GlutenTox® Pro Test for the Detection of Gluten in Select Foods and Surfaces

The GlutenTox® Pro Test is an immunochromatographic test for the detection of gluten in foods and on surfaces with varying compositions and levels of processing, from raw foods/ingredients to final product testing. The Method Developer evaluation for the validation of the GlutenTox Pro Test Kit (Biomedal Diagnostics, Sevilla, Spain) for the detection of gluten in foods and on surfaces was conducted at Biomedal, S. L., Camas, Sevilla, Spain. The GlutenTox Pro test method was evaluated by testing the following: cross-reactivity, interference, specificity and sensitivity, robustness, stability, lot-to-lot variation, food matrix, and environmental surface. To evaluate the performance of the GlutenToxPro test for the detection of gluten, 10 matrixes were selected: rice flour, bread/biscuit, rolled oat, pâté, and yogurt (and a second bread matrix for incurred sampled testing) for the food matrix study and food-grade painted wood, plastic, rubber, sealed ceramic, and stainless steel for the environmental surface matrix study. For the food matrix study, 30 replicates were evaluated at six spiked levels of gluten (0, 3, 8, 15, 25, and 45 ppm) against four detection thresholds (5, 10, 20, and 40 ppm) for each food matrix. Additionally, 10 replicates were evaluated at a concentration of 10,000 ppm using all four detection thresholds only for rice flour matrix. Three replicates of each concentration level of gluten were analyzed using paired samples by the AOAC OMA 2012.01 reference method for each food matrix. For the environmental surface study, 30 replicates were evaluated at a low spike level of gluten (16 ng/16 cm2), five replicates at a high spike level of gluten (400 ng/16 cm2), and five replicates at an unspiked control level (0 ng/16 cm2) for each surface matrix. Upon completion of testing, the probability of detection values and confidence intervals were calculated and plotted versus the concentration level as determined by the reference method when applicable. An independent laboratory evaluation of the GlutenTox Pro Test Kit with rice flour and stainless steel environmental surface was conducted at Q Laboratories, Inc. (Cincinnati, OH). The GlutenTox Pro Test Kit demonstrated reliability as an effective rapid method for the detection of gluten in food matrixes (LOD 5 ppm gluten; threshold limits 5, 10, 20, and 40 ppm gluten) and on environmental surfaces (amount of detection 16 ng/16 cm2).

Firmness prediction in Prunus persica 'Calrico' peaches by visible/short-wave near infrared spectroscopy and acoustic measurements using optimised linear and non-linear chemometric models

BACKGROUND

In this work, near infrared spectroscopy (NIR) and an acoustic measure (AWETA) (two non-destructive methods) were applied in Prunus persica fruit 'Calrico' (n = 260) to predict Magness-Taylor (MT) firmness.

METHODS

Separate and combined use of these measures was evaluated and compared using partial least squares (PLS) and least squares support vector machine (LS-SVM) regression methods. Also, a mutual-information-based variable selection method, seeking to find the most significant variables to produce optimal accuracy of the regression models, was applied to a joint set of variables (NIR wavelengths and AWETA measure).

RESULTS

The newly proposed combined NIR-AWETA model gave good values of the determination coefficient (R(2)) for PLS and LS-SVM methods (0.77 and 0.78, respectively), improving the reliability of MT firmness prediction in comparison with separate NIR and AWETA predictions. The three variables selected by the variable selection method (AWETA measure plus NIR wavelengths 675 and 697 nm) achieved R(2) values 0.76 and 0.77, PLS and LS-SVM.

CONCLUSION

These results indicated that the proposed mutual-information-based variable selection algorithm was a powerful tool for the selection of the most relevant variables.

Optical behavior of dental zirconia and dentin analyzed by Kubelka-Munk theory

OBJECTIVES

To use the Kubelka-Munk theory to evaluate the scattering (S), absorption (K) and transmittance (T) of non-colored and colored dental zirconia systems and human (HD) and bovine (BD) dentins.

METHODS

Two zirconia systems were used: ZC- ZirCAD (Ivoclar Vivadent) and LV-LAVA (3M ESPE). Specimens from each ceramic system were divided into 3 groups (n=5): ZC1 and LV1 (non-colored); ZC2 and LV2 colored to shade A1, and ZC3 and LV3 colored to shade A3. Five human and bovine anterior teeth were flattened and polished through 1200 grit SiC paper to expose the superficial buccal dentin. All samples were prepared to a final thickness of 0.5 mm. Diffuse reflectance was measured against white and black backgrounds, using a spectroradiometer in a viewing booth with D65 illuminant and d/0° geometry. S and K coefficients and T were calculated using Kubelka-Munk's equations. Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient.

RESULTS

Spectral distributions of S, K and T were wavelength dependent. The spectral behavior of S and T was similar to HD (VAF≥96.80), even though they were statistically different (p≤0.05). The spectral behavior of K was also similar to HD, except for LV1 (VAF=38.62), yet all ceramics were statistically different from HD (p≤0.05). HD and BD showed similar values of S and T (p>0.05).

SIGNIFICANCE

The dental professional should consider the optical behavior differences between the zirconia systems evaluated and the human dentin to achieve optimal esthetics in restorative dentistry.

Evaluation of small intestine grafts decellularization methods for corneal tissue engineering

Advances in the development of cornea substitutes by tissue engineering techniques have focused on the use of decellularized tissue scaffolds. In this work, we evaluated different chemical and physical decellularization methods on small intestine tissues to determine the most appropriate decellularization protocols for corneal applications. Our results revealed that the most efficient decellularization agents were the SDS and triton X-100 detergents, which were able to efficiently remove most cell nuclei and residual DNA. Histological and histochemical analyses revealed that collagen fibers were preserved upon decellularization with triton X-100, NaCl and sonication, whereas reticular fibers were properly preserved by decellularization with UV exposure. Extracellular matrix glycoproteins were preserved after decellularization with SDS, triton X-100 and sonication, whereas proteoglycans were not affected by any of the decellularization protocols. Tissue transparency was significantly higher than control non-decellularized tissues for all protocols, although the best light transmittance results were found in tissues decellularized with SDS and triton X-100. In conclusion, our results suggest that decellularized intestinal grafts could be used as biological scaffolds for cornea tissue engineering. Decellularization with triton X-100 was able to efficiently remove all cells from the tissues while preserving tissue structure and most fibrillar and non-fibrillar extracellular matrix components, suggesting that this specific decellularization agent could be safely used for efficient decellularization of SI tissues for cornea TE applications.

Investigating a novel nanostructured fibrin-agarose biomaterial for human cornea tissue engineering: rheological properties

In this work, the rheological properties of the biomaterial fibrin with different agarose concentrations, used for the generation of a bioengineered human corneal stroma by tissue engineering, before and after using a nanostructuring technique, were analyzed. The transparency of these artificial human stromas was also investigated. The temporal evaluation of the properties of these biomaterials is essential for the design of functional biological human corneal replacements. The nanostructuring technique used for the generation of nanostructured corneal constructs (NCCs) had a major influence on the rheological properties of the fibrin-agarose corneal equivalents. For an oscillatory shear stress of 1 Hz, well in the order of the natural oscillations of the human cornea, the NCCs had viscoelasticity values higher than those of non-nanostructured corneal constructs (N-NCCs), but similar to those of an ex vivo native cornea. The model that most resembled the rheological behavior of the native cornea was a fibrin-0.1% agarose concentration nanostructured construct. In addition, this artificial cornea model displayed optimal levels of transparency, similar to the native tissue. All these properties indicate that the fibrin-0.1% agarose concentration nanostructured construct might serve as an adequate candidate for the generation of an artificial complete cornea, not only for transplanting use but also for conducting pharmaceutical testing and biomedical research.

Prediction of color change after tooth bleaching using fuzzy logic for Vita Classical shades identification

Tooth bleaching is becoming increasingly popular among patients and dentists since it is a relatively noninvasive approach for whitening and lightening teeth. Instruments and visual assessment with respect to commercial shade guides are currently used to evaluate tooth color. However, the association between these procedures is imprecise and the degree of color change after tooth bleaching is known to vary substantially between studies; there are currently no objective guidelines to predict the effectiveness of a tooth-bleaching treatment. We propose a new methodology based on fuzzy logic as a natural means of representing the imprecision present when modeling the color change produced by a tooth-bleaching treatment on the basis of a tooth's initial chromatic values. This system has the advantage of producing a set of interpretable fuzzy rules that can subsequently be used by scientists and dental practitioners. The fuzzy system obtained has the special characteristic whereby the rule antecedents correspond to prebleaching shades of the well-known Vita commercial shade guide. Additionally, the rule consequents directly correspond with the expected CIELAB postbleaching values for each Vita shade, thanks to a modification of the system's inference structure. Finally, the values of these postbleaching CIELAB coordinates have been associated with Vita shades by evaluating their respective membership functions, thereby approximating which posttreatment Vita shades are to be expected for each prebleaching shade.

Stability and reproducibility of radiometric properties of light curing units (LCUs). Part I: QTH LCUs

The present study, divided into two parts, analyses the stability and reproducibility of the spectral and energy emission of the present light-curing units (LCUs), quartz tungsten halogen (QTH) and light-emitting diodes (LEDs). In part I, QTH LCUs were studied. The results showed that the QTH LCUs studied presented high stability and reproducibility in terms of their spectral emission with VAF (variance accounting for) values from the Cauchy-Schwarz inequality, all close to 100%. With respect to the energy stability, the QTH LCUs studied can be considered stable under practical clinical conditions, although for some devices the initial irradiance value is critical. This result should be taken into account in those works which is researched in polymerization kinetics of dental materials as well as in clinical practice.

Study of the Variation between CIELAB .DELTA.E* and CIEDE2000 Color-differences of Resin Composites

This study sought to assess the significance of the corrections introduced in the new CIEDE2000 color difference formula with respect to deltaE*ab. The purpose of which was to provide sounder knowledge, and hence more informed decision-making, about applying this new formula to dental resin composites. With two different hybrid composites, color differences were calculated between unpolymerized and polymerized resin composites, between polymerized resin composites of different thicknesses (1 and 2 mm), and between polymerized resin composites cured with halogen and LED light curing units (LCUs). The two formulas differed significantly, with VAB(E) (equal size) values higher than the inter-observer variability (VAB (E)=11%) and VAB(O) (original size) values greater than 25% for each of the data sets analyzed. Results obtained in this study agreed with and thus supported the recent recommendation of the Commission Internationale de l'Eclairage (CIE), whereby the new CIEDE2000 formula should be used to evaluate color differences of resin composites.

[Socioeconomic inequalities in the provision and uptake of prenatal care]

OBJECTIVE

To describe socioeconomic inequalities in the provision and uptake of prenatal care among women in Barcelona (Spain) between 1994 and 2003.

METHODS

Cross-sectional study of women in Barcelona who delivered a child without birth defects. Information was obtained from hospital medical records and a personal interview with women included in the Barcelona Birth Defects Registry, containing a random sample of 2% of all pregnant women in the city (n = 2299).

DEPENDENT VARIABLES

number of obstetric visits, the trimester of the first visit, the number of obstetric ultrasound scans, the fifth-month diagnostic ultrasound scan, invasive procedures, prenatal folic acid intake, pregnancy planning, smoking and smoking cessation. The independent variables were maternal age and social class. Logistic regression models were filted for each dependent variable.

RESULTS

In social classes with manual occupations, there was a higher proportion of pregnant women who attended less than six obstetric visits and who attended the first obstetric visit after the first trimester. Moreover, these women were less likely to have undergone an invasive procedure, to have taken folic acid supplements, to have planned the pregnancy, to be non-smokers and to stop smoking. In the more privileged classes, there was a higher proportion of women who attended more than 12 obstetric visits and who underwent more than three ultrasound scans.

CONCLUSIONS

Socioeconomic inequalities were found in the provision and uptake of prenatal care in Barcelona. Uptake was greater in the more advantaged social classes but excessive medicalization was found in all classes. Rationalizing the use of healthcare resources and reducing excessive medicalization would reduce inequalities in prenatal care in Barcelona.