17 research outputs found

    Anaphylaxis Imaging: Non-Invasive Measurement of Surface Body Temperature and Physical Activity in Small Animals

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    <div><p>In highly sensitized patients, the encounter with a specific allergen from food, insect stings or medications may rapidly induce systemic anaphylaxis with potentially lethal symptoms. Countless animal models of anaphylaxis, most often in BALB/c mice, were established to understand the pathophysiology and to prove the safety of different treatments. The most common symptoms during anaphylactic shock are drop of body temperature and reduced physical activity. To refine, improve and objectify the currently applied manual monitoring methods, we developed an imaging method for the automated, non-invasive measurement of the whole-body surface temperature and, at the same time, of the horizontal and vertical movement activity of small animals. We tested the anaphylaxis imaging in three <i>in vivo</i> allergy mouse models for i) milk allergy, ii) peanut allergy and iii) egg allergy. These proof-of-principle experiments suggest that the imaging technology represents a reliable non-invasive method for the objective monitoring of small animals during anaphylaxis over time. We propose that the method will be useful for monitoring diseases associated with both, changes in body temperature and in physical behaviour.</p></div

    Papain Degrades Tight Junction Proteins of Human Keratinocytes In Vitro and Sensitizes C57BL/6 Mice via the Skin Independent of its Enzymatic Activity or TLR4 Activation

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    Papain is commonly used in food, pharmaceutical, textile, and cosmetic industries and is known to induce occupational allergic asthma. We have previously shown that the papain-like cysteine protease Dermatophagoides pteronyssinus 1 from house dust mite exhibits percutaneous sensitization potential. We aimed here to investigate the potential of papain itself in epicutaneous sensitization. The effects of papain on tight junction (TJ) proteins were tested in vitro in human primary keratinocytes. Using C57BL/6 wild-type and Toll-like receptor 4 (TLR4)-deficient mice, we analyzed the sensitization potential of papain, its effects on the skin barrier, and immune cell recruitment. Our results show that papain affects the skin barrier by increasing transepidermal water loss, degrading TJ proteins and inducing vasodilation. When topically applied, papain exhibited a high epicutaneous inflammatory potential by recruiting neutrophils, mast cells, and CD3-positive cells and by induction of a TH2-biased antibody response. However, its high potency for specific sensitization via the skin was TLR4 independent and, in spite of its capacity to degrade epidermal TJ proteins, does not rely on its enzymatic function. From our data, we conclude that papain has all features to act as a strong allergen via the skin

    The schematic (left panels) and real set up (right panels) of the imaging cage.

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    <p>(A) The complete device is composed of a type II animal cage, a photo- and a thermo-camera, which are connected to a computer and software. (1) Outer box. (2) Outer sidewall. (3) Above the cage and height-adjustable, a heat camera or heat image camera (false colour infrared camera or infrared camera) is fixed with a reference heat electrode placed in the field of view for precise calibration against a reference temperature module. (4) Mounted true colour camera, which records live real image pictures during the experiment. (5) Data are recorded and processed, and translated by software to a personal computer for processing, identifying grey scales in video input from connected infrared camera 3. The software comprises a data processing part and (7) a graphical user interface, which is commonly displayed on (6) a screen. (B) Four small animals, in this case mice, can be placed and monitored at the same time in the cage. (8) Transparent enclosure adapted to house four mice. (9) The cage comprises four outer sidewalls and (10) two inner walls, as well as a bottom portion. (11) Vertical movements can be additionally recorded to the imaging data by photo sensors comprising transmitters and receivers. (C) The mice are individually monitored, where the thermo measurements and the live video from the cage appear at the same time on the monitor. (12) False colour screen output. Two pictures are recorded and may be visualized on screens. The software translates the grey image recordings from the infrared camera (Fig 1A-3) in real-time into a false colour screen output. (13) True colour image of the true colour camera is displayed in parallel. (D) Rectal temperature (RT) was measured manually before and 20 minutes after i.v. allergen challenge of hypersensitive or negative control mice. Immediately after the challenge, the same mice were placed into the imaging cage (0 min), and the cameras monitored surface body temperature and movement activity continuously for 20 minutes (20 min).</p

    Monitoring of surface body temperature in the peanut allergy model.

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    <p>Mice M1-M3 were sham-treated (PBS), M4-M6 were specifically sensitized with peanut allergen Ara h 2 (Ara h 2), all mice were i.v. challenged with Ara h 2 and monitored in the imaging cage over 20 minutes, with an image frequency of 4 frames/sec. (A) Temperature curves of individual mice; y-axis represents temperature in °C, x-axis: number of frames during 20 min. (B) The mean drops of the body surface temperatures over time of each mouse group were compared and differed significantly (*** p<0.001).</p

    Surface body temperature imaging in the milk allergy model.

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    <p>Mice M1-M3 were sham-treated (PBS), M4-M6 were specifically sensitized with aluminium-absorbed milk allergen casein (alum-casein), all mice were i.v. challenged with casein and monitored in the imaging cage over 20 minutes, with an image frequency of 4 frames/sec. (A) Temperature curves of individual mice; y-axis represents temperature in °C, x-axis: number of frames during 20 min. (B) The mean results of drop of the body surface temperatures over time of each mouse group were compared and differed significantly (** p<0.01).</p

    Horizontal physical activity of mice in the milk allergy model.

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    <p>Heat image frames of animals were captured (4 frames/second), and centre-of-heat-points and the distance among them calculated over a pre-set period of time. Y-axis: moved distance (pixel); x-axis: number of frames (images) captured during 20 min. Mice M1-M3 were sham-treated (PBS), M4-M6 were specifically sensitized against aluminium-absorbed milk allergen casein (alum-casein), all mice were i.v. challenged with casein. (A) Distance records of individual mice during 20 min; boxes: corresponding tracking curves of horizontal moves of each mouse. (B) Statistical comparison of the sum of moved distances between the PBS and alum-casein groups (mean+SD) showed a significant difference (****p<0.0001).</p
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