In vitro and in vivo evaluation of anti-inflammatory agents using nanoengineered alginate carriers: towards localized implant inflammation suppression

The aim of this research was to develop nanoengineered alginate microspheres for localized delivery of anti-inflammatory drugs (dexamethasone and diclofenac sodium) for implantable "Smart tattoo" glucose biosensor used for continuous glucose monitoring. The formulation was prepared and characterized for in vitro drug release from uncoated and polyelectrolyte-coated microparticles. Biocompatibility was then tested using L929 cell-line; pilot in vivo studies with Sprague-Dawley (SD) rat subjects were performed to test the suppression of inflammation and fibrosis associated with implantation and was analyzed using standard hematoxylin and eosin staining method. The drug-loaded microspheres were able to deliver the drug for 30 days at a controlled rate with zero-order kinetics. The layer-by-layer self-assembly technique was used to effectively limit the burst release of drug from the matrix. Cell culture studies prove that the material are not cytotoxic and showed acceptable >80% cell viability in all the tested samples. In vivo studies show that both drugs were successful in controlling the implant/tissue interface by suppressing inflammation at the implant site. It was clearly evident that the combined approach of drug loaded carriers along with implanted biosensor shows promise in improving sensor biocompatibility and functionality. Thus, suggesting potential application of alginate microspheres as "smart-tattoo" glucose sensors.     

Relationship between aggregation properties and antimicrobial activities of alkylphosphocholines with branched alkyl chains

Synthesis of five alkylphosphocholines with branched alkyl chains (Isophol-PCs) with different length of alkyl chains was described. Isophol₈-PC and Isophol₁₂-PC represent new compounds. The physico-chemical properties of Isophol-PCs were determined, critical micelle concentration and types of formed aggregates in aqueous solutions were investigated. The biological activities of Isophol-PCs have been studied for the first time in the present study. Antimicrobial activities of alkylphosphocholines were studied against bacteria (Staphylococcus aureus, Escherichia coli), yeast (Candida albicans) and pathogenic free-living amoebae (Acanthamoeba lugdunensis and Acanthamoeba quina). A. lugdunensis and A. quina are relatively insusceptible to action of miltefosine (standard compound of alkylphosphocholines) and therefore they are good models for studies of amoebicidal action of the investigated compounds. Relationship between structure, physico-chemical and biological activities of Isophol-PCs was discussed. S. aureus and C. albicans were sensitive to action of Isophol₁₆-PC, Isophol₂₀-PC. E. coli was not sensitive to action of all studied alkylphosphocholines in the concentrations equal to, or less than 10 mM. Among all the synthesized compounds, Isophol₁₆-PC had the highest level of activity against both strains of Acanthamoeba. The minimum trophocidal concentrations of Isophol₁₆-PC against A. lugdunensis and A. quina are about four times lower than the minimum trophocidal concentrations of miltefosine against booth strains.     

Exhaustion of tumor-specific CD8⁺ T cells in metastases from melanoma patients

In chronic viral infections, CD8⁺ T cells become functionally deficient and display multiple molecular alterations. In contrast, only little is known of self- and tumor-specific CD8⁺ T cells from mice and humans. Here we determined molecular profiles of tumor-specific CD8⁺ T cells from melanoma patients. In peripheral blood from patients vaccinated with CpG and the melanoma antigen Melan-A/MART-1 peptide, we found functional effector T cell populations, with only small but nevertheless significant differences in T cells specific for persistent herpesviruses (EBV and CMV). In contrast, Melan-A/MART-1–specific T cells isolated from metastases from patients with melanoma expressed a large variety of genes associated with T cell exhaustion. The identified exhaustion profile revealed extended molecular alterations. Our data demonstrate a remarkable coexistence of effector cells in circulation and exhausted cells in the tumor environment. Functional T cell impairment is mediated by inhibitory receptors and further molecular pathways, which represent potential targets for cancer therapy.     

Academy of Nutrition and Dietetics Benchmarks for Nutrition in Child Care 2011: Are Child-Care Providers across Contexts Meeting Recommendations?

The Academy of Nutrition and Dietetics (Academy) recommends feeding practices for child-care providers to establish nutrition habits in early childhood to prevent obesity. With >12 million US children in child care, little is known about child-care providers’ feeding practices. The purpose of this study was to examine child-care providers’ feeding practices to assess whether providers met the Academy’s benchmarks and whether attainment of benchmarks varied across child-care contexts (Head Start, Child and Adult Care Food Program [CACFP], and non-CACFP). Cross-sectional data was collected in 2011 and 2012 from 118 child-care providers who completed self-administered surveys regarding their feeding practices for 2- to 5-year-old children. χ² tests and analysis of variance were used to determine variation across contexts. Head Start providers sat more frequently with children during meals (P=0.01), ate the same foods as children (P=0.001), and served meals family style (P<0.0001) more often compared with CACFP and non-CACFP providers. Head Start providers (P=0.002), parents (P=0.001), and children (P=0.01) received more nutrition-education opportunities compared with CACFP and non-CACFP. Head Start providers encouraged more balance and variety of foods (P<0.05), offered healthier foods (P<0.05), modeled healthy eating (P<0.001), and taught children about nutrition (P<0.001) compared with CACFP and non-CACFP providers. Providers across all three contexts used significantly more non-internal than internal mealtime verbal comments (P<0.0001). Head Start providers had greater compliance with the Academy’s benchmarks compared with CACFP and non-CACFP providers. Possible reasons for this compliance might be attributed to Head Start nutrition performance standards and increased nutrition-training opportunities for Head Start staff. Head Start programs can serve as a model in implementing the Academy’s benchmarks.     

Measuring agreement between rating interpretations and binary clinical interpretations of images: a simulation study of methods for quantifying the clinical relevance of an observer performance paradigm

Laboratory receiver operating characteristic (ROC) studies, that are often used to evaluate medical imaging systems, differ from 'live' clinical interpretations in several respects which could compromise their clinical relevance. The aim was to develop methodology for quantifying the clinical relevance of a laboratory ROC study. A simulator was developed to generate ROC ratings data and binary clinical interpretations classified as correct or incorrect for a common set of images interpreted under clinical and laboratory conditions. The area under the trapezoidal ROC curve (AUC) was used as the laboratory figure-of-merit and the fraction of correct clinical decisions as the clinical figure-of-merit. Conventional agreement measures (Pearson, Spearman, Kendall and kappa) between the bootstrap-induced fluctuations of the two figures of merit were estimated. A jackknife pseudovalue transformation applied to the figures of merit was also investigated as a way to capture agreement existing at the individual image level that could be lost at the figure-of-merit level. It is shown that the pseudovalues define a relevance-ROC curve. The area under this curve (rAUC) measures the ability of the laboratory figure-of-merit-based pseudovalues to correctly classify incorrect versus correct clinical interpretations. Therefore, rAUC is a measure of the clinical relevance of an ROC study. The conventional measures and rAUC were compared under varying simulator conditions. It was found that design details of the ROC study, namely the number of bins, the difficulty level of the images, the ratio of disease-present to disease-absent images and the unavoidable difference between laboratory and clinical performance levels, can lead to serious underestimation of the agreement as indicated by conventional agreement measures, even for perfectly correlated data, while rAUC showed high agreement and was relatively immune to these details. At the same time rAUC was sensitive to factors such as intrinsic correlation between the laboratory and clinical decision variables and differences in reporting thresholds that are expected to influence agreement both at the individual image level and at the figure-of-merit level. Suggestions are made for how to conduct relevance-ROC studies aimed at assessing agreement between laboratory and clinical interpretations. The method could be used to evaluate the clinical relevance of alternative scalar figures of merit, such as the sensitivity at a predifined specificity.