Inflammatory response to burn trauma: nicotine attenuates proinflammatory cytokine levels.

OBJECTIVE: The immune response to an inflammatory stimulus is balanced and orchestrated by stimulatory and inhibitory factors. After a thermal trauma, this balance is disturbed and an excessive immune reaction with increased production and release of proinflammatory cytokines results. The nicotine-stimulated anti-inflammatory reflex offsets this. The goal of this study was to verify that transdermal administration of nicotine downregulates proinflammatory cytokine release after burn trauma. METHODS: A 30% total body surface area full-thickness rat burn model was used in Sprague Dawley rats (n = 35, male). The experimental animals were divided into a control group, a burn trauma group, a burn trauma group with additional nicotine treatment, and a sham + nicotine group with 5 experimental animals per group. The last 2 groups received a transdermal nicotine administration of 1.75 mg. The concentrations of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 were determined in homogenates of hearts, livers, and spleens 12 or 24 hours after burn trauma. RESULTS: Experimental burn trauma resulted in a significant increase in cytokine levels in hearts, livers, and spleens. Nicotine treatment led to a decrease of the effect of the burn trauma with significantly lower concentrations of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 compared to the trauma group. CONCLUSIONS: This study confirms in a standardized burn model that stimulation of the nicotinic acetylcholine receptor is involved in the regulation of effectory molecules of the immune response. Looking at the results of our study, further experiments designed to explore and evaluate the potency and mechanisms of the immunomodulating effects of this receptor system are warranted.

[The current evidence-based guidelines regarding prophylaxis of venous thrombembolism and their relevance for plastic surgery]. / Die aktuelle S3-Leitlinie zur Prophylaxe der venösen Thromboembolie und ihre Implikation für die Plastische Chirurgie.

INTRODUCTION: In Germany, clinically and experimentally proven, evidence-based guidelines for the perioperative prophylaxis of thromboembolism in plastic surgery have not yet been developed. The ever-expanding complexity of microsurgical reconstructive procedures associated with the immense technical progress in the medical field have once more highlighted the urgent need for evidence-based guidelines. Moreover, this urgency is underlined by more and more complex reconstructive procedures needing to be performed in elderly patients presenting with grave comorbidities and the related high risk for thromboembolic events. These facts prompted us to review and discuss the relevance of the updated S3-guidelines on prophylaxis of venous thromboembolic events for the field of plastic and reconstructive surgery . MATERIAL AND METHODS: The existing S3-guidelines represent the result of a consensus between 27 medical societies and organisations. Delegates of the German Society of Plastic, Reconstructive and Aesthetic Surgery (DGPRAEC) also participated in this consensus process and the development of the guidelines, which provide evidence-based and clinically oriented recommendations for the prophylaxis of venous thromboembolism for operative and non-operative as well as outpatient and inpatient settings. In the results section of this paper, general and specific recommendations with regard to plastic and reconstructive surgery are outlined. RESULTS: Indications for the pharmacological prophylaxis of thromboembolic events are oriented on the specific risk categories for surgical interventions with regard to the dispositional individual risk factors. Furthermore, the recommendations for the field of plastic and reconstructive surgery are subdivided into the various regions of the body. DISCUSSION: Evidence-based recommendations for perioperative prophylaxis of venous thromboembolism in plastic surgery are not available yet. The establishment of an algorithm to screen and estimate the procedure-associated risks for thromboembolism is needed. The discussed S3-guidelines of the AWMF Society on the prophylaxis of venous thromboembolism meet these formal requirements. Gathering of evidence-based data and the generation of recommendations leading to a reduction of the perioperative risk of thromboembolic events is a pivotal element to improve patient outcomes and safety in microsurgery.

A novel human skin chamber model to study wound infection ex vivo.

Wound infections with multi-drug resistant bacteria increase morbidity and mortality and have considerable socioeconomic impact. They can lead to impaired wound healing, resulting in rising treatment costs. The aim of this study was to investigate an ex vivo human wound infection model. Human full-thickness skin from the operating room (OR) was placed into the Bo-Drum and cultivated for 7 days in an air-liquid interphase. On day 8, the skin was inoculated with either (1) Pseudomonas aeruginosa, (2) Staphylococcus aureus (10(5) CFU, n = 3) or (3) carrier control. 1, 3 and 7 days after inoculation colony forming units in the tissue/media were determined and cytokine expression was quantified. A reliable and reproducible wound infection could be established for 7 days. At this time point, 1.8 x 10(8) CFU/g tissue of P. aeruginosa and 2 x 10(7) CFU/g tissue of S. aureus were detected. Immunohistochemical analysis demonstrated bacterial infection and epidermolysis in infected skin. RT-PCR analysis exhibited a significant induction of proinflammatory cytokines after infection. The BO-drum is a robust, easy-to-use, sterilizable and reusable ex vivo full-skin culture system. For investigation of wound infection, treatment and healing, the BO-drum presents a convenient model and may help to standardize wound research.

Insight in human skin microcirculation using in vivo reflectance-mode confocal laser scanning microscopy.

Reflectance-mode confocal laser scanning microscopy allows in vivo imaging of the human skin. We hypothesized that this high-resolution technique enables observation of dynamic changes of the cutaneous microcirculation. Twenty-two volunteers were randomly divided in two groups. Group 1 was exposed to local heating and group 2 to local cold stress. Confocal microscopy was performed prior t (0) (control), directly t (1) and 5 min t (2) after local temperature changes to evaluate quantitative blood cell flow, capillary loop diameter, and density of dermal capillaries. In group 1, blood flow increased at t (1) (75.82 +/- 2.86/min) and further at t (2) (84.09 +/- 3.39/min) compared to the control (61.09 +/- 3.21/min). The control capillary size was 9.59 +/- 0.25 microm, increased to 11.16 +/- 0.21 microm (t (1)) and 11.57 +/- 0.24 microm (t (2)). The dermal capillary density increased in t (1) (7.26 +/- 0.76/mm(2)) and t (2) (8.16 +/- 0.52/mm(2)), compared to the control (7.04 +/- 0.62/mm(2)). In group 2, blood flow decreased at t (1) (41.73 +/- 2.61/min) and increased at t (2) (83.27 +/- 3.29/min) compared to the control (60.73 +/- 2.90/min). The control capillary size was 9.55 +/- 0.25 microm, decreased at t (1) (7.78 +/- 0.26 microm) and increased at t (2) (11.38 +/- 0.26 microm). Capillary density decreased at t (1) (5.01 +/- 0.49/mm(2)) and increased at t (2) (7.28 +/- 0.53/mm(2)) compared to the control (7.01 +/- 0.52/mm(2)). Confocal microscopy is a sensitive and noninvasive imaging tool for characterizing and quantifying dynamic changes of cutaneous microcirculation on a histomorphological level.

Monitoring of microcirculation in free transferred musculocutaneous latissimus dorsi flaps by confocal laser scanning microscopy--a promising non-invasive methodical approach.

INTRODUCTION: For the survival of a microvascular tissue transfer, early detection of vascular complications is crucial. In vivo confocal laser scanning microscopy allows real-time, non-invasive evaluation of tissue microcirculation with a high cellular resolution. The aim of this study was to evaluate confocal laser scanning microscopy for early recognition of flap failure. METHODS: Fourteen patients (ages: 40.2+/-12.4 years) were monitored postoperatively for a period of 24h following free microvascular M. latissimus dorsi transfer to the lower extremity using confocal laser scanning microscopy (Vivascope1500; Rochester; New York; USA). The following parameters were evaluated: quantitative blood-cell flow, diameter of capillary loops and minimal thickness of the epidermis. RESULTS: Venous congestion was characterised by a decrease in blood-cell flow of up to 41%, accompanied by an increase of the diameter of capillary loops of up to 22% and the minimal thickness of the epidermis up to 32%. By contrast, arterial occlusion was clearly verified by a decrease in blood flow of up to 90%, accompanied by an insignificant change of both capillary loop size and epidermal thickness. CONCLUSION: Confocal laser scanning microscopy appears to be a useful non-invasive tool for early recognition of flap failure during the monitoring of microsurgical tissue transfer prior to its clinical manifestation.

[A comparative in vitro study of cell toxicity of clinically used antiseptics]. / Vergleichende In-vitro-Studie zur Zytotoxizität klinisch eingesetzter Antiseptika.

PURPOSE: Local skin antiseptics are the standard of care for chronic and non-healing wounds. However, little is known about their potential toxic properties. This study investigates the impact of three commercially available and widely used antiseptics on vitality and proliferation of human cutaneous cells. MATERIAL AND METHODS: Three antiseptics, Lavasept (PHMB), Octenisept (octenidine) and Betaisodona (PVP-iodine) were tested for their cytotoxic effects towards HaCaT cells, primary human keratinocytes and fibroblasts using MTT assay and BrDU ELISA. RESULTS: Lavasept showed only slight to moderate toxic effects on cellular vitality and proliferation. Ocentisept and Betaisodona induced severe reduction of cell vitality (p<0.05) to 0% surviving fibroblasts at 7.5% (Betaisodona) and 12.5% Octenisept, respectively. Furthermore, poliferative activity was reduced to 0% in keratinocytes at 7.5% concentration of Betaisodona and Ocentisept. CONCLUSION: This study shows that frequently used wound- and skin antiseptics show severe cytotoxic effects towards cutaneous cells. Furthermore, antimicrobial efficacy and toxic properties must be included in the clinical decision process for optimal therapy of chronic wounds. The PHMB solution Lavasept showed best results regarding toxicity in this study.

[Surgical intensive care medicine. Current therapy concepts for septic diseases]. / Chirurgische Intensivmedizin. Aktuelle Therapiekonzepte septischer Erkrankungen.

The clinical appearance of septic disorders is characterized by an enormous dynamic. The sepsis-induced dysbalance of the immune system necessitates immediate and aggressive therapeutic interventions to prevent further damage progression of the disease to septic shock and multiple organ failure. This includes supportive therapy to normalize and maintain organ and tissue perfusion as well as the identification of the infection focus. In cases where an infectious focus is identified, surgical source control frequently is a key element of the treatment strategy besides pharmacologic and supportive measures. The integrative approach of the management of septic patients requires rapid communication between the involved medical disciplines and the nursing personnel. Therefore, this article outlines current therapeutic concepts of septic diseases as well as central nursing aspects.

Is superficial burn caused by ultraviolet radiation (sunburn) comparable to superficial burn caused by heat--a histomorphological comparison by in vivo Reflectance-Mode-Confocal Microscopy.

BACKGROUND: Regardless of the underlying cause, both sunburn and superficial thermal injuries are classified as first-degree burns, since data on morphological differences are scarce. Reflectance-Mode-Confocal Microscopy (RMCM) enables high-resolution non-invasive investigation of the human skin. OBJECTIVE: We studied in vivo histomorphological alterations in both sunburn and superficial thermal injuries using RMCM. METHODS: Ten patients (6 female, 4 male; aged 28.4 +/- 10.6 years) with first-degree thermal-contact Injuries (TI group), and 9 sunburned patients (SB group; 7 female, 2 male; aged 30.2 +/- 16.4 years), to a maximum extent of 10% of the body surface were evaluated 24 h after burn injury using RMCM. The following parameters were obtained using RMCM: stratum corneum thickness, epidermal thickness, basal layer thickness, granular cell size. RESULTS: Compared to the controls (12.8 +/- 2.5 microm), stratum corneum thickness decreased significantly to 10.6 +/- 2.1 microm in the TI group, whereas it increased significantly to 16.4 +/- 3.1 microm in the SB group. The epidermal thickness did not differ significantly in the TI group (47.9 +/- 2.3 microm) and SB group (49.1 +/- 3.5 microm); however, both increased significantly compared to their respective controls (41.8 +/- 1.4 microm). The basal layer thickness increased more in the SB group compared to the TI group (17.9 +/- 1.4 microm vs. 15.6 +/- 1.1 microm). Both differed also significantly compared to their controls (13.8 +/- 0.9 microm). The granular cell size increased significantly in both groups compared to the controls (731 +/- 42 microm); however, a significantly higher increase was observed in the TI group (852 +/- 58 microm) compared to the SB group (784 +/- 61 microm). CONCLUSIONS: Ultraviolet radiation seems to influence predominantly deeper epidermal layers, whereas heat-induced burns affect more superficial epidermal layers. The term 'First-degree burn' should not be used synonymously for sunburn and superficial thermal burn injuries. Conflicts of interest None declared.

[Plastic reconstructive surgery for burn injuries]. / Plastische rekonstruktive Chirurgie nach Verbrennungsverletzungen.

The stage-adjusted therapy of thermal injuries is based on pathophysiologic mechanisms as well as functional and aesthetic requirements. Plastic reconstructive surgical approaches are highly important in the prevention of the frequent grave sequelae of thermal trauma and to achieve optimal functional rehabilitation and favourable outcome. In reconstructive surgery of burns operative goals are subdivided into acute, secondary reconstructive, functional and aesthetic indications. The achievement of early wound closure to preserve functional skin and soft tissue components is an essential part of acute reconstructive procedures. Functional reconstructive and aesthetic procedures supplement the conservative treatment modalities of the secondary phase of burn care with physical therapy, ergotherapy and psychological support.

[Innovative wound therapy and skin substitutes for burns]. / Innovative Wundtherapie und Hautersatz bei Verbrennungen.

The success of modern burn therapy is based mainly on special burn intensive care, topical treatment, early eschar excision, and wound closure by immediate skin grafting or skin substitutes. This paper describes the current state of wound care and skin substitutes in burn therapy.

Should human chondrocytes fly? The impact of electromagnetic irradiation on chondrocyte viability and implications for their use in tissue engineering.

A significant logistic factor as to the successful clinical application of the autologous tissue engineering concept is efficient transportation: the donor cells need to be delivered to tissue processing facilities which in most cases requires air transportation. This study was designed to evaluate how human chondrocytes react to X-ray exposure. Primary cell cultures were established, cultured, incubated and exposed to different doses and time periods of radiation. Subsequently, quantitative cell proliferation assays were done and qualitative evaluation of cellular protein production were performed. Our results show that after irradiation of chondrocytes with different doses, no significant differences in terms of cellular viability occurred compared with the control group. These results were obtained when chondrocytes were exposed to luggage transillumination doses as well as exposure to clinically used radiation doses. Any damage affecting cell growth or quality was not observed in our study. However, information about damage of cellular DNA remains incomplete.

G-CSF during large field radiotherapy reduces bone marrow recovery capacity.

OBJECTIVE: Side effects of chemo- and radiotherapy are granulo- and thrombocytopenia. However, the long-term effects of in vivo granulocyte-colony-stimulating factor (G-CSF) stimulation of the hematopoietic system during radiotherapy are not yet completely understood. In the present study, we sought to determine the bone marrow effect of G-CSF during radiotherapy. MATERIAL AND METHODS: In a prospective, randomized clinical trial 10 patients (6 m, 4 f, 30-64 yrs, mean 50.6 yrs) were assigned to large field radiotherapy (RT). 7 patients (pat.) with non-Hodgkin lymphoma, one patient with Hodgkin's disease and 2 patients with small-cell carcinoma of the lung were included. The patients were randomized to either radiotherapy alone (group A) or radiotherapy with simultaneous G-CSF (group B) treatment and assessed for acute and late toxicity. Blood samples were drawn and analyzed before and after G-CSF stimulation. The mobilization effectivity of G-CSF on CD34 superset+ progenitor cells was measured using flow cytometry and colony forming units (CFU) testing on admission and during the complete follow-up period (1, 3 and 18 months post RTx). RESULTS: Overall, 50 pat. were intended to be included to the protocol. However, the preliminary analysis revealed a significant decrease of thrombocytes and CD34 superset+ progenitor cells in the G-CSF treatment group. According to the study protocol further treatment was stopped. Peripheral leukocyte counts ranged between 2800 - 4375 /mul in 9/10 pat. In group B mean thrombocyte levels dropped below 30.000 mg/l and CD34 superset+ progenitor cells to 50% (interruption criteria, p<0.02, Student's t-test). Hemoglobin values did not vary. Differential blood smears showed differences in granulocyte counts and a higher proportion of neutrophils in group B. Lymphocyte counts of patients randomized to group A were significantly decreased when compared to group B. In group A, 3/5 pat. developed an overshooting reaction (4,7 x increase) after G-CSF-stimulation. In arm B circulating CD34 superset+ progenitor cells dropped. In arm A, 3/5 pat. had an initial overshoot reaction when compared to none in group B. CFU (> 40 cells) and cluster (4 -39 cells) showed considerable variations. CONCLUSION: Our results demonstrate that simultaneous treatment with G-CSF during radiotherapy reduces the mobilization of CD34+ progenitor cells and exhaust the bone marrow capacity while peripheral leukocyte counts remain at baseline levels.

[Early surgical management of severe burns]. / Primäre chirurgische Therapie bei Verbrennungen.

The success of modern burn therapy is based on an understanding of the pathophysiology and application of burn intensive care implying fluid resuscitation and management of pulmonary or other organ failure. With the development of early eschar excision and wound closure by immediate grafting, survival and cosmetic outcome were further improved. Especially in post-acute therapy, early physical rehabilitation, early reintegration, and early plastic surgical correction of the sequelae are indispensable for the outcome.

[Propane-induced tissue damage: burn or freezing injury?]. / Verletzungen durch flüssiges Propan: Verbrennung oder Erfrierung?

Tissue damage due to direct contact of liquid propane with the integument is extremely rare. Only five such cases have been described in the literature. We report the case of a girl who sustained a full-thickness skin necrosis of 14.5 % of her body surface area. There is little agreement about the optimal treatment of these injuries in previous reports. The pathophysiological mechanism suggests a freezing injury. The treatment, however, should be analogous to that of third-degree burns.

Clinical long-term in vivo evaluation of poly(L-lactic acid) porous conduits for peripheral nerve regeneration.

It was the purpose of this study to evaluate the clinical long-term effects of PLLA degradation in vivo on nerve regeneration in the rat sciatic nerve model. Thirty-one Sprague Dawley rats were utilized. Two groups of animals were selected. The control group of 10 animals received a 12 mm reversed isograft into the right sciatic nerve from 5 donor animals. The experimental group (n = 21) received a 12 mm empty PLLA conduits placed into a 12 mm defect in the right sciatic nerve. The left leg served as an internal control. Walking track analysis was performed monthly through 8 months. At the end of 4 and 8 months, animals in the control isograft and experimental group had the medial and lateral gastrocnemius muscles harvested and weighed for comparison. The midconduit/isograft and the distal nerve in these same animals were harvested and histomorphologically analyzed. Multiple samples were collected and expressed as means +/- standard error. A two-sample t-test and Wilcoxon rank sum test was used to compare the variables. Significance level was set at alpha = 0.05. After Bonferroni correction for multiple testing, a p value of < or = 0.01 was considered statistically significant. Throughout all time periods, the PLLA conduit remained structurally intact and demonstrated tissue incorporation and vascularization. There was no evidence of conduit collapse or breakage with limb ambulation. Moreover, there was no evidence of conduit elongation at 8 months as previously observed with the 75:25 poly(DL-lactic-co-glycolic acid) (PLGA) conduits. The mean absolute value of the sciatic functional index (SFI) demonstrated no group differences from isograft controls measured over the 8 months except at 3 months where the isograft values were higher (p = 0.0379) and at 7 months were the isograft group was significantly lower (p = 0.0115). At 4 and 8 months, the weight of the gastrocnemius muscles of the experimental group was not significantly different from isografts. At 4 months the number of axons/mm2 and nerve fiber density was not significantly different between the isograft control and experimental groups in either the midconduit/isograft or distal nerve. At 8 months the number of axons/mm2 was significantly lower in the isograft compared to the midconduit experimental group (p = 0.006). The number of axons/mm2 in the distal nerve and the nerve fiber density in the midconduit and distal nerve were not significantly different between the two groups. The study confirmed our initial hypothesis that PLLA conduits are a viable scaffold for clinical long-term nerve gap replacement. We are critically aware however that longer evaluation of polymer degradation is warrented. Further studies on these individual nerve components are continuing, with the ultimate goal being the fabrication of a bioactive conduit that meets or exceeds the functional results of isografts.