The effect of recombinant human bone morphogenetic protein-2 on the integration of porous hydroxyapatite implants with bone.

To determine if recombinant human bone morphogenetic protein-2 (rhBMP-2) can be adsorbed onto porous ceramic hydroxyapatite (HA) and promote the integration of HA to host bone, 54 subperiosteal pockets were created on the skulls of 19 adult Pasteurella-free white rabbits. Fourteen HA implants were saturated with saline and placed in subperiosteal pockets (control), 22 HA implants were saturated with saline and placed into subperiosteal pockets after burring 1-2 mm of calvarium to expose bleeding cancellous bone, and 18 HA implants were saturated with rhBMP-2 and placed into subperiosteal pockets. The animals were sacrificed at 1 month with examination to determine implant mobility. Histology was used to determine the amount of bone growth into the implant. Of the 14 control sites, 10 implants were found to be freely mobile, five demonstrated host bone resorption, and only one exhibited bone growth into the implant. Of the 22 burred sites, eight were freely mobile and 10 demonstrated bone growth into the implant (p = 0.04). Of the 18 rhBMP-2 sites, only two were freely mobile, none demonstrated host bone resorption, and 16 exhibited bone growth into the implant (p = 0.00002). This study supports the use of porous ceramic HA as a biocompatible, osteoconductive implant material for use in craniomaxillofacial augmentation and reconstruction. It also provides evidence that rhBMP-2 enhances osseointegration, thereby fixing the implant in position against the host-bone interface. In the clinical setting, osseous fixation of the implant should aid in preventing displacement, minimizing host bone resorption, and decreasing the incidence of extrusion.

Fibroblast growth factor-induced motor end plate regeneration in atrophic muscle.

OBJECTIVE: To determine whether fibroblast growth factor 1 implanted with viable nerve into atrophic muscle will stimulate formation of functional, acetylcholine producing motor end plates. DESIGN: Twelve male Lewis rats underwent predenervation of the hamstring muscle 8 weeks before implantation of the nerve at a site distant from the original motor end plate. Six animals underwent implantation of the tagged nerve ending into atrophic muscle with 50 microgram of fibroblast growth factor 1 in a fibrin adhesive carrier (group 1). Three animals underwent implantation with nerve, fibrin adhesive, and no fibroblast growth factor 1 (group 2); and three animals underwent implantation with fibroblast growth factor 1 and fibrin adhesive with no nerve (group 3). Animals were killed 9 weeks after implantation and nerve and muscle specimens were harvested. MAIN OUTCOME MEASURES: Histoenzymologic methods for acetylcholinesterase and silver impregnation of nerve fibers were performed 9 weeks after fibroblast growth factor 1-fibrin adhesive implantation. Variables included the number of motor end plates per highpower field and motor end plate length. RESULTS: Robust axonal sprouting and formation of multiple motor end plates were found arborized in serial fashion equidistant around the implanted nerve ending. Rare extrasynaptic staining occurred. End plate lengths were significantly shorter in the fibroblast growth factor 1-treated muscles (group 1) than in the specimens without fibroblast growth factor 1 (group 2) (31.2 vs 58.5 micron; P>001, paired t test). The arborization of motor end plates, rare extrasynaptic staining, and shorter end plate lengths seen in group 1 were all consistent with mature motor end plates. Controls (group 3) displayed limited motor end plate formation and extensive extrasynaptic staining typical of denervation. CONCLUSION: This study presents encouraging evidence that fibroblast growth factor 1 with fibrin adhesive carrier can facilitate the reinnervation of atrophied muscle by enhancing the formation or revitalization of motor end plates. Future studies will address muscle function and use of different carrier materials.

Role of fine-needle aspiration in the evaluation of neck masses.

Fine-needle aspiration has assumed a large role in the evaluation of head and neck masses. It has been found to be simple, quick, accurate, and cost-effective in the workup of patients with unknown head and neck masses. This article reviews these advantages and the role of fine-needle aspiration in the evaluation of head and neck masses.

Prognostic significance of sinus histiocytosis in metastatic laryngeal cancer.

A histopathologic analysis of regional lymph node specimens in 48 patients with previously untreated squamous cell carcinoma of the larynx was performed to determine which parameters, if any, correlated with 3-year patient survival. The presence of sinus histiocytosis in lymph nodes containing metastatic squamous cell carcinoma was statistically related to survival (P < .007). Multivariate analysis confirmed the independent significance of this variable compared to tumor stage, nodal status, and extracapsular spread from lymph nodes. Previous studies have linked improved survival with an active immunologic response in head and neck cancer patients. However, few studies have examined a homogeneous group of patients who all underwent the same type of treatment. This study's findings support the concept that an active immunologic response in lymph nodes has prognostic significance in squamous cell carcinoma of the larynx.

Blindness resulting from orbital complications of sinusitis.

Loss of vision remains a potential complication of orbital infection. Appropriate evaluation and management of the patient with signs and symptoms of orbital inflammation may prevent progression to blindness. Evaluation of patients with orbital inflammation from sinusitis includes a comprehensive clinical examination and radiographic studies. Clinical examination should test for changes in visual acuity, pupillary reactivity, and extraocular motion. Computerized tomography (CT) has facilitated the diagnosis of orbital infections and aids in diagnosis. However, CT can be misleading in patients with acute orbital infections and should not be relied on to determine the need for surgical intervention. We reviewed the records of all patients admitted to Parkland Memorial Hospital from 1978 to 1988 with orbital complications resulting from sinusitis. Four of 159 patients in this group had permanent blindness. The presence of an abscess, which was ultimately found at surgical exploration, was not diagnosed by CT in any of these four patients. Clinical examination remains the most important indicator for surgical intervention in patients with orbital complications of sinusitis. We present our findings and give guidelines for surgical intervention in patients with orbital infections resulting from sinusitis.