Erhan Demir

The topical use of non-thermal dielectric barrier discharge (DBD): Nitric oxide related effects on human skin

Dielectric barrier discharge (DBD) devices generate air plasma above the skin containing active and reactive species including nitric oxide (NO). Since NO plays an essential role in skin physiology, a topical application of NO by plasma may be useful in the treatment of skin infections, impaired microcirculation and wound healing. Thus, after safety assessments of plasma treatment using human skin specimen and substitutes, NO-penetration through the epidermis, the loading of skin tissue with NO-derivates in vitro and the effects on human skin in vivo were determined. After the plasma treatment (0-60 min) of skin specimen or reconstructed epidermis no damaging effects were found (TUNEL/MTT). By Franz diffusion cell experiments plasma-induced NO penetration through epidermis and dermal enrichment with NO related species (nitrite 6-fold, nitrate 7-fold, nitrosothiols 30-fold) were observed. Furthermore, skin surface was acidified (~pH 2.7) by plasma treatment (90 s). Plasma application on the forearms of volunteers increased microcirculation fourfold in 1-2 mm and twofold in 6-8 mm depth in the treated skin areas. Regarding the NO-loading effects, skin acidification and increase in dermal microcirculation, plasma devices represent promising tools against chronic/infected wounds. However, efficacy of plasma treatment needs to be quantified in further studies and clinical trials.

Non-Thermal Dielectric Barrier Discharge (DBD) Effects on Proliferation and Differentiation of Human Fibroblasts Are Primary Mediated by Hydrogen Peroxide

The proliferation of fibroblasts and myofibroblast differentiation are crucial in wound healing and wound closure. Impaired wound healing is often correlated with chronic bacterial contamination of the wound area. A new promising approach to overcome wound contamination, particularly infection with antibiotic-resistant pathogens, is the topical treatment with non-thermal “cold” atmospheric plasma (CAP). Dielectric barrier discharge (DBD) devices generate CAP containing active and reactive species, which have antibacterial effects but also may affect treated tissue/cells. Moreover, DBD treatment acidifies wound fluids and leads to an accumulation of hydrogen peroxide (H2O2) and nitric oxide products, such as nitrite and nitrate, in the wound. Thus, in this paper, we addressed the question of whether DBD-induced chemical changes may interfere with wound healing-relevant cell parameters such as viability, proliferation and myofibroblast differentiation of primary human fibroblasts. DBD treatment of 250 μl buffered saline (PBS) led to a treatment time-dependent acidification (pH 6.7; 300 s) and coincidently accumulation of nitrite (~300 μM), nitrate (~1 mM) and H2O2 (~200 μM). Fibroblast viability was reduced by single DBD treatments (60–300 s; ~77–66%) or exposure to freshly DBD-treated PBS (60–300 s; ~75–55%), accompanied by prolonged proliferation inhibition of the remaining cells. In addition, the total number of myofibroblasts was reduced, whereas in contrast, the myofibroblast frequency was significantly increased 12 days after DBD treatment or exposure to DBD-treated PBS. Control experiments mimicking DBD treatment indicate that plasma-generated H2O2 was mainly responsible for the decreased proliferation and differentiation, but not for DBD-induced toxicity. In conclusion, apart from antibacterial effects, DBD/CAP may mediate biological processes, for example, wound healing by accumulation of H2O2. Therefore, a clinical DBD treatment must be well-balanced in order to avoid possible unwanted side effects such as a delayed healing process.

Intraalveolar TNF-α in combined burn and inhalation injury compared with intraalveolar interleukin-6.

The objective of this study was to evaluate the role of intraalveolar tumor necrosis factor-&agr; (TNF-&agr;) and interleukin-6 (IL-6) in a combination of skin burn and smoke inhalation injuries because this combined trauma is associated with an increased morbidity and mortality compared with either of these traumas alone. We used a standardized small animal model (rats n = 84) to investigate the early intraalveolar excretion of TNF-&agr; during the first one, three, and six hours after a singular skin burn injury, singular smoke inhalation injury, and a combination involving both the traumas. The data were compared with the data from control rats that only received preparation and mechanical ventilation. The TNF-&agr; serum levels and intraalveolar IL-6 concentrations were also measured. One hour after trauma, there was a significant difference in the TNF-&agr; concentration between the controls and both the singular traumas (control vs burn P < .0444 and control vs smoke P < .005) and between the inhalation injury and the combined trauma (smoke vs burn + smoke P < .0084). After three and six hours, no significant differences among the groups were observed. Compared with the controls, both the singular skin burn and smoke inhalation injuries led to increased intraalveolar TNF-&agr; excretion, whereas the combined trauma showed the least intraalveolar TNF-&agr; levels at three and six hours post-trauma. These findings differed from the serum TNF-&agr; levels. Compared with the IL-6 levels, we observed a negative correlation within the intraalveolar cytokine concentrations after one hour (r = −.809), three hours (r = −.627), and six hours (r = −.746). This study confirms the importance of the intraalveolar cytokine reaction in the early posttraumatic stage after a combined burn and inhalation injury. The differences between the combined and singular traumas indicate that TNF-&agr; plays a role in the immunologic hyporesponsiveness of the lung and therefore in the systemic pathophysiological pathway, that often leads to patient mortality. In addition, an inverse correlation between TNF-&agr; and IL-6, both classical markers of inflammation, in the intraalveolar space was observed.

Blue light inhibits transforming growth factor‐β1‐induced myofibroblast differentiation of human dermal fibroblasts

Transforming growth factor‐β1 (TGF‐β1) is the major promoter of phenotypic shift between fibroblasts and myofibroblasts accompanied by the expression and incorporation of α‐smooth muscle actin (α‐SMA). This differentiation is crucial during normal wound healing and wound closure; however, myofibroblasts are considered as the main effecter cell type in fibrosis, for example in scleroderma and hypertrophic scarring. As blue light has exerted antiprolific and toxic effects in several cell types, we investigated whether blue light irradiations with a light‐emitting diode array (420 nm) were able to affect proliferation and differentiation of human dermal fibroblasts (HDF). We found that repeated irradiation with non‐toxic doses significantly inhibits TGF‐β1‐induced differentiation of HDF into myofibroblasts shown by α‐SMA immunocytochemistry and Western blotting. Additionally, used doses reduced proliferation and myofibroblast contractibility measured by resazurin and collagen gel contraction assays. It could be demonstrated that blue light mediates cell toxicity by oxidative stress due to the generation of singlet oxygen. We postulate that irradiations at non‐toxic doses induce low‐level oxidative stress and energy‐consuming cellular responses, which both may effect proliferation stop and interfere with myofibroblast differentiation. Thus, targeting differentiation, proliferation and activity of myofibroblasts by blue light may represent a useful strategy to prevent or reduce pathological fibrotic conditions.

Etiology, incidence and gender-specific patterns of severe burns in a German Burn Center - Insights of 25 years

INTRODUCTION Burns often require special treatment in specialized burn centers. One of the specialized German burn centers is located in Cologne-Merheim. Only little is known about the etiology of burns in Germany, their monthly distribution and changes over the past 25 years. METHODS We therefore retrospectively analyzed the etiology for all patients treated at the burn intensive care unit (BICU) of Cologne in the last 25 years and categorized them into groups. Thereafter all groups were analyzed according to distribution of age, gender and occurrence. RESULTS In this way we were able to show that the number of severe burns did not decrease over the time under evaluation and that it did not show seasonal variation. Injured females were older than males but fewer in number. The highest numbers of burns were related to fire, followed by electricity, hot liquids, chemicals and heat contact. Work-related burns occurred mostly with males. However, most of the burns were not work-related for either gender. CONCLUSION The number of burns in Germany and in the world is still high, and prevention strategies do not always have the desired effect. This study aims to fill the gap in published burn knowledge in Germany by way of describing the gender differences and etiology characteristics. It can therefore help to identify risks and expand effective burn prevention strategies.

Chirurgische Behandlung von Gesichtsverbrennungen

Die Verbrennung der Gesichtsregionen stellt eine grose Herausforderung fur alle in der Verbrennungsbehandlung tatig werdenden Berufsgruppen dar. Neben psychologischen Beeintrachtigungen aufgrund der vorliegenden Gesichtsdeformitaten bei Betroffenen kann es gerade bei Kindern zu Alterationen mit schweren Gesichtsentstellungen und Vernarbungen wahrend der einzelnen Phasen der Gesichtsentwicklung kommen (Fricke et al. 1999, Achauer 1992). Der Rekonstruktion der Kopf- und Halsregion als elementarer Bestandteil der personlichen Identitat, Kommunikationsorgan und Trager von Sinnesorganen kommt daher eine grose Bedeutung zu. Die Behandlung der Gesichtsverbrennung erfordert ein solides Wissen in rekonstruktiv-chirurgischen Prinzipien. Des weiteren sind fundierte Grundlagen in der Narbentherapie wie die Kompressionsbehandlung, die Steroidinjektion oder die ablativen Verfahren, wie z. B. die Lasertherapie essentiell.

Vitamin D deficiency may stimulate fibroblasts in Dupuytren’s disease via mitochondrial increased reactive oxygen species through upregulating transforming growth factor-β1

Dupuytrens disease, a benign fibroproliferative disorder of the palmar fascia, represents an ideal model to study tissue fibrosis. Transforming growth factor-β1 (TGF-β1) and its downstream Smad signaling system is well established as a keyplayer during fibrogenesis. Vitamin D has been extensively studied as an anti-fibrotic agent in malignant chronic diseases. A number of studies have shown that myofibroblasts are main target cells of 1,25(OH)2D3 inhibitory action. The myofibroblast in the palmar aponeurosis of patients in different stages of Dupuytrens disease was found by electron microscopy to contain a large number of mitochondria. Mitochondria play a critical role in cell metabolism being the major source of reactive oxygen species (ROS) in cells. TGF-β1 has been shown to increase mitochondrial ROS production in different cell types, which mediate fibrosis related gene expression and myofibroblast differentiation. TGF-β1 increases mitochondrial ROS production in patients with Dupuytrens contracture potentially in consequence of Vitamin D deficiency, leading to myofibroblast differentiation. Thus, targeting this basic pathomechanism seems suitable to establish new treatment strategies.

Growth Differentiation Factor 5 Accelerates Wound Closure and Improves Skin Quality During Repair of Full-Thickness Skin Defects

BACKGROUND: A fast and stable wound closure is important, especially for extended and unstable wounds found after burn injuries. Growth can regulate a variety of cellular processes, including those involved in wound healing. Growth differentiation factor 5 (GDF-5) can accelerate fibroblast cell migration, cell proliferation, and collagen synthesis, which are essential for wound healing. Nevertheless, no standardized evaluation of the effect of GDF-5 on the healing of full-thickness wounds has been published to date. METHODS: Five full-thickness skin defects were created on the backs of 6 minipigs. Three wounds were treated with GDF-5 in different concentrations with the help of a gelatin-collagen carrier, and 2 wounds served as control group. The first was treated with the gelatin carrier and an Opsite film (Smith & Nephew, Fort Worth, Texas), and the other was treated solely with an Opsite film that was placed above all wounds and renewed every second day. RESULTS: Growth differentiation factor 5 accelerates wound closure (10.91 [SD, 0.99] days) compared with treatment with the carrier alone (11.3 [SD, 1.49] days) and control wounds (13.3 [SD, 0.94] days). Epidermal cell count of wounds treated with GDF-5 revealed a higher number of cells compared with the control group. In addition, mean epidermal thickness was significantly increased in GDF-5–treated wounds compared with the control wounds. CONCLUSIONS: Because of its ability to improve skin quality, GDF-5 should be considered when developing composite biomaterials for wound healing.

Intensivtherapie bei Brandverletzungen

1.1 Einleitung Brandverletzungen sind Folge einer traumatischen Sch€adigung der Haut durch Hitzeeinwirkung. Die Bandbreite von thermischen Verletzungen reicht von Verbrennungen und Verbr€uhungen €uber chemische Ver€atzungen bis zu Elektroverbrennungen. W€ahrend Verbrennungen durch Flammen oder durch Kontakt mit heißen Gegenst€anden entstehen, werden Verbr€uhungen durch heiße Fl€ussigkeiten oder heißen Dampf verursacht. Bei Kindern ist der h€aufigste Unfallmechanismus zumeist eine Verbr€uhung. Nichtthermische Noxen wie z. B. elektrischer Strom oder Strahlung können analoge Hautsch€aden hervorrufen. Die chemische oder toxische Hautsch€adigung wird schließlich aufgrund ihrer pathophysiologischen Ähnlichkeit zu Verbrennungen als Paraverbrennung bezeichnet (Jelenko 1974). Im europ€aischen Raum liegt die j€ahrliche Inzidenzrate zwischen 0,2 und 2,9 Verbrennungen pro 10.000 Einwohner mit einer r€uckl€aufigen Tendenz. Verbrennungsverletzungen in ihrer gesamten Bandbreite benötigen grunds€atzlich eine ad€aquate Erstbehandlung vor Ort und im Anschluss eine kompetente Folgebehandlung. Das Überleben, die private und berufliche Rehabilitation mit Wiederherstellung von Funktion und Ästhetik sind eine große Herausforderung f€ur das gesamte Kompetenzteam, das sich in einem Verbrennungszentrum aus Spezialisten f€ur Plastische und Rekonstruktive Chirurgie, An€asthesie und Intensivmedizin, besonders spezialisiertem Pflegepersonal sowie Physiound Ergotherapie, Psychologie und Ern€ahrungstherapie zusammensetzt (Pallua und von Heimburg 1999). DieWertigkeit der Verbrennungszentren f€ur die notwendigen speziellen Therapieschritte im Hinblick auf das positive Gesamtergebnis sind weiterhin als hoch einzustufen. Jegliche bilanzkalkulatorisch motivierte Entscheidung, sog. „kleine“ Verbrennungen von verbrannten Fl€achen <10 % der Körperoberfl€ache (KOF) nicht der Behandlung in Verbrennungszentren zuzuf€uhren, sind damit weiterhin als fehlerhafte Tendenz anzusehen (Rennekampf 2011). Die klinischen Verl€aufe nach Verbrennungen reichen von leichten Bagatellverletzungen bis hin zu lebensbedrohlichen Traumata mit der Notwendigkeit einer Intensivtherapie in spezialisierten Verbrennungszentren und operativen Maßnahmen, gefolgt von Maßnahmen der Rehabilitation und sekund€aren operativen Rekonstruktionen. Epidemiologische Daten aus Europa im Erfassungszeitraum zwischen 1985 und 2009 konnten eine Mortalit€atsrate bei Verbrennungen zwischen 1,4 % und 18 % mit einer Abnahme €uber die Zeit ermitteln (Rennekampf 2011). Eine ad€aquate Behandlung einer thermischen Verletzung beginnt mit der genauen fachgerechten Beurteilung der Brandwunden und eventueller Begleitverletzungen. Zum einen wird die Verbrennungstiefe abgesch€atzt, daraus erfolgt die Indikation zur konservativen oder operativen Behandlung. Zum anderen ist die Ausdehnung des thermischen Schadens bezogen auf die gesamte Körperoberfl€ache und die Lokalisation der Verletzung von Bedeutung. Das Vorliegen eines