Human organoid biofilm model for assessing antibiofilm activity of novel agents

Bacterial biofilms cause 65% of all human infections and are highly resistant to antibiotic therapy but lack specific treatments. To provide a human organoid model for studying host-microbe interplay and enabling screening for novel antibiofilm agents, a human epidermis organoid model with robust methicillin-resistant Staphylococcus aureus (MRSA) USA300 and Pseudomonas aeruginosa PAO1 biofilm was developed. Treatment of 1-day and 3-day MRSA and PAO1 biofilms with antibiofilm peptide DJK-5 significantly and substantially reduced the bacterial burden. This model enabled the screening of synthetic host defense peptides, revealing their superior antibiofilm activity against MRSA compared to the antibiotic mupirocin. The model was extended to evaluate thermally wounded skin infected with MRSA biofilms resulting in increased bacterial load, cytotoxicity, and pro-inflammatory cytokine levels that were all reduced upon treatment with DJK-5. Combination treatment of DJK-5 with an anti-inflammatory peptide, 1002, further reduced cytotoxicity and skin inflammation.Immunogenetics and cellular immunology of bacterial infectious disease

Optimized whole genome association scanning for discovery of HLA class I-restricted minor histocompatibility antigens

Patients undergoing allogeneic stem cell transplantation as treatment for hematological diseases face the risk of Graft-versus-Host Disease as well as relapse. Graft-versus-Host Disease and the favorable Graft-versus-Leukemia effect are mediated by donor T cells recognizing polymorphic peptides, which are presented on the cell surface by HLA molecules and result from single nucleotide polymorphism alleles that are disparate between patient and donor. Identification of polymorphic HLA-binding peptides, designated minor histocompatibility antigens, has been a laborious procedure, and the number and scope for broad clinical use of these antigens therefore remain limited. Here, we present an optimized whole genome association approach for discovery of HLA class I minor histocompatibility antigens. T cell clones isolated from patients who responded to donor lymphocyte infusions after HLA-matched allogeneic stem cell transplantation were tested against a panel of 191 EBV-transformed B cells, which have been sequenced by the 1000 Genomes Project and selected for expression of seven common HLA class I alleles (HLA-A*01:01, A*02:01, A*03:01, B*07:02, B*08:01, C*07:01, and C*07:02). By including all polymorphisms with minor allele frequencies above 0.01, we demonstrated that the new approach allows direct discovery of minor histocompatibility antigens as exemplified by seven new antigens in eight different HLA class I alleles including one antigen in HLA-A*24:02 and HLA-A*23:01, for which the method has not been originally designed. Our new whole genome association strategy is expected to rapidly augment the repertoire of HLA class I-restricted minor histocompatibility antigens that will become available for donor selection and clinical use to predict, follow or manipulate Graft-versus-Leukemia effect and Graft-versus-Host Disease after allogeneic stem cell transplantation.Development and application of statistical models for medical scientific researc

Specific Heat of Liquid Helium in Zero Gravity very near the Lambda Point

We report the details and revised analysis of an experiment to measure the specific heat of helium with subnanokelvin temperature resolution near the lambda point. The measurements were made at the vapor pressure spanning the region from 22 mK below the superfluid transition to 4 uK above. The experiment was performed in earth orbit to reduce the rounding of the transition caused by gravitationally induced pressure gradients on earth. Specific heat measurements were made deep in the asymptotic region to within 2 nK of the transition. No evidence of rounding was found to this resolution. The optimum value of the critical exponent describing the specific heat singularity was found to be a = -0.0127+ - 0.0003. This is bracketed by two recent estimates based on renormalization group techniques, but is slightly outside the range of the error of the most recent result. The ratio of the coefficients of the leading order singularity on the two sides of the transition is A+/A- =1.053+ - 0.002, which agrees well with a recent estimate. By combining the specific heat and superfluid density exponents a test of the Josephson scaling relation can be made. Excellent agreement is found based on high precision measurements of the superfluid density made elsewhere. These results represent the most precise tests of theoretical predictions for critical phenomena to date.Comment: 27 Pages, 20 Figure

Cryogenic design of the liquid helium experiment ``critical dynamics in microgravity``

Although many well controlled experiments have been conducted to measure the static properties of systems near criticality, few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is reported here. Measurements of the thermal gradient across the superfluid (He II) -- normal fluid (He I) interface in helium under microgravity conditions will be performed as a heat flux holds the system away from equilibrium. New technologies are under development for this experiment, which is in the definition phase for a space shuttle flight

Analysis of biomarkers and composite scores in IBD patients using probabilistic fuzzy systems

The incidence of inflammatory bowel disease (IBD) is rising worldwide. Preventing disease progression by tight monitoring of disease activity using non-invasive procedures is important to prevent disease progression. In literature composite scores, combining biomarkers and clinical activity scores, have been described which aim to detect disease activity.In this paper we analyze the components of these composite scores in a data-driven manner using probabilistic fuzzy system (PFS). In this paper, we define a specific PFS for the analysis of the relationship between the biomarker fecal calprotectin (FC), with biomarkers erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and clinical activity scores for two disease phenotypes, namely Crohn's disease and ulcerative colitis.We report the relations between these biomarkers and clinical activity scores using the proposed PFS, and show how the statistical properties of FC indicator relates to the remaining biomarkers and clinical activity scores. Furthermore, we related the findings on the clinical activity scores to the conventional thresholds used in the literature to define susceptibility of disease activity to support clinical interpretation of results. The results show that analyzing the recently available data using PFS lead to valuable information for detecting IBD disease activity where most conventional thresholds for disease indicators are in line with the data-based findings

Analysis of biomarkers and composite scores in IBD patients using probabilistic fuzzy systems

The incidence of inflammatory bowel disease (IBD) is rising worldwide. Preventing disease progression by tight monitoring of disease activity using non-invasive procedures is important to prevent disease progression. In literature composite scores, combining biomarkers and clinical activity scores, have been described which aim to detect disease activity.In this paper we analyze the components of these composite scores in a data-driven manner using probabilistic fuzzy system (PFS). In this paper, we define a specific PFS for the analysis of the relationship between the biomarker fecal calprotectin (FC), with biomarkers erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and clinical activity scores for two disease phenotypes, namely Crohn's disease and ulcerative colitis.We report the relations between these biomarkers and clinical activity scores using the proposed PFS, and show how the statistical properties of FC indicator relates to the remaining biomarkers and clinical activity scores. Furthermore, we related the findings on the clinical activity scores to the conventional thresholds used in the literature to define susceptibility of disease activity to support clinical interpretation of results. The results show that analyzing the recently available data using PFS lead to valuable information for detecting IBD disease activity where most conventional thresholds for disease indicators are in line with the data-based findings

Optimized Whole Genome Association Scanning for Discovery of HLA Class I-Restricted Minor Histocompatibility Antigens

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