Testing of antibiotic releasing implant coatings to fight bacteria in combat-associated osteomyelitis - an in-vitro study.

PURPOSE: Surgical procedures to prevent osteomyelitis after trauma can be supported by local application of antibiotics. This in-vitro study investigated the release and impact of antibiotics from implant coatings against bacteria associated with combat-related osteomyelitis. METHODS: K-wires were coated with poly(D,L-lactide) and ciprofloxacin, gentamicin, colistin, daptomycin or cefoxitin in different concentrations. The release was quantified and antimicrobial activity tested for different gram-positive or gram-negative bacteria, alone and in combination. To exclude toxic effects, primary osteoblast-like cells were exposed to antibiotic coating concentrations. RESULTS: All antibiotics alone and in combination showed an initial burst release with dose dependent antimicrobial activity and no negative effects on osteoblast-like cells, except for cefoxitin. CONCLUSIONS: Implant coatings can be customized with single or double antibiotic coatings to effectively fight different bacteria and also mixed infections in the treatment of a combat-acquired osteomyelitis. However, optimal drug load and degradation behaviour of individual antibiotics have to be considered.

Empathy in children with autism and conduct disorder: group-specific profiles and developmental aspects.

BACKGROUND: A deficit in empathy is discussed to underlie difficulties in social interaction of children with autism spectrum disorder (ASD) and conduct disorder (CD). To date, no study has compared children with ASD and different subtypes of CD to describe disorder-specific empathy profiles in clinical samples. Furthermore, little is known about age influences on the development of empathic skills. The aim of the current study was to compare cognitive and emotional empathy in different age groups of children with ASD, CD with elevated or low callous-unemotional-traits (CU+ vs. CU-) and a matched control group (CG). METHODS: Fifty-five boys with ASD, 36 boys with CD-CU+, 34 boys with CD-CU- and 67 controls were included. The study implemented three tasks on emotion recognition, perspective taking and emotional affection induced by another person's situation. Multivariate Analysis of variance with the factors group and age (median split) including their interaction term was performed to describe disorder-specific profiles. RESULTS: Empathy profiles showed differential impairment in children with ASD and CD-CU+. Boys with ASD were impaired in cognitive empathy while participants with CD-CU+ were impaired in emotional empathy. Children with CD-CU- did not differ from the CG. However, boys with CD-CU- were less emotionally reactive in response to film stimuli than children with ASD. Furthermore, we found strong age effects indicating an increase in cognitive and affective empathic skills beyond early infancy in all groups. CONCLUSIONS: In this study, distinct empathic profiles in children with ASD and CD-CU+ were found. Furthermore, the work demonstrates improvement of empathic skills throughout childhood and adolescence, which is comparable for individuals with psychiatric disorders and control children. These results yield implications for further research as well as for therapeutic interventions.

Chip-based human liver-intestine and liver-skin co-cultures--A first step toward systemic repeated dose substance testing in vitro.

Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air-liquid interface for the skin model during their co-culture with the liver equivalents respectively at (1)/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver-skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance - troglitazone - to the chip-based co-cultures.

Performance evaluation of kits for bisulfite-conversion of DNA from tissues, cell lines, FFPE tissues, aspirates, lavages, effusions, plasma, serum, and urine.

DNA methylation analyses usually require a preceding bisulfite conversion of the DNA. The choice of an appropriate kit for a specific application should be based on the specific performance requirements with regard to the respective sample material. In this study, the performance of nine kits was evaluated: EpiTect Fast FFPE Bisulfite Kit, EpiTect Bisulfite Kit, EpiTect Fast DNA Bisulfite Kit (Qiagen), EZ DNA Methylation-Gold Kit, EZ DNA Methylation-Direct Kit, EZ DNA Methylation-Lightning Kit (Zymo Research), innuCONVERT Bisulfite All-In-One Kit, innuCONVERT Bisulfite Basic Kit, innuCONVERT Bisulfite Body Fluids Kit (Analytik Jena). The kit performance was compared with regard to DNA yield, DNA degradation, DNA purity, conversion efficiency, stability and handling using qPCR, UV, clone sequencing, HPLC, and agarose gel electrophoresis. All kits yielded highly pure DNA suitable for PCR analyses without PCR inhibition. Significantly higher yields were obtained when using the EZ DNA Methylation-Gold Kit and the innuCONVERT Bisulfite kits. Conversion efficiency ranged from 98.7% (EpiTect Bisulfite Kit) to 99.9% (EZ DNA Methylation-Direct Kit). The inappropriate conversion of methylated cytosines to thymines varied between 0.9% (innuCONVERT Bisulfite kits) and 2.7% (EZ DNA Methylation-Direct Kit). Time-to-result ranged from 131 min (innuCONVERT kits) to 402 min (EpiTect Bisulfite Kit). Hands-on-time was between 66 min (EZ DNA Methylation-Lightning Kit) and 104 min (EpiTect Fast FFPE and Fast DNA Bisulfite kits). Highest yields from formalin-fixed and paraffin-embedded (FFPE) tissue sections without prior extraction were obtained using the innuCONVERT Bisulfite All-In-One Kit while the EZ DNA Methylation-Direct Kit yielded DNA with only low PCR-amplifiability. The innuCONVERT Bisulfite All-In-One Kit exhibited the highest versatility regarding different input sample materials (extracted DNA, tissue, FFPE tissue, cell lines, urine sediment, and cellular fractions of bronchial aspirates, pleural effusions, ascites). The innuCONVERT Bisulfite Body Fluids Kit allowed for the analysis of 3 ml plasma, serum, ascites, pleural effusions and urine.