[show abstract][hide abstract] ABSTRACT: The fast and direct identification of possibly pathogenic microorganisms in air is gaining increasing interest due to their threat for public health, e.g. in clinical environments or in clean rooms of food or pharmaceutical industries. We present a new detection method allowing the direct recognition of relevant germs or bacteria via fluorescence-labeled antibodies within less than one hour. In detail, an air-sampling unit passes particles in the relevant size range to a substrate which contains antibodies with fluorescence labels for the detection of a specific microorganism. After the removal of the excess antibodies the optical detection unit comprising reflected-light and epifluorescence microscopy can identify the microorganisms by fast image processing on a single-particle level. Fir st measurements with the system to identify various test particles as well as interfering influences have been performed, in particular with respect to autofluorescence of dust particles. Specific antibodies for the detection of Aspergillus fumigatus spores have been established. The biological test system consists of protein A-coated polymer particles which are detected by a fluorescence-labeled IgG. Furthermore the influence of interfering particles such as dust or debris is discussed.
[show abstract][hide abstract] ABSTRACT: There is an increasing need for allergen inhalation systems to perform basic clinical research and test anti-allergic drugs under well-controlled conditions. This requires stability of environmental conditions like temperature and humidity, as well as allergen concentration and reproducible induction of allergic symptoms.
The aim of this study was to validate an environmental exposure unit for controlled human pollen inhalation studies in participants with seasonal allergic rhinitis.
Temperature, relative humidity, and air flow rate were kept constant with an air conditioning system. Pollen atmosphere was generated using a specially designed feeding system and monitored online by laser counter and offline using rotating rod samplers. Efficacy (total nasal symptom score, nasal air flow rate, nasal secretion) and safety (lung function) parameters were evaluated at different pollen concentrations and repeated allergen challenges.
Temperature, humidity, and air flow rate in the environmental exposure unit remained constant within a range of <2%. The spatial distribution and the temporal stability of the pollen concentration varied only slightly over 4 h (+/-10% and <4%, respectively). Dose-dependent induction of allergic rhinitis symptoms, reduction in nasal air flow rate, and increase in nasal secretion were observed over time. These effects were reproducible from day to day. Lung function remained clinically normal at all concentrations and from day to day.
Thus, pollen exposure in the environmental exposure unit is an effective, reproducible, safe, and suitable method for single-centre clinical studies on the efficacy of anti-allergic treatment or basic clinical research.
[show abstract][hide abstract] ABSTRACT: An expansion type cloud condensation nucleus counter/Kelvin spectrometer has been operated with water and various organic liquids. Heterogeneous nucleation is markedly different depending on the particle/vapor material combination. .
[show abstract][hide abstract] ABSTRACT: DE 102008060614 A1 UPAB: 20100621 NOVELTY - The method comprises providing a liquid spray formulation, which contains a solvent, a carrier substance and an allergen, producing an aerosol by spray drying, where the aerosol particles contain the carrier substance and the allergen, and distributing the aerosol into a room air of an exposure room, where the exposure room has a device element for generation a temporal and spatially constant allergen room air concentration. A freeze-dried allergen extract of a natural allergen-carrier or a recombinantly produced allergen is used for the production of the aerosol by spray drying. DETAILED DESCRIPTION - The method comprises providing a liquid spray formulation, which contains a solvent, a carrier substance and an allergen, producing an aerosol by spray drying, where the aerosol particles contain the carrier substance and the allergen, and distributing the aerosol into a room air of an exposure room, where the exposure room has a device element for generation a temporal and spatially constant allergen room air concentration. A freeze-dried allergen extract of a natural allergen-carrier or a recombinantly produced allergen is used for the production of the aerosol by spray drying. An aqueous spray solution is used for the spray drying. The allergen consists of Der p1 mite allergen, flower pollen allergen, domestic animal allergen and/or house dust allergen. The allergen in the liquid spray formulation is present in a concentration (C(A)) of 0.1-1000 mu g/ml. The carrier substance in the liquid spray formulation is present in a concentration of 0.1-20 wt.%. The atomization of the spray formulation takes place with an atomization device, which is selected from an ultrasonic atomizer, atomizer plate and/or a compressed air spray nozzle. The aerosol particles have a median diameter (d50) of 10-25 mu m. The exposure room has a room volume of 3-300 m3. The simultaneous distribution of the aerosol takes place in the room air by turbulent mixing air flow. The distribution of the aerosol is caused by swirl outlets introduced in an air supply, cover ventilators and/or a floor heater in the exposure room. The distribution of the spray formulation takes place below the cover ventilator and the formed aerosol particles are evenly distributed in the exposure room through the ventilator flow and the turbulent fresh air flow. The atomization device is centrally introduced below the cover ventilator and/or in the immediate proximity to the swirl outlet. The spray formulation is supplied to a dosing device for adjusting a suitable liquid mass flow and subsequently fed back to the atomization device. The air volume flow Q through the exposure room is 600-2000 m3/h. The exposure room is operated with an air change rate of 1000-1600. The distribution of the aerosol leads to allergen concentration in the room air of the exposure room in the range of 0.01-1 mu g/m3. The allergen concentration in the room air of the exposure room is constantly kept with a maximum deviation of 20% over a time period of 1-5 hours. An aerosol monitor and/or laser particle counter are introduced in the exposure room for determining the allergen concentration. An INDEPENDENT CLAIM is included for a device for carrying out an inhalative allergen provocation. USE - Method for producing inhalation atmosphere in an exposure room for inhalative allergen provocation (claimed). ADVANTAGE - The method allows realistic simulation of environmental exposure, site of action in the respiratory tract and bioavailability, high flexibility with respect to the allergen or allergen spectrum to be examined and very good control of allergen spectrum, allergen concentration and particle size, and uses only a technical procedure for the generation and monitoring.