Electroencephalographic study showing that tactile stimulation by fabrics of different qualities elicit graded event-related potentials.

BACKGROUND/PURPOSE: Neurophysiologic data on reactions of the human brain towards tactile stimuli evoked by fabrics moved on the skin are scarce. Furthermore, evaluation of fabrics' pleasantness using questionnaires suffers subjective biases. That is why we used a 64-channel electroencephalography (EEG) to objectively evaluate real-time brain reactions to fabric-skin interactions. METHODS: Tactile stimuli were triggered by selected fabrics of different qualities, i.e. modal/polyamide single jersey, cotton double rib and a jute fabric, applied hidden to either the palm or forearm of 24 subjects via a custom-made fabric-to-skin applicator called SOFIA. One-way anova analysis was carried out to verify the EEG data. RESULTS: The modal/polyamide fabric applied to the forearm and palm led to slightly stronger emotional valence scores in the brain than the conventional or baseline fabric. Furthermore, the single jersey elicits significant higher event-related potential (ERP) signals in all subjects when applied to the forearm, suggesting less distraction and better cognitive resources during the fabric/skin interaction. The brain thus reacts with instantaneous ERP to tactile stimulation of fabrics and is able to discriminate different qualities via implicit preferences. CONCLUSION: The test procedure described here may be a tool to evaluate the fabric feel with the exclusion of subjective biases.

Adipogenic differentiation of scaffold-bound human adipose tissue-derived stem cells (hASC) for soft tissue engineering.

Adipose tissue engineering, instead of tissue substitution, often uses autologous adipose tissue-derived stem cells (hASC). These cells are known to improve graft integration and to support neovascularization of scaffolds when seeded onto biomaterials. In this study we thought to engineer adipose tissue using scaffold-bound hASC, since they can be differentiated into the adipocyte cell lineage and used for soft tissue regeneration. We show here by microscopy and gene expression of the peroxysome proliferator-activated receptor gene (PPARγ2) that hASC growing on polypropylene fibrous scaffolds as well as on three-dimensional nonwoven scaffolds can be turned into adipose tissue within 19 days. Freshly isolated hASC displayed a higher differentiation potential than hASC cultured for eight passages. In addition, we proved a modified alginate microcapsule to directly induce adipogenic differentiation of incorporated hASC. The results may help to improve long-term success of adipose tissue regeneration, especially for large-scale soft tissue defects, and support the development of cell-scaffold combinations which can be shaped individually and directly induce the adipogenic differentiation of incorporated hASC at the site of implantation.

A model of the transmission of micro-organisms in a public setting and its correlation to pathogen infection risks.

AIM: Gastro-intestinal infections are widespread in the community and have considerable economic consequences. In this study, we followed chains of infection from a public toilet scenario, looking at infection risks by correlating the transmission of bacteria, fungi and viruses to our current knowledge of infectious doses. METHODS AND RESULTS: Transmission of Escherichia coli, Bacillus atrophaeus spores, Candida albicans and bacteriophage MS2 from hands to surfaces was examined in a transmission model, that is toilet brush, door handle to water tap. The load of viable pathogens was significantly reduced during transfer from hands to objects. Nevertheless, it was shown that pathogens were successfully transferred to other people in contagious doses by contact with contaminated surfaces. CONCLUSIONS: Our results suggest that infection risks are mainly dependent on current infectious doses of pathogens. For enteritic viruses or bacteria, for example Norovirus or EHEC, only a few particles or cells are sufficient for infection in public lavatories, thus bearing a high risk of infection for other persons. However, there seems to be only a low probability of becoming infected with pathogens that have a high infectious dose whilst sharing the same bathroom. SIGNIFICANCE AND IMPACT OF THE STUDY: The transmission model for micro-organisms enables a risk assessment of gastro-intestinal infections on the basis of a practical approach.