Michele R. Colonna

Effect of recombinant adeno-associated virus vector-mediated vascular endothelial growth factor gene transfer on wound healing after burn injury.

ObjectiveThe purpose of this study was to investigate the effect of recombinant adeno-associated viral (rAAV) vector-mediated human vascular endothelial growth factor (VEGF165) transfer on experimental burn wounds. DesignRandomized experiment. SettingResearch laboratory. SubjectsC57BL/6 male mice weighing 25–30 g. InterventionsMice were immersed in 80°C water for 10 secs to achieve a partial-thickness scald burn. Animals were randomized to receive at two injection sites on the edge of the burn either 1011 copies of the rAAV-VEGF165 or the vector carrying the control and inert gene &bgr;-galactosidase (rAAV-LacZ). On day 14 the animals were killed. Burn areas were used for histologic examination, evaluation of VEGF expression (immunohistochemistry) and VEGF wound content (enzyme-linked immunosorbent assay), determination of wound nitrite, and measurement of messenger RNA (mRNA) for endothelial and inducible nitric oxide synthase (eNOS and iNOS). Measurements and Main ResultsrAAV-VEGF165 increased epithelial proliferation, angiogenesis, and maturation of the extracellular matrix. Furthermore, gene transfer enhanced VEGF expression, studied by immunohistochemistry, and the wound content of the mature protein (rAAV-LacZ, 11 ± 5 pg/wound; rAAV-VEGF165, 104 ± 7 pg/wound). Moreover, VEGF165 gene transfer increased wound content of nitrate. Finally, rAAV-VEGF165 administration enhanced the messenger RNA for eNOS (rAAV-VEGF165, 1.1 ± 0.2 relative amount of eNOS mRNA; rAAV-LacZ, 0.66 ± 0.3 relative amount of eNOS mRNA) and iNOS (rAAV-VEGF165, 0.8 ± 0.09 relative amount of iNOS mRNA; rAAV-LacZ, 0.45 ± 0.05 relative amount of iNOS mRNA). ConclusionOur study suggests that rAAV-VEGF gene transfer may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

Lipid peroxidation inhibition by raxofelast improves angiogenesis and wound healing in experimental burn wounds.

We investigated the effects of raxofelast, a lipid peroxidation inhibitor, in an experimental model of burn wounds. C57BL/6 male mice of 25-30 g were immersed in 80°C water for 10 seconds to achieve a partial-thickness scald burn. Animals received intraperitoneally either raxofelast (20 mg/kg/day for 14 days in 100 μL) or its vehicle alone (100 μL/day for 14 days). On day 14, burn areas were used for measuring conjugated dienes, reduced glutathione levels, histological damage, neoangiogenesis by immunohistochemistry and expression (Western blot) of the specific endothelial marker CD31 as well as quantification of microvessel density, VEGF wound content, endothelial and inducible nitric oxide synthase (eNOS and iNOS) expression and wound nitrite content. Raxofelast decreased tissue conjugated dienes (vehicle 6.1 ± 1.4 ΔABS/mg protein; raxofelast 3.7 ± 0.8 ΔABS/mg protein), prevented tissue glutathione consumption (vehicle 3.2 ± 0.9 μmol/g protein; raxofelast 6.7 ± 1.8 μmol/g protein), increased epithelial proliferation, extracellular matrix maturation, and augmented neoangiogenesis as suggested by the marked increase in microvessel density and by the robust expression of the specific endothelial marker CD31 (vehicle 9.4 ± 1.1 integrated intensity; raxofelast 14.8 ± 1.8 integrated intensity). Furthermore, raxofelast enhanced VEGF wound content (vehicle 1.4 ± 0.4 pg/mg protein; raxofelast 2.4 ± 0.6 pg/mg protein), caused a marked expression of eNOS (vehicle 16.1 ± 3 integrated intensity; raxofelast 26.2 ± 4 integrated intensity) and iNOS (vehicle 9.1 ± 1.8 integrated intensity; raxofelast 16.2 ± 3.5 integrated intensity) and increased wound nitrite content. Lipid peroxidation inhibition by raxofelast may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

A FREE VEIN GRAFT CAP INFLUENCES NEUROMA FORMATION AFTER NERVE TRANSECTION

Neuroma formation is a major problem in nerve surgery and consensus about its prevention has not been reached. It has been suggested that vein covering can reduce neuroma formation in transected nerves. In this article, the Authors propose an easy and novel method of covering by nerve stump capping with a free vein graft.

Inhibition of inflammasome activation improves the impaired pattern of healing in genetically diabetic mice

Type 2 diabetes impairs the healing process because of an exaggerated and persistent inflammatory response, and an altered expression pattern of angiogenic molecules. We investigated the effects of inflammasome blockade in diabetes‐related wound‐healings defects, in genetically diabetic mice.

Use of free scapular crest flap in pediatric epiphyseal reconstructive procedures

Studies have been underway since 1981 on the scapular anatomic unit as a new donor site for reconstructive surgery. Anatomic studies have proven that this diaphyseal bone has a large osteocartilaginous growth epiphysis at its inferior pole, which is responsible for development of 80% of the surface of the scapula. Experimental investigations and clinical studies have revealed minimal functional limitation because of loss of the scapular crest and that its growth plate can be used beneficially for vascularized bone transfer. Four cases are reported with good results based on 2 to 14 years followup without significant impairment of the donor site.

The umbilicus: a rare site for melanoma. Clinical considerations in two cases. Case reports.

The umbilicus is a rare site for malignant melanoma. We report two cases of umbilical melanoma and analyse the mechanisms of diffusion of the neoplasm in relationship to the arterial, venous, and lymphatic anatomy of the region. Because of the peculiarity of these connections, we propose a revision of the concept of melanoma stage for the umbilical region.

Free osteocutaneous scapular apophysis flap for reconstruction of the lateral malleolus.

Lateral malleolus avulsion is uncommon, and fusion of the syndesmosis of the ankle joint is usually performed in such cases. Others have reported successful reconstruction of the lateral malleolus with a vascularized fibular head. A case of reconstruction in a 17-year-old girl, with a free scapular apophysis flap, is presented and compared with alternative flaps available. The anatomy and development of the scapular crest with its cartilaginous apophysis are discussed.

AAV vector encoding human VEGF165–transduced pectineus muscular flaps increase the formation of new tissue through induction of angiogenesis in an in vivo chamber for tissue engineering: A technique to enhance tissue and vessels in microsurgically engineered tissue

In regenerative medicine, new approaches are required for the creation of tissue substitutes, and the interplay between different research areas, such as tissue engineering, microsurgery and gene therapy, is mandatory. In this article, we report a modification of a published model of tissue engineering, based on an arterio-venous loop enveloped in a cross-linked collagen–glycosaminoglycan template, which acts as an isolated chamber for angiogenesis and new tissue formation. In order to foster tissue formation within the chamber, which entails on the development of new vessels, we wondered whether we might combine tissue engineering with a gene therapy approach. Based on the well-described tropism of adeno-associated viral vectors for post-mitotic tissues, a muscular flap was harvested from the pectineus muscle, inserted into the chamber and transduced by either AAV vector encoding human VEGF165 or AAV vector expressing the reporter gene β-galactosidase, as a control. Histological analysis of the specimens showed that muscle transduction by AAV vector encoding human VEGF165 resulted in enhanced tissue formation, with a significant increase in the number of arterioles within the chamber in comparison with the previously published model. Pectineus muscular flap, transduced by adeno-associated viral vectors, acted as a source of the proangiogenic factor vascular endothelial growth factor, thus inducing a consistent enhancement of vessel growth into the newly formed tissue within the chamber. In conclusion, our present findings combine three different research fields such as microsurgery, tissue engineering and gene therapy, suggesting and showing the feasibility of a mixed approach for regenerative medicine.

Dorsalis Pedis Adipofascial Perforator flap for great toe reconstruction: Anatomical study and clinical applications

Defects of the dorsum of the foot can be challenging to reconstruct, none more so than the dorsum of the toe. The reverse Dorsalis Pedis Adipofascial Perforator (DPAP) flap is one possible reconstructive option for defects in this region. The aim of this study was to first demonstrate the anatomy of this flap, particularly the consistency of the perforators arising from the dorsalis pedis artery. Second, we present a clinical series based on this flap to demonstrate how it can be used. For the anatomical studies, 22 fresh cadaveric lower extremities were dissected, and injection studies were used to delineate the vascular territories. The presence of the distal perforator, distance to the first metatarso-phalangeal joint and diameter of each perforator were recorded. The cadaveric studies confirmed the presence of distal perforators to the first metatarso-phalangeal joint in 100% of limbs examined. The clinical study demonstrated the feasibility of the use of the adipofascial turn-over perforator flap for dorsal foot reconstruction. These anatomic findings provide an alternative method of reconstruction of great toe defects using the reverse DPAP flap.

Babysitting procedures in proximal nerve trunk injuries: two case reports and a review

One of the most important goals in treating proximal nerve injuries is to maintain the function of distal effectors during axonal regeneration. Babysitting, that is, connecting the injured nerve to a healthy trunk provides a bypass for distal neural regeneration or reactivation. It avoids degeneration of sensory and motor terminations, with minimal donor nerve damage. We present a technique where a nerve graft is used between ulnar and median nerve through two end-to-side sutures in the distal third of the forearm, in two different cases of proximal ulnar nerve injury. Both patients were young manual workers, the former suffered a total nerve disruption proximal to the elbow following a car accident and the latter suffered a perineurial scar from a high voltage injury at the proximal third of the forearm. The proximal injury was grafted with a sural nerve in the former and treated by neurolysis in the latter. Results were graded by the Highet-Zachary scale for both sensory and motor recovery. The outcomes of our series were compared to six other case reports in the literature (including median nerves) treated with this technique. Both clinical and experimental data show that babysitting effectively protects distal effectors.