Quantification of Polystyrene Uptake by Different Cell Lines Using Fluorescence Microscopy and Label-Free Visualization of Intracellular Polystyrene Particles by Raman Microspectroscopic Imaging.

Environmental pollution caused by plastic is a present problem. Polystyrene is a widely used packaging material (e.g., Styrofoam) that can be broken down into microplastics through abrasion. Once the plastic is released into the environment, it is dispersed by wind and atmospheric dust. In this study, we investigated the uptake of polystyrene particles into human cells using A549 cells as a model of the alveolar epithelial barrier, CaCo-2 cells as a model of the intestinal epithelial barrier, and THP-1 cells as a model of immune cells to simulate a possible uptake of microplastics by inhalation, oral uptake, and interaction with the cellular immune system, respectively. The uptake of fluorescence-labeled beads by the different cell types was investigated by confocal laser scanning microscopy in a semi-quantitative, concentration-dependent manner. Additionally, we used Raman spectroscopy as a complementary method for label-free qualitative detection and the visualization of polystyrene within cells. The uptake of polystyrene beads by all investigated cell types was detected, while the uptake behavior of professional phagocytes (THP-1) differed from that of adherent epithelial cells.

Acetylcholinesterase and neuropathy target esterase activities in 11 cases of symptomatic flight crew members after fume events.

In modern aviation, so-called fume events such as exposure to an unknown mixture of chemicals introduced into the aircraft cabin with bleed air drawn off at the engines may occur. Human exposure may result in (neuro)toxic symptoms described as so-called "aerotoxic syndrome." Currently, among other agents organophosphates (OP) are regarded as a likely cause of the observed adverse effects. After fume events 11 flight crew members (9 female/2 male; ages 23-58 yr) were admitted for a medical examination within 5 d post exposure. Individual acetylcholinesterase (AChE) and neuropathy target esterase (NTE) activities were determined. Anamnesis and clinical findings confirmed prominent symptoms of an intoxication, including headache, cognitive difficulties, and neurological disorders, among others. Patient AChE activities ranged from 37 to 50 U/g hemoglobin (reference values: 26.7-50.9 U/g hemoglobin). Ten individuals showed NTE activities ranging from 3.14 to 6.3 nmol phenyl valerate/(min × mg protein) (reference values: 3.01-24), with one patient exhibiting low NTE activity of 1.4. Biochemical effect monitoring was applied to encompass a broad range of AChE-inhibiting compounds such as OP, carbamates, and isocyanates, or to detect inhibition of NTE. The measured AChE activities indicated a subordinate contribution of OP or related compounds to the observed symptoms. All noted NTE activities were clustered at low levels. Our data suggest a likely inhibition of NTE activities in patients after fume events, which warrants further investigation. The observed symptoms may be linked to known chemical compounds in fume events, and it is not possible to infer a direct correlation between manifestations and AChE -inhibiting compounds at this time.

Exposure to allergens of different cattle breeds and their relevance in occupational allergy.

INTRODUCTION: Cattle are an important source of allergens in the working area of farmers. Asthma caused by cow allergens is a significant occupational problem. Yet in allergological testing, the results of in vivo and in vitro diagnostic tests are often inconsistent even in cases with clearly cattle-related symptoms. OBJECTIVES AND METHODS: The aim of this study was to investigate four different commercial cow allergen extracts and to compare them with self prepared extracts of different cattle breeds by means of SDS-PAGE and immunoblotting using the sera of 42 German farmers with asthma and rhino-conjunctivitis caused by cattle contact. RESULTS: The commercial extracts investigated in this study showed only minor differences in protein pattern. Using sera in immunoblotting experiments distinct bands were found for all symptomatic farmers, even in 13 farmers with a negative result in commercially available serological allergy tests. Bands with molecular weights in the range between about 11 and 67 kDa were observed; reactivity with the major allergen Bos d 2 at about 20 kDa was detected in all farmers, although it was not the strongest band in all cases. CONCLUSIONS: We demonstrate for the first time the allergenic relevance of additional proteins with molecular weights of 14, 30, 55 and approx. 67-97 kDa in more than 50% of farmers with cattle related symptoms. One of our most striking results was that 32% of the investigated farmers with cattle related symptoms showed negative results with commercial serological tests but distinct reactions with cow allergen in immunoblotting experiments. The Bos d 2 content in hair showed differences between certain breeds whereas German Brown and Simmental had particularly higher quantities of Bos d 2 in their hair than breeds such as Holstein-Friesian. These results strongly support the following recommendation: test results with commercial extracts that are contradictory to the clinical symptoms should be supplemented by skin tests using extracts of the hair of the farmers' own cattle.

Environmental exposure to allergens of different dog breeds and relevance in allergological diagnostics.

In our environment, dogs are a relevant source of allergens, but diagnosing dog-related allergies may present difficulties, as in diagnostic tests with commercial dog allergens, some patients show only slight positive or negative results, even though they suffer from dog-related symptoms. Occasionally, allergy tests with extracts of dog hair belonging to patients' dogs or from dogs of the same breed were found to yield more reliable results, possibly due to breed-specific allergen components. The purpose of this study was to determine breed-specific differences or possibly hypo- or hyperallergenic dog breeds. The dog allergen content and protein patterns of different commercial and self-prepared dog allergen extracts were compared. Protein extracts were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and stained with silver. The major allergen Can f 1 was quantified using the commercially available enzyme-linked immunosorbent assay (ELISA) technique. The majority of the bands in the self-prepared extracts of different breeds had a molecular mass lower than 30 kD. Notably, the self-prepared extracts of hair of common breeds showed distinct protein bands with a molecular mass lower than 14 kD, which the commercial extracts did not. With regard to Can f 1 content, a marked variability occurred. Factors related to individual dogs seem to influence the allergenicity more than breed or gender. This is the first report to describe allergens with low molecular mass that are absent in extracts of commercial test kits. Consequently, skin tests with self-prepared dog allergen extracts need to be performed in case of inconsistent test results with commercial extracts.

German cattle allergy study (CAS): public health relevance of cattle-allergic farmers.

INTRODUCTION: Allergic reactions caused by animals are a common and significant occupational health concern. In a large population-based study on occupational asthma in Europe, farming has been among the occupations with the highest risk. OBJECTIVES: Characteristics of cattle-allergic farmers are described in a retrospective observational design. METHODS: The study covers farmers from all regions of Germany which were reported to the Agricultural Institutions for Statutory Accident Insurance and Prevention (Landwirtschaftliche Berufsgenossenschaften, LBGs) between 1990 (January) and 2002 (December) with a suspected occupational cattle-allergic airways disease. For these farmers, the following parameters were considered: age, gender, onset of airways symptoms related to contact with cattle, begin of employment disability, total and specific Immunoglobulin E (IgE) against cattle allergens, and results of lung function measurements. RESULTS: A total of 513 patients (age 14-74, mean 40.7 years; 45.6% women, 54.4% men) had been reported for a suspected occupational cattle-allergic airways disease. Of these patients 24.8% showed cattle-related symptoms of asthma, 11.7% of rhinitis, and 60% of both asthma and rhinitis, while only 34.5% of all reported patients showed an airways obstruction in the first documented lung function test. A total of 62.5% out of the group of patients with an officially recognized occupational disease (42.1%, n=216) have an initial employment disability with a rating of 20% or above. CONCLUSIONS: Our results underline the high public health relevance of cattle allergy in farmers, especially in the light of the large number of young patients. Considering the known difficulties in diagnosing cattle allergy due to the number of false negative test results, we are convinced that its relevance is even higher than the number of reported cases suggests. The high rate of initial employment disability among the affected patients underlines the need for improved preventive measures.