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.

EPHB4 tyrosine-kinase receptor expression and biological significance in soft tissue sarcoma

Soft tissue sarcomas (STS) are heterogeneous malignant tumors of mesenchymal origin. Due to low incidence and high number of different histological subtypes, their pathogenesis and thus potential targets for their therapy remain barely investigated. Several studies revealed significant higher EPHB4 expression in malignancies such as prostate and colorectal cancer showing survival advantages for these tumor cells. Therefore we studied the expression of EPHB4 in a total of 46 clinical human specimens of different STS and human fibroblasts. EPHB4 mRNA and protein expression were significantly increased in synovial sarcoma. After targeting EPHB4 in fibrosarcoma, synovial sarcoma, liposarcoma and MFH sarcoma cell lines by siRNA or by inhibition of autophosphorylation using the specific EPHB4 kinase inhibitor NVP-BHG712 a decreased proliferation rate/vitality of synovial- and fibrosarcoma cells was observed. Silencing of EPHB4 significantly reduced the transmigration of synovial sarcoma cells towards fibroblasts and endothelial cells. In addition, we assessed the anti-metastatic effect of EPHB4 inhibition in vivo by intraperitoneal administration of the EPHB4 inhibitor in an appropriate sarcoma lung metastasis xenograft model. As result 43% of NVP-BHG712 treated mice (n = 3/7) developed pulmonary metastases whereas all control mice (n = 5) revealed lung metastases. The residual 57% of mice (n = 4/7) showed only small local tumor cell spots. Size measurements of the Vimentin positive area explained significant decrease in lung metastasis formation (p < 0.05) after EPHB4 kinase inhibition. In summary, these data provide first evidence of the importance of EPHB4 in the tumorigenesis of synovial sarcoma and present EPHB4 as a potential target in the therapy of this malignancy.

Characteristics and differences in necrotizing fasciitis and gas forming myonecrosis: a series of 36 patients

BACKGROUND AND AIMS

Necrotizing fasciitis (NF) and gas forming myonecrosis (GFM), both being subtypes of necrotizing soft tissue infection (NSTI), are life threatening conditions sharing certain similarities. Despite the necessity of early and radical surgical debridement in necrotizing infections, the distinction between these entities is of clinical relevance since gas forming myonecrosis in a number of cases results from an underlying abdominal cause and the focus of infection can be missed. This study was to evaluate the incidence and risk factors as well as the mortality rate in patients with NSTI and GFM.

MATERIAL AND METHODS

All patients with NSTI treated in the authors' hospital between January 2005 and Decem-ber 2009 were enrolled in the study. Medical records, histological slides, microbiological and laboratory parameters as well as Computerized Tomography (CT) and magnetic resonance imaging (MRI) scans were reviewed for all patients. Differences between NF and GFM regarding hospital stay, number of surgical interventions and pre-existing comorbidities as well as mortality rate were analyzed. The laboratory risk factor for necrotizing fasciitis (LRINEC) score was calculated in all patients on admission.

RESULTS AND CONCLUSIONS

Thirty patients (17 female, 13 male) with necrotizing fasciitis with a mean age of 55 years (SD 15.5) were included in the study. There was no statistically significant difference between survivors and deceased patients comparing the LRINEC score (n.s.). Patients with necrotizing fasciitis secondarily involving the trunk had a significantly higher mortality rate (OR 11.2; 95% CI=1.7-72.3). In the majority of cases (12 cases), minor skin lesions were identified as the site of origin. Amongst all necrotizing soft tissue infections six patients (female n=3; male n=3) with a mean age of 61.5 years (SD 12.2) with non-clostridial gas forming myonecrosis were identified. Three patients had a history of malignancy and in three patients the infection was secondary to major surgery. The mean LRINEC score was 8.5 (SD 1). Three patients (50%) died due to GFM. Early diagnosis and appropriate intervention is critical to provide accurate treatment decisions. Eradicating the differing primary sources of infection in GFM and NF will have a positive impact on outcome.

[Recent update on tumour biology and treatment of Merkel Cell carcinoma]

Merkel cell carcinoma (MCC) is a carcinoma arising from Merkel cells located in the basal layer of the epidermis. The skin of the head and neck is a common site for MCC, occurring generally in fair-skinned elderly patients. MCC is considered as the most lethal skin cancer. Radical surgical excision with pathological verification of complete removal of the tumour is the recommended treatment. Early MCC can be cured by surgery with or without postoperative radiation therapy, whereas advanced MCC is currently considered to be incurable. In the year 2008, a new polyoma virus was found in the tumour genome of the MCC tumours. MCPyV (Merkel cell polyoma virus) appears to be the first example of a human oncogenic polyoma virus. Specific mutations in the viral genome and its clonal integration to the tumour genome are strong evidence against MCPyV as being a passenger virus that secondarily infects MCC tumours. The purpose of this review article is to shed light on this rare skin cancer and introduce the latest advances in research on MCC.

[Surgical treatment of extravasation injuries]

OBJECTIVE

Extravasations account for most iatrogenic injuries. The aim of the study was to analyse the results of surgery in patients with extravasations and to draw conclusions for future treatment.

MATERIALS AND METHODS

24 patients with soft-tissue defects after extravasations were treated between 1999 and 2009 in our hospital. The cases were analysed retrospectively. We looked at the drugs causing tissue necrosis and the localisation in relation to the number of interventions and reconstruction complexity.

RESULTS

In 83 % (n = 20) of cases tissue necrosis was caused by chemotherapeutic agents, in 8 % (n = 2) by contrast mediums and in 4 % (n = 1) by antibiotics and insulin. 70 % of the cases involved the upper extremity, in 30 % the thoracic wall was affected. 38 % of the extravasations occurred over venous access ports. In mean 2 ± 1.5 interventions were necessary for defect coverage. Two patients died as a direct result of the extravasations, one due to sepsis originating from an infected necrosis area and one due to right-heart failure with prior pulmonary damage.

CONCLUSION

Most extravasations can be treated without surgery. In cases of toxic extravasations or pressure-caused ischaemia rapid surgical intervention is necessary to prevent the necrosis progressing to deeper tissue layers.

[Proximal radial nerve palsy resulting from acute Epstein-Barr virus infection]

Irreparable peripheral nerve palsies rarely present as neurological complications in infectious mononucleosis. A case of isolated proximal radial nerve palsy resulting from an acute infection with Epstein-Barr virus is reported. The hand function was restored by multiple tendon transfer surgery.

[Three case reports of frostbite. Management and literature]

Due to social and demographic changes as well as new leisure activities, the number of frostbite injuries in the general population is on the increase. Because the injuries are primarily located on the hands and feet the consequences for those concerned are devastating. We provide help in grading and introduce concrete therapeutic regimes for frostbite which are illustrated by three case reports from our clinical experience with varying risk profiles.

Expression of antimicrobial peptides in cutaneous infections after skin surgery

BACKGROUND

Increasing numbers of antibiotics have lost efficiency because of bacterial resistance. The consequences can be severe when surgical wounds become infected during postoperative care. Natural peptide antibiotics, the so-called host defence peptides (HDPs), have been investigated since the 1990s in a search for alternative treatment strategies. HDPs build up a protection shield against pathological microorganisms, especially in human epithelium. The use of HDPs is currently being discussed as a new antimicrobial therapeutic strategy. Accordingly, a profound knowledge of the quantitative relationships of the effectors is essential.

OBJECTIVES

To evaluate differences in HDP expression between postoperatively inflamed and healthy epithelium.

METHODS

Expression profiles of the genes encoding HDP human beta-defensin (hBD)-1 (DEFB1, previously known as HBD-1), hBD-2 (DEFB4A, previously known as HBD-2), hBD-3 (DEFB103A, previously known as HBD-3) and psoriasin (S100A7) were assessed in samples of surgical wound healing disorders (n = 27) and healthy epithelium (n = 16) by using real-time polymerase chain reaction. Immunohistochemical staining was performed in the same samples.

RESULTS

A significant overexpression of DEFB4A (P < 0.001), DEFB103A (P = 0.001) and S100A7 (P < 0.001) was found in cutaneous surgical site infections. Immunohistochemistry revealed intensely elevated protein levels of psoriasin in infected wounds, and differences in distribution with respect to the epithelial layers.

CONCLUSIONS

The study demonstrates upregulated mRNA expression and protein levels of HDPs in postoperatively inflamed epithelium. The results may be a starting point for novel pharmacological treatments.

Moist Exposed Burn Ointment (MEBO) in partial thickness burns - a randomized, comparative open mono-center study on the efficacy of dermaheal (MEBO) ointment on thermal 2nd degree burns compared to conventional therapy

OBJECTIVE

Wound healing in burn wounds presents a challenge in healthcare, and there is still a lack of alternatives in topical burn wound treatments. - The purpose of this study was to evaluate the efficacy of a new therapeutic ointment (MEBO) in the treatment of partial thickness burns.

METHODS

40 patients received either topical treatment with Moist Exposed Burn Ointment (MEBO) or standard Flammazine treatment. All patients suffered from partial-thickness burn injuries (< 20% TBSA). Wounds were evaluated for 60 up to days regarding wound healing, water loss, inflammation, and pain alleviation.

RESULTS

For transepidermal water loss, there was a difference of 2.3 gr/m2/h between MEBO, and Flammazine, favoring MEBO. However, this difference was not statistically significant (p=0.78). For all secondary efficacy parameter results were similar. -

CONCLUSIONS

This study showed that MEBO ointment for topical treatment of burn injuries presents an attractive alternative for the topical treatment of limited partial thickness thermal burns.

Lymph node metastases in soft tissue sarcomas: a single center analysis of 1,597 patients

PURPOSE

The aim of this study was to examine the clinical course of patients with the rare finding of regional lymph node metastasis (RLNM) from soft tissue sarcoma.

MATERIALS AND METHODS

Data from 28 out of 1,597 consecutive soft tissue sarcoma patients with RLNM were from the patients' charts and interviewing patients and general practitioners. Survival, including possible influencing factors, was statistically calculated.

RESULTS

RLNM was seen in 21.4% for epithelioid sarcoma and 17.6% for clear cell sarcoma. All other entities presented RLNM rates below 10%. At follow-up after an average of 9.6 years, only three patients were alive with no evidence of disease. Survival was independent from surgical resection status of the primary tumor and the RLNM as well as from adjuvant radiation and chemotherapy. Tumor entity as well as the length of the time period from primary to RLNM affect survival.

CONCLUSIONS

Surgical treatment as well as radiation and chemotherapy may improve survival in selected cases but probably have their value much more in terms of local disease control and improvement life quality of patients who probably already suffer from an aggressive systemic disease at time of nodal involvement.

Transient non-viral cutaneous gene delivery in burn wounds

BACKGROUND

Gene transfer to burn wounds could present an alternative to conventional and often insufficient topical and systemic application of therapeutic agents to aid in wound healing. The goals of this study were to assess and optimize the potential of transient non-viral gene delivery to burn wounds.

METHODS

HaCaT cells were transfected with luciferase or beta-galactosidase transgene using either pure plasmid DNA (pDNA) or complexed with Lipofectamine 2000, FuGENE6, or DOTAP-Chol. Expression was determined by bioluminescence and fluorescence. Forty male Sprague-Dawley rats received naked pDNA, lipoplexes, or carrier control intradermally into either unburned skin, superficial, partial, or full-thickness scald burn. Animals were sacrificed after 24 h, 48 h, or 7 days, and transgene expression was assessed.

RESULTS

Gene transfer to HaCaT cells showed the overall highest expression for DOTAP/Chol (77.85 ng luciferase/mg protein), followed by Lipofectamine 2000 (33.14 ng luciferase/mg protein). pDNA-derived gene transfer to superficial burn wounds showed the highest expression among burn groups (0.77 ng luciferase/mg protein). However, lipoplex-derived gene transfer to superficial burns and unburned skin failed to show higher expression.

CONCLUSIONS

Lipofectamine 2000 and DOTAP/Chol lipoplex showed significantly enhanced gene transfer, whereas no transfection was detectable for naked DNA in vitro. In contrast to the in vitro study, naked DNA was the only agent with which gene delivery was successful in experimental burn wounds. These findings highlight the limited predictability of in vitro analysis for gene delivery as a therapeutic approach.

Antimicrobial activity of the recombinant designer host defence peptide P-novispirin G10 in infected full-thickness wounds of porcine skin

OBJECTIVES

The growing number of patients with impaired wound healing and the development of multidrug-resistant bacteria demand the investigation of alternatives in wound care. The antimicrobial activity of naturally occurring host defence peptides and their derivatives could be one alternative to the existing therapy options for topical treatment of wound infection. Therefore, the aim of this study was to investigate the antimicrobial activity of proline-novispirin G10 (P-novispirin G10) in vitro and in the infected porcine titanium wound chamber model.

METHODS

The new derived designer host defence peptide P-novispirin G10 was tested in vitro against Gram-positive and Gram-negative bacterial strains. Additionally, cytotoxicity and haemolytic activities of P-novispirin G10 and protegrin-1 were measured. For in vivo studies, six wound chambers were implanted on each flank of Göttinger minipigs (n = 2, female, 6 months old, 15-20 kg). Eleven wound chambers were inoculated 8 days post-operatively with 5 x 10(8) of Staphylococcus aureus; one wound chamber remained uninfected as a system control. After wound infection had been established (4 days after inoculation), each wound chamber was topically treated with P-novispirin G10, protegrin-1 or carrier control. Wound fluid was harvested every hour for a total follow up of 3 h.

RESULTS

P-novispirin G10 demonstrated broad-spectrum antimicrobial activity with moderate haemolytic and cytotoxic activities compared with protegrin-1. In the infected wound chamber model P-novispirin G10 demonstrated a 4 log(10) reduction in bacterial counts.

CONCLUSIONS

This implicates the potential of P-novispirin G10 as an alternative in future antimicrobial wound care. However, more studies are necessary to further define clinical applications and potential side effects in greater detail.

Improved Neovascularization of PEGT/PBT Copolymer Matrices in Response to Surface Modification by Biomimetic Coating

PEGT/PBT (polyethylene glycol terephthalate/polybutylene terephthalate) copolymer matrices with three different surface coatings [calcium-phosphate (Ca-P), collagen, and gas plasma] were placed into dorsal skinfold chambers of 24 balb/c mice. Untreated PEGT/PBT matrices served as the controls. The basal surfaces of the implants directly contacted the striated skin muscle. Neovascularization of the implants was analyzed by intravital fluorescence microscopy. Microcirculatory observations were performed in the surrounding skin muscle, at the border zone of the implant, and in the center of the implant. The functional vessel density (FVD; mm/mm2), as the length of perfused microvessels per observation area, was measured by computer-assisted analysis. The FVD served as the parameter of neovascularization. At the end of the protocol, histological observation of hematoxylin/eosin-standard-stained sections was performed by light microscopy. The FVD in the center of the implant on day 8 was only observed in gas-plasma-coated (8.8 +/- 10.2 mm/mm2) and Ca-P-coated implants (0.8 +/- 2.0 mm/mm2). None of the other groups showed perfused microvessels in the center of the implant on day 8 (p < 0.05). The FVD values in the center of the gas-plasma-coated and the Ca-P-coated implants were 20.7 +/- 8.2 and 19.2 +/- 15.5 mm/mm2 as compared with 7.1 +/- 17.4 and 7.7 +/- 5.9 mm/mm2 for collagen-coated and untreated implants on day 16. The histological examination confirmed the profound microvascular ingrowth into the matrix pores of the gas-plasma-treated and the Ca-P-coated copolymer matrices in the center of the implants. The study showed that the ingrowth of microvessels into PEGT/PBT matrices can be accelerated by Ca-P coating and gas plasma treatment in the dorsal skinfold chamber in mice.

Metachronous bilateral soft tissue sarcoma of the extremities

BACKGROUND AND AIMS

Synchronous and heterochronous multiple soft tissue sarcoma of the extremities is very rare. Out of 1,201 of our patients, 4 patients presented with symmetrical bilateral soft tissue sarcoma of the extremities. The aim of this study was to identify possible reasons for this unusual manifestation of sarcomas.

MATERIALS AND METHODS

The patients' data was acquired by review of the patients' charts and follow-up information was gathered by phone calls to the patients or their relatives and their general practitioners.

RESULTS

All tumours were located at the extremities and were diagnosed as leiomyosarcoma in two patients, malignant fibrous histiocytoma and clear cell sarcoma in one patient each. No other individual or family history of cumulation of neoplasms was known in the patients. The median interval between the diagnoses was 3 1/2 years (range: 4 months to 9 1/2 years). In two patients a second primary sarcoma of the same entity was considered the most likely diagnosis, whereas in one patient a contralateral lymph node metastasis and in one other patient an atypical soft tissue metastasis had to be taken into account. A positive family history with a father with malignant fibrous histiocytoma may indicate a hereditary predisposition in one patient. Aside from irradiation effects, exposition to other carcinogenic agents or genetic predisposition, the reasons for the clustering of soft tissue sarcoma in one same patient remain still unclear. Only one patient, although suffering from disseminated metastatic disease was living at follow-up time, the other three patients had already died.

CONCLUSION

The interpretation of the bilateral manifestation of soft tissue sarcoma remains open, but predicts an unfavourable outcome.

Analysis of biodegradation of copolymer dermis substitutes in the dorsal skinfold chamber of balb/c mice

PEGT/PBT-block-copolymer dermis substitutes were inserted into dorsal skinfold chambers of balb/c mice (n=36). Scaffolding matrices with 3 different pore diameters (pore diameter: <75 micro m, 75-212 micro m and 250-300 micro m) were analyzed on days 7, 14, and 21 post implantation by scanning electron and light microscopy. The quantification of matrix fragmentation was performed using image-analytical software analySIS(R). The fragmentation rate in scaffolding matrices with a pore size of < 75 micro m was observed to be higher than in matrices of larger pore sizes. Image-analytical evaluation over 21 days revealed a reduction of the copolymer matrix by approximately 32% for the <75 micro m matrices, 23% for the 75-212 micro m matrices and 18% for the matrices, where pore size ranged between 250 micro m and 300 micro m. Twenty-one days after implantation, the matrix pores of 75-212 micro m and 250-300 micro m scaffolds were totally filled by vascularized fibrous tissue. Contrarily, an increased formation of foreign-body giant cells was observed in matrices with pore size <75 micro m. The pore size of the scaffolding PEGT/PBT dermis substitutes affects their degradative behaviour in vivo.

Differenzialdiagnose „steriler“ phlegmonöser Entzündungen der Hand

INTRODUCTION

Bacterial infections represent a large proportion of emergencies in hand surgery. In some cases, pyoderma gangrenosum and mycobacterial infection may present with the same symptoms of swelling, pain, and purulent secretion. In these cases, operative treatment would be harmful. Therefore two cases-pyoderma gangrenosum and tuberculosis-are presented here in relation to common bacterial hand infection.

METHODS

Using two case reports of diseases that only rarely affect the hands, their relevance to differential diagnosis is shown with reference to the literature.

RESULTS

In both cases, we found clinical symptoms of bacterial hand infection with negative bacterial smear tests. After several debridements, pyoderma gangrenosum of the dorsum of the hand was diagnosed in one patient after pyodermiform lesions at the thigh and the nasal septum were detected and pre-existing colitis ulcerosa was taken into consideration. Corticoid therapy induced complete remission. The second patient with similar clinical symptoms had been operated on at another hospital several times before being transferred to our institution. The presumptive diagnosis of pyoderma gangrenosum was made, and under treatment with prednisone the symptoms quickly improved. After 2 weeks, the wound conditions and the patient's condition rapidly worsened. Following amputation at the upper arm level, the patient died of septic multiple organ failure. Autopsy studies revealed tuberculous sepsis originating from the hand.

DISCUSSION

Patient history should be evaluated carefully because of its value to correct diagnosis. In case of negative smear tests, especially from immunocompromised, elderly patients and in patients with a history of pulmonary tuberculosis, Ziehl-Neelsen staining should be obtained. In case of multilocular affection or pre-existing chronic inflammatory bowel disease, the presumptive diagnosis of pyoderma gangrenosum can be confirmed by biopsies from the lesions margin. In both cases, unnecessary traumatizing operations could thus be avoided and treatment optimized.

Polybrene improves transfection efficacy of recombinant replication-deficient adenovirus in cutaneous cells and burned skin

BACKGROUND

The hostile environment found in acute and chronic wounds decreases the physiological half-life of purified synthetic or recombinant peptides dramatically. Gene therapy, on the other hand, may be a viable option since it relies on the cellular machinery of the host to locally manufacture the proteins of interest. The aim of this study was to evaluate and optimize the local administration of transient cutaneous adenoviral gene delivery in wounds.

METHODS

Primary human keratinocytes (HKC) and HaCaT cells were transfected with replication-deficient adenovirus (Ad5) containing the reporter gene for beta-galactosidase (LacZ). The vector was used alone or precoated with either (1) Lipofectamine 2000, (2) FuGENE 6, or (3) Polybrene. For in vivo testing a rat burn model was used. Animals were randomized into three groups: (1) Ad5-LacZ alone; (2) Ad5-LacZ precoated with Polybrene, or (3) carrier control (phosphate-buffered saline (PBS)). Samples were harvested from burned and unburned tissue sections after either 48 h or 7 days. Transgene expression was quantified by bioluminometric assay and localized using immunohistochemistry. A BrdU assay was performed to determine the influence of the used transfection reagents on cell proliferation.

RESULTS

Transfection efficacy was significantly improved in vitro (p < 0.001) as well as in partial thickness burned (p = 0.015) and unburned skin (p > 0.001) after precoating Ad5 with Polybrene compared to Ad5 alone. Transgene expression was 10-fold higher in burned skin (9305 pg/mg protein) compared to unburned skin (859 pg/mg protein).

CONCLUSIONS

It is feasible to improve transfection efficacy in vitro and in vivo by precoating the adenovirus with Polybrene.

Transient cutaneous adenoviral gene therapy with human host defense peptide hCAP-18/LL-37 is effective for the treatment of burn wound infections

Host defense peptides (HDP) are naturally occurring effector molecules of the innate immune system, which might be an alternative to currently used antibiotics. The objective of this study was to investigate the efficiency of transient cutaneous adenoviral transfection with human cathelicidin hCAP-18/LL-37 in infected burn wounds. Specific transgene expression was analyzed in vitro on mRNA and protein level using real-time PCR and Western-blot. Male Sprague-Dawley rats (n=40) received a second degree scald burn on both flanks (5% BSA), which were inoculated with 10(8) colony-forming units (CFU) Pseudomonas aeruginosa. Two days later, rats were randomized into the following groups: (1) adenoviral delivery of LL-37 (Ad5-hCAP-18, n=10), (2) synthetic host defense peptide LL-37 (1 mg; n=10), (3) carrier control (PBS, n=10) and (4) empty-virus control (Ad5-LacZ, n=10). Agents were injected intradermally and subcutaneously into both flanks. After either 2 or 7 days, skin samples were harvested and homogenized. CFU per gram tissue were determined. The hCAP-18/LL-37 expression was confirmed by real-time PCR and localized using in situ hybridization. In vitro transfection of cutaneous cells delivered a specific response on mRNA production. Western blot analysis revealed protein expression of hCAP-18/LL-37 in conditioned medium and cell pellet. The host defense peptide LL-37 was detectable after cleavage of the inactive pro-form hCAP-18/LL-37 with human elastase. Ad5-hCAP-18 showed a significant bacterial inhibition of approximately 10 000 fold compared to the control group (P<0.001) and 1000-fold (P<0.001) compared to the synthetic HDP LL-37 7 post-transfection. No inhibition was observed for the carrier or empty-virus control. Real-time PCR and in situ hybridization confirmed expression of hCAP-18/LL-37. In conclusion, transient cutaneous adenoviral delivery of the host defense peptide hCAP-18/LL-37 is significantly more effective than administration of synthetic host defense peptides and might be a potential adjunct for wound treatment in the near future.

[Serious complications of injections--retrospective analysis of incidences, complication-management, prophylaxis and economic aspects]

The parenteral drug application is a routinely used method in all medical disciplines. Intramuscular, intraarticular, intravenous injections and infusions can cause local complications such as abscesses, articular infections or paravasates. These local complications can lead to bacteraemia, sepsis and may lead to multiple organ failure associated with high morbidity and mortality. Although these complications are rare, they are sometimes disastrous and result in life threatening clinical conditions. During a retrospective analysis (review period 1998-2002) 24 patients were admitted and hospitalized in our department. Within this report we demonstrate 7 patients with fatal complications after injections. In the majority of cases minor patients' complaints were proceeding before major complications were present. A long and expensive treatment period with multiple surgical interventions ends up in functional disabilities and unsatisfactory aesthetic results. Instead of delayed surgical treatment immediate radical surgical care is crucial to prevent disastrous complications. In case of the inability of sufficient debridement, amputations are sometimes indicated in the sense of "life before limb". Besides the consequences for the patient these disastrous complications have a high socioeconomic impact and result in reduced reimbursement for the hospital stay.

A qualitative and quantitative analysis of protein loss in human burn wounds

INTRODUCTION

It is well known that in patients suffering from major burn injuries of more than 15% of total body surface area (TBSA), capillary leak and loss of proteins including immunoglobulins (Ig) lead to cardiovascular failure and significantly elevated risk of infections. However, knowledge of the resulting protein profiles is limited. In order to elucidate quantitative and qualitative protein loss in human burn wounds we compared wound fluid (WF) protein content with serum protein levels.

MATERIAL AND METHODS

Eleven patients suffering from second degree burns of 18-68% TBSA were enrolled in the study. Immediately after admission burn wounds were enclosed in cutaneous vinyl wound chambers covering a 2.25 cm(2) wound surface area. WF and serum samples were harvested every 8 h with a follow up of 48 h and analyzed for total protein content, albumin and the immunoglobulins A, E, G and M.

RESULTS

Protein levels in serum were significantly lower as compared to physiological levels while WF protein levels were elevated and remained high. Total protein (TP) and albumin (AL) accumulated in high concentrations on the wound surface (average accumulation on 10% burnt TBSA within 8 h: TP=16.59+/-8.86 g; AL=12.39+/-5.87 g). The albumin fraction in WF showed increasing values (24 h: 69%; 32 h: 86%) although the serum albumin fraction remained nearly unchanged (55%). Peak values were initially found for all immunoglobulins both in serum and WF. IgA, E and M reached a steady state 32 h post-trauma, whereas IgG continuously decreased until 40 h. IgG values in serum were significantly below physiological levels at all time points.

CONCLUSIONS

This study qualifies and quantifies a significant protein loss in second degree burn wounds. Protein concentrations in wound fluid correlate highly with serum concentrations until 48 h post-burn. A patient's entire amount of serum proteins accumulates in wound fluid in a 20% TBSA burn within approximately 24h. In contrast to capillary leak theory proteins and immunoglobulins extravasate to wound fluid even after 48 h post-trauma.

Activity of histone H1.2 in infected burn wounds

OBJECTIVES

Infections with multidrug-resistant microorganisms (e.g. Pseudomonas aeruginosa and Staphylococcus aureus) cause immense complications in wound care and in the treatment of immunosuppressed patients. Like most antimicrobial peptides, histones are relatively small polycationic proteins located in each eukaryotic nucleus, which naturally supercoil DNA. The aim of this study was to investigate the in vitro and in vivo activity of histone H1.2 in infected burn wounds and its potential toxicity.

METHODS

To characterize the antimicrobial properties of histone H1.2 against potential causative organisms of burn wound infections, the in vitro radial diffusion assay and modified NCCLS microbroth dilution MIC assay were carried out. Haemolytic and cytotoxic properties were determined in human red blood cells and primary human keratinocytes. In vivo antimicrobial activity was tested in an infected rat burn model with P. aeruginosa (ATCC 27853). All results were compared with the naturally occurring broad-spectrum antimicrobial peptide protegrin-1 and with antibiotics clinically used against the corresponding bacteria.

RESULTS

Human histone H1.2 exerted good antimicrobial activity against all tested microorganisms without significant haemolytic activity. Surprisingly, histone H1.2 showed cytotoxicity with an LD50 of 7.91 mg/L in primary human keratinocytes. The in vivo burn model data revealed a significant three-fold higher reduction in bacterial counts within 4 h compared with carrier control.

CONCLUSIONS

These findings indicate that histone H1.2 is a potential candidate for use as a local and, because of its low haemolytic activity, systemic antimicrobial agent. However, further investigations are needed to specify the cytotoxicity and the dose-response relationship for histone H1.2.

New model for in vivo investigation after microvascular breakdown in burns: use of intravital fluorescent microscopy

BACKGROUND

The breakdown of skin microcirculation is assumed to play a key role in the pathophysiology after burn injury. The aim of the present study was to develop a burn model, which allows repetitive quantitative in vivo analysis of the microcirculation after a burn injury, focusing on the interaction between leukocytes and the endothelium.

MATERIALS AND METHODS

Experiments were carried out on male hairless mice. Deep partial thickness burns were inflicted with a no-touch-technique to the ears. Intravital fluorescent microscopy in combination with FITC-dextran as a plasma marker was used to assess microcirculatory parameters. Leukocytes were stained with rhodamine 6G. Preburn baseline data was obtained before as well as 1, 3, 7 and 14 days subsequent to the burn injury.

RESULTS

The non-perfused area decreased significantly over the observed period and perfusion was almost completely restored at day 14. The functional vessel density was characterized by reduction of perfused vessels immediately after burn and an increase after 24h. Leukocyte endothelium interaction significantly increased immediately after injury; baseline values were reached 1 day later. The extravasation of the plasma marker into the surrounding tissue increased immediately after burn, decreased at day 1 and remained at this level during the following observation time. The venular as well as the arterial blood flow increased immediately subsequent to the burn injury, decreased after 1 day and reached baseline values at day 3.

CONCLUSION

The presented burn model allows quantitative assessment of the dynamics of microcirculatory disturbances after thermal trauma by high quality visualization of both plasma stained microvessels and leukocyte-endothelium interaction.

[Gorham-Stout disease: report of a case affecting the right hand with a follow-up of 24 years]

Gorham-Stout disease is a rare idiopathic syndrome with distinctive clinical, pathologic and radiologic features. It is a variant form of osseus angiomatosis associated with massive osteolysis of bone. Usually appearing after trauma, the disease is described to occur at any age. Especially in case of thoracic involvement (chylothorax), lethal outcomes are reported. In Medline, about 200 cases have been described. A patient with osteolysis of the right hand following contusion at the age of two years is reported. Despite radiotherapy and repeated bone grafting, the osteolysis progressed until today (24 years). The pathologic features and various treatment methods for hand involvement are discussed.

Host defense peptides in burns

Overuse of antibiotics and failure to apply basic infection control policies and procedures have contributed to the increasing multi-drug resistance of many nosocomial pathogens. The alarming increase of multi-drug-resistant bacteria (e.g. Pseudomonas aeruginosa, methicilin-resistant Staphylococci, vancomycin-resistant Enterococci) causes infected wounds associated with high mortality and morbidity in burned patients and focuses attention on the need for better treatment and prevention of wound infections. The review points out and discusses some emerging alternatives to antibiotics used in clinical practice, with special emphasis on the role of the innate immune response and potential application of human host defense peptides in thermal injury.

The impact of topical antiseptics on skin microcirculation

AIM

Antiseptics are commonly used in clinical practice to disinfect tissue and to avoid infections. However, topical antiseptics are assumed to have an influence on skin microcirculation, per se. Thus, the aim of the study was to analyse the influence of topically applied antiseptics on the microcirculation of intact skin in vivo.

MATERIALS AND METHODS

The investigation was carried out on ears of male hairless mice (SKH-1hr, n = 25). The influence of four antiseptics was examined. Sodium chloride 0.9% served as control. An alcohol-based solution with a mixture of ethanol, 2-propanol and purified water (Softasept), an antiseptic with octenidine dihydrochloride and phenoxyethanol as the main active agents (Octenisept), as well as hexamethylenbiguanide (Lavasept) and 70% ethanol were tested. Intravital fluorescence microscopy in combination with intravenous injection of the fluorescence dyes FITC-Dextran as plasma marker and Rhodamine 6G (leukocyte staining) allowed a quantitative analysis of standard microcirculatory parameters (vessel diameter, functional capillary density, red blood cell velocity, FITC-leakage and leukocyte endothelium interaction). Recordings of the microcirculation in several regions of interest (ROI) were made prior to application and after 10 min exposure time and 60 min after the baseline data. Data were evaluated off-line with aid of computer assisted analysis.

RESULTS

The diameter of arterioles decreased after the treatment with the alcoholic solutions. The other two antiseptics (Octenisept and Lavasept) caused a significant increase. Functional capillary density (FCD) was significantly reduced after application of ethanol and Softasept. There was no reduction of FCD following application of Octenisept. After treatment with ethanol and Softasept there was a significant decrease in red blood cell velocity (RBCV). The use of Lavasept revealed a decrease of FCD and RBCV. In the Octenisept treated group RBCV shows a mild increase after 10 minutes. The application of ethanol, Softasept and Lavasept was characterized by a significant increase of leukocyte endothelium interaction (LEI). After treatment with saline and Octenisept LEI remained constant. All used antiseptics except of Octenisept caused a significant leakage of FITC-Dextran.

CONCLUSION

The antiseptics used in this study all showed an influence on skin microcirculation. As expected, our findings show that the alcoholic solutions are most aggressive to skin microcirculation.

Liposuktion?kein Problem?

Subcutaneous liposuction in tumescent technique is the most frequent aesthetic plastic procedure in the United States. In Germany, nearly 250,000 liposuctions are done per year by a variety of surgical and nonsurgical specialists including plastic surgeons, dermatologists, gynecologists, oral surgeons, and otolaryngologists in settings ranging from hospital operating rooms to physicians' offices. The method is applied and promoted as an easy-to-learn technique that is suited as an outpatient procedure. Although major complications seem to be rare, there are definite risks, including death at a rate of 1/5,000 procedures. Major risk factors are insufficient hygiene standards, multiliter wetting solution infiltration, megavolume aspiration, multiple cosmetic procedures in one setting, sedative and anesthetic drug hangover threatening ventilation, permissive postoperative discharge, and mistakes in patient selection. When major complications occur, office-based practitioners may refer patients to hospital emergency departments, where medical personnel unfamiliar with this procedure may underestimate the risk of major complications.

[Intravital microscopic analysis of perfusion, leukocyte-endothelial cell interaction and neovascularization after burns: an in vivo study of SKH-1/hr hairless mice]]

Breakdown of skin microcirculation is supposed to play a key role in pathophysiology of burn injury. The aim of the study was to develop a burn model, which allows repetitive quantitative in vivo analysis of microcirculation after burn injury with special focus on leukocyte endothelium interaction over a longer period of time. Male hairless mice (SKH-1/hr) were used. Deep partial thickness burns were inflicted in no-touch-technique to the ears. Intravital fluorescent microscopy in combination with FITC-dextran as a plasma-marker was used to assess standard microcirculatory parameters. Leukocytes were stained with rhodamine-6-G to study their interaction with the endothelium.

Protegrin-1 enhances bacterial killing in thermally injured skin

OBJECTIVE

Septic complications and the emergence of drug-resistant microbes represent serious risks to patients. Recently, naturally occurring peptides have been discovered that possess potent and broad-spectrum antimicrobial activity. Protegrin-1 is particularly attractive for clinical use in human wounds because, unlike defensins, protegrin-1 retains broad antimicrobial and antifungal activity at physiologic salt concentration and in the presence of serum. The objective of this study was to examine the efficacy of protegrin-1 in killing multiple drug-resistant microbes isolated from human burn patients.

DESIGN

For thein vitroexperiment, bilayer radial diffusion was performed comparing standard antibiotics with protegrin-1 on multiple-drug-resistant microbial organisms isolated from infected burn wounds. In vivo, rats received a 20% total body surface area partial-thickness burn by immersion in 60 degrees C water for 20 secs followed by wound seeding with 106 colony forming units of Silvadene-resistant Pseudomonas aeruginosa.

SETTING

University of Michigan research laboratory.

SUBJECTS

Adult, male Sprague-Dawley rats.

INTERVENTIONS

Rats were randomized into three groups: those receiving synthetic protegrin-1, acetic acid (carrier), or gentamicin (positive control). Protegrin-1 was administered by topical application or intradermal injection. Wound tissues were harvested aseptically at different time points for quantitative bacterial counts.

MEASUREMENTS AND MAIN RESULTS

In vivo and in vitro experiments revealed rapid and significant decreases in bacterial counts for protegrin-1-treated groups compared with controls.

CONCLUSIONS

This study shows that protegrin-1 potentially may be used as an alternative or adjunct therapy to standard agents used to treat wound infections.

Feasibility of biolistic gene therapy in burns

Skin is an especially attractive target for genetic manipulation because it is readily accessible and easily monitored for both the presence and the expression of inserted genes. This study was designed to assess the feasibility of particle mediated gene transfer to burned skin and to compare the transfection efficiency, anatomic distribution, and duration of transgene expression achievable in normal versus burned skin. Two days following scald injury of varying depths in 60 degrees C water (10 s: superficial partial; 20 s: deep partial; 40 s: full thickness) reporter gene (beta-galactosidase) constructs were delivered using a gene gun at various helium pressures (200-600 psi) to normal and burned skin. A time course study was performed to examine the kinetics of transgene expression. Animals received a superficial partial thickness burn and were sacrificed 12 h, 1, 3, 5, 7, 14, or 21 days after gene transfer. India Ink injection and immunohistochemistry were used to assess the depth of the scald injury. Transfection efficiency was measured in skin homogenates 24 h after gene transfer by morphometric and chemoluminescent assays. We found that the extent of tissue damage was directly related to the duration of heat source exposure. Reporter gene activity was significantly higher in superficial partial thickness burns compared to normal controls and gradually declined with increasing tissue injury. No activity was seen in the full thickness burn group. Beta-galactosidase activity reached a maximum level 12 h after gene transfer in both normal and superficial partial thickness burned skin with no levels seen after 5 days post-transfection. These findings indicate that particle-mediated gene transfer in thermally injured skin is feasible and may provide a means of introducing biologic agents into injured tissue capable of enhancing bacterial clearance and improving wound healing.

Lipopolysaccharide-binding protein accelerates and augments Escherichia coli phagocytosis by alveolar macrophages

BACKGROUND

The first step in bacterial clearance by leukocytes is attachment and phagocytosis. Although lipopolysaccharide-binding protein (LBP) is best known for potentiating LPS-induced cytokine production through a CD14-dependent pathway, recent studies suggest that LBP plays a critical role in clearance of gram-negative bacteria and is essential for survival after bacterial challenge. We therefore sought to examine LBP's effect on Escherichia coli phagocytosis by alveolar macrophages (AMs) and to determine if this effect is mediated through CD14.

MATERIALS AND METHODS

Phosphatidylinositol-specific phospholipase C (PIPLC)-treated and untreated rat AMs were incubated in the presence of increasing doses of recombinant LBP or negative control protein (choramphenicol acetyltransferase) prior to E. coli-FITC (Ec-F) BioParticle challenge. Phagocytosed bacteria were assayed by fluorescence measurement. A time course study was also performed.

RESULTS

LBP potentiated phagocytosis of Ec-F BioParticles by AMs in a dose-dependent fashion. Kinetic studies showed that LBP augmented Ec-F phagocytosis by 76% at 30 min. Treatment of AMs with PIPLC to remove CD14 resulted in only a partial decrease in LBP-mediated enhancement of phagocytosis.

CONCLUSION

These results clearly demonstrate that LBP plays an important role in enhancing Ec-F binding and phagocytosis in a time- and dose-dependent manner. This observed increase may not require the presence of CD14 as significant potentiation of phagocytosis still occurred after PIPLC treatment. We postulate that the LBP-mediated increase in Ec-F phagocytosis can occur in the absence of CD14 through the presence of another receptor.

Skin lipopolysaccharide-binding protein and IL-1beta production after thermal injury

In response to a burn injury, skin can have an inflammatory response characterized by the production of inflammatory cytokines, recruitment of immune cells, containment of invading organisms, and clearance of noxious substances from the wound. Lipopolysaccharide-binding protein (LBP) is a molecule that is capable of coordinating all 4 functions; we previously found evidence that suggested that LBP is produced within surgical wounds. Because of the central role of LBP in the response to bacterial infection, as well as in the high rate of infection after burn injuries, we sought to determine whether a thermal injury could affect wound LBP production and thereby affect host responses against bacterial infection. Rats were given either a burn or a sham burn and were killed 24, 48, and 72 hours after the injuries. Wound specimens were assayed for bacterial counts and for the presence of LBP, messenger (m)RNA, and interleukin (IL)-1beta mRNA. Wound LBP mRNA was significantly upregulated at 24 hours in the group with burn injuries (P < .05; burn vs sham burn); this was followed by decreases at 48 and 72 hours. Immunohistochemistry showed LBP protein in the epidermis of animals with burns. Bacterial counts increased in the group with burn injuries (P < .05; burn vs sham burn) and continued to rise for 72 hours. IL-1beta mRNA levels were elevated at all time points in the group with burn injuries (P < .05). These results suggest an inverse correlation between burn wound LBP expression and bacterial wound counts. This failure to maintain local LBP production after severe thermal injury despite localized inflammation shown by high IL-1beta levels may predispose local wounds to bacterial invasion.

Kupffer cell activation by lipopolysaccharide in rats: role for lipopolysaccharide binding protein and toll-like receptor 4

Lipopolysaccharide (LPS) binding protein (LBP) is a key serum factor that mediates LPS activation of mononuclear cells. In the presence of LBP, 1/1,000 the concentration of LPS is sufficient to activate peripheral blood monocytes. Previous studies with Kupffer cells have shown a variable effect of serum on LPS activation of these cells and led to the conclusion that, unlike extrahepatic mononuclear cells, Kupffer cells do not respond to LPS in an LBP-dependent fashion. Because there are multiple components in serum other than LBP that might affect LPS activation, these reports with serum are difficult to interpret. To investigate the specific role of LBP in LPS activation of Kupffer cells, we produced a functional recombinant rat LBP using a baculovirus expression system, which we used to selectively examine the role of LBP's on Kupffer-cell function. Isolated Kupffer cells exposed to increasing concentrations of LPS (0, 1, 10 ng/mL) showed a dose-dependent increase in TNF-alpha production, which was augmented and accelerated by the presence of LBP. The effects of LBP on Kupffer cell activation by LPS are dependent on a functional Toll-like receptor 4 (Tlr 4) because Kupffer cells from C3H/HeJ mice failed to respond to LPS in the presence of LBP. LBP plays an important role in mediating Kupffer cell activation by LPS, and these effects are dependent on the presence of functioning Tlr 4.