Faculty Bibliography

Worldwide, there is a tremendous need to improve the healing of long bone defects and fractures. The purpose of thisstudy was to explore the theoretical feasibility of a novelapproach to bone healing. Using a vacuum assisted scaffoldsystem, we performed a theoretical analysis and computationalmodeling. Results indicate that a standard extracorporeal devicecan create enough negative pressure to develop a pressure dropacross a scaffold that will enhance fluid flow through thescaffold. The velocity of fluid flow is affected by fibrin depositionand scaffold permeability. The fluid flow is predicted to createshear stress that would increase cell growth and migration

Bisphosphonates (BPs) are the standard of care for patients with metastatic cancer and multiple myeloma to prevent skeletal complications (e.g., severe bone pain, pathologic fracture, etc.) and to treat osteoporosis. The cause and effect relationship between BPs and BP-related osteonecrosis of the jaws (BRONJ) is not well established. Current research suggests that bacterial biofilms may play a significant role in the pathogenesis of BRONJ. Recently, we have shown that BRONJ lesions are heavily colonized by oral bacteria and present many clinical challenges as they are difficult to culture and antibiotic resistance may result in misguided antibiotic therapy. Here we highlight the crosstalk among the oral bacteria and host immune response in BRONJ subjects. Using 16S rDNA molecular technique we characterize the total bacterial profile of BRONJ, BP and control subjects. Denaturing gradient gel electrophoresis cluster analysis revealed three clusters each representing the three groups, control, BP and BRONJ indicating that the microbiome present in tissue samples was distinct to each group. DGGE band pattern indicated that the BRONJ group had less bacterial diversity as compared to control indicating that high abundance of specific bacteria colonizing the BRONJ lesion. 16S sequencing and clonal analysis showed 6 phyla in all three groups. The phylum Firmicutes was predominant in BRONJ group (72%) followed by BP group (70%) as compared to control group (59%). The Chi-square test also showed significant differences in percent relative distribution of phyla, between control/BP groups (p<0.001), control/BRONJ (p<0.001) and BP/BRONJ (p<0.05). There was significantly increase in the gram positive bacteria in BRONJ group. PCR Array analysis indicated that the host genes responsible for antibacterial response such as MPO, CTSG, and NOD2 were significantly down regulated. Deficient innate immune responses to microorganisms together with poor healing and repair provide continuous opportunities for expanding!

Aim. This study aimed to observe the morphological and molecular effect of laminin-1 doping to nanostructured implant surfaces in a rabbit model. Materials and Methods. Nanostructured implants were coated with laminin-1 (test; dilution, 100 mug/mL) and inserted into the rabbit tibiae. Noncoated implants were used as controls. After 2 weeks of healing, the implants were removed and subjected to morphological analysis using scanning electron microscopy (SEM) and gene expression analysis using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results. SEM revealed bony tissue attachment for both control and test implants. Real-time RT-PCR analysis showed that the expression of osteoblast markers RUNX-2, osteocalcin, alkaline phosphatase, and collagen I was higher (1.62-fold, 1.53-fold, 1.97-fold, and 1.04-fold, resp.) for the implants modified by laminin-1 relative to the control. All osteoclast markers investigated in the study presented higher expression on the test implants than controls as follows: tartrate-resistant acid phosphatase (1.67-fold), calcitonin receptor (1.35-fold), and ATPase (1.25-fold). The test implants demonstrated higher expression of inflammatory markers interleukin-10 (1.53-fold) and tumour necrosis factor-alpha (1.61-fold) relative to controls. Conclusion. The protein-doped surface showed higher gene expression of typical genes involved in the osseointegration cascade than the control surface.

AbstractPurpose. To describe occurrences of oral squamous cell carcinoma (SCC) in patients who had received long-term pegylated liposomal doxorubicin (PLD) for ovarian cancer.Patients and Methods. In our cohort of patients on maintenance PLD for ovarian and related mullerian epithelial malignancies, we encountered two patients with invasive SCC of the oral cavity (one of them multifocal) and one with high-grade squamous dysplasia. Review of patients at our institution receiving PLD for recurrent ovarian cancer identified three additional patients. The duration of treatment, cumulative PLD dose, human papillomavirus (HPV) positivity, BRCA status, stage at diagnosis, outcome, and other characteristics are reviewed.Results. All five cases were nonsmokers with no known risk factors for HPV and four were negative for p16 expression. Four of the patients had known BRCA mutations whereas one tested negative. Cumulative doses of PLD were >1,600 mg/m(2) given over 30-132 months. Three had SCCs staged as T1N0 oral tongue, alveolar ridge (gingival), and multifocal oral mucosa; one had a T2N0 oral tongue; and one had dysplasia. After excision, two were given radiation but recurred shortly thereafter; the others remain well and have had no further exposure to cytotoxic drugs, including PLD.Conclusion. Awareness of this possible long-term complication during PLD treatment should enhance the likelihood of early detection of oral lesions in these patients. Decisions to continue maintenance PLD after complete response of the original cancer should perhaps consider the benefits of delaying ovarian cancer recurrence versus the possible risk for a secondary cancer.