Silver absorption on burns after the application of Acticoat : data from pediatric patients and a porcine burn model

Silver dressings have been widely used to successfully prevent burn wound infection and sepsis. However, a few case studies have reported the functional abnormality and failure of vital organs, possibly caused by silver deposits. The aim of this study was to investigate the serum silver level in the pediatric burn population and also in several internal organs in a porcine burn model after the application of Acticoat. A total of 125 blood samples were collected from 46 pediatric burn patients. Thirty-six patients with a mean of 13.4% TBSA burns had a mean peak serum silver level of 114 microg/L, whereas 10 patients with a mean of 1.85% TBSA burns had an undetectable level of silver (<5.4 microg/L). Overall, serum silver levels were closely related to burn sizes. However, the highest serum silver was 735 microg/L in a 15-month-old toddler with 10% TBSA burns and the second highest was 367 microg/L in a 3-year old with 28% TBSA burns. In a porcine model with 2% TBSA burns, the mean peak silver level was 38 microg/L at 2 to 3 weeks after application of Acticoat and was then significantly reduced to an almost undetectable level at 6 weeks. Of a total of four pigs, silver was detected in all four livers (1.413 microg/g) and all four hearts (0.342 microg/g), three of four kidneys (1.113 microg/g), and two of four brains (0.402 microg/g). This result demonstrated that although variable, the level of serum silver was positively associated with the size of burns, and significant amounts of silver were deposited in internal organs in pigs with only 2% TBSA burns, after application of Acticoat.

The evaluation of a clinical scar scale for porcine burn scars

This study describes the evaluation of a clinical scar scale for our porcine burn scars, which includes scar cosmetic outcome, colour, height and hair, supplemented with reference porcine scar photographs representing each scar outcome and scar colour scores. A total of 72 porcine burn scars at week 6 after burn were rated in vivo and/or on photographs. Good agreements were achieved for both intra-rater reliability (correlation is 0.86-0.98) and inter-rater reliability (ICC=80-85%). The results showed statistically significant correlations for each pair in this clinical scar scale (p<0.01), with the best correlation found between scar cosmetic outcome and scar colour. A multivariate principle components analysis revealed that this clinical scar assessment was highly correlated with scar histology, wound size, and re-epithelialisation data (p<0.001). More severe scars are clinically characterised by darker purple colouration, more elevation, no presence of hair, histologically by thicker scar tissue, thinner remaining normal dermis, are more likely to have worse contraction, and slower re-epithelialisation. This study demonstrates that our clinical scar scale is a reliable, independent and valuable tool for assessing porcine burn outcome and truthfully reflects scar appearance and function. To our knowledge, this is the first study demonstrating a high correlation between clinical scar assessment and scar histology, wound contraction and re-epithelialisation data on porcine burn scars. We believe that the successful use of porcine scar scales is invaluable for assessing potential human burn treatments.

Burn healing is dependent on burn site : a quantitative analysis from a porcine burn model

This retrospective review examines healing in different sites on a porcine burn model; 24 pairs of burns on 18 pigs from other animal trials were selected for analysis. Each pair of burns was located on the either the cranial or the caudal part of the thoracic ribs region, on the same side of the animal. The burns were 40-50 cm(2) in size and of uniform deep-dermal partial thickness. Caudal burns healed significantly better than cranial burns, demonstrated by earlier closure of wounds, less scar formation and better cosmesis. To our knowledge, this is the first detailed study reporting that burn healing is affected by location on a porcine burn model. We recommend that similar symmetrical burns should be used for future comparative assessments of burn healing.

High-level expression of Rhodotorula gracilis d-amino acid oxidase in Pichia pastoris

By combining gene design and heterologous over-expression of Rhodotorula gracilis D-amino acid oxidase (RgDAO) in Pichia pastoris, enzyme production was enhanced by one order of magnitude compared to literature benchmarks, giving 350 kUnits/l of fed-batch bioreactor culture with a productivity of 3.1 kUnits/l h. P. pastoris cells permeabilized by freeze-drying and incubation in 2-propanol (10% v/v) produce a highly active (1.6 kUnits/g dry matter) and stable oxidase preparation. Critical bottlenecks in the development of an RgDAO catalyst for industrial applications have been eliminated.

Development and characterization of a novel, antimicrobial, sterile hydrogel dressing for burn wounds : single-step production with gamma irradiation creates silver nanoparticles and radical polymerization

Patients with burn wounds are susceptible to wound infection and sepsis. This research introduces a novel burn wound dressing that contains silver nanoparticles (SNPs) to treat infection in a 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na(+) ) hydrogel. Silver nitrate was dissolved in AMPS-Na(+) solution and then exposed to gamma irradiation to form SNP-infused hydrogels. The gamma irradiation results in a cross-linked polymeric network of sterile hydrogel dressing and a reduction of silver ions to form SNPs infused in the hydrogel in a one-step process. About 80% of the total silver was released from the hydrogels after 72 h immersion in simulated body fluid solution; therefore, they could be used on wounds for up to 3 days. All the hydrogels were found to be nontoxic to normal human dermal fibroblast cells. The silver-loaded hydrogels had good inhibitory action against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Results from a pilot study on a porcine burn model showed that the 5-mM silver hydrogel was efficient at preventing bacterial colonization of wounds, and the results were comparable to the commercially available silver dressings (Acticoat(TM) , PolyMem Silver(®) ). These results support its use as a potential burn wound dressing.

Cytotoxicity testing of silver-containing burn treatments using primary and immortal skin cells

A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles (silver AMPS). This study compared the cytotoxicity of this dressing to the commercially available silver products; Acticoat™, PolyMem Silver® and Flamazine™ cream. Human keratinocytes (HaCaT and primary HEK) and normal human fibroblasts (NHF) were exposed to dressings incubated on Nunc™ polycarbonate inserts for 24, 48 and 72h. Four different cytotoxicity assays were performed including; Trypan Blue cell count, MTT, Celltiter-Blue™ and Toluidine Blue surface area assays. The results were expressed as relative cell viability compared to an untreated control. The cytotoxic effects of Acticoat™ and Flamazine™ cream were dependent on exposure time and cell type. After 24h exposure, Acticoat™ and Flamazine™ cream were toxic to all tested cell lines. Surprisingly, HaCaTs treated with Acticoat™ and Flamazine™ had an improved ability to survive at 48 and 72h while HEKs and NHFs had no improvement in survival with any treatment. The novel silver hydrogel and PolyMem Silver® showed low cytotoxicity to all tested cell lines at every time interval and these results support the possibility of using the novel silver hydrogel as a burn wound dressing. Researchers who rely on HaCaT cells as an accurate keratinocyte model should be aware that they can respond differently to primary skin cells.

Evaluation of haemoglobin in blister fluid as an indicator of paediatric burn wound depth

The early and accurate assessment of burns is essential to inform patient treatment regimens; however, this first critical step in clinical practice remains a challenge for specialist burns clinicians worldwide. In this regard, protein biomarkers are a potential adjunct diagnostic tool to assist experienced clinical judgement. Free circulating haemoglobin has previously shown some promise as an indicator of burn depth in a murine animal model. Using blister fluid collected from paediatric burn patients, haemoglobin abundance was measured using semi-quantitative Western blot and immunoassays. Although a trend was observed in which haemoglobin abundance increased with burn wound severity, several patient samples deviated significantly from this trend. Further, it was found that haemoglobin concentration decreased significantly when whole cells, cell debris and fibrinous matrix was removed from the blister fluid by centrifugation; although the relationship to depth was still present. Statistical analyses showed that haemoglobin abundance in the fluid was more strongly related to the time between injury and sample collection and the time taken for spontaneous re-epithelialisation. We hypothesise that prolonged exposure to the blister fluid microenvironment may result in an increased haemoglobin abundance due to erythrocyte lysis, and delayed wound healing

Antimicrobial efficacy of a novel silver hydrogel dressing compared to two common silver burn wound dressings: Acticoat™ and PolyMem Silver

A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles. This study compared the antimicrobial efficacy of this novel dressing to two commercially available silver dressings; Acticoat™ and PolyMem Silver(®). Three different antimicrobial tests were used: disc diffusion, broth culture, and the Live/Dead(®) Baclight™ bacterial viability assay. Burn wound pathogens (P. aeruginosa, MSSA, A. baumannii and C. albicans) and antibiotic resistant strains (MRSA and VRE) were tested. All three antimicrobial tests indicated that Acticoat™ was the most effective antimicrobial agent, with inhibition zone lengths of 13.9-18.4mm. It reduced the microbial inocula below the limit of detection (10(2)CFU/ml) and reduced viability by 99% within 4h. PolyMem Silver(®) had no zone of inhibition for most tested micro-organisms, and it also showed poor antimicrobial activity in the broth culture and Live/Dead(®) Baclight™ assays. Alarmingly, it appeared to promote the growth of VRE. The silver hydrogel reduced most of the tested microbial inocula below the detection limit and decreased bacterial viability by 94-99% after 24h exposure. These results support the possibility of using this novel silver hydrogel as a burn wound dressing in the future

Wirtschaftssprache deutsch in studium und beruf - curriculumentwicklung an der schwedischen wirtschaftsuniversität in Finnland.

An der Schwedischen Wirtschaftsuniversität in Finnland wurde in einem mehrjährigen Projekt das gesamte deutsche Sprachcurriculum einer grundlegenden Revision unterzogen mit dem Ziel, unter Berücksichtigung der neuesten Forschungsergebnisse der angewandten Sprachwissenschaft ein zeitgemäßes und konsistentes Deutschcurriculum für Studierende der Wirtschaftswissenschaften zu schaffen. Durch das Projekt wurde für die deutsche Sprachausbildung ein deutliches Profil geschaffen, dessen Fokus auf fachkommunikativer Kompetenz und interkultureller Geschäftskommunikation liegt. Die von der Deutschabteilung entwickelten Lehr- und Lernmaterialien sind weitgehend auf der Basis eigener Forschungsergebnisse konzipiert und evaluiert worden und wurden gleichzeitig an den Gemeinsamen europäischen Referenzrahmens für Sprachen (CEFR) angepasst.

Hur mycket IKT behöver en studerande? Virtuelle kurskonzepte und ihre auswirkungen auf leistung, zufriedenheit und arbeitsstrategien

In dem vorliegenden Aufsatz wird eine vergleichende Untersuchung eines Deutschkurses (Tyska V: Interkulturelle Themen) an der Schwedischen Wirtschaftsuniversität Helsinki (Hanken) präsentiert, der im Jahr 2002 vollständig virtuell und im Jahr 2003 mit virtuellen Lernphasen und Kontaktunterricht im Wechsel realisiert wurde, wobei sich das virtuelle Kursmaterial jeweils in der Lernumgebung WebCT befand. In der Untersuchung werden die Leistungen, die Kursevaluationen und die Arbeitsstrategien der Studierenden in den beiden Kurskonzepten analysiert und miteinander verglichen. In Bezug auf die Leistungen der Studierenden hat sich gezeigt, dass die guten Studierenden in beiden Kurskonzepten gleich gute Ergebnisse erzielen. Die Untersuchung zeigt jedoch, dass der Kontaktunterricht des teils-virtuellen Kurskonzeptes gerade für die schwächeren Studierenden eine wichtige Funktion erfüllt – die schwächeren Studierenden erzielen im Kurskonzept mit Kontaktunterricht deutlich bessere Ergebnisse als die schwächeren Studierenden im ganz virtuellen Kurskonzept. Ein Vergleich der Arbeitsstrategien zeigt, dass die schwächeren Studierenden im Unterschied zu den guten Studierenden deutliche Schwierigkeiten mit dem Zeit- und Materialmanagement haben. Für die Weiterentwicklung des Kurskonzeptes sind zum einen die technischen Rahmenbedingungen zu verbessern, und zum anderen muss der Kontaktunterricht neu überdacht werden, da die Einführung des Themas Arbeitsstrategien in der virtuellen Lernumgebung als eigenständiger Themenbereich dringend notwendig erscheint.

Teología, 2004, Tomo XLI nº 084 (número completo)

Nota del Director. Advertencia sobre los números de tomos -- La “gracia del invitado”. Hacia una hermenéutica teológica del camino de Emaús – Hitos de una dogmática fundamental intercultural / Margit Eckholt -- La identidad específica del catequista / Víctor Manuel Fernández -- Nuevos escenarios y líneas emergentes en la teología católica contemporánea / Marcelo González – Navega mar adentro: expresión y proyección del reciente itinerario teológico-pastoral de la Iglesia en Argentina / Gerardo Daniel Ramos scj -- La fórmula cristológica una persona en dos naturalezas en el contexto de los sermones de San León Magno / Hernán Martín Giudice -- Algunas reflexiones en torno a la problemática “cerebro-mente” / Juan Demetrio Jiménez -- La integración de la exégesis en la reflexión teológica / Luis Heriberto Rivas -- Luis Heriberto Rivas: un sembrador de la Palabra / Carlos M. Galli -- Laudatio / Julio Raúl Méndez -- Notas bibliográficas

Espacios de paz : nuevos caminos de teologías interculturales de la paz

Resumen: Los múltiples movimientos de migración causados por la guerra, la violencia, la pobreza y las diversas violaciones de los derechos humanos son signos de nuestro tiempo. Históricamente, el término “paz” se asocia con la libertad y el espacio habitable de la ciudad. ¿Qué significa hablar de “paz” en un mundo en el cual las ciudades, espacios de libertad y seguridad, se tornan cada vez más fracturadas e incluso destruidas? Con este trasfondo, este aporte intenta trazar pistas para una teología intercultural de la paz e ilustrar algunos “espacios de paz” creados por mujeres.

Teología, 2006, Tomo XLIII nº 090 (número completo)

Nota del Director. Renovación y diálogo -- El cristianismo y las religiones / Piero Coda -- No sin ti. El caminante herido y el Dios desconocido / Margit Eckholt -- La teología en diálogo con la cultura / Eduardo Briancesco -- América Latina y una lógica de la reconciliación / José Carlos Caamaño -- Mozart, amado de Dios / Fernando Ortega -- Balance del Primer Simposio Internacional de Teología sobre la Shoah en Argentina / Víctor Manuel Fernández -- Teología y literatura. Lenguaje y acontecimiento / Cecilia Inés Avenatti de Palumbo -- Ricardo Ferrara: Dios es espíritu, luz y amor -- Notas bibliográficas