HaCaT Keratinocytes Response on Antimicrobial Atelocollagen Substrates: Extent of Cytotoxicity, Cell Viability and Proliferation

The effective and widely tested biocides: Benzalkonium chloride, bronopol, chitosan, chlorhexidine and irgasan were added in different concentrations to atelocollagen matrices. In order to assess how these antibacterial agents influence keratinocytes cell growth, cell viability and proliferation were determined by using MTT assay. Acquired data indicated a low toxicity by employing any of these chemical substances. Furthermore, cell viability and proliferation were comparatively similar to the samples where there were no biocides. It means that regardless of the agent, collagen-cell-attachment properties are not drastically affected by the incorporation of those biocides into the substrate. Therefore, these findings suggest that these atelocollagen substrates enhanced by the addition of one or more of these agents may render effectiveness against bacterial stains and biofilm formation, being the samples referred to herein as “antimicrobial substrates” a promising view in the design of novel antimicrobial biomaterials potentially suitable for tissue engineering applications.

Polyphenolic extracts of edible flowers incorporated onto atelocollagen matrices and their effect on cell viability

The phenolic extract of chives flowers (Allium schoenoprasum, Liliaceae), introduced Sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale, Asteraceae) were characterised by High Performance Liquid Chromatography and incorporated in different concentrations onto atelocollagen thin films. In order to assess the biological impact of these phenolic compounds on cell viability, human immortalised non-tumorigenic keratinocyte cell line was seeded on the thin films and cell proliferation was determined by using an MTT assay. In addition, their antimicrobial activity was estimated by using an agar diffusion test. Data indicated the concomitance between cell viability and concentration of polyphenols. These findings suggest that these phenolic-endowed atelocollagen films might be suitable for tissue engineering applications, on account of the combined activity of polyphenols and collagen.

Feeding habits and trophic ecology of Dasyatis longa (Elasmobranchii: Myliobatiformes): sexual, temporal and ontogenetic effects

Sexual, ontogenic and temporal effects in the diet of Dasyatis longa were evaluated to determine feeding habits and trophic ecology. Numeric indices and the index of relative importance were applied to establish the feeding strategy of the species. Independence of the diet with respect to sex, dry or rainy season and size was evaluated with contingency tables, correspondence analysis and multivariate analysis (MANOVA). The trophic relationships of D. longa (by sex and size intervals) were determined using Levin's niche breadth index and the Pianka's diet overlap index and their significance was determined by null models. The trophic level for each size interval and the species was also calculated. Dasyatis longa showed a narrow niche breadth feeding mainly on shrimps and fishes and its diet was dependent on size, but not on sex or season. Juvenile individuals (class I) fed on shrimps, sub-adults (class II) on fishes and adults (class III) on stomatopods. Significant overlaps between size classes I and II and classes II and III were found. The trophic level shows D. longa to be a secondary or tertiary consumer. Due to considerable fishing pressures on shrimps, the principal prey of D. longa, it will be important to determine their ability to adapt to changes in prey populations.

[Validity and reliability of the QOLIE-10 instrument for assessing health related quality of life in epilepsy of refractory epilepsy adult patients at a Colombian neurological center]

AIM

To determine feasibility, reliability and validity of the shortened version of the Quality of Life in Epilepsy Inventory-10 (QOLIE-10) in a population of refractory epilepsy adult patients in the Colombian Caribbean.

PATIENTS AND METHODS

Data were collected from 63 adult refractory epilepsy patients. The ten items of QOLIE-10 were derived from the Spanish version of QOLIE-89. We assess feasibility, validity, factorial analysis with communalities, reliability through internal consistency and sensitivity to change.

RESULTS

Clinical and demographic features were determined; quality of life was established through frequencies. Construct validity: through factor analysis communalities there were no items considered irrelevant and were grouped into one single dimension. Kaiser-Meyer-Olkin: 0.891. Bartlett's test of sphericity: p < 0.001. Average intraclass correlation coefficient 0.843. The internal consistency reliability coefficient (Cronbach's alpha) was 0.98. The QOLIE-10 questionnaire for the assessment of health-related quality of life was validated in Spanish for adult patients with refractory epilepsy with excellent validity, reliability parameters and easy, quick filling.

CONCLUSIONS

The QOLIE-10 questionnaire is a valid and reliable tool for use in adult patients with refractory epilepsy in Colombia. Health professionals are encouraged to use this questionnaire to routinely examine the influences of the disease process in epilepsy patients.