Search results for " contact"

Peripheral, central and behavioral responses to the cuticular pheromone bouquet in Drosophila melanogaster males.

2011

International audience; Pheromonal communication is crucial with regard to mate choice in many animals including insects. Drosophila melanogaster flies produce a pheromonal bouquet with many cuticular hydrocarbons some of which diverge between the sexes and differently affect male courtship behavior. Cuticular pheromones have a relatively high weight and are thought to be -- mostly but not only -- detected by gustatory contact. However, the response of the peripheral and central gustatory systems to these substances remains poorly explored. We measured the effect induced by pheromonal cuticular mixtures on (i) the electrophysiological response of peripheral gustatory receptor neurons, (ii) …

Local skin necroses after intramuscular injection -Experimental animal studies-.

1977

The pathogenesis of local skin necroses after intramuscular injection of various drugs such as phenylbutazone (Embolia cutis medicamentosa, Nicolau's syndrome) is not clear. In an attempt to simulate this clinical feature experiments were performed on the rabbit ear lobe. A 20% phenylbutazone solution was injected paraarterial, intraarterial and paraarterial after perforation of the vessel. The drug produced a violent inflammation with all kinds of application. The local inflammation induced by paraarterial injection resulted in a fine scarring. Both other kinds of application produced necroses or even perforations. The histological examinations in these cases revealed massive destructions …

Chronic Urticaria After Implantation of a Mitral Annuloplasty Ring in a Nickel-Allergic Patient

2017

The effect of body posture on long range time-to-contact estimation

2011

On Earth, gravity accelerates freely moving objects downward, whereas upward-moving objects are being decelerated. Do humans take internalised knowledge of gravity into account when estimating time-to-contact (TTC, the time remaining before the moving object reaches the observer)? To answer this question, we created a motion-prediction task in which participants saw the initial part of an object's trajectory moving on a collision course prior to an occlusion. Observers had to judge when the object would make contact with them. The visual scene was presented with a head-mounted display. Participants lay either supine (looking up) or prone (looking down), suggestive of the ball either rising…

Refining the dual olfactory hypothesis: Pheromone reward and odour experience

2009

In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are ‘innately’ attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided co…

In vivo cimetidine immunomodulatory effects on the cutaneous reaction to oxazolone in the chicken.

1997

The effect of the histamine H2-receptor antagonist, cimetidine, on the cutaneous Arthus-like hypersensitivity to oxazolone elicited injecting subcutaneously oxazolone conjugated to egg-albumin (EA-OX) has been examined in the chicken. Cimetidine had opposite effects on the cutaneous reaction to oxazolone in relation to a different immunization schedule. Cimetidine enhanced the cutaneous reaction to oxazolone obtained immunizing chickens with oxazolone dissolved in ethanol (Eth-OX); instead cimetidine inhibited the cutaneous reaction obtained in chickens immunized with oxazolone dissolved in complete Freund adjuvant (CFA-OX). Optimum enhancement of the cutaneous arthus-like reaction to oxazo…

Stereoacuity with simultaneous vision multifocal contact lenses.

2010

Our purpose was to evaluate near stereoacuity (SA) with Focus Progressives and PureVision Multifocal simultaneous vision contact lenses. In a cross-over study design, 20 presbyopic subjects were fitted with either the Focus Progressives or PureVision Multifocal lenses. After 1 month, SA was measured with the vectographic Titmus, Random dot stereotests, and the Howard-Dolman apparatus under photopic conditions (85 lux) at 40 cm. Binocular high-contrast visual acuity at distance and near was examined. Subjects were then refitted with the alternative correction and the procedure was repeated. Mean SA with the Focus Progressive was 21 +/- 7 sec arc, 54 +/- 17 sec arc, and 51 +/- 21 sec arc, wit…

Contact sensitizers modulate mechanisms of receptor-mediated endocytosis but not fluid-phase endocytosis in murine epidermal Langerhans cells.

1995

In order to define the influence of contact allergens on the fluid-phase endocytosis (FPE) of soluble molecules of murine epidermal Langerhans cells (LC), we studied the internalization of FITC-labeled bovine serum albumin (FITC-BSA), TRITC-labeled dextrane (TRITC-DEX) as well as horseradish peroxidase by LC. A 3-parameter flow-cytometric technique was performed for quantification of internalized FITC-BSA in LC using quantum red-labeled reagents for detection of la-antigen expression by LC and propidium iodide for exclusion of dead cells from analysis. A temperature-dependent rapid accumulation of FITC-BSA was noticed in time-course studies reaching a plateau between 1 and 2 h of in vitro c…

An approach to predictive testing of contact sensitizers in vitro by monitoring their influence on endocytotic mechanisms.

1996

Endocytotic activation of epidermal Langerhans cells (LC) by immunogenic haptens is an early event during development of allergic contact dermatitis. In this work a fast and objective flow-cytometric assay for predictive in vitro testing of contact sensitizers by monitoring their influence on endocytotic mechanisms in murine LC was developed. Epidermal cell suspensions were labelled with a monoclonal antibody directed to MHC class II molecules and pH-sensitive fluorochrome-coupled second-step reagents. For untreated LC a significant quenching of fluorescence intensity by internalization of the MHC-antibody complexes into acidic compartments was noticed. Similar results were obtained in the …

Cardiac kinematic parameters computed from video of in situ beating heart

2017

AbstractMechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial veloc…