Test Patch Research Articles

Color constancy in a scene with bright colors that do not have a fully natural surface appearance

Theoretical and experimental approaches have proposed that color constancy involves a correction related to some average of stimulation over the scene, and some of the studies showed that the average gives greater weight to surrounding bright colors. However, in a natural scene, high-luminance elements do not necessarily carry information about the scene illuminant when the luminance is too high for it to appear as a natural object color. The question is how a surrounding color's appearance mode influences its contribution to the degree of color constancy. Here the stimuli were simple geometric patterns, and the luminance of surrounding colors was tested over the range beyond the luminosity threshold. Observers performed perceptual achromatic setting on the test patch in order to measure the degree of color constancy and evaluated the surrounding bright colors' appearance mode. Broadly, our results support the assumption that the visual system counts only the colors in the object-color appearance for color constancy. However, detailed analysis indicated that surrounding colors without a fully natural object-color appearance had some sort of influence on color constancy. Consideration of this contribution of unnatural object color might be important for precise modeling of human color constancy.

Color constancy influenced by unnatural spatial structure

The recognition of spatial structures is important for color constancy because we cannot identify an object's color under different illuminations without knowing which space it is in and how that space is illuminated. To show the importance of the natural structure of environments on color constancy, we investigated the way in which color appearance was affected by unnatural viewing conditions in which a spatial structure was distorted. Observers judged the color of a test patch placed in the center of a small room illuminated by white or reddish lights, as well as two rooms illuminated by white and reddish light, respectively. In the natural viewing condition, an observer saw the room(s) through a viewing window, whereas in an unnatural viewing condition, the scene structure was scrambled by a kaleidoscope-type viewing box. Results of single room condition with one illuminant color showed little difference in color constancy between the two viewing conditions. However, it decreased in the two-rooms condition with a more complex arrangement of space and illumination. The patch's appearance under the unnatural viewing condition was more influenced by simultaneous contrast than its appearance under the natural viewing condition. It also appears that color appearance under white illumination is more stable compared to that under reddish illumination. These findings suggest that natural spatial structure plays an important role for color constancy in a complex environment.

The achromatic locus: Effect of navigation direction in color space

An achromatic stimulus is defined as a patch of light that is devoid of any hue. This is usually achieved by asking observers to adjust the stimulus such that it looks neither red nor green and at the same time neither yellow nor blue. Despite the theoretical and practical importance of the achromatic locus, little is known about the variability in these settings. The main purpose of the current study was to evaluate whether achromatic settings were dependent on the task of the observers, namely the navigation direction in color space. Observers could either adjust the test patch along the two chromatic axes in the CIE u*v* diagram or, alternatively, navigate along the unique-hue lines. Our main result is that the navigation method affects the reliability of these achromatic settings. Observers are able to make more reliable achromatic settings when adjusting the test patch along the directions defined by the four unique hues as opposed to navigating along the main axes in the commonly used CIE u*v* chromaticity plane. This result holds across different ambient viewing conditions (Dark, Daylight, Cool White Fluorescent) and different test luminance levels (5, 20, and 50 cd/m(2)). The reduced variability in the achromatic settings is consistent with the idea that internal color representations are more aligned with the unique-hue lines than the u* and v* axes.

Eosinophilic Esophagitis In The Puerto Rican Pediatric Population

RationaleEosinophilic esophagitis (EoE) has been rarely recognized in Hispanics. Our goal is to describe the clinical characteristics, skin prick test (SPT) and food atopy patch test (APT) results in a Puerto Rican pediatric population with EoE.MethodsA retrospective analysis of all pediatric patients with EoE seen at the Allergy/Immunology Clinics of the University of Puerto Rico School of Medicine between July 2012 and June 2013.ResultsThirty six patients (age 0.8-18 years) with biopsied-confirmed EoE were identified. Seventy one percent were males. Most were atopic (91.4%). Allergic rhinitis was the most frequent diagnosis (83.3%) and dust mite was the most common sensitivity (83.3%). EoE symptoms included abdominal pain, emesis, dysphagia, and nauseas (56.3%, 56.3%, 46.8%, and 43.7% respectively). Food SPT was positive in 88.9% of cases. Egg, milk, oat, and corn (44.4%, 29.6%, 25.9%, and 25.9% respectively) were the most prevalent positives. APTs were positive in 88.9%. Wheat, beef, and chicken (41.7%, 36.1%, and 36.1% respectively) were the most prevalent positives. There was an association between SPT oat (RR = 0.43) with eosinophil counts in esophageal biopsy, unlike APT wheat (RR = -0.28), chicken (RR = -0.19) and beef (RR = -0.10).ConclusionsThis is the first study to describe results of both food SPT and APT in a Hispanic EoE pediatric population. APT results differed from other published cohorts. Dietary, gut microbial flora and host immune factors may explain these differences. Prospective studies are needed to evaluate efficiency of combining these testing methods in directing successful dietary elimination. RationaleEosinophilic esophagitis (EoE) has been rarely recognized in Hispanics. Our goal is to describe the clinical characteristics, skin prick test (SPT) and food atopy patch test (APT) results in a Puerto Rican pediatric population with EoE. Eosinophilic esophagitis (EoE) has been rarely recognized in Hispanics. Our goal is to describe the clinical characteristics, skin prick test (SPT) and food atopy patch test (APT) results in a Puerto Rican pediatric population with EoE. MethodsA retrospective analysis of all pediatric patients with EoE seen at the Allergy/Immunology Clinics of the University of Puerto Rico School of Medicine between July 2012 and June 2013. A retrospective analysis of all pediatric patients with EoE seen at the Allergy/Immunology Clinics of the University of Puerto Rico School of Medicine between July 2012 and June 2013. ResultsThirty six patients (age 0.8-18 years) with biopsied-confirmed EoE were identified. Seventy one percent were males. Most were atopic (91.4%). Allergic rhinitis was the most frequent diagnosis (83.3%) and dust mite was the most common sensitivity (83.3%). EoE symptoms included abdominal pain, emesis, dysphagia, and nauseas (56.3%, 56.3%, 46.8%, and 43.7% respectively). Food SPT was positive in 88.9% of cases. Egg, milk, oat, and corn (44.4%, 29.6%, 25.9%, and 25.9% respectively) were the most prevalent positives. APTs were positive in 88.9%. Wheat, beef, and chicken (41.7%, 36.1%, and 36.1% respectively) were the most prevalent positives. There was an association between SPT oat (RR = 0.43) with eosinophil counts in esophageal biopsy, unlike APT wheat (RR = -0.28), chicken (RR = -0.19) and beef (RR = -0.10). Thirty six patients (age 0.8-18 years) with biopsied-confirmed EoE were identified. Seventy one percent were males. Most were atopic (91.4%). Allergic rhinitis was the most frequent diagnosis (83.3%) and dust mite was the most common sensitivity (83.3%). EoE symptoms included abdominal pain, emesis, dysphagia, and nauseas (56.3%, 56.3%, 46.8%, and 43.7% respectively). Food SPT was positive in 88.9% of cases. Egg, milk, oat, and corn (44.4%, 29.6%, 25.9%, and 25.9% respectively) were the most prevalent positives. APTs were positive in 88.9%. Wheat, beef, and chicken (41.7%, 36.1%, and 36.1% respectively) were the most prevalent positives. There was an association between SPT oat (RR = 0.43) with eosinophil counts in esophageal biopsy, unlike APT wheat (RR = -0.28), chicken (RR = -0.19) and beef (RR = -0.10). ConclusionsThis is the first study to describe results of both food SPT and APT in a Hispanic EoE pediatric population. APT results differed from other published cohorts. Dietary, gut microbial flora and host immune factors may explain these differences. Prospective studies are needed to evaluate efficiency of combining these testing methods in directing successful dietary elimination. This is the first study to describe results of both food SPT and APT in a Hispanic EoE pediatric population. APT results differed from other published cohorts. Dietary, gut microbial flora and host immune factors may explain these differences. Prospective studies are needed to evaluate efficiency of combining these testing methods in directing successful dietary elimination.

Clinical characteristics and sensitivity to food and inhalants among children with eosinophilic esophagitis

BackgroundTo understand the clinical characteristics and the diagnostic procedures in pediatric patients with eosinophilic esophagitis and to evaluate the sensitivity of the patients to food and inhalant allergens. A cross-sectional study was performed in 35 children with eosinophilic esophagitis during the time period from January 2010 to January 2011. The clinical and epidemiological data were obtained using a questionnaire and medical chart analysis. The body mass index for age was used for the nutritional evaluation (via the Z score). The sensitivity to foods and inhalants was evaluated by performing a skin prick test and atopy patch test.ResultsPatients (35 in total, median age 10 years) with a diagnosis of eosinophilic esophagitis were evaluated. The most prevalent symptoms in the patients were vomiting (71.4%) and abdominal pain (51.4%). Endoscopic alterations were observed in 97.2% of the patients. A good nutritional state was observed in 82.8% of the children. The tests demonstrated the presence of food sensitivities and/or aeroallergens in 27 (77.1%) patients, whereas 8 (22.9%) patients did not test positive in any of the tests performed. Among the patients with positive tests, 24 (68.5%) exhibited sensitivity to aeroallergens and 16 (45.7%) were sensitive to foods. The comparison between the sensitive and insensitive groups displayed statistically significant results with respect to sex, symptom prevalence, and 24-hour esophageal pH monitoring.ConclusionsThe patients evaluated in this study displayed clinical characteristics of eosinophilic esophagitis similar to those reported in the literature. The sensitivity to foods determined by the tests was less than that observed in prior studies; however, a marked sensitivity to aeroallergens was observed. The different allergen sensitivity profiles observed in this study suggests that, similar to asthma, the eosinophiic esophagitis disease may exhibit several phenotypes.

Lustrous material appearances: Internal and external constraints on triggering conditions for binocular lustre.

Lustrous surface appearances can be elicited by simple image configurations with no texture or specular highlights, as most prominently illustrated by Helmholtz' demonstration of stereoscopic lustre. Three types of explanatory framework have been proposed for stereoscopic lustre, which attribute the phenomenon to a binocular luminance conflict, an internalised physical regularity (Helmholtz), or to a disentangling of “essential” and “accidental” attributes in surface representations (Hering). In order to investigate these frameworks, we used haploscopically fused half-images of centre-surround configurations in which the luminances of the test patch were dynamically modulated. Experiment 1 shows that stereoscopic lustre is not specifically tied to situations of a luminance conflict between the eyes. Experiment 2 identifies a novel aspect in the binocular temporal dynamics that provides a physical basis for lustrous appearances, namely the occurrence of a temporal luminance counter-modulation between the eyes. This feature sheds some light on the internal principles underlying a disentangling of “accidental” and “essential” surface attributes. Experiment 3 reveals an asymmetry between a light and a dark reference level for the counter-modulations. This finding again suggests an interpretation in terms of an internalised physical regularity with respect to the dynamics of perceiving illuminated surfaces.

The assessment of pulsed dye laser treatment of port-wine stains with reflectance confocal microscopy

Background: Reflectance confocal microscopy (RCM) is a noninvasive technique for evaluating cutaneous lesions with cellular level resolution close to conventional histopathology. The aim of this study is to observe the vascular changes in Port-wine (PWS) lesions and assess the clinical efficacy of Pulsed Dye Laser (PDL) treatment by examining vessel diameter and density with RCM. Materials and methods: Eleven adult patients with PWS, each had four test patches carried out with different pulse durations (1.5, 3, 6, and 10 ms), respectively; fluences of 9–12 J/cm2; and a spot size of 7 mm. The PDL treatment was repeated 3–5 times at a 2-month interval. Photographs and measurements with RCM were taken before each treatment and 2 months after the last treatment. Results: The PDL treatment exhibited increasing clearance with reducing pulse durations. Vessel diameters and densities were significantly decreased in the same pulse-duration groups after treatment. There was significant difference between 1.5 ms pulse-duration group and other pulse-duration groups in reducing blood vessel diameter at the depth of 150 μm. Conclusions: RCM can be used to assess the clinical efficacy of PDL treatment.

Evaluation of food allergy to wheat, cow milk, egg, soy and peanuts in patients suffering from atopic dermatitis

Few large studies concerning the importance of food allergy in adolescents and adult patients with atopic dermatitis exist. The evaluation of food allergy to egg white and yolk, peanuts, soy, cow milk and wheat in patients suffering from atopic dermatitis. Two hundred forty patients (70 men, 170 women) were examined. Complete dermatological and allergological examination was performed in all patients, including specific IgE, skin prick test and atopy patch test. The challenge test was performed according to the results of examinations with suspected foods. The food allergy to peanuts was confirmed in 20% of patients, to egg in 6%, to soy in 3.3%, to wheat in 2.5% and to milk in 0.8% – altogether in 65 patients (27.5%). The positive results in examinations without clinical symptoms of food allergy were recorded in another 78 patients (32.5%). The diagnostic work-up should comprise not only the laboratory methods, but also the diagnostic hypoallergenic diet and the challenge test.

Scotopic hue percepts in natural scenes.

Traditional trichromatic theories of color vision conclude that color perception is not possible under scotopic illumination in which only one type of photoreceptor, rods, is active. The current study demonstrates the existence of scotopic color perception and indicates that perceived hue is influenced by spatial context and top-down processes of color perception. Experiment 1 required observers to report the perceived hue in various natural scene images under purely rod-mediated vision. The results showed that when the test patch had low variation in the luminance distribution and was a decrement in luminance compared to the surrounding area, reddish or orangish percepts were more likely to be reported compared to all other percepts. In contrast, when the test patch had a high variation and was an increment in luminance, the probability of perceiving blue, green, or yellow hues increased. In addition, when observers had a strong, but singular, daylight hue association for the test patch, color percepts were reported more often and hues appeared more saturated compared to patches with no daylight hue association. This suggests that experience in daylight conditions modulates the bottom-up processing for rod-mediated color perception. In Experiment 2, observers reported changes in hue percepts for a test ring surrounded by inducing rings that varied in spatial context. In sum, the results challenge the classic view that rod vision is achromatic and suggest that scotopic hue perception is mediated by cortical mechanisms.

The potential of linear discriminative Laplacian eigenmaps dimensionality reduction in polarimetric SAR classification for agricultural areas

In this paper, the linear discriminative Laplacian eigenmaps (LDLE) dimensionality reduction (DR) algorithm is introduced to C-band polarimetric synthetic aperture radar (PolSAR) agricultural classification. A collection of homogenous areas of the same crop class usually presents physical parameter variation, such as the biomass and soil moisture. Furthermore, the local incidence angle also impacts a lot on the same crop category when the vegetation layer is penetrable with C-band radar. We name this phenomenon as the “observed variation of the same category” (OVSC). The most common PolSAR features, e.g., the Freeman–Durden and Cloude–Pottier decompositions, show an inadequate performance with OVSC. In our research, more than 40 coherent and incoherent PolSAR decomposition models are stacked into the high-dimensionality feature cube to describe the various physical parameters. The LDLE algorithm is then performed on the observed feature cube, with the aim of simultaneously pushing the local samples of the same category closer to each other, as well as maximizing the distance between local samples of different categories in the learnt subspace. Finally, the classification result is obtained by nearest neighbor (NN) or Wishart classification in the reduced feature space. In the simulation experiment, eight crop blocks are picked to generate a test patch from the 1991 Airborne Synthetic Aperture Radar (AIRSAR) C-band fully polarimetric data from of Flevoland test site. Locality preserving projections (LPP) and principal component analysis (PCA) are then utilized to evaluate the DR results of the proposed method. The classification results show that LDLE can distinguish the influence of the physical parameters and achieve a 99% overall accuracy, which is better than LPP (97%), PCA (88%), NN (89%), and Wishart (88%). In the real data experiment, the Chinese Hailaer nationalized farm RadarSat2 PolSAR test set is used, and the classification accuracy is around 94%, which is again better than LPP (90%), PCA (88%), NN (89%), and Wishart (85%). Both experiments suggest that the LDLE algorithm is an effective way of relieving the OVSC phenomenon.

Relationship between skin prick and atopic patch test reactivity to aeroallergens and disease severity in children with atopic dermatitis

BackgroundThe immunological mechanism in aetiology of atopic dermatitis (AD) shows significant differences from other allergic diseases. Allergen inhalation exacerbates AD lesions and AD patients’ complaints decrease in house dust mite (HDM) low level environments, which reveals the importance of inhalant allergens. ObjectiveWe evaluated the skin prick test (SPT) and atopy patch test (APT) positivity rates with aeroallergens and studied the effect of test results, and aimed to determine the value of allergic test reactivity on the clinical characteristics of children with AD. MethodsForty-five children aged 2–15 years with AD were included to study between May 2006 and May 2007 in GATA Haydarpasa Teaching Hospital, Allergy Department. The reactivity to inhalant allergens using SPT and APT was evaluated. The severity of AD, which was assessed with SCORAD, was compared with aeroallergen hypersensitivity. ResultsThe highest positivity of APT was seen against HDM (48.9%). HDM SPT positivity and subjective symptoms score were statistically correlated (P<0.05). Patients with strong SPT positivity to HDM had a higher total SCORAD score (P<0.05). Although there was no statistical correlation between HDM APT and SCORAD parameters, APT positive patients had generally higher SCORAD parameters. The statistical significance was only shown between the extent of the disease and strong APT positive reactions to Dermatophagoides pteronyssinus. ConclusionHDM allergens play an important role in determining the clinical severity of AD and strong APT positivity could be more meaningful clinically.

Ultra low concentration deltamethrin loaded patch development and evaluation of its repellency against dengue vector Aedes (S) albopictus.

BackgroundMosquito repellents and emanators confer protection against mosquito bites through spatial action of emanated vapours which are released into the adjoining environment. Synthetic insecticides released into the environment in ultra low volume vapour phase deter the mosquitoes from biting humans in a protected space.MethodsFormulation patches were prepared using the solvent evaporation method over a backing membrane and using Dibutylphthalate (DBT) as a plasticizer. The effect of formulation variables on the deltamethrin release from the patch matrices were studied under accelerated conditions, whereas, HPLC was used for quantitative estimation of deltamethrin. The prepared patch formulations were subjected to physicochemical studies, such as, deltamethrin content, thickness, weight variation, percent moisture content, moisture uptake, surface area and surface pH determination. Deltamethrin-polymer interaction and compatibility was ascertained using DSC and FT-IR, while surface morphology and deltamethrin distribution in the patch were studied using SEM technique. Repellent activity of the patch formulations was evaluated against Ae. albopictus mosquitoes.ResultsBlends of polymeric combinations of polyvinylpyrrolidone (PVP) and ethyl-cellulose (EC) with admixture of deltamethrin provided prolonged repellent activity against Ae. albopictus mosquitoes. Physicochemical characterisation indicated the suitability of deltamethrin patch formulation with the polymeric combinations of PVP and EC. Patches were very effective against laboratory reared Ae. albopictus mosquitoes. No significant difference was observed between the performance of test patches and commercially available repellent cream Mosqshield®.ConclusionDeltamethrin loaded patches provided effective repellency against Ae. albopictus mosquitoes. The study emphasised that deltamethrin released to the environment in low concentration could be an excellent spatial repellent against hematophagous mosquitoes.

Geometrical structure of perceptual color space is affine

Color spaces (e.g., CIE, Macleod-Boynton, and CIELUV) are invaluable for specifying colors. However, CIE and M-B space only predict which spectral distributions will match, while CIELUV deals with the discrimination of small color differences. There is much more to color perception than matching and discrimination. For example, similarities between colors (Zaidi & Bostic, 2008) and between color changes (Zaidi, 1998) can be used to identify materials across illuminants. Uniform color spaces based on multi-dimensional scaling of similarity ratings do exist, but these rely on Euclidean assumptions shown to be untenable (Wuerger, et al, 1995). We investigated the geometrical structure underlying relative similarity judgments. In a metric space, the distance between chromaticities would represent their magnitude of similarity, but even in a weaker affine space, ratios of distances between colors on a line would provide measures of relative similarity, and parallelism would define similarity between color changes. We tested whether affine geometry holds for a mid-point setting task. We chose two large quadrilaterals in the M-B equiluminant color plane. On each trial, observers viewed three colored patches, two of which were the endpoint colors forming one side of the quadrilateral. Observers were instructed to consider the color change between the test patches in terms of "reddish-greenish" and "bluish-yellowish" components and to set the color of the middle patch, by adjusting its hue and saturation, to the combined midpoint of the change on the two dimensions. After finding the mid-point for the four sides, observers set the midpoints between the two pairs of facing mid-points. For four observers, the two final mid-points for each quadrilateral coincided, thus satisfying Varignon’s Theorem and passing the affine test. A perceptual color space based on relative similarities across large color differences thus has an affine structure. Meeting abstract presented at VSS 2013

Linking appearance to neural activity through the study of the perception of lightness in naturalistic contexts

The present paper deals with the classical question how a psychological experience, in this case apparent lightness, is linked by intervening neural processing to physical variables. We address two methodological issues: (a) how does one know the appropriate physical variable (what is the right x?) to look at, and (b) how can behavioral measurements be used to probe the internal transformation that leads to psychological experience. We measured so-called lightness transfer functions (LTFs), that is the functions that describe the mapping between retinal luminance and perceived lightness for naturalistic checkerboard stimuli. The LTFs were measured for different illumination situations: plain view, a cast shadow, and an intervening transparent medium. Observers adjusted the luminance of a comparison patch such that it had the same lightness as each of the test patches. When the data were plotted in luminance-luminance space, we found qualitative differences between mapping functions in different contexts. These differences were greatly diminished when the data were plotted in terms of contrast. On contrast-contrast coordinates, the data were compatible with a single linear generative model. This result is an indication that, for the naturalistic scenes used here, lightness perception depends mostly on local contrast. We further discuss that, in addition to the mean adjustments, one may find it useful to consider also the variability of an observer's adjustments in order to infer the true luminance-to-lightness mapping function.

Oleosines in sesame allergy

Methods We present the case of a 31 y.o. woman with repeated anaphylactic reactions most of them upon eating at oriental restaurants. A vast allergic study was carried out in another center ruling out allergy/intolerance to several food additives and foods. The key fact for the diagnosis was an anaphylactic reaction upon eating home-made humus made of chickpea, olive oil and sesame oil. We performed wide skin prick testing (SPT) and specific IgE (both CAP and ISAC) for nuts, legumes, and sesame seed (commercial extract, natural raw sesame seed) as well as prick test, prick-prick, and prick patch with sesame oil, and open food challenge test (OFCT) with sesame seed.

A Bayesian model of lightness perception that incorporates spatial variation in the illumination.

The lightness of a test stimulus depends in a complex manner on the context in which it is viewed. To predict lightness, it is necessary to leverage measurements of a feasible number of contextual configurations into predictions for a wider range of configurations. Here we pursue this goal, using the idea that lightness results from the visual system's attempt to provide stable information about object surface reflectance. We develop a Bayesian algorithm that estimates both illumination and reflectance from image luminance, and link perceived lightness to the algorithm's estimates of surface reflectance. The algorithm resolves ambiguity in the image through the application of priors that specify what illumination and surface reflectances are likely to occur in viewed scenes. The prior distributions were chosen to allow spatial variation in both illumination and surface reflectance. To evaluate our model, we compared its predictions to a data set of judgments of perceived lightness of test patches embedded in achromatic checkerboards (Allred, Radonjić, Gilchrist, & Brainard, 2012). The checkerboard stimuli incorporated the large variation in luminance that is a pervasive feature of natural scenes. In addition, the luminance profile of the checks both near to and remote from the central test patches was systematically manipulated. The manipulations provided a simplified version of spatial variation in illumination. The model can account for effects of overall changes in image luminance and the dependence of such changes on spatial location as well as some but not all of the more detailed features of the data.

Food Protein-induced Enterocolitis Syndrome: Insights from Review of a Large Referral Population

Food protein-induced enterocolitis (FPIES) is a rare non-IgE mediated disease. Most studies have been limited in nature, with the largest cohort being 66 patients. The most common foods that have been reported are milk and soy. A retrospective chart review of patients seen in the Allergy Section at The Children's Hospital of Philadelphia with International Classification of Diseases Ninth Revision code of 558.3 (Allergic Gastroenteritis and Colitis) between 2007 and 2012 was conducted to identify patients with suspected FPIES. Diagnosis of FPIES was confirmed based on meeting clinical criteria of delayed reaction with pronounced vomiting and/or diarrhea. Data regarding patient characteristics and features of their reactions were collected for analysis and comparison with existing studies. A total of 462 cases were identified in our chart review. Patients had a similar demographic profile to the normal allergy patients seen in our clinic. The most common foods identified were milk (67%), soy (41%), rice (19%), oat (16%), and egg (11%). Patients had onset of FPIES to milk and soy around 7 months of age compared with 12 months of age for solid foods. FPIES reactions were identified to meats, tree nuts, peanuts, fruits, and vegetables; 70% of the patients reacted to one or two foods. Skin prick testing and atopy patch testing were not helpful in identifying the foods. FPIES reactions were seen more frequently than previously described. However, the presentation and clinical features were similar to previous reports. Milk- and soy-triggered FPIES were common, and 43.5% of patients who had a milk trigger reacted to soy. There is no laboratory test to identify foods that cause FPIES, and clinician-supervised oral food challenge is the only definitive test available.

39 Evaluation of the Nanoduct sweat test method after newborn screening for cystic fibrosis

Objectives: The approved methods for sweat testing, Gibson-Cooke Pilocarpine Iontophoresis (GCQPIT) or the Wescor Macroduct® Sweat Test system, have many steps that can and do lead to errors. The GCQPIT method is 54 years old, was never intended for newborns, has scared parents and burned infants. Thus, there is a critical need to improve sweat testing technology. Methods: The CF Quantum® Sweat Test (CFQT) System consists of: a. a controller and electrode set that is worn on the arm for pilocarpine iontophoresis; b. a chloride test patch that collects the sample. Chloride ions in the sweat sample come into contact with silver chromate in the test patch, and an ion exchange reaction occurs which creates silver chloride, an insoluble white precipitate formed in the center of the patch; c. a CF Analyzer utilizes a camera and proprietary software that scans the reacted chloride test patch and calculates the concentration of chloride and volume of sweat collected. Herein are preliminary results of a multicenter study. Patients with a previous diagnosis of CF or referred to the sweat testing lab had bilateral GCQPIT or Macroduct® and bilateral CFQT tests performed. Thus far, 57 subjects with a known diagnosis of CF and 56 subjects referred to the sweat test lab have had both tests performed. There is excellent agreement of sweat chloride values between GCQPIT/Macroduct® and CFQT with a Pearson correlation coefficient of r = 0.97. In a post-test questionnaire, 85% of parents/patients preferred the CFQT. Conclusion: The CFQT yields sweat chloride values that are equivalent to that of GCQPIT/Macroduct sweat testing. Supported by: Legacy of Angels Foundation, PolyChrome Medical, Inc.

Retinal mesopic adaptation model for brightness perception under transient glare

A glare source in the visual field modifies the brightness of a test patch surrounded by a mesopic background. In this study, we investigated the effect of two levels of transient glare on brightness perception for several combinations of mesopic reference test luminances (Lts) and background luminances (Lbs). While brightness perception was affected by Lb, there were no appreciable effects for changes in the Lt. The highest brightness reduction was found for Lbs in the low mesopic range. Considering the main proposal that brightness can be inferred from contrast and the Lb sets the mesopic luminance adaptation, we hypothesized that contrast gain and retinal adaptation mechanisms would act when a transient glare source was present in the visual field. A physiology-based model that adequately fitted the present and previous results was developed.

Our perspective of the treatment of naevus of Ota with 1,064-, 755- and 532-nm wavelength lasers

Naevus of Ota (NO) is a disfiguring pigmentary disorder affecting the face. Q-switched neodymium-doped yttrium aluminium garnet (QS Nd:YAG)-1,064 nm is a standard laser treatment because it causes highly selective destruction of melanin within the aberrant dermal melanocytes. However, not all lesions respond. This study aims to evaluate the efficacy/safety of QS Nd:YAG-1,064 nm and the shorter wavelength QS Alexandrite-755 nm and QS Nd:YAG-532 nm lasers in treating NO. Data were evaluated from 21 patients treated in our laser centre from 2004 to 2012. Lesional skin was irradiated with QS-532 nm/QS-755 nm/QS-1,064 nm, with settings titrated according to responses. All received initial test patches to direct initial wavelength choice, with subsequent treatments at 3-monthly intervals until clearance/lack of further response. Laser modality was switched following repeated test patches if there was no or no sustained improvement. Two thirds of patients had ≥ 90% improvement compared to baseline photographs. In 20% of patients, QS-1,064 nm was most efficacious with 97% mean improvement. The mean improvement was 80% for those in whom QS-755 nm was superior, and 90% for QS-532 nm. Median number of overall laser treatments was 8 (range 4-13). Number of treatments required varied significantly according to lesional colour and site: grey lesions and those on the forehead/temple were most resistant. We confirm successful treatment of NO with QS Nd:YAG-1,064 nm and the shorter wavelength QS-755 nm/QS-532 nm lasers without serious or irreversible side effects. We recommend judicious test patch analysis before treatment and a modality switch if complete clearance is not obtained.