A 62-Year-Old Woman With Acute Respiratory Failure and a Painful Right Lower Limb.

CASE PRESENTATION: A 62-year-old woman with no medical history was admitted to the ED for fever, acute respiratory failure, and pain in the right lower limb. Three months prior to presentation, she had spent 45 days travelling through India and Thailand. She presented with no signs of traveler's disease such as fever or diarrhea during that trip. Two weeks following her return to France, the patient presented with an episode of bronchitis and received 5 days of treatment with cefixime (a third-generation cephalosporin). Despite this antibiotic treatment, her symptoms worsened and she developed, over the following 3 weeks, general weakness and arthralgia/myalgia. Due to the severity of hypoxemia, the patient was immediately transferred to the ICU.

Hemodialysis vascular graft as a focus of persistent Q fever.

Vascular access infection is a frequent complication in hemodialysis patients. We report the second case worldwide of a prosthetic hemodialysis vascular graft infection by Coxiella burnetii, with intense hypermetabolism on PET-CT, Q fever serology consistent with persistent infection, and positive C. burnetii DNA in the blood and removed vascular graft.

In Vivo Evaluation and Imaging of a Bilayered Self-Assembled Skin Substitute Using a Decellularized Dermal Matrix Grafted on Mice.

As time to final coverage is the essence for better survival outcome in severely burned patients, we have continuously strived to reduce the duration for the preparation of our bilayered self-assembled skin substitutes (SASS). These SASS produced in vitro by the self-assembly approach have a structure and functionality very similar to native skin. Recently, we have shown that a decellularized dermal matrix preproduced by the self-assembly approach could be used as a template to further obtain self-assembled skin substitute using a decellularized dermal template (SASS-DM) in vitro. Thus, the production period with patient cells was then reduced to about 1 month. Herein, preclinical animal experiments have been performed to confirm the integration and evolution of such a graft and compare the maturation of SASS and SASS-DM in vivo. Both tissues, reconstructed from adult or newborn cells, were grafted on athymic mice. Green fluorescent protein-transfected keratinocytes were also used to follow grafted tissues weekly for 6 weeks using an in vivo imaging system (IVIS). Cell architecture and differentiation were studied with histological and immunofluorescence analyses at each time point. Graft integration, macroscopic evolution, histological analyses, and expression of skin differentiation markers were similar between both skin substitutes reconstructed from either newborn or adult cells, and IVIS observations confirmed the efficient engraftment of SASS-DM. In conclusion, our in vivo graft experiments on a mouse model demonstrated that the SASS-DM had equivalent macroscopic, histological, and differentiation evolution over a 6-week period, when compared with the SASS. The tissue-engineered SASS-DM could improve clinical availability and advantageously shorten the time necessary for the definitive wound coverage of severely burned patients.

Tissue-engineered vascular adventitia with vasa vasorum improves graft integration and vascularization through inosculation.

Tissue-engineered blood vessel is one of the most promising living substitutes for coronary and peripheral artery bypass graft surgery. However, one of the main limitations in tissue engineering is vascularization of the construct before implantation. Such a vascularization could play an important role in graft perfusion and host integration of tissue-engineered vascular adventitia. Using our self-assembly approach, we developed a method to vascularize tissue-engineered blood vessel constructs by coculturing endothelial cells in a fibroblast-laden tissue sheet. After subcutaneous implantation, enhancement of graft integration within the surrounding environment was noted after 48 h and an important improvement in blood circulation of the grafted tissue at 1 week postimplantation. The distinctive branching structure of end arteries characterizing the in vivo adventitial vasa vasorum has also been observed in long-term postimplantation follow-up. After a 90-day implantation period, hybrid vessels containing human and mouse endothelial cells were still perfused. Characterization of the mechanical properties of both control and vascularized adventitia demonstrated that the ultimate tensile strength, modulus, and failure strain were in the same order of magnitude of a pig coronary artery. The addition of a vasa vasorum to the tissue-engineered adventitia did not influence the burst pressure of these constructs. Hence, the present results indicate a promising answer to the many challenges associated with the in vitro vascularization and in vivo integration of many different tissue-engineered substitutes.