Impact of Er:YAG laser on wound healing following nonsurgical therapy: A pilot study.

The purpose is to examine early wound healing through histological analysis by characterizing connective tissue distribution and organization in the treated periodontium following nonsurgical therapy. Periodontal disease is a multifactorial pathological process that leads to the loss of the surrounding periodontium. Traditional periodontal therapies have proven beneficial in halting the progression of disease. The aim of this study is to investigate early wound healing in periodontal patients following hand/ultrasonic instrumentation alone, erbium-doped yttrium aluminum garnet laser instrumentation alone, or a combination of hand/ultrasonic instrumentation and Er:YAG laser instrumentation for the nonsurgical treatment of periodontitis by histologic evaluation. Twenty-one patients were randomized to receive nonsurgical therapy for the treatment of chronic periodontitis with three modalities prior to surgical therapy. Baseline clinical measurements were obtained prior to treatment. Wound healing was assessed by obtaining an otherwise discarded tissue sample following nonsurgical therapy of the selected study site. Samples were obtained at 2 or 6 weeks following initial therapy with a step-back incision and fixated for histological and immunohistochemical analysis. There were minimal between-group differences in the amount of collagen distribution when analyzing the Mallory-Heidenhain Azan trichrome, Picrosirus Red stain, and proliferating cell nuclear antigen at both time points. Descriptive analysis of baseline measurements showed no differences in probing depth change, bleeding on probing, and clinical attachment level following initial therapy between the three treatment groups at 2 or 6 weeks. Each treatment modality was effective in treating moderate to severe chronic periodontitis; however, the results of this study are inconclusive regarding superiority of any one treatment approach from a histologic and immunohistochemical perspective. Based on this assessment, there was increased fibroblast proliferation and collagen maturation between the 2- and 6-week time point after treatment in all treatment groups, with few apparent differences between treatment groups. This pilot study qualitatively evaluated early wound healing in periodontal patients following non surgical therapy with various treatment modalities. When comparing descriptive outcomes of Er:YAG laser therapy and hand/ultrasonic instrumentation there were minimal differences in collagen distribution and density between groups. The evaluated modalities were each effective treating periodontal patients with non surgical therapy.

Hemangiopericytoma of the parapharyngeal space.

Hemangiopericytomas of the head and neck are rarely found in the parapharyngeal space. We report the case of a 53-year-old woman who presented with a globus sensation in her throat. Imaging detected a left submucosal oropharyngeal mass that extended into the prestyloid parapharyngeal space. The tumor was surgically excised en bloc. Histopathologic examination identified it as a hemangiopericytoma. We discuss the diagnosis and management of this rare entity.

Setup and characterization of a human head and neck squamous cell carcinoma xenograft model in nude rats.

OBJECTIVE: To develop and characterize a new head and neck cancer animal model. STUDY DESIGN: A human head and neck squamous cell carcinoma (HNSCC) xenograft model in nude rats was established via subcutaneous inoculation of a human-origin HNSCC cell line, SCC-4. The tumor was evaluated for growth characteristics, pathologic features by hematoxylin-eosin (HE) staining, and immunohistochemistry of epidermal growth factor receptor (EGFR). 2-[18F] fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET) imaging characteristics were studied too. RESULTS: A new HNSCC animal model was successfully established. Tumor sizes reached about 1 cm3 on day 15 after tumor cell inoculation. HE staining pathology has confirmed that this tumor is a typical SCC. EGFR immunohistochemistry demonstrated this tumor model to be strongly EGFR positive. 18F-FDG PET study has shown that 18F-FDG accumulated in tumors. CONCLUSIONS: This study has demonstrated that this tumor model is an appropriate HNSCC tumor model for animal studies on HNSCC.

Inhibition of osteoporosis in autoimmune disease prone MRL/Mpj-Fas(lpr) mice by N-3 fatty acids.

OBJECTIVE: Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disease involving the breakdown of cartilage and juxta-articular bone, which is often accompanied by decreased bone mineral density (BMD) and increased risk of fracture. Anti-inflammatory omega-3 fatty acids may prevent arthritis and bone loss in MRL/lpr mice model of arthritis and in humans. METHODS: In this study, the effect of long term feeding of 10% dietary n-3 (fish oil (FO)) and n-6 (corn oil (CO)) fatty acids begun at 6 weeks of age on bone mineral density (BMD) in different bone regions in an MRL/lpr female mouse model of RA was measured at 6, 9, and 12 months of age by dual energy x-ray absorptiometry (DEXA). After sacrificing the mice at 12 months of age, antioxidant enzyme activities were measured in spleen, mRNA for receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) was measured by RT-PCR in lymph nodes, and synovitis was measured in leg joints. RESULTS: At 6, 9 and 12 months of age, BMD was significantly higher (p < 0.05) in distal femur, proximal tibia, and lumbar spine of FO fed mice than those of CO fed mice. Spleen catalase (CAT) and superoxide dismutase (SOD) activities were also significantly higher (p < 0.01) in FO fed mice than in CO fed mice. Histology of knee joints revealed mild synovitis in CO fed mice, which was not present in FO fed mice. RT-PCR analysis of lymph nodes revealed decreased RANKL mRNA (p < 0.001) expression and enhanced OPG mRNA expression (p < 0.01) in FO fed mice compared to CO fed mice. CONCLUSIONS: These results suggest beneficial effects of long-term FO feeding in maintaining higher BMD and lower synovitis in this mouse model. These beneficial effects may be due, in part, to increased activity of antioxidant enzymes, decreased expression of RANKL, and increased expression of OPG in FO fed mice thereby altering the RANKL/OPG ratio. These significant beneficial effects on BMD suggest that FO may serve as an effective dietary supplement to prevent BMD loss in patients with RA.