Characterization and serum inhibition of neutral collagenase from cultured dog gingival tissue.

1. Explants of dog gingiva, maintained in culture for 9 days in the absence of serum, released a collagenase (EC 3.4.24.3) into the medium. The yield of active enzyme reached a maximum after 5-8 days with concomitant release of collagen degradation products from the explants. 2. The enzyme attacked undenatured collagen in solution at 25 degrees C resulting in a 58% loss of specific viscosity and producing the two characteristic products TCA(3/4) and TCB(1/4). Electron microscopy of segment-long-spacing crystallites of these reaction products showed the cleavage locus of the collagen molecule at interband 40. 3. Optimal enzyme activity was observed over the pH range 7.5-8.5 and a molecular weight of approximately 35,000 was derived from gel filtration studies. EDTA, 1,10-phenanthroline, cysteine and dithiothreitol all inhibited collagenase activity. Proteoglycan derived from porcine and human cartilage did not inhibit the enzyme. 4. The enzyme was inhibited by the dog serum proteins alpha2-macroglobulin and a smaller component of molecular weight approximately 40,000. This small component was purified by column chromatography utilising Sephadex G-200, DEAE A-50, and G-100 (superfine grade). Agarose electrophoresis of the purified component showed it to represent a beta-serum protein. alpha1-Antitrypsin did not inhibit the enzyme. 5. The physiological importance of the natural serum inhibitors and gingival collagenase are discussed in relation to latent enzyme and periodontal disease.

Epithelial cell proliferative activity and oral cancer progression.

Accurate, predictive assessment of the behaviour and progression of oral cancers and precancers remains elusive in clinical practice. Archival tissue specimens from 10 previously treated patients with oral lesions of known clinical outcome (3 years post-treatment) were re-examined histopathologically, and proliferative cell labelling indices (LIs) determined for Ki67, cyclin A and histone mRNA cell cycle markers. While histone mRNA labelling ultimately proved unreliable, both Ki67 and cyclin A LIs demonstrated a clear trend for enhanced labelling to occur in increasingly dysplastic and neoplastic tissue, with particular emphasis on suprabasal labelling in abnormal tissue. Perhaps of greatest significance was the observation of increased LIs and suprabasal labelling in lesions with poor clinical outcome, such as patients developing recurrent disease or cervical lymph node metastasis. Measurement of cell proliferative activity in individual oral epithelial dysplastic lesions or invasive squamous cell carcinomas may thus provide unique, predictive information on clinical outcome.

Morphological changes in cultured human periodontal ligament cells exposed to dental materials.

The cytotoxicity of a range of dental restorative cements was assessed by continuous observation of cultures with inverted microscopy and by light microscopic study of fixed preparations, using an in vitro model with cultured test cells derived from human periodontal ligament. The sequential morphological changes observed over a seven day period showed different degrees of cell loss and patterns of injury in response to different restorative materials, reflecting primarily either nuclear or cytoplasmic damage. Attempts at recovery were frequently identified as the culture period was extended and were characterized by recolonization of denuded areas of the culture well. It was concluded that differing dental cements damage cells through a variety of mechanisms and that the test cells exhibit differing degrees of susceptibility to injury. Assays based on short-term cultures may overestimate cytotoxicity by not allowing for cell recovery from reversible injury or repopulation of monolayers by proliferation of resistant cells.

Synchronous unilateral parotid neoplasms of different histological types.

The occurrence of multiple tumours in the salivary glands is an unusual phenomenon and the simultaneous development of tumours different types is extremely rare. Two cases are presented with synchronous tumours of the parotid gland of different histological types. The first was a Warthin tumour in combination with a metastatic lung carcinoma and the second was a pleomorphic adenoma in combination with non-Hodgkin's malignant lymphoma.

Head and neck skin involvement by non-cutaneous head and neck cancers: free flap reconstruction.

INTRODUCTION: Patients with skin involvement from head and neck cancer have a poor prognosis, with a median survival time of 2 months. METHOD AND RESULTS: During a 9 year period, 31 patients with skin involvement above the clavicle by non-cutaneous malignant tumours of the head and neck were treated. In 19 males and 12 females with a mean age of 62 years, the parotid gland (32%) and the oral cavity (29%) were the commonest sites of primary disease and 77% of the cases were squamous cell carcinomas. Twenty-six had recurrent disease, 20 had received previous radiotherapy and all underwent surgical resection with free flap reconstruction, the commonest being the radial forearm (78%). Complete histological clearance was achieved in 53% of the cases, and adjuvant post-operative irradiation was given to 60%. With this form of management, palliation was extended to a mean survival of 23 months. Six patients are currently alive and disease free at a mean follow up of 4.5 years. CONCLUSIONS: Patients with head and neck skin involvement by non-cutaneous head and neck malignancies have a very poor prognosis, but surgical resection combined with free microvascular flap reconstruction and planned post-operative radiotherapy, can offer good long-term palliation.

Histopathological and ultrastructural findings in a case of Papillon-Lefèvre syndrome.

Gingiva from a 3-year-old Iranian boy suffering from Papillon-Lefèvre syndrome was examined by light and electron microscopy. Deep pockets associated with predominantly Gram-negative plaque were present. The gingival lesion was dominated by plasma cells, many of which were degenerate. Russell bodies were a prominent feature. No defect of epithelium was detected.

The progression of gingivitis to periodontitis in the beagle dog: a histological and morphometric investigation.

The spread of the inflammatory cell infiltrate in the progression of gingivitis to periodontitis in the Beagle dog follows the course of blood vessels. Buccolingually this is towards the periosteal surface of the bone and interdentally towards the midpoint and angles of the interdental septum. Interdentally the path of spread may be modified by the local anatomy. Bone resoprtion buccolingually progresses from the periosteal surface towards the tooth and interproximally along the crest of the interdental septa and within marrow spaces. The pathway of spread of the inflammatory cell infiltrate, the anatomic relationships of the teeth to each other and the original morphology of the alveolar bone may influence the pattern of bone loss in periodontitis.

A morphometric study of age changes in the human lingual artery.

A morphometric study of 100 human lingual arteries demonstrated an increase in wall thickness and decrease in lumen: artery ratio with age. The changes were related to the degree of coronary artery stenosis present in the same subjects.

Intimal cushions in the lingual artery of neonates and children.

Focal musculo-elastic thickenings were identified in the intima. The distribution of these cushions may be related to haemodynamic stresses.

Effect of amphotericin B on human periodontal ligament cells cultured in vitro.

Three micrograms of amphotericin B/ml nutrient medium markedly inhibited the monolayer outgrowth of cells from explants of human periodontal ligament. Amphotericin B (1.5 microgram/ml) retarded outgrowth with morphological evidence of cell injury. The addition of 3 micrograms/ml amphotericin B to existing monolayers initially caused disruption of the majority of cells but those which survived then proliferated. Thus, routine use of amphotericin B is contra-indicated in tissue culture of human periodontal ligament.

Cultural and morphological characteristics of human periodontal ligament cells in vitro.

Primary cell lines from explants of human periodontal ligament were established in vitro to assess their suitability as test cells in a biocompatibility assay. They were maintained over nine passages. The constituent fibroblast-like cells (F-cells) were monitored throughout by light and electron microscopy. Although F-cells from several different donors displayed stable and consistent growth characteristics, after the ninth subculture changes in the fine structure suggested that some cells were undergoing differentiation or senescence. It is therefore recommended that cells from earlier passages be used in in vitro biocompatibility assays.

Altered MUC1 and MUC2 glycoprotein expression in laryngeal cancer.

The purpose of this study was to determine whether mucin expression is altered in laryngeal cancer. MUC1 and MUC2 mucin expression was examined in biopsy specimens from 80 patients that comprised 23 laryngeal dysplasias, 36 laryngeal carcinomas, and 21 normal larynx control specimens. High MUC1 expression was found in all 3 groups (P = 0.689, Fisher exact test). However, significantly higher levels of MUC2 expression were detected in carcinomas compared with dysplasias and control specimens (P = 0.009, Fisher exact test). Altered MUC2 expression may be an important step in carcinogenesis in laryngeal cancer.

Adnexal adenocarcinoma of the upper lip.

A case of poorly differentiated adenocarcinoma of adnexal origin in the upper lip of a man aged 75 is reported which on presentation and initial biopsy was thought to be a salivary neoplasm. He had been aware of the lesion for 10 years but had sought treatment because of recent increase in size of the tumour. He subsequently developed bilateral metastases in cervical nodes. The histopathologic features and relationship of the tumour to the orbicularis oris muscle were consistent with a poorly differentiated adnexal adenocarcinoma of sweat-gland origin. Although carcinomas of skin adnexae are rare they should be considered in the differential diagnosis of tumours in the orofacial region.

Odontodysplasia, gingival manifestations, and accompanying abnormalities.

Regional odontodysplasia is an uncommon developmental dental disorder that may occasionally be accompanied by other abnormalities. A case is described in which the chief report was of a gingival enlargement arising in a female patient who also had dolichocephaly, thin calvarium, clinodactyly and transverse grooving of her fingernails, and a history of abnormal hair. Previously suggested etiologic factors and cases reported in association with other abnormalities are reviewed.

Ectopic salivary gland tissue in the palatine and lingual tonsil.

A case is reported of a child born with a developmental field defect of the first branchial arch in whom there was partial obstruction of the oropharynx by a horseshoe-shaped mass of what was thought to be tonsillar tissue. 'Tonsillectomy' was performed but histopathological examination of the excised specimens showed them to be almost entirely made up of salivary gland tissue.

Fibrous histiocytoma of the larynx.

Fibrous histiocytoma is uncommon in the head and neck region and rare in the larynx. Its behaviour is unpredictable. A case is reported in a 54-year-old male which was treated conservatively initially and which recurred several times over a seven year period. During that time the appearances of the lesion changed from those of a densely collagenous, cytologically benign tumour to those of a richly cellular and potentially malignant neoplasm. Laryngectomy was eventually undertaken.

Cystic lymphangioma in the adult parotid.

Cystic lymphangioma is a congenital lesion which rarely presents in adult life and even less commonly arises within salivary tissue. We report the sudden appearance of a large cystic lymphangioma within the parotid gland of a young man and discuss the management of this rare condition.

Fibrosarcoma of the ethmoid.

Fibrosarcoma may involve the ethmoid sinus by extension from the maxillary antrum or, more rarely, arise as a primary neoplasm. A case of a well differentiated primary fibrosarcoma of the ethmoid sinuses is reported which presented in a 24-year-old male. The tumour was treated by wide local resection. From a review of similar cases in the literature together with their treatment modalities and outcome, it is concluded that wide local resection is the treatment of choice.

Leiomyomatous hamartoma of the posterior tongue: a case report.

A case of a rare leiomyomatous hamartoma arising in the posterior tongue of a sixteen-month-old male is reported. There has been no recurrence following simple excision and presenting symptoms of choking on swallowing have resolved. Most other leiomyomatous hamartomas in the upper aerodigestive tract have been reported in Japanese patients and have involved the maxillary gingiva and hard palate.

Late development of a squamous carcinoma in a reconstructed pharynx.

We report a case in which a squamous cell carcinoma was found to have arisen from a delto-pectoral skin flap used in pharyngeal reconstruction. The flap had been forming a neo-pharynx for 24 years. No other signs of recurrent disease had developed in this period. This raises the possibility of tumour induction in heterotopic skin used for oropharyngeal reconstruction.