Faculty Bibliography

This study was undertaken to evaluate whether 40 percent of the hypoglossal nerve, which showed optimal efficacy in restoring orbicularis oculi muscle (OOM) function after different percentages of partial neurectomy in a previous study would be effective after prolonged denervation time. Twenty Sprague-Dawley rats were divided into four groups. In first-stage surgery the left facial nerve of all animals was transected at the level of the stylomastoid foramen and main zygomatic branch. Group A (controls) consisted of animals with only left facial nerves transected (no repair). In Groups B, C, and D the facial nerve was transected and the facial musculature was denervated for a period of 4, 8, and 12 weeks respectively. During a second-stage procedure, a 40 percent neurectomy was performed on the hypoglossal nerve. Subsequently, a nerve transfer was performed by coaptations of a saphenous nerve graft to the neurectomized hypoglossal nerve and the main zygomatic branch of the facial nerve that innervated the OOM. Behavioral analysis of blink reflex, electrophysiology, and axon and motor end-plate counts in Groups B, C, and D showed superior results compared to Group A. There was no statistically significant difference observed among Groups B, C, and D (p > 0.05). Despite the diminished number of axons in the zygomatic branch and motor end-plates in the orbicularis oculi muscle after 12 weeks of denervation, there was still sufficient muscle target recovery to effect some eye closure in all groups except the controls. This study demonstrated in this model that the 40 percent partial neurectomy of the XII to VII component of the 'baby-sitter' procedure was effective even after prolonged denervation

Preclinical studies in animal models and early results of clinical trials in patients suggest that intramuscular injection of naked plasmid DNA encoding vascular endothelial growth factor (VEGF) can promote neovascularization of ischemic tissues. Such neovascularization has been attributed exclusively to sprout formation of endothelial cells derived from preexisting vessels. We investigated the hypothesis that VEGF gene transfer may also augment the population of circulating endothelial progenitor cells (EPCs). In patients with critical limb ischemia receiving VEGF gene transfer, gene expression was documented by a transient increase in plasma levels of VEGF. A culture assay documented a significant increase in EPCs (219%, P<0.001), whereas patients who received an empty vector had no change in circulating EPCs, as was the case for volunteers who received saline injections (VEGF versus empty vector, P<0.001; VEGF versus saline, P<0.005). Fluorescence-activated cell sorter analysis disclosed an overall increase of up to 30-fold in endothelial lineage markers KDR (VEGF receptor-2), VE-cadherin, CD34, alpha(v)beta(3), and E-selectin after VEGF gene transfer. Constitutive overexpression of VEGF in patients with limb ischemia augments the population of circulating EPCs. These findings support the notion that neovascularization of human ischemic tissues after angiogenic growth factor therapy is not limited to angiogenesis but involves circulating endothelial precursors that may home to ischemic foci and differentiate in situ through a process of vasculogenesis

Microdermabrasion is the general term applied to the technique of abrading the skin with a high-pressure flow of crystals. Patient selection, equipment, and technique for face, hands, and chest are described. Results of a survey on the efficacy of the treatment are provided

Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations

PURPOSE: The aim of this study was to compare the cost-effectiveness of mandibular fracture treatment by closed reduction with maxillomandibular fixation (CRF) with open reduction and rigid internal fixation (ORIF). PATIENTS AND METHODS: This was a retrospective study of 85 patients admitted to the Oral and Maxillofacial Surgery Service at San Francisco General Hospital and treated for mandibular fractures from January 1 to December 31, 1993. The patients were divided into 2 groups: 1) those treated with CRF and 2) those treated with ORIF. The outcome variables were length of hospital stay, duration of anesthesia, and time in operating room. The charge for primary fracture treatment included the fees for the operation and hospitalization without any complications. Within the group of 85 patients treated for mandibular fractures in 1993, 10 patients treated with CRF and 10 patients treated with ORIF were randomly selected, and hospital billing statements were used to estimate the average charge of primary treatment. The average charge to manage a major postoperative infection also was estimated based on the billing statements of 10 randomly selected patients treated in 1992 (5 treated with CRF, 5 with ORIF) who required hospital admission for the management of a complication. The average total charge was computed by using the average charge for primary treatment plus the incidence of postoperative infection multiplied by the average charge for management of that complication. RESULTS: Eighty-five patients were included in the study. The average charge for primary treatment was $10,100 for the CRF group and $28,362 for the ORIF group. The average charge for the inpatient management of a major postoperative infection was $26,671 for the CRF group and $39,213 for the ORIF group. The average total charge for management of a mandible fracture with CRF was $10,927; the total charge for the ORIF group was $34,636. CONCLUSION: The results of this retrospective study suggest that the use of CRF in the management of mandibular fractures at our institution provides considerable savings over treatment by using ORIF. The use of ORIF should be reserved for patients and fracture types with specific indications

OBJECTIVE:The purposes of this investigation were to study the feasibility of placing endosseous implants in children and adolescents with ectodermal dysplasia and to assess the position and stability of such implants during growth. This article reports on 6 subjects with long-term follow-up. Study design. A prospective study was commenced in 1991. Patients with hereditary ectodermal dysplasia who were over the age of 5 years and who presented to the University of California San Francisco Ectodermal Dysplasia Clinic for dental treatment were included and maintained in the study. In each case, clinical and radiographic records were obtained before treatment, immediately after implant placement, at delivery of the prosthesis, and subsequently at yearly intervals. Six subjects are reported, 4 as members of the prospective study group and 2 who had been treated before the study began. RESULTS:A total of 41 implants (19 maxillary, 22 mandibular) were placed. The average follow-up after implant placement was 7.8 years (range, 6-11 years), and the average time since restoration was 6 years (range, 5-10 years). Forty implants successfully integrated and have been restored. There was no evidence that implant placement or prosthetic rehabilitation resulted in restriction of transverse or sagittal growth. One mandibular implant, placed in a partially dentate 5-year-old, became submerged because of adjacent alveolar development and required placement of a longer abutment. Four maxillary implants placed in a partially dentate 7-year-old also became submerged and required prosthetic revision and the placement of longer abutments. CONCLUSIONS:This preliminary report suggests that endosseous implants can be successfully placed and can provide support for prosthetic restoration in patients with hereditary ectodermal dysplasia. However, vertical dentoalveolar growth results in submergence of the implant relative to the adjacent natural dentition when implants are placed adjacent to erupting permanent teeth.

To generate structures consistent with both the local and nonlocal interactions responsible for protein stability, 3 and 9 residue fragments of known structures with local sequences similar to the target sequence were assembled into complete tertiary structures using a Monte Carlo simulated annealing procedure (Simons et al., J Mol Biol 1997; 268:209-225). The scoring function used in the simulated annealing procedure consists of sequence-dependent terms representing hydrophobic burial and specific pair interactions such as electrostatics and disulfide bonding and sequence-independent terms representing hard sphere packing, alpha-helix and beta-strand packing, and the collection of beta-strands in beta-sheets (Simons et al., Proteins 1999;34:82-95). For each of 21 small, ab initio targets, 1,200 final structures were constructed, each the result of 100,000 attempted fragment substitutions. The five structures submitted for the CASP III experiment were chosen from the approximately 25 structures with the lowest scores in the broadest minima (assessed through the number of structural neighbors; Shortle et al., Proc Natl Acad Sci USA 1998;95:1158-1162). The results were encouraging: highlights of the predictions include a 99-residue segment for MarA with an rmsd of 6.4 A to the native structure, a 95-residue (full length) prediction for the EH2 domain of EPS15 with an rmsd of 6.0 A, a 75-residue segment of DNAB helicase with an rmsd of 4.7 A, and a 67-residue segment of ribosomal protein L30 with an rmsd of 3.8 A. These results suggest that ab initio methods may soon become useful for low-resolution structure prediction for proteins that lack a close homologue of known structure.