Severe burn injuries induced by PUVA chemotherapy.

Psoralen-ultraviolet A (PUVA) chemotherapy is an established treatment for certain skin diseases. Burn injury is a serious complication of PUVA therapy. Reports regarding this complication are limited. The aim of this study was to determine the management and outcome of severe PUVA burns. A retrospective review of the medical records of PUVA burns treated at our burn center from 2000 to 2010 was conducted. Data collected included age, sex, condition, mode of PUVA, site, surface area involved, depth of burns, onset of reactions, treatment, and inpatient stay. To evaluate the incidence of this severe complication, a survey of all listed burn care units in Germany, Austria, and Switzerland as well as the legal advisory boards of the medical associations of the federal states of Germany was conducted. The conditions leading to photochemotherapy were three cases of psoriasis vulgaris and one case of severe chronic graft vs host disease. All patients received oral psoralen. Incorrect handling of the radiation system was the reason for all burns. The mean affected TBSA was 73±18%. All patients were treated conservatively and healed without surgical intervention. Burn injury is a serious and preventable complication of PUVA photochemotherapy. Patients should be advised regarding the potential risk of major burns. Care should be given to not exceed the safe dose of psoralen. Burn care specialists must restrain surgical intervention as even deep partial thickness PUVA burns have the potential to heal spontaneously.

Establishing efficient xenograft models with intrinsic vascularisation for growing primary human low-grade sarcomas.

BACKGROUND: There are no xenograft models of low-grade soft tissue sarcoma. Transplant survival remains an obstacle in sarcoma xenograft models and is attributed to post-transplantation hypoxia. Models with an intrinsic tissue - engineered vascular supply may overcome this obstacle. The aim of this study was to establish a novel xenograft model of primary human low grade soft tissue sarcoma. MATERIALS AND METHODS: Primary low-grade liposarcoma fragments were transplanted into a silicon chamber, placed around the superficial epigastric vessels in athymic nude mice. Xenograft samples were assessed histologically (light/electron microscopy and immunohistochemistry for S100). RESULTS: All xenotransplants of low grade primary soft tissue liposarcoma (n=4) engrafted, led to the development of solid tumours in mice. Histological and immunohistochemical staining confirmed the xenografts as being well-differentiated liposarcomas identical to the original tumor tissue. CONCLUSION: Successful transplantation of human low-grade liposarcoma tissue in mice was established for the first time using a model with an intrinsic vascular supply.

Surface modification by glow discharge gasplasma treatment improves vascularization of allogenic bone implants.

Sufficient induction of blood vessel ingrowth decisively influence transplant functionality. In this study, microvascular response to transplants of surface modified bone substitutes were assessed in vivo. The surface modification of allogenic bone substitutes (dehydrated human femoral head) was achieved in a double-conductive low-pressure gasplasma reactor (Ar(2) /O(2) , 13.65 MHz, 1,000 W, 5 Pa). The modified bone substitutes (n = 10) as well as untreated bone substitutes serving as controls (n = 10) were placed into the dorsal skinfold chamber of female balb/c mice (n = 10). Dynamic assessment of microcirculatory parameters was performed using intravital fluorescence microscopy during an implantation period of 10 days. The angiogenic response was found markedly accelerated in gasplasma-treated bone. Compared to untreated implants, the gasplasma-activated bone substitutes showed significantly higher microvascular density on days 5 and 10. The quantification of the microvascular diameters, red blood cell velocity, and microvascular permeability displayed stable perfusion and vascular integrity of the newly developed blood vessels throughout the 10-day observation period. The surface activation via cold low-pressure glow discharge gasplasma supports the vascular integration of allogenic bone by earlier induction of the angiogenesis.

Enhanced neovascularization of dermis substitutes via low-pressure plasma-mediated surface activation.

PURPOSE: The effect of cold low-pressure plasma treatment on neovascularization of a dermis substitute was evaluated in a mouse model. MATERIAL AND METHODS: Collagen-elastin matrices (Matriderm(®)) were used as scaffolds. Low-pressure argon/hydrogene plasma-treated scaffolds were transplanted into the dorsal skinfold chambers of balb/c mice (group 1, n=10). Untreated scaffolds served as controls (group 2, n=10). Intravital fluorescence microscopy was performed within the border zone of the scaffolds on days 1, 5 and 10. Functional vessel density (FVD), vessel diameter, intervascular distance, microvascular permeability, and leukocyte-endothelium interaction were analyzed. RESULTS: An increase of FVD associated with a reduction of the intervascular distance was observed. Statistical analysis revealed that the functional vessel density in the border zone of the scaffolds was significantly enhanced in the plasma-treated group compared to controls. For group 1, an increase of FVD from 282±8 cm/cm(2) on days 5 to 315±8 cm/cm(2) on day 10 was observed. Whereas values of 254±7 cm/cm(2) on day 5 and 275±13 cm/cm(2) on day 10 have resulted in group 2 (mean±S.E.M., Student's t-test, p<0.05). CONCLUSION: The surface treatment by cold low-pressure plasma intensifies the angiogenesis and accelerates the neovascularization of collagen-elastin matrix.