A New Ex Vivo Human Skin Burn Model.

Currently, most burn models for preclinical testing are on animals. For obvious ethical, anatomical, and physiological reasons, these models could be replaced with optimized ex vivo systems. The creation of a burn model on human skin using a pulsed dye laser could represent a relevant model for preclinical research. Six samples of excess human abdominal skin were obtained within one hour after surgery. Burn injuries were induced on small samples of cleaned skin using a pulsed dye laser on skin samples, at varying fluences, pulse numbers and illumination duration. In total, 70 burn injuries were performed on skin ex vivo before being histologically and dermato-pathologically analyzed. Irradiated burned skin samples were classified with a specified code representing burn degrees. Then, a selection of samples was inspected after 14 and 21 days to assess their capacity to heal spontaneously and re-epithelize. We determined the parameters of a pulsed dye laser inducing first, second, and third degree burns on human skin and with fixed parameters, especially superficial and deep second degree burns. After 21 days with the ex vivo model, neo-epidermis was formed. Our results showed that this simple, rapid, user-independent process creates reproducible and uniform burns of different, predictable degrees that are close to clinical reality. Human skin ex vivo models can be an alternative to and complete animal experimentation, particularly for preclinical large screening. This model could be used to foster the testing of new treatments on standardized degrees of burn injuries and thus improve therapeutic strategies.

Recurrent embolic strokes due to antiphospholipid syndrome and non-bacterial thrombotic endocarditis in a patient with basal cell carcinoma.

BACKGROUND: Non-Bacterial Thrombotic Endocarditis (NBTE) is a common form of aseptic thrombotic endocarditis that primarily affects mitral valves and less frequently aortic valves. NBTE is caused by systemic inflammatory reactions. This condition induces valve thickening or attached sterile mobile vegetation. NBTE is mostly asymptomatic; however, major clinical manifestations result from systemic emboli rather than valve dysfunction. When significant damage occurs, valvular insufficiency or stenosis can appear and promote heart failure occasionally requiring valve replacement surgery. NBTE is associated with hypercoagulable states, systemic lupus erythematous (SLE), antiphospholipid syndrome, or malignancies. CASE PRESENTATION: We report successful biological aortic valve replacement surgery including cardiopulmonary bypass for a 78-year-old man with NBTE and voluminous vegetation on the aortic valve inducing moderate aortic insufficiency and acute heart failure. The histopathological analysis of the valve sample showed myxoid degeneration, fibrous remodeling, and partial necrosis without any bacteria, thus indicating marantic endocarditis. Initially, the patient presented to the emergency department with an acute stroke. He was already using Apixaban treatment for a history of atrial fibrillation and cardioembolic stroke. Because of the recurrence of stroke and appearance of aortic vegetation, the investigations were extended. The antiphospholipid antibodies were positive without any indication of bacterial endocarditis. The malignancy screening was positive for basal cell carcinoma (BCC). The surgery and postoperative course were uneventful, and the patient was discharged with vitamin K antagonists (VKA). To our knowledge, NBTE with such a volume is rare and its apparent association with BCC has not been previously reported. CONCLUSION: Outside of SLE and antiphospholipid syndrome, NBTE is a rare and underdiagnosed disease associated with thromboembolic events. Adequate anticoagulation is a cornerstone of its treatment. Anticoagulation management during perioperative care and valve surgery deserves specific attention and helps to protect the patient from embolic complications. In the case of stroke and thromboembolic events of unclear cause or suspected NBTE, echocardiography and thrombophilia assessments including an immunological workup are recommended.