in house dust and relationship to residential factors.

To investigate the year-to-year variation of mite antigen density (Der p I, Der fI) in dust from mattresses and the relevance of residential factors for antigen load, information derived from an epidemiologic study including two surveys carried out in the households of a cohort of elementary school children (n = 1291) was analysed. When considering residences with measurements taken in both years in question (n = 1050), rank-correlation indicated a predominance of stability for both antigens (Der p I: rs = 0.82, P = 0.0001; Der f I: rs = 0.72, P = 0.0001). Using multiple regression analyses, significant associations between antigen concentrations and a variety of residential factors were found. Use of a blanket of animal hair, use of a cover or underblanket, wet spots in the bedroom, higher relative humidity and a low storey level were significantly associated with increased concentrations of Der p I, whereas inverse relationships between this antigen and room temperature, number of persons per m2 as well as use of underfloor heating were seen. Regarding Der fI, older mattresses, use of a cover or underblanket, higher weight of sampled dust, high educational level and higher ratio of inhabitants per m2 were significantly associated with increased concentrations of the antigen. On the other hand, lower Der fI concentrations were found when interior sprung mattresses were used and when the mattress was 'treated regularly'. In conclusion, two measurements, 1 year apart from each other, show that stability of mite antigen concentrations predominated.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗

PubMed1994

Influence of skin prick test criteria on estimation of prevalence and incidence of allergic sensitization in children.

In a prospective cohort study on atopy in childhood, three skin prick tests (SPT) were performed in 1135 primary schoolchildren over a 2-year period. We studied the development of average sizes of allergen wheals in reactive children and of average sizes of histamine wheals in all children, and we investigated the influence of choice of SPT criterion on the prevalence and incidence of sensitization. A year-to-year increase of average allergen wheal sizes as well as of average histamine wheal sizes was observed. These increases seemed to be related to the natural growth of the children. Furthermore, an observer bias effect of the person who did the pricking on average wheal sizes was found. There were considerable differences in estimations of prevalences and incidences depending on the definition of SPT criterion. Estimations using a criterion based solely on the allergen wheal size were affected by variation of allergen wheal sizes caused by growth and observer effects. The ratio criterion was not influenced by observer effects, nor did it seem to be affected by aging effects. In conclusion, our data suggest that the ratio criterion, which relates the size of the allergen wheal to the size of the histamine wheal, is the most appropriate SPT criterion because it is not affected by growth of allergen wheals in childhood and it appears to compensate for possible observer bias.

Allergens↗

PubMed1994

[The impact of reproductive loss for human fertility. Results of the German part of a European study of the epidemiology of infertility and subfertility].

Within the German part of an European Community study of the epidemiology of infertility and subfecundity we analysed the fetal loss (i.e. spontaneous abortions, artificial abortions, ectopic pregnancies, stillbirth, early neonatal death and all babies who died after the 7th day within the first year of life). For this investigation women from 5 urban and rural regions in Germany in the age group 25-45 years were selected in five districts from random samples of the local registers. 1531 interviews were conducted in 1992 by trained female interviewers in the same way as in the other participating European countries. 1248 of the women had a positive reproductive anamnesis with 3018 pregnancies. 565 (= 45.3% of women who were pregnant at any time) had fetal loss. In East Germany as well as in West Germany we found a positive age and pregnancy association. The main loss we observed in the age group under 20 and over 35 years. In all groups artificial abortion was the most important part of fetal loss (rural region of East Germany: 15.5% and West Germany: 13.1% of all registered pregnancies). The time to pregnancy (TTP) was prolonged in women over 30 years of age. Here we also found an increasing rate of spontaneous abortions. Smokers are more prevalent in women with ectopic pregnancies, spontaneous abortions and live born babies who died within the first 7 days after delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗

PubMed1993

Relationship between exposure to dust mite allergen and bronchial response to exercise in schoolchildren sensitized to dust mites.

We assessed the relationship between the exposure to dust mite allergens and a bronchial response to exercise in 8-year-old schoolchildren. Dust was collected from the mattresses of 1,291 children and the concentration of mite allergens was estimated by a commercially available ELISA test using monoclonal antibodies (ALK, Copenhagen) against the major allergens of Dermatophagoides pteronyssinus (Der pt) and Dermatophagoides farinae (Der f). A positive bronchial response to exercise (decrease of peak expiratory flow > or = 15% after exercise) occurred in 21 (22.6%) of 101 children sensitized to mite allergens (wheal size > or = 4 mm) and in 51 (4.8%) of 1,070 nonsensitized children. In the highest exposure groups (> 10 micrograms allergen/g dust), 15% of children sensitized to Der f and 20% of children sensitized to Der pt were responsive to exercise. Corresponding figures for the lowest exposure groups (< 0.4 micrograms allergen/g dust) were 11 and 28%, respectively. This negative finding may indicate that measurement of allergen concentration in mattresses does not reflect true exposure or alternatively that at the age of 8 years high exposure to dust mite allergens does not affect bronchial response to exercise in sensitized children.

Allergens↗

PubMed1993

Risk factors for childhood asthma and recurrent wheezy bronchitis.

Using cross-sectional data of an epidemiological study, risk factors for asthma and recurrent wheezy bronchitis were investigated in 1812 primary school children. Children with asthma (n = 63) had a similar pattern but a higher frequency of chronic respiratory symptoms than those with recurrent wheezy bronchitis (n = 136). Logistic regression analyses showed similar risk factors for both disorders, however, more pronounced for asthma. Prematurity was a significant risk factor for asthma and for recurrent wheezy bronchitis. Children with asthma more often had a family history of paternal or maternal asthma and their mothers tended to be younger. Effects of paternal asthma and prematurity were also found when the atopic status of the child (defined as skin test positivity to any of seven aero allergens) was taken into account. Next to genetic effects, adverse circumstances in early life seem to be important for the development of asthma. In school children recurrent wheezy bronchitis and asthma seem to be similar disorders which differ in quantitative but not qualitative aspects.

Asthma↗

PubMed1993

Sensitization to four common inhalant allergens within 302 nuclear families.

The coincidence of allergic sensitization was investigated in 302 school-aged children and their parents. Specific sensitization to four common inhalant allergens (grass and birch pollens, cat dander, Dermatophagoides pteronyssinus) was ascertained by means of skin-prick tests (SPT) carried out on the complete family unit at the beginning of a 22-month follow-up period. The same test procedure was then repeated on the children twice at 11-month intervals to provide cumulative prevalences of sensitization. A clinical history of atopy in the children (hay fever or asthma; n = 47), which was derived from an interview, is associated with sensitization (positive SPT in 89%). For three allergens (grass and birch pollens, cat dander) sensitization occurs significantly more frequently in the children of mothers who are sensitized to the same allergen (odds-ratios (ORs), 2.5-4.1). Additionally, in three of the four explanatory models related to a single antigen, maternal sensitization to one of the complementary allergens is of importance (ORs, 2.7-3.7). In contrast to this finding, none of the paternal sensitizations has statistical significance. Based on a reaction to at least one of the four allergens, the child's relative risk to be sensitized is increased in case of maternal (OR, 2.88; P = 0.001) but not of paternal (OR, 1.06; P = 0.83) sensitization. In conclusion, our data indicate that the maternal status is more predictive than that of the father with regard to the child's risk of sensitization.

Administration, Inhalation↗

PubMed1993

Relation between response to exercise and diurnal variability of peak expiratory flow in primary school children.

BACKGROUND: Variability in peak expiratory flow (PEF) has been proposed as a simple method of screening for asthma in epidemiological studies. This study was designed to assess whether the bronchial response to exercise and the diurnal variation in PEF identified the same subjects. METHODS: Bronchial response to a free running exercise test was assessed in a cohort of 918 seven year old children and was compared with variability of PEF as assessed by twice daily recordings for a one week period. Mini Wright peak flow meters were used throughout the study. RESULTS: Baseline PEFs of both tests were highly correlated but there was no significant correlation between a response to exercise and variability of PEF. Of 33 children with a physician's diagnosis of asthma, 18 had at least one abnormal test, but only five children were abnormal in both tests, showing that the tests did not identify the same subjects. CONCLUSION: Increased variability of PEF, as well as a response to exercise, was associated with respiratory symptoms, but only a response to exercise was closely associated with atopy (defined as a positive skin test to any of seven aero-allergens).

Asthma↗

PubMed1993

Influence of maternal smoking on variability of peak expiratory flow rate in school children.

Diurnal variability of peak expiratory flow rates (PEFRs) was assessed in 1,237 children. The PEFR was measured twice daily over a 1-week period. As an index of variability, the log of a week's mean of daily amplitude was calculated. Linear regression analyses revealed a significant positive association between maternal smoking and the variability of PEFR for nonasthmatic children. For these children, exposure to maternal smoking was associated with a 13.7 percent increase (confidence interval [CI], 3.8 to 24.7 percent) in PEFR variability. For asthmatic children an effect was found for nonatopic (54.7 percent increase; CI, 5.5 to 226.8 percent) but not for atopic children (-8.5 percent change; CI, -41.2 to 42.3 percent). In the latter group, there was evidence that mothers changed their smoking habits subsequent to the development of disease in their children. We conclude that exposure to maternal smoking can increase the variability of PEFR and thus might contribute to the development of asthma.

Adult↗

PubMed1993

[Variability of peak expiratory flow in an unselected sample of school children].

In the framework of an epidemiological study, the information by peak flow variability (PEFV) was compared to the history of asthma in a non-selected population of primary-school children (n = 1812). PEFV as assessed by twice daily recordings of PEF for a one week period (n = 1237) was calculated as average of daily amplitudes (AVAM: average amplitude mean) in the case of at least complete data for five days (n = 991). Elevated PEFV defined as AVAM > 12%, was cross-tabulated with the asthma history (self-administered questionnaire). The median (90%-confidence-interval) of AVAM is 6.3% (2.2-15.9%). In 11.2% (n = 111) of the population, AVAM > 12% occurred). The sensitivity of AVAM > 12% with regard to "doctor's diagnosed asthma" (n = 35) is 37%. Under exclusion of children with recurrent wheezy bronchitis a specificity for AVAM > 12% of 90% is found. Our data on primary-school children suggests that PEFV is a specific but only slightly sensitive measurement with regard to previously diagnosed bronchial asthma.

Adult↗

PubMed1992

Maternal smoking in early childhood: a risk factor for bronchial responsiveness to exercise in primary-school children.

The relationship between maternal smoking and bronchial hyperresponsiveness as assessed by a standardized free running test was investigated in a cohort of 1812 primary-school children in first grade. A child's exposure to maternal smoking during pregnancy, the first year of life, and the study year was recorded. Current exposure was not positively associated with bronchial hyperresponsiveness. The prevalence of this disorder was higher when maternal smoking during the child's first year of life was reported (9%) than when it was not (5.9%). The odds of being hyperresponsive were significantly higher in children exposed to maternal smoking in their first year of life (odds ratio, 2.82; 95% confidence interval, 1.25 to 6.34; p less than 0.01), especially in children with asthma (odds ratio, 20.55; 95% confidence interval, 2.5 to 168.9; p less than 0.01). Current exposure to maternal smoking was associated with less hyperresponsiveness. The effect of current maternal smoking might reflect changes in smoking habits by mothers of children with symptoms, whereas exposure to tobacco smoke in early life might be causally related to bronchial hyperresponsiveness. Our findings support the general hypothesis that early lung injuries have an impact on the later respiratory health of children.

Asthma, Exercise-Induced↗