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Biomedical subjects

Dennis Nowak

Publications and source records attributed to Dennis Nowak.

At least 19 recordsLinked to original sources
PubMed2006

Exposure to a farming environment has allergen-specific protective effects on TH2-dependent isotype switching in response to common inhalants.

BACKGROUND: IgE synthesis by human B cells results from allergen-dependent, T(H)2-mediated isotype switching. Exposure to a farming environment protects against IgE responses. OBJECTIVE: We reconstructed allergen-dependent switching patterns in vivo to identify the level or levels at which farm exposure acts to protect against atopy. METHODS: Serum IgG1 to IgG4 and IgE to grass (rPhl p 1 and rPhl p 5), cat (rFel d 1), and mite (rDer p 2) were assessed by means of ELISA in the Allergy and Endotoxin study population (812 children). Farm exposure was defined as currently living on a farm, exposure to stables/farm milk in the first year of life, or both. RESULTS: Farm exposure did not affect allergen-specific IgG2 and IgG3 levels but had complex allergen-specific effects on IgG1, IgG4, and IgE levels. Exposure protected against grass-specific responses at every step along the IgG1/IgG4/IgE switching pathway but had no significant effect on mite responses. Protection from cat responses was concentrated at the IgG1 level. For all allergens, failure to express IgG1 was associated with low prevalence of IgG4 or IgE responses. Notably, coexpression of IgG1, IgG4, and IgE to grass was associated with increased risk of allergic disease and higher IgE levels compared with production of IgG1 and IgE without IgG4, suggesting IgG4 coexpression marks stronger activation of T(H)2-dependent events. CONCLUSION: The protective effects of farm exposure were confined to T(H)2-dependent IgG1, IgG4, and IgE expression and were allergen and switch stage specific, suggesting that distinct mechanisms regulate individual steps within allergen-induced class switching in vivo. CLINICAL IMPLICATIONS: Environmental interventions to prevent IgE expression might need to be tailored to specific allergens.

Agriculture↗
PubMed2006

Management of asthma with anti-immunoglobulin E: a review of clinical trials of omalizumab.

Immunoglobulin E (IgE) is a key mediator of the inflammatory reactions that are central to the pathogenesis of allergic diseases such as asthma and rhinitis. The recognition of the importance of IgE in allergic disease led to the development of omalizumab, a humanized monoclonal anti-IgE antibody that binds free circulating IgE and prevents the interaction between IgE and high-affinity (FcepsilonRI) and low-affinity (FcepsilonRII) IgE receptors on inflammatory cells. By removing free IgE, omalizumab also markedly downregulates the expression of high-affinity receptors on basophils, mast cells and dendritic cells. Several studies have shown that omalizumab effectively reduces the risk of exacerbations and hospitalization and improves symptom control, lung function and quality of life in patients with severe persistent allergic asthma. Importantly, omalizumab has been shown to be effective in patients with poorly controlled severe persistent allergic asthma, a group of patients with few effective additional treatment options. In addition, omalizumab has been shown to provide effective relief from the symptoms of allergic rhinitis (including patients with concomitant asthma). Patients with uncontrolled severe persistent allergic asthma are a challenging and difficult-to-treat population for whom omalizumab might represent an important new treatment option. In addition, omalizumab may provide a means to address comorbid allergic disease in patients with asthma. Further investigation is also warranted to explore potential applications of omalizumab in occupational asthma.

Anti-Asthmatic Agents↗
PubMed2006

Geographical distribution of acute symptoms after a train collision involving epichlorohydrin exposure.

In September 2002, two freight trains collided in a northern German town. The inhabitants were potentially exposed to the probable human carcinogen epichlorohydrin. As no objective data on the level of exposure were available, we aimed to assess the geographical distribution of acute symptoms among local residents and subjects occupationally involved in the accident (e.g., firemen). A random sample of 932 adult local residents and 342 occupationally involved subjects were invited to answer a mail-in questionnaire. The main outcome measures were self-reported acute symptoms potentially associated with combustion products (e.g., irritation of the eyes, nose, or throat) and stress-related nonspecific symptoms. The main location during the first 26 h after the accident served as exposure proxy. For occupationally involved subjects, the time spent at the accident site was also used. The overall prevalence of symptoms potentially associated with combustion products was 9.8% for residents and 25.4% for occupationally involved subjects. After adjustment, subjects whose main location was close to the accident site had an increased risk for such symptoms. Among occupationally involved subjects the risk increased with duration at the accident site. Neither main location nor time at the accident site was significantly associated with non-specific symptoms. We could provide an example for designing and carrying out an epidemiologic study shortly after a local accident with potential public health impact. We could define parts of the population at increased risk for symptoms potentially specific for the exposure under study.

Accidents↗
PubMed2006

Chronic cough due to occupational factors.

Within the large variety of subtypes of chronic cough, either defined by their clinical or pathogenetic causes, occupational chronic cough may be regarded as one of the most preventable forms of the disease. Next to obstructive airway diseases such as asthma or chronic obstructive pulmonary disease, which are sometimes concomitant with chronic cough, this chronic airway disease gains importance in the field of occupational medicine since classic fiber-related occupational airway diseases will decrease in the future. Apart from acute accidents and incidental exposures which may lead to an acute form of cough, there are numerous sources for the development of chronic cough within the workplace. Over the last years, a large number of studies has focused on occupational causes of respiratory diseases and it has emerged that chronic cough is one of the most prevalent work-related airway diseases. Best-known examples of occupations related to the development of cough are coal miners, hard-rock miners, tunnel workers, or concrete manufacturing workers. As chronic cough is often based on a variety of non-occupational factors such as tobacco smoke, a distinct separation into either occupational or personally -evoked can be difficult. However, revealing the occupational contribution to chronic cough and to the symptom cough in general, which is the commonest cause for the consultation of a physician, can significantly lead to a reduction of the socioeconomic burden of the disease.

Journal Article↗
PubMed2006

Acute blood neutrophilia induced by short-term compost dust exposure in previously unexposed healthy individuals.

OBJECTIVES: Systemic effects of organic dust inhalation have been described in farming environments. The purpose of this study was to examine whether a single exposure at a biowaste composting facility could also exert systemic effects in healthy volunteers not previously exposed to organic dust from such facilities. METHODS: Seventeen subjects (age 20-35 years) were exposed to organic dust for 2 h (exposure day) during moderate exercise; 12 of these subjects also took part in a control experiment (control day). Spirometry was performed before and immediately after the exposure. White blood cell counts and levels of tumor-necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) in peripheral blood were determined before and 3 h after exposure. RESULTS: Exposures did not result in significant changes in lung function or blood cytokine levels. In contrast, the number and percentage of neutrophils increased during the exposure day [median (range) percent change of percentages 14 (-2; 67) %; P=0.002], but not during the control day [5 (-22; 35) %; P=0.66). Furthermore, there was a decrease in the number and percentage of eosinophils during the exposure day [-47 (-57; 0.0) %; P=0.002], whereas the change during the control day was smaller [-8 (-56; 71) %; P=0.68]. CONCLUSION: Short-term exposure of healthy, young subjects to organic dust from composting facilities had opposite effects on the numbers of blood neutrophils and blood eosinophils. These effects, though mild, suggest that even during a limited period of moderate work a sufficient amount of bioactive material can be deposited in the lung to elicit acute systemic alterations.

Adult↗
PubMed2006

Personal dosimetry of exposure to mobile telephone base stations? An epidemiologic feasibility study comparing the Maschek dosimeter prototype and the Antennessa SP-090 system.

The aim of our study was to test the feasibility and reliability of personal dosimetry. Twenty-four hour exposure assessment was carried out in 42 children, 57 adolescents, and 64 adults using the Maschek dosimeter prototype. Self-reported exposure to mobile phone frequencies were compared with the dosimetry results. In addition, dosimetry readings of the Maschek device and those of the Antennessa DSP-090 were compared in 40 subjects. Self-reported exposures were not associated with dosimetry readings. The measurement results of the two dosimeters were in moderate agreement (r(Spearman) = 0.35; P = .03). Personal dosimetry for exposure to mobile phone base station might be feasible in epidemiologic studies. However, the consistency seems to be moderate.

Adolescent↗
PubMed2006

Adolescents' jobs and the course of dermatitis symptoms throughout puberty.

OBJECTIVES: This study evaluated the course of dermatitis symptoms throughout puberty taking into account occupational exposures in a population-based study. METHODS: Participants enrolled in the ISAAC-II (International Study of Asthma and Allergies in Childhood) study in Munich and Dresden in 1995 and 1996 were sent a postal questionnaire in 2002 (age at follow-up 16 to 18 years). The questionnaire included items on atopic diseases, jobs, including holiday jobs and vocational training, and potential confounders. The most recent of the adolescents' jobs held for at least 8 hours a week, and for at least 1 month, were coded according to the ISCO-88 system. RESULTS: Overall, data of 3785 adolescents were included in the analyses. The incidence of dermatitis symptoms during puberty among those without such symptoms at baseline was 7%. Altogether 31% of the participants reported an employment history. Those already employed were more likely to report a new onset of dermatitis symptoms. Jobs associated with a new onset of symptoms were work in the health care sector, vocational training in bakeries, and cleaning. The first 9 months of exposure were particularly relevant for new cases of dermatitis symptoms (odds ratio 3.7, 95% confidence interval 1.5-9.6). CONCLUSIONS: Early occupational exposure is associated with the development of symptoms of dermatitis. The types of skin alterations need to be assessed in the next stage of the study.

Adolescent↗
PubMed2006

Case-based e-learning in occupational medicine--The NetWoRM Project in Germany.

The aim of the NetWoRM Project is the development, evaluation and implementation of a case-based e-learning tool for occupational medicine to increase the knowledge in clinical aspects of occupational medicine. To date, 19 e-learning cases have been developed. Cases were validated by 2 experts and user evaluated. Results of the user evaluation at 3 German Medical Schools are presented. Of 557 medical students registered for the online course 377 answered the online evaluation form (68%). Depending on the case, the median time spent on a case ranged from 25-43 minutes. Students enjoyed working with the cases and asked to replace more seminars by case-based e-learning. The level of knowledge required to work on the cases was rated high. This was supported by the fact that on median only 47-71% of the questions were answered correctly. Cases focusing on occupational health problems such as needle stick injuries were rated highest with respect to fun, importance for future career and the overall score. Students enjoy working on e-learning cases as an add-on to traditional teaching. Because of the high international interest the NetWoRM project is currently shared on an international base.

Computer-Assisted Instruction↗
PubMed2005

Effects of working permanent night shifts and two shifts on cognitive and psychomotor performance.

OBJECTIVES: The study aimed to clarify whether cognitive and psychomotor performance, which are important for occupational and traffic safety, are impaired by working permanent night shifts (NSs) compared with early-late two shifts (TSs) and whether age and chronobiological type influences the relationship between shift and performance. METHODS: The study included 44 male automobile workers, 20 working TSs and 24 working NSs. Chronobiological type was determined by questionnaire (D-MEQ). Each subject was tested at the beginning and end of the shift for alertness [by a visual analogue scale (VAS)]; feeling of well-being (Basler); concentration and accuracy (d2); reaction speed, orientation and reaction to stress (Vienna System). RESULTS: TS workers were more frequently morning types whereas the NS workers were more frequently evening types. In the performance tests, the TS and NS workers did not differ at shift start or shift end. Over the course of the shift, concentration and accuracy improved in both groups, as did reaction to stress. Chronobiological type alone or in combination with shift type had no effect on performance. CONCLUSIONS: The results of this study indicate that-if chosen voluntarily-working NSs has no immediate negative effects on cognitive and psychomotor performance when compared with working TSs. There was no indication of an increased risk of accidents after working NSs. The unequal distribution of the circadian types in the shift groups may indicate selection.

Adult↗
PubMed2005

Opposite effects of CD 14/-260 on serum IgE levels in children raised in different environments.

BACKGROUND: Most complex diseases are the result of interactions between polymorphisms in the genome and environmental exposures. OBJECTIVE: We sought to investigate the previously reported association between a polymorphism in the promoter region of CD 14 (CD 14/-260 C-->T) and serum IgE levels in relation to the environment to which children are exposed. METHODS: In 624 children living in 2 rural communities in Europe, we compared total and specific serum IgE levels between the genotypes of CD 14/-260 in relation to exposure to animals and in relation to house dust endotoxin. RESULTS: We found that the C allele of CD 14/-260 was associated with higher levels of both total and specific serum IgE to aeroallergens in children with regular contact with pets, whereas an association in the opposite direction was found in children with regular contact with stable animals. This modifying effect of animal exposure was not explained by levels of house dust endotoxin. However, in children with high levels of house dust endotoxin, the C allele was associated with less specific IgE, independently from animal exposure. CONCLUSION: Because CD 14 is a pattern recognition receptor for microbial molecules, the results suggest that the type and concentrations of such molecules present in the environment strongly determine the direction of the association between CD 14/-260 and serum markers of atopy.

Animals↗
PubMed2005

The physical and biological doses of methacholine are different for Mefar MB3 and Jaeger APS sidestream nebulizers.

BACKGROUND: Within a study on respiratory symptoms in rural areas, we used the European Community Respiratory Health Survey methacholine challenge protocol. For quicker and more reliable handling, we had to change the nebulizer in the bronchial challenge system from Mefar model MB3 (Bovezzo, Italy) to Jaeger APS Sidestream (similar to Mefar; Würzburg, Germany). Therefore, we compared the physical properties of the two systems, adapted the challenge protocol, and compared the results of both systems in subjects with and without airway hyperresponsiveness to methacholine. METHOD: The physical properties of both systems were characterized by the residual method indicating a similar particle size distribution and an average output of 6 muL/s for Mefar MB3 and 1.25 muL/s for APS Sidestream. In the comparison study, 34 subjects were included. Airway responsiveness was quantified by provocative dose of methacholine causing a 20% fall in FEV(1). RESULTS: A significant difference was found between the two challenge systems (p =0.004, McNemar test). Nine subjects reached a 20% drop in FEV(1) with the APS Sidestream only. The FEV(1) dropped by > 20% using either system in eight subjects. In 17 subjects, none of the two systems caused a 20% decrease in FEV(1). CONCLUSION: Even if the physical dose is determined with elaborate methods, the biological dose may vary between two nebulizer systems, causing incomparable outcomes for subjects tested with different systems.

Adult↗
PubMed2005

Epidemiology and health economics of COPD across Europe: a critical analysis.

COPD is a major cause of morbidity and mortality in Europe. The purpose of this literature review was to critically evaluate published data on COPD prevalence and the cost of COPD interventions in European countries. Selection of literature was based on article retrieval from a systematic literature search using PubMed and EMBASE. Only articles providing data in European countries published between January 1990 and March 2003 were included. European epidemiological (cross-sectional, cohort, case-control) and economic (cost-of-illness-, cost-minimization-, cost-effectiveness-, cost-benefit-, cost-utility-analysis) studies were included. Of 74 retrieved epidemiologic studies, only seven (9%) fulfilled the inclusion criteria. In the selected literature, COPD prevalence ranged from 3% among Finnish women to 57% among Italian men and women, 45 years and older. Of 56 economic studies, 24 satisfied entry criteria. Results from the final cost-of-illness studies indicated that hospital care and medication represented the major portion of costs associated with COPD. In a survey conducted in 1998/99, annual direct expenditures for COPD treatment per patient in Europe ranged from Euro 530 in France to Euro 3238 in Spain. There was a differential increase in COPD prevalence predominantly related to an aging patient population, with a high incidence of exposure to cigarette smoke. Data also showed differences in the economic impact of COPD in Europe based on the proportion of patients with severe COPD, frequency of exacerbations, and number of hospitalizations. Overall, results of this review demonstrated the need for global epidemiologic and economic studies to allow for more uniform guidelines for the prevention and cost-effective treatment of patients with COPD.

Cost-Benefit Analysis↗
PubMed2005

Exposure to farming environments in early life and type 1 diabetes: a case-control study.

It has been hypothesized that a stimulation of regulatory cytokines by microbial compounds reduces autoimmune as well as atopic diseases. Farm-related contact to microbial compounds protects from allergies, but no data on the association between farm contact and type 1 diabetes is available. The aim of this study was to test this association. A case-control study was conducted in five children's hospitals. Regular contact to farm animals and potential confounders were assessed using a postal questionnaire. Eligible subjects were all prevalent cases with type 1 diabetes registered in the hospitals and hospital-based control subjects (response rate 91%). Included were children aged 6-16 years living in rural areas with German nationality (242 case and 224 control subjects). Regular contact to stables (adjusted odds ratio 1.2 [95% CI 0.5-2.7]) was not associated with type 1 diabetes. In addition, regular contact to specific farm animals was not associated with case status. There was a tendency for an inverse relationship between allergic rhinitis and type 1 diabetes (0.6 [0.3-1.1]; P = 0.11). There was no evidence that early exposure to farm animals largely decreases the risk in children for developing type 1 diabetes.

Adolescent↗
PubMed2005

Concentrations of dust, allergens and endotoxin in stables, living rooms and mattresses from cattle farmers in southern Bavaria.

Agricultural work is considered to be a major risk factor for occupational diseases. In particular, allergic reactions to cow dander cause numerous cases of airway disorders. We measured the concentration of allergens (e.g. Bos d2, Der p1) and endotoxin in the stables, living-rooms and mattresses of 46 farmers with a diagnosis of occupational asthma or allergic rhinitis caused by cow dander allergen. The concentration of cow dander allergen was highest in stables (median 20,400 microg/g) but also noticeable in dust samples from living-rooms (median 155 microg/g) and mattresses (median 195 microg/g). The sensitization threshold (20-50 microg/g) was exceeded in most cases. Thus, allergen transport from the stables to bed must be prevented by optimizing the hygiene of farmers and family members.

Adult↗
PubMed2004

Prevalence of weather sensitivity in Germany and Canada.

Several studies have shown that atmospheric conditions can affect well-being or disease, and that some individuals seem to be more sensitive to weather than others. Since epidemiological data on the prevalence of weather-related health effects are lacking, two representative weather sensitivity (WS) surveys were conducted independently in Germany and Canada. The objectives of this paper are: (1) to identify the prevalence of WS in Germany and Canada, (2) to describe weather-related symptoms and the corresponding weather conditions, and (3) to compare the findings in the two countries. In Germany 1,064 citizens (age >16 years) were interviewed in January 2001, and in Canada 1,506 persons (age >18 years) were interviewed in January 1994. The results showed that 19.2% of the German population thought that weather affected their health "to a strong degree," 35.3% that weather had "some influence on their health" (sum of both = 54.5% weather sensitive), whereas the remaining 45.5% did not consider that weather had an effect on their health status. In Canada 61% of the respondents considered themselves to be sensitive to the weather. The highest prevalence of WS (high + some influence) in Germans was found in the age group older than 60 years (68%), which was almost identical in the Canadian population (69%). The highest frequencies of weather-related symptoms were reported in Germany for stormy weather (30%) and when it became colder (29%). In Canada mainly cold weather (46%), dampness (21%) and rain (20%) were considered to affect health more than other weather types. The most frequent symptoms reported in Germany were headache/migraine (61%), lethargy (47%), sleep disturbances (46%), fatigue (42%), joint pain (40%), irritation (31%), depression (27%), vertigo (26%), concentration problems (26%) and scar pain (23%). Canadian weather-sensitive persons reported colds (29%), psychological effects (28%) and painful joints, muscles or arthritis (10%). In Germany 32% of the weather-sensitive subjects reported themselves to be unable to do their regular work because of weather-related symptoms at least once in the previous year, and 22% of them several times. Co-morbidity was significantly higher in weather-sensitive subjects both in Germany and Canada. These results clearly showed the important impact of WS on public health and the economy. These findings prompted us to start studies on the causal factors of weather-related health effects.

Adolescent↗