Faculty Bibliography

Background : Reports after the 2005 Hurricane Katrina have documented an increase in stress reactions and environmental teratogens (arsenic, mold, alcohol). Objective : To assess the incidence of cleft pathology before and after the hurricane, and the distribution of cleft cases by gender and race. Methods : Retrospective chart review of cleft lip with or without cleft palate (CL/P) and cleft palate (CP) cases registered with the Cleft and Craniofacial Team at Children's Hospital of New Orleans, the surgical center that treated cleft cases in Greater New Orleans between 2004 and 2007. Live birth data were obtained from the Louisiana State Center for Health Statistics. Results : The incidence of cleft cases, beginning 9 months after the hurricane (i.e., June 1, 2006) was significantly higher compared with the period before the hurricane (0.80 versus 1.42; p = .008). Within racial group comparisons showed a higher incidence among African Americans versus whites (0.42 versus 1.22; p = .01). The distribution of CL/P and CP cases by gender was significant (p = .05). Conclusion : The increase in the incidence of cleft cases after the hurricane may be attributable to increased stress and teratogenic factors associated with the hurricane. The increase among African Americans may have been due to comparatively higher exposure to environmental risk factors. These findings warrant further investigation to replicate the results elsewhere in the Gulf to determine whether there is a causal relationship between environmental risk factors and increased cleft pathology.

The supraclavicular artery island (SAI) flap is a viable fasciocutaneous option for the reconstruction of head and neck defects. Although authors have reported success using SAI flaps for various reconstructive indications, concerns of a tenuous blood supply and distal ischemia have previously limited its use in the posterolateral skull base. This case series reports the outcomes of 5 consecutive patients receiving SAI flaps for posterolateral skull base reconstruction. All flaps were harvested in less than 1 hour with primary closure of all donor sites. A single patient developed superficial necrosis of the distal flap, which was repaired with a full-thickness skin graft. There were no other complications, and no donor site morbidity was observed. The SAI flap is an excellent option for the reconstruction of posterolateral skull base defects. The close color match, easy harvest within 1 hour, lack of microsurgical anastomosis, and absence of donor site morbidity support its continued utilization.

Ear mesenchymal stem cells (EMSCs) represent a readily accessible population of stem-like cells that are adherent, clonogenic, and have the ability to self-renew. Previously, we have demonstrated that they can be induced to differentiate into adipocyte, osteocyte, chondrocyte, and myocyte lineages. The purpose of the current study was to characterize the growth kinetics of the cells and to determine their ability to form colonies of fibroblasts, adipocytes, osteocytes, and chondrocytes. In addition, the immunophenotypes of freshly isolated and culture-expanded cells were evaluated. From 1 g of tissue, we were able to isolate an average of 7.8 x 10(6) cells exhibiting a cell cycle length of approximately 2-3 days. Colony-forming unit (CFU) assays indicated high proliferation potential, and confirmed previously observed multipotentiality of the cells. Fluorescence-activated cell sorting (FACS) showed that EMSCs were negative for hematopoietic markers (CD4, CD45), proving that they did not derive from circulating hematopoietic cells. The FACS analyses also showed high expression of stem cell antigen-1 (Sca-1) with only a minor population of cells expressing CD117, thus identifying Sca-1 as the more robust stem cell biomarker. Additionally, flow cytometry data revealed that the expression patterns of hematopoietic, stromal, and stem cell markers were maintained in the passaged EMSCs, consistent with the persistence of an undifferentiated state. This study indicates that EMSCs provide an alternative model for in vitro analyses of adult mesenchymal stem cells (MSCs). Further studies will be necessary to determine their utility for tissue engineering and regenerative medical applications.

Mesenchymal and hematopoietic tissues are important reservoirs of adult stem cells. The potential of tissue resident mesenchymal stem cells (MSCs) to differentiate into cells of mesodermal and ectodermal lineages has been reported previously. We examined the hypothesis that adherent adipose tissue resident mesenchymal stem cells (ASCs) are capable of generating cells with hematopoietic characteristics. When cultured in differentiation media, clonally isolated ASCs develop into cells with hematopoietic attributes. The hematopoietic differentiated cells (HD) express early hematopoietic (c-kit, PROM1, CD4) as well as monocyte/macrophage markers (CCR5, CD68, MRC1, CD11b, CSF1R). Additionally, HD cells display functional characteristics of monocyte/macrophages such as phagocytosis and enzymatic activity of α-Naphthyl Acetate Esterase. HD cells are also responsive to stimulation by IL-4 and LPS as shown by increased CD14 and HLA-DRB1 expressions and release of IL-2, IL10, and TNF. Taken together, this study characterizes the potential of ASCs to generate functional macrophages in vitro, and therefore paves way for their possible use in cell therapy applications.

Reconstruction following oncologic resection in the head and neck is complex due to large surgical defects left after removal of skin, subcutaneous, and skeletal structures. It is essential to adequately fill the defect as well as provide an acceptable tissue match in terms of tone, texture, thickness and contour. A 55-year-old male presented with an advanced melanoma in the right pre-tragal area. Surgical resection was performed including a total auriculectomy. A tunnelled right supraclavicular artery island (SAI) flap was used to repair the surgical defect. A Doppler probe ensured adequate circulation within the flap, especially in the distal tip. Reconstruction using the SAI flap after oncologic ear resection reduced operating room time, required less technical expertise, and provided excellent tissue match compared to more traditional methods of surgical defect reconstruction including free flaps, local flaps, and pedicled myocutaneous flaps. Successful use of the SAI flap in this case further expands the flaps versatility. We recommend that the reconstructive surgeon consider the SAI flap when presented with challenging infratemporal fossa and lateral skull base cases.

OBJECTIVES/HYPOTHESIS: AlloDerm (LifeCell Corp., Branchburg, NJ) is commonly employed for reconstruction of ablative soft tissue and mucosal defects following surgical resections. Although devoid of growth factors, AlloDerm may serve as an adhesive matrix for binding of growth factors, increasing local angiogenesis, and wound healing. We hypothesized that AlloDerm would enhance angiogenesis and might be altered with autologous blood products to enhance initiation of the angiogenic response. METHODS: We used a human placental vein in a fibrin-thrombin clot-based angiogenesis model. Four groups, human placental vein (HPVM), HPVM with AlloDerm, HPVM with AlloDerm plus platelet-poor plasma, and HPVM with AlloDerm plus platelet-rich plasma were evaluated. Endothelial cell growth was evaluated visually (40x). Hematoxylin and eosin staining and immunofluorescent staining for growth within the AlloDerm matrix were also performed. To assess human umbilical vein endothelial cell (HUVEC) sites of attachment to AlloDerm, we incubated HUVEC cells with AlloDerm for a period of 2 weeks and evaluated attachment with anti-factor VIII immunofluorescence. RESULTS: Angiogenic initiation decreased in the combined placental vein with AlloDerm group (P < .0001 at day 7, 14, 21). Additionally, initiation in the AlloDerm plus platelet-poor plasma group was significantly better than the AlloDerm alone group when placentas 2 and 3 were compared (P < .0001). On hematoxylin and eosin staining and immunofluorescent factor VIII staining, no endothelial growth into the AlloDerm was noted in the samples analyzed. CONCLUSIONS: AlloDerm may be enriched with platelet-poor plasma to stimulate greater initiation and wound healing; however, AlloDerm inhibits angiogenic initiation in this model.