Faculty Bibliography

BACKGROUND: The aim of this study was to calculate and analyze the cost of treatment for stage IV pressure ulcers. METHODS: A retrospective chart analysis of patients with stage IV pressure ulcers was conducted. Hospital records and treatment outcomes of these patients were followed up for a maximum of 29 months and analyzed. Costs directly related to the treatment of pressure ulcers and their associated complications were calculated. RESULTS: Nineteen patients with stage IV pressure ulcers (11 hospital-acquired and 8 community-acquired) were identified and their charts were reviewed. The average hospital treatment cost associated with stage IV pressure ulcers and related complications was $129,248 for hospital-acquired ulcers during 1 admission, and $124,327 for community-acquired ulcers over an average of 4 admissions. CONCLUSIONS: The costs incurred from stage IV pressure ulcers are much greater than previously estimated. Halting the progression of early stage pressure ulcers has the potential to eradicate enormous pain and suffering, save thousands of lives, and reduce health care expenditures by millions of dollars

BACKGROUND:: Pediatric temporomandibular joint (TMJ) dysfunction, resulting from either soft tissue or skeletal disorders, may be congenital or acquired. Congenital TMJ disorders are uncommon. Here we review our experience with pediatric TMJ disorders and propose a new classification system. METHOD:: Clinical records, cephalograms, computed tomography, magnetic resonance images, and pathologic specimens of all pediatric patients (< 18 years) with trismus or restricted mandibular excursion from 1976-2008 were reviewed. Cases were stratified according to soft tissue or skeletal pathology; skeletal abnormalities were further characterized as intra- or extra-capsular. RESULTS:: 38 patients, ranging in age from 1 day to 18 years of age at diagnosis, were identified with TMJ disorders. Ten cases (26.3%) were due to soft tissue pathology. The remaining 28 cases (73.7%) were due to skeletal pathology, consisting of 14 congenital and 14 acquired cases (50% each). Acquired skeletal deformities included 12 (85.7%) intracapsular ankyloses and 2 (16.7%) extracapsular ankylosis (extra-articular bone blocks). Congenital skeletal deformities accounted for 5 (35.7%) intracapsular ankyloses and 9 (64.3%) extracapsular ankyloses. CONCLUSION:: On initial survey, the data are consistent with published reports that attribute TMJ dysfunction to acquired pathology (i.e., trauma and infection). However, we observed a significantly higher percentage (50%) of congenital TMJ skeletal disorders than previously reported. Most congenital cases involved extracapsular pathology (i.e., coronoid hypertrophy); only a minority of cases had glenocondylar fibro-osseous fusion (i.e., intracapsular ankyloses). Since the diagnosis and classification of TMJ disorders determines treatment options, we provide a new classification that characterizes the extent of capsular involvement

OBJECTIVE: Radiotherapy, an essential modality in cancer treatment, frequently induces fibrotic processes in the skin, including accumulation of extracellular matrix. Transforming growth factor-beta is essential in regulating extracellular matrix gene expression and is dependent on Smad3, an intracellular mediator/transcription factor. Our study characterized the genetic expression involved in extracellular matrix accumulation during radiation-induced fibrosis. We performed Smad3 gene silencing in an attempt to abrogate the effects of radiation. STUDY DESIGN: Laboratory research. SETTING: University laboratory. SUBJECTS AND METHODS: C57 murine dermal fibroblasts were irradiated with 20 Gy RNA isolated (0, 6, 12, 24, 48, 72 hours postirradiation) and mRNA analyzed (reverse transcriptase polymerase chain reaction) for known regulators (Smad3, interleukin-13 [IL-13]), tumor necrosis factor-alpha [TNF-alpha]) and mediators of fibrosis (collagen 1A1 [Col1A1]), TGF-beta, matrix metalloprotease-1 and -2 (MMP-1, MMP-2), and tissue inhibitor of metalloprotease-1 (TIMP-1). Smad3 gene expression was silenced using siRNA in an effort to restore an unirradiated gene profile. RESULTS: Following irradiation, there was a steady increase in mRNA expression of Smad3, IL-13, TGF-beta, Col1A1, MMP-2, TIMP-1, with peak at 12 to 24 hours and subsequent decline by 72 hours. TNF-alpha expression remained elevated throughout. MMP-1 showed minimal expression initially, which decreased to negligible by 72 hours. Inhibition of Smad3 significantly decreased expression of Col1A1, TGF-beta, MMP-2, and TIMP-1. IL-13 and TNF-alpha expression was not affected by Smad3 silencing. CONCLUSION: We have characterized the early-phase mRNA expression profiles of the major mediators of radiation-induced fibrosis. Smad3 siRNA effectively abrogated the elevation of Col1A1, TGF-beta, TIMP-1, and MMP-2. IL-13 and TNF-alpha were unaffected by Smad3 silencing and appear to be minor regulators in fibrosis. These findings suggest a therapeutic rationale for Smad3 silencing in vivo

The present study focused on determining the effect of high strain rate loading on the deformation and fracture characteristics of syntactic foams and relating them with the initial foam microstructure. The high strain rate testing was carried out using a split-Hopkinson pressure bar system and the damage evaluation was carried out using microCT-scan and scanning electron microscope. The strength was found to be 50-150% higher at high strain rates when compared to quasi-static values for various grades of syntactic foams. Damage evaluation revealed crushing of particles in the surface layer, shear cracking, and propagation of longitudinal cracks as the main fracture modes at different strain rates and material compositions. Wall thickness and volume fraction of hollow particles used in syntactic foams played an important role in determining the failure mechanism. At low strain rates shear cracking of specimens was prominent, whereas at high strain rates longitudinal cracks were the main failure mode. Understanding the strain rate dependence of failure mechanisms is important for aerospace applications of these lightweight composites. (C) 2010 Elsevier B.V. All rights reserved.

Cocktail stick (CS) ingestion injury has rarely been reported in the literature. It is a serious clinical problem with considerable morbidity and mortality, largely due to the fact that the event is unnoticed by the patient. We report a case of CS ingestion that went unrecognised by the patient and caused a perforation in the mid-small bowel. We discuss how injuries from such events can become a diagnostic challenge. The history should be re-evaluated in any undiagnosed abdominal pain which has an unclear aetiology and negative radiology.

PURPOSE: To evaluate the bone healing response to different implant root shape designs in a dog model. MATERIALS AND METHODS: Three by eight millimeter screw-type short-pitch (SP) and large-pitch (LP) implants (Intra-Lock International, Boca Raton, FL, USA), and 4.5 x 6 mm plateau (P) implants (Bicon LLC, Boston, MA, USA) were placed along the proximal tibia of six dogs for 2 and 4 weeks. The combination of implant design and final osteotomy drilling resulted in healing chambers for the LP and P implants. The implants were nondecalcified processed to plates of approximately 30-microm thickness and were evaluated by optical microscopy for healing patterns and bone-to-implant contact (BIC). One-way analysis of variance at 95% level of significance and Tukey's test were utilized for multiple comparisons among the groups' BIC. RESULTS: Microscopy showed a approximately 150-microm region of newly deposited bone along the whole perimeter of SP implants, near the edge of the LP implant threads, and plateau tips for P implants. Rapid woven bone formation and filling was observed in regions where surgery and implant design resulted in healing chambers. No significant differences in BIC were observed (p > .75). CONCLUSIONS: Different implant design/surgical protocol resulted in varied bone healing patterns. However, the BIC and bone morphology evolution between implant designs were comparable. Regardless of the combination between implant design and final osteotomy drilling, bone morphology evolution from 2 to 4 weeks was comparable.