Distribution of factor XIIIa-containing cells and collagenous components in radicular cysts: histochemic and immunohistochemic studies.

The distribution of subunit A of Factor XIII (FXIIIa) and of collagenous components was investigated by the avidin-biotin-peroxidase complex (ABC) method for FXIIIa and by the Sirius red F3BA method, respectively, in 43 cases of radicular cysts. Besides the covering epithelial layer, the radicular cyst wall was composed of the following three layers: an inner granulomatous layer, an outer fibrous connective tissue layer, and an intermediate layer. In each layer, a positive reaction for FXIIIa was observed in certain connective tissue cells. These FXIIIa-containing cells were few in number in the inner layer where collagenous components were also sparse. In the slightly to moderately fibrous intermediate layer, these cells markedly increased in number and were dendritic or stellate in shape. In the outer densely fibrous connective tissue layer, they decreased slightly in number and were slender and spindle-shaped. The results obtained in the present study indicate the close relationship between the distribution of FXIIIa-containing cells and of collagenous components. Such a relationship suggests that these cells play an important role in the process of fibrosis occurring in the radicular cyst wall.

[Demonstration of PGE2 by immunofluorescence in the wall of radicular cysts]. / Mise en évidence des prostaglandines PGE2 par immunofluorescence au sein de la paroi des kystes radiculo-dentaires.

The present study gives the first evidence, through immunofluorescence, of the prostaglandins PGE2 in radicular cysts. The results are in agreement with literature. In addition, the immunofluorescence technique has also demonstrated the localization of prostaglandins inside the cyst cavity. In opposition to previous data, the present study also shows that epithelial cells seem to synthesize more PGE2 than fibroblasts and mononuclear components of the external connective tissue.

Immunostaining of involucrin in odontogenic epithelial tumors and cysts.

An immunoperoxidase method was used to detect involucrin in 47 odontogenic tumors and 35 radicular cysts. Of a total of 40 ameloblastomas, 9 cases were positive for involucrin expression and those positive cases exhibited acanthomatous or follicular patterns. Squamous odontogenic tumors were strongly positive for involucrin, whereas adenomatoid odontogenic tumors gave a negative staining reaction. Involucrin expression in odontogenic tumors was divided into three categories: single cell positive, focally positive, and squamous metaplastic cell positive. Radicular cysts showed a very irregular distribution of involucrin; nonstratified epithelium was generally negative or showed only trace staining for involucrin, whereas suprabasilar stratified squamous epithelial cells were strongly positive. Cells positive for involucrin in odontogenic tumors and in cystic epithelium are probably direct signs of epithelial differentiation; such cells were squamoid in appearance.

Interleukin 1-like activity in cystic lesions of the jaw.

Odontogenic cyst capsules were cultured in vitro and the culture media analysed for bone-resorption and interleukin 1-like activity. Five cysts synthesised a non-dialysable bone resorbing factor with significant interleukin 1-like activity. One specimen thought to be a cyst with little interleukin 1 activity proved to be antral lining. The results indicate that interleukin 1 may play an important role in cyst expansion by its direct effects on fibroblast proliferation and bone resorption and by stimulating prostaglandin synthesis in stromal fibroblasts of the cyst capsule.

Quantitation of lactoferrin in odontogenic cyst fluids.

A competitive enzyme linked immunosorbent assay (ELISA) method was used to measure the concentration of lactoferrin in fluids from 36 odontogenic keratocysts, 15 dentigerous cysts, and 30 radicular/residual cysts. Keratocyst fluids contained significantly higher concentrations of lactoferrin than fluids from the other two types of cyst (p less than 0.001); but the range of values obtained within each group was large. Although lactoferrin represents a larger proportion of the total protein in keratocyst fluids than in dentigerous or radicular cyst fluids, lactoferrin concentration is not an absolute diagnostic marker for keratocysts. Lactoferrin concentration correlated strongly with the numbers of neutrophils present in keratocyst fluids (p less than 0.001), less so for dentigerous cyst fluids (p less than 0.05, and not at all in the case of radicular cyst fluids. It is suggested that neutrophils are the source of lactoferrin in the three categories of cyst studied but that the relatively impermeable nature of the keratocyst lining probably accounts for the particularly high concentrations of lactoferrin found in their fluids. Given that most keratocysts were asymptomatic, acute inflammation itself does not explain the reason for the high numbers of neutrophils in many of the fluids.

Lactoferrin in aspirates of odontogenic cyst fluid.

The possibility that the presence of lactoferrin in aspirates of odontogenic cyst fluid might be a useful preoperative diagnostic marker for odontogenic keratocyst was investigated. Using qualitative and quantitative immunodiffusion methods fluid from 29 of 29 dental (radicular) cysts, 12 of 14 dentigerous cysts and 27 of 31 keratocysts were found to contain lactoferrin. Although some of the highest concentrations of lactoferrin were detected in fluids from keratocysts, there was no significant difference between lactoferrin concentrations among the three groups. Neutrophil elastase was detected in 20 of 24 samples tested, 22 of which also contained lactoferrin. Immunocytochemical localisation of both lactoferrin and elastase was confined to neutrophils infiltrating cyst walls. These results suggest that lactoferrin in fluid from odontogenic cysts is derived from infiltrating neutrophils and that its presence in aspirated fluids is not a useful diagnostic marker for odontogenic keratocyst.

Quantification and analysis of the glycosaminoglycans in human odontogenic cyst linings.

Glycosaminoglycans (GAG) were extracted from the connective tissue of 15 dental cysts, 2 dentigerous cysts and 7 keratocysts, and separated electrophoretically and chromatographically. Hyaluronic acid (dental, 2.38; dentigerous, 3.98; keratocyst, 3.19 micrograms uronic acid/mg lyophilized tissue) was the major GAG detected, with lesser amounts of heparin (dental, 1.70; dentigerous, 1.95; keratocyst, 1.80 micrograms uronic acid/mg lyophilized tissue) and chrondroitin-4-sulphate (dental, 1.33; dentigerous, 2.85; keratocyst, 1.37 micrograms uronic acid/mg lyophilized tissue). It is suggested that enzymic release of these GAGs allows their diffusion into the luminal fluid where they may contribute to expansile cyst growth.

Immunohistochemical detection of 6-oxo-PGF1 alpha and PGE2 in radicular cysts.

Prostaglandin synthesis in the wall of radicular cysts was determined by immunohistochemistry and radiothinlayer chromatography. PGE2 is predominantly produced by plasma cells and histiocytic elements, whereas much less is synthesized by fibroblasts and endothelial cells as estimated using immunohistochemistry. 6-oxo-PGF1 alpha, however, was primarily found to be generated by endothelial cells and fibroblasts; only small amounts seem to be derived from histiocytic elements and plasma cells. The response of the cystic epithelium to anti-PGE2 and anti-6-oxo-PGF1 alpha antibodies was negative or showed only minimal staining. It can thus be concluded that the granulation tissue and its cellular components modulating the inflammatory process are the main source of prostaglandin synthesis in the wall of radicular cysts and may therefore be responsible for the resultant osteolytic activity.

Concentration of phenoximethylpenicillin, clindamycin and tinidazole in dental cysts.

In the treatment of bacterial infections, adequate antibiotic concentrations must be realised at the site of infection. Levels of 3 antibiotics--phenoximethylpenicillin, clindamycin and tinidazole - were measured in serum and fluid of periapical odontogenic cysts in 30 patients undergoing enucleation of periapical cysts. After a single dose of 500 mg tinidazole, the concentration of tinidazole in the cystic fluid was 4.3 micrograms/ml, which was about 1/3 of the concentration in the serum. No measurable levels were achieved in the cystic fluid with phenoximethylpenicillin or clindamycin.

Microspectrophotometric determination of DNA in oral lesions.

The DNA content of the epithelial basal cells of oral lesions was determined by Feulgen microspectrophotometry. The DNA histograms of the radicular cysts showed a definite peak in the diploid range and a slight deviation to the right. The keratocysts also showed a well-defined modal peak in the diploid range; however, another cell population defined a peak in the tetraploid range. In leukoplakias of the oral cavity, two different profiles of DNA distribution were found. Where both the clinical and microscopic traits defined a nondysplastic lesion, the histogram showed a diploid peak and a percentage of cells in diploid-tetraploid range. For the more active lesion, a shift of the mode towards higher values was evident. The microspectrophotometric studies of oral epidermoid carcinomas showed a broad distribution towards the right and ill-defined modal values.