Biomedical subjects
Publications and source records attributed to A S High.
A case of unicystic ameloblastoma which recurred after 15 years showing unusual histological features is reported. The prominent pseudo-glandular features present are described. This case highlights the importance of extensive histological examination for more characteristic features of ameloblastoma to reach a correct diagnosis.
A case of a rare extra-osseous ameloblastoma is presented. It meets identical histological criteria as intra-osseous ameloblastoma, but its clinical presentation and behaviour are very different. It is non-invasive and may be locally excised without recurrence.
The technique of differential hybridization was used to compare gene transcription between normal oral mucosa and odontogenic keratocyst lining. Protease inhibitors, elafin and stefin-B as well as beta-actin and two epithelial-specific small proline-rich (spr) proteins, which we have named SPRC and SPRK and which are distinct from salivary proline-rich proteins, were differentially expressed. Increased abundance of alpha I(I) collagen and elafin transcripts was demonstrated in the keratocyst, with decreased abundance of stefin B, SPRC and cytokeratins 4 and 13 transcripts compared to normal palatal mucosa. The deduced protein sequences of SPRC and SPRK were described and compared, and the relative abundance of their respective cDNAs in palatal and keratocyst libraries determined. Identification of factors controlling transcription of these genes could advance our understanding of the development of odontogenic keratocysts.
Fibroblasts were grown from explants of normal gingiva and foreskin, and from walls of dentigerous, radicular and residual cysts, as well as keratocysts of basal-cell naevus syndrome and non-syndrome origin. Dentigerous-cyst fibroblast adhesion to poly-L-lysine-coated glass was unaffected by all adhesion-related glycoproteins. Chondroitin sulphate, fibronectin and heparan sulphate enhanced attachment of all other fibroblasts. Chondroitin-sulphate and fibronectin-enhanced adhesion was blocked by an arg-gly-asp peptide. Fibronectin, chondroitin sulphate and laminin all promoted collagen lattice contraction using normal gingival fibroblasts and low-serum media. Fibronectin had a greater effect than chondroitin sulphate and laminin. In media with standard serum, all cyst fibroblast lines examined demonstrated similar gel contraction curves with the exception of dentigerous cyst-derived fibroblasts, which contracted at decreased rates. Suppression of gel contraction was seen with dentigerous-cyst fibroblasts with all extracellular matrix glycoproteins and low serum. Dentigerous-cyst fibroblast attachment to glass and behaviour in gel lattices suggest that these cells express different functional attachment factors from other cyst fibroblast types.
Polycystic (dysgenetic) disease of the parotid glands is a rare disorder with only three fully documented reports in the literature containing a total of six cases. This developmental disorder of the distal ductal system appears limited to the parotid glands of female patients and is usually bilateral. We present two further cases with a confirmed familial background to add to the literature. This is the first documented report of familial polycystic disease of the parotid glands. The pathogenesis, mode of inheritance, clinical features, histological appearance and management of this interesting condition are discussed.
A genomic library derived from a virulent isolate of Legionella pneumophila was constructed in Escherichia coli JM 83 using the cloning vector pUC19. The clones were screened by filter immunoassay using L. pneumophila rabbit polyclonal antisera and in the absence of in situ bacterial lysis one such clone, LP 116, expressed L. pneumophila-specific antigens on the surface of E. coli. Restriction endonuclease digest analysis and agarose gel electrophoresis revealed a fragment measuring approximately 750 bp. Southern hybridization confirmed that the fragment was L. pneumophila DNA. Sequencing data showed that the fragment was 810 bp in length with an open reading frame (ORF) of 678 bp. The outer-membrane profiles of the E. coli parent, the L. pneumophila DNA-contributing strain and clone LP 116 were compared by SDS-PAGE. A protein of 25 kDa was found in outer-membrane preparations of both the clone LP 116 and L. pneumophila but not in E. coli JM 83. This was in agreement with the molecular mass of the deduced peptide of the mature protein. Immunoblots using L. pneumophila-specific polyclonal antiserum confirmed that this 25 kDa outer-membrane protein (OMP) was a L. pneumophila polypeptide. Both direct immunofluorescence assay and immunoblots using the commercially produced monoclonal antibody specific for the common antigen of the major outer-membrane protein (MOMP) confirmed that the 25 kDa protein produced by LP 116 was involved with the MOMP complex. The gene encoding this protein has been designated ompM.(ABSTRACT TRUNCATED AT 250 WORDS)
We have identified strong expression of a 38-kD cell surface glycoprotein (gp38), a marker of basal cell carcinomas (BCCs), in basal and suprabasal epithelial cell membranes of parakeratinised odontogenic keratocysts. In contrast, orthokeratinised cysts and most other odontogenic cyst types, ameloblastomas, normal stratified oral epithelium, cell rests of Malassez and glands of Serres, all proved negative. To our knowledge this is the first histochemical marker to distinguish between these major cyst types. It has obvious uses in the diagnosis of inflamed keratocysts and the separation of ameloblastomas from BCCs and may find a role in studies of the developmental biology of other odontogenic structures.
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Herpes simplex virus type 1 (HSV1) can be rapidly identified in saliva from patients with acute herpetic gingivostomatitis, by in vitro amplification using the polymerase chain reaction and specific primers. Amplification of DNA results in a product of 110 bp length corresponding to the region 1381-1490 bp of the HSV1 thymidine kinase gene. The specificity of the reaction was demonstrated in three ways: (i) the presence of a Sma 1 restriction enzyme site in the amplified product sequence; (ii) Southern blot using a biotinylated HSV1-specific oligonucleotide probe and (iii) direct sequencing of amplified product. At high titres of virus (> 5 x 10(5) virions/ml saliva), saliva may be added directly to the amplification assay for detection purposes. However, at lower titres of HSV1 viral DNA must be purified from saliva before in vitro amplification. HSV was identified in the saliva from symptomatic patients with acute herpetic gingivostomatitis and was absent in saliva collected from controls.
Atypical fibroxanthoma, a more recently recognised variant of malignant fibrous histiocytoma, is described arising at the site of an earlier squamous cell carcinoma, in a patient treated with radiotherapy 21 years previously. Distinction between atypical fibroxanthoma and a poorly-differentiated squamous cell carcinoma proved to be difficult by ordinary light microscopy and it was only after immunohistochemical staining that the second lesion was confirmed as atypical fibroxanthoma. The natural history, differential diagnosis and histological pitfalls of this poorly characterised mesenchymal lesion are discussed.
An investigation is reported on the in-vitro behaviour, characteristics and properties of three gentamicin-containing radiopaque bone cements that are considered to be promising retrograde root-filling materials. Three commercially available cements, CMW-1G, CMW-3G and Palacos R with gentamicin were studied with regard to bacteriocidal properties, tissue compatibility in cell culture, and ability to seal tooth cavities as evidenced by dye diffusion. Results were compared and contrasted with those obtained with an amalgam. The antibiotic-containing cements investigated are considered to have some distinct advantages over amalgam when used as retrograde root-filling materials in vitro. Amalgam was found to have poor bacteriocidal properties and poor tissue compatibility but slightly better apical sealing abilities than the cements. No apparent drawbacks were found with the cements.
A case of an aggressive giant cell lesion is reported. In view of the problems associated with histopathological diagnosis, long-term clinical and radiographic follow-up of any giant cell lesion is mandatory.
An incidental radiographic finding in a 17-year-old woman aroused suspicions of neoplasia. However at operation it was found to be due to an unusual calcified foreign body lodged in the posterior nares.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
There appears to be no information concerning changes in bite strength following wisdom tooth removal. A gnathodynanometer was constructed, calibrated and then tested on 20 normal subjects. Sixty five patients scheduled for third molar surgery were assessed by this device immediately before operation and on the seventh post-operative day. Post-operatively, they were asked to complete a McGill pain questionnaire (MPQ) and indicate their present pain on a numerical rating scale (NRS). Bite strength was reduced in all cases. The side which was most painful tended to have the larger reduction. The reduction in bite strength was found to have a highly significant correlation with the numerical rating scale and a significant correlation with the sensory descriptors of the McGill pain questionnaire. It would appear, therefore, that the gnathodynanometer holds promise as a research tool in oral surgery.