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Biomedical subjects

S Kabani

Publications and source records attributed to S Kabani.

At least 19 recordsLinked to original sources

GBR in human extraction sockets and ridge defects prior to implant placement: clinical results and histologic evidence of osteoblastic and osteoclastic activities in DFDBA.

This study evaluated new bone formation in 3 types of osseous defects following treatment with demineralized freeze-dried bone allografts (DFDBA) and cell-occlusive membranes. For 8 patients electing to receive implant treatment, a distinction was made among 3 clinical situations: (1) existing alveolar ridge defects; (2) extraction sockets with lost buccal plate; and (3) extraction sockets with an intact alveolus. Implants were placed a mean of 6 months after the regenerative procedure. Clinical examination of bone width and height at the time of implant placement showed sufficient augmentation or preservation, and implants were inserted without incident. Histologic examination of hard tissue biopsies obtained from the implant sites revealed no discernible differences among the 3 types of defects. Specifically, all sites demonstrated DFDBA particles surrounded by woven or lamellar bone. No fibrous encapsulation of DFDBA or inflammatory reaction was observed. Osteoblasts were found lining marrow spaces. Howeship's lacunae, with and without resident osteoclasts, were clearly seen in several DFDBA particles; this finding supports the belief that DFDBA undergoes osteoclasis in vivo. These results demonstrate that commercially available DFDBA has osteoconductive properties that lead to appositional new bone growth in both self-contained and non-self contained osseous defects.

Adult↗

Diagnosis of head and neck precancerous lesions in an animal model using fluorescence spectroscopy.

Laser-induced fluorescence (LIF) of tissues depends on their biochemical and histomorphologic characteristics. LIF spectroscopic properties of 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced precancerous and early cancerous lesions in a hamster buccal pouch mucosa model were studied. Fluorescence spectra from neoplastic lesions showed a characteristic fluorescence peak in the red region of the visible spectrum centered between 630 and 640 nm when excited with 410-nm light. Using this as a diagnostic criterion, 45 of 49 lesions studied were correctly diagnosed, including early dysplastic lesions. Follow-up study of four dysplastic lesions over 2 weeks revealed an increase in red fluorescence intensity. The findings of these experiments suggest that LIF spectroscopy may be a valuable noninvasive technique not only for early diagnosis of head and neck cancer, but also to probe a possible biochemical surrogate biomarker in the follow-up of suspected lesions.

9,10-Dimethyl-1,2-benzanthracene↗

Autofluorescence characteristics of oral mucosa.

BACKGROUND: The fluorescence characteristics of tissues depend upon their biochemical composition and histomorphological architecture, both of which undergo a change during malignant transformation. These changes are detectable as an alteration in the fluorescence spectral profile of the tissues. METHODS: Biopsy specimens from clinically suspicious lesions and normal-appearing oral mucosa were obtained from patients. Fluorescence spectroscopic measurements were obtained to study the differences between normal and dysplastic tissues and to determine the most appropriate excitation wavelength(s) for exploiting these differences. RESULTS: Fluorescence spectra from a total of 12 histologically normal (healthy mucosa or benign lesions) and ten abnormal (dysplastic or malignant) tissue samples were compared. Significant spectral differences were seen between the two groups. These differences were most marked at the excitation wavelength of 410 nm. Using this wavelength, fluorescence correctly diagnosed 20 of 22 samples studied. CONCLUSIONS: This technique accurately differentiates normal from abnormal tissues in vitro and has the potential applications for in vivo use as a noninvasive diagnostic tool.

Biopsy↗

Early diagnosis of upper aerodigestive tract cancer by autofluorescence.

OBJECTIVE: To explore the potential of autofluorescence spectroscopy as a tool for early detection of upper aerodigestive tract cancer. DESIGN: Autofluorescence spectral characteristics of 19 untreated oral and oropharyngeal lesions in 13 patients were studied with excitation wavelengths of 370 and 410 nm generated by a nitrogen pumped dye laser. Ten healthy volunteers were recruited to characterize the fluorescence spectra of normal mucosa at different oral sites and to study individual variations. Fluorescence intensity and line shape of the spectra from lesions were compared with the same parameters from the contralateral control site in the same individual. SETTING: Otolaryngology Research Center, Department of Otolaryngology-Head and Neck Surgery, New England Medical Center, Boston, Mass. RESULTS: The ratio of peak fluorescence intensities of the neoplastic lesions to contralateral normal control mucosa were consistently different compared with these ratios in benign lesions or normal mucosa. These differences were seen in 2 distinct regions of the fluorescence spectrum with both of the excitation wavelengths, but were more obvious with the excitation wavelength of 410 nm. Using these differences, we were able to correctly diagnose 17 of the 19 lesions studied, with 2 false-positive results. CONCLUSIONS: Neoplastic oral mucosa shows consistent differences in autofluorescence spectral intensity and line shape when compared with the normal mucosa in the same individual. These early results show that fluorescence spectroscopy may represent a useful technique for noninvasive early diagnosis of cancer of the upper aerodigestive tract.

Adult↗

Lack of TGF-alpha and TGF-beta 1 synthesis by human eosinophils in chronic oral ulcers.

We recently demonstrated that eosinophils infiltrate prominently into cutaneous wounds in the Syrian hamster and represent a source of transforming growth factor-alpha and transforming growth factor-beta. In this study, we assessed the role of the eosinophil and eosinophil-derived transforming growth factors in human oral ulcers that exhibit delayed healing, descriptively termed traumatic ulcerative granuloma with stromal eosinophilia. Our aim was to determine whether eosinophils, which characteristically infiltrate traumatic ulcerative granuloma with stromal eosinophilia lesions, produced transforming growth factor-alpha or transforming growth factor-beta. Twelve cases of traumatic ulcerative granuloma with stromal eosinophilia were examined for transforming growth factor-alpha and transforming growth factor-beta mRNA and cellular protein by in situ hybridization and immunohistochemistry. Eosinophils in 92% of the cases did not express detectable cellular levels of mRNA for either of the transforming growth factors. In addition, only a small percentage of the many eosinophils infiltrating these lesions produced transforming growth factor-alpha or transforming growth factor-beta. The lack of significant synthesis of transforming growth factors by eosinophils in most of the cases of traumatic ulcerative granuloma with stromal eosinophilia is in striking contrast to the expression of transforming growth factors by the eosinophils that infiltrate the animal wound-healing model. Our findings may help to explain the delayed healing that is typical of TUGSE lesions.

Adult↗

Adverse effects of mouthwash use. A review.

Many persons use mouthrinses as a part of their routine oral hygiene. Although rinses impart some benefits to users, improper use of mouthrinses may result in various side effects. This paper reviews the adverse effects of mouthwash use as reported in the English-language literature.

Drug Hypersensitivity↗

Anatomic basis for disk displacement in temporomandibular joint (TMJ) dysfunction.

This study was designed to investigate the site of lateral pterygoid muscle insertion into the temporomandibular joint (TMJ) disk, and the relationship between that attachment and the disk displacement. One hundred and ten TM joints from 78 cadavers were collected and sectioned in the sagittal plane. Sixty-two unilateral specimens were available and 16 additional specimens were selected randomly from the remaining cadavers in which both condyles were available. Thus statistical comparisons were not confounded by autocorrelation and were based on 78 independent specimens. The sites of muscle attachment in relation to the disk were identified histologically. Of the 78 joints 49 had anterior disk displacement. Of the 42 cases with insertion directly into the disk, 30 had anterior disk displacement. In contrast, only 19 of the 36 disks without direct muscle insertion were displaced. This finding indicated a statistically significant relationship between functional muscle attachment and disk displacement (chi 2 = 9.28, df = 1, p = 0.006). However, the superior head of the lateral pterygoid muscle (SLP) may not be the precipitating factor for anterior disk displacement even though it does coordinate disk movement on closure. Since other factors (e.g., trauma) can result in disk displacement, the SLP can maintain disk displacement only when it inserts directly into the disk. In cases of normal disk arrangement and condylar attachment, the muscle may not play a clinically significant role in disk displacement because disk attachment at the medial and lateral poles of the condyle allows the disk to move freely with the condyle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Dental findings in a patient with biliary atresia.

The dental treatment of a 3-year-old male with biliary atresia is discussed. The patient was scheduled for a liver transplant and was receiving Cyclosporine A. Due to the severity of the dental condition and to reduce the possibility of infection, all twenty primary teeth were extracted. The extracted teeth displayed a marked greenish discoloration of both the crowns and the roots. Histological examination revealed extensive interglobular dentin, a number of faint yellow-brown lines contouring the developmental pattern and a distinctive fluorescent line. The dental and pharmacological considerations relating to the treatment plan for this case are reviewed.

Biliary Atresia↗

Comparative tissue tolerance of a new endodontic sealer.

An experimental radiopaque resin root canal sealer was tested for tissue biocompatibility in rat connective tissue. The controls were four widely used sealers: Sealapex, Kerr's sealer, AH-26, and Roth's sealer. Polyethylene tubes were filled with the sealers and allowed to set for 24 hours in 100% humidity. Each sealer was implanted in the connective tissue of Sprague-Dawley rats and removed after 3, 10, 20, 30, and 60 days, fixed, and histologically prepared for light microscope evaluation. At each time period there was practically no difference in the reaction of all the sealers. By 60 days, the total picture was one of well-tolerated biocompatibility.

Animals↗

Oral hairy leukoplakia with extensive oral mucosal involvement. Report of two cases.

Oral hairy leukoplakia (HL) is a lesion that occurs predominantly on the tongue in HIV-infected persons. Evidence strongly indicates that HL is related to the presence of Epstein-Barr virus in the epithelial cells. The lesion appears on the lateral border of the tongue as a painless, white plaque varying in size from a few millimeters to extensive lingual involvement. Histopathologically, the characteristic findings are hyperparakeratosis, hyperplasia, and ballooning of prickle cells resembling koilocytosis. HL is now considered a frequent, early, and specific sign of HIV infection and a strong indicator that AIDS will develop in the patient. We report on two cases of HL with marked oral mucosal involvement with extension to the pharyngeal mucosa.

Adult↗

Atypical lymphohistiocytic infiltrate (pseudolymphoma) of the oral cavity.

In the oral cavity, differentiation between reactive and neoplastic lymphoproliferative lesions can, at times, be very difficult. We report an unusual case in which immunohistochemical findings were necessary to determine that the lesion was reactive despite the original interpretation of malignant lymphoma. The relationship of this lesion to atypical histiocytic granuloma, angiolymphoid hyperplasia with eosinophilia, and traumatic ulcerative granuloma with stromal eosinophilia is discussed and possible pathogenetic mechanisms are proposed. The value of immunohistochemistry in the diagnosis of extranodal lymphoproliferative lesions is emphasized.

Adult↗