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Biomedical subjects

H K Williams

Publications and source records attributed to H K Williams.

9 recordsLinked to original sources
PubMed1995

Immunocytochemical detection of ornithine decarboxylase (ODC) in paraffin-embedded tissues as a possible prognostic indicator for oral lesions.

Intracellular levels of ornithine decarboxylase (ODC) are raised following mitogenic stimulus and in neoplasia. Because lesions of the oral cavity are often difficult to assess histologically, we have determined the value of immunocytochemical detection of ODC as a prognostic indicator in 74 routinely fixed and paraffin-embedded oral biopsies using peroxidase-antiperoxidase and immunogold-silver staining. The latter proved more sensitive, yielding positive reactions in 32 of 43 oral carcinomas (11/14 well differentiated, 16/21 moderately differentiated and 3/5 poorly differentiated) and 7/11 potentially malignant lesions, compared with 19/45 carcinomas and 1/15 potentially malignant lesions, by peroxidase anti-peroxidase. Hyperplastic lesions (n = 7) and normal non-keratinized buccal mucosa (n = 7) were all negative. Follow-up was possible in 13 of the carcinoma patients. Of 7 positive ODC reactions but clinically node-free at biopsy, 2 died and 2 had recurrences within 3 years, whereas all of 6 with no immunoreactivity were symptom-free after 3-5 years. Immunostaining for ODC may be helpful for the prognostic assessment of routinely processed oral lesions and in choosing treatment.

Animals↗
PubMed1989

Persistent sialadenitis of the minor glands--stomatitis glandularis.

In a recurring lesion on the palate of a 60-year-old male, histological features of a chronic inflammatory disease of the minor salivary glands resembling those found in cheilitis glandularis were found. The similarities between the clinical and histological features of our case and cheilitis glandularis are discussed and the inherent nature of the disease emphasised. We propose the terms persistent sialadenitis of the minor glands or stomatitis glandularis, for this condition.

Humans↗
PubMed1988

Mandibular African histoplasmosis: imitation of neoplasia or giant-cell granuloma?

The lesion reported in this article destroyed much of the right side of the mandible in a 14-year-old boy. Clinically, it resembled Burkitt's lymphoma and was initially treated as such. After correct microscopic diagnosis, the mass regressed with the use of intravenous amphotericin B and surgical reduction. The histologic comparison with giant-cell granuloma is considered.

Adolescent↗
PubMed1987

Mesenchymal chondrosarcoma.

2 cases of this rare tumour in Nigerian subjects is described. Clinical features indicated relatively slow but painful growth, aggravated in 1 case by dental extractions. Radical resection was followed by 6-year survival without recurrence or overt metastasis. Microscopic differential diagnosis is discussed.

Adult↗
PubMed1987

Osteosarcoma of the jaws--a series from Kaduna, Nigeria.

15 primary and one metastatic osteosarcoma of the jaw bones in Nigerians are described. The age range was typical of this tumour; most cases were in the mandible. Clinical and radiographic features were often diagnostic but the microscopic appearances were varied and problematical. No metastases were detected and effective surgical treatment depended upon the degree of spread in soft tissue. Inoperable tumours had infiltrated the pharyngeal and tonsillar area. Some resected cases survived for one year or more.

Adolescent↗
PubMed1987

Primary culture of human oral epithelial cells. Growth requirements and expression of differentiated characteristics.

Epithelial cell cultures were initiated from explants of normal human oral mucosa. Growth parameters, cell type, and degree of maturation/cytodifferentiation were assessed by morphological and surface topographical criteria (light and scanning electron microscopy) together with immunofluorescence studies with a panel of antibodies to cytokeratins and extracellular matrix components. The effects of different media formulations were compared. Whereas stromal cell over-growth soon became apparent in media containing 10% serum, in low serum (0.5%) media containing insulin, hydrocortisone, epidermal growth factor (EGF), and/or cholera toxin (CT), epithelial growth was maintained with minimal or absent stromal cell contamination. Cell proliferation, maturation, and differentiation were modulated by EGF and CT: cultures maintained on EGF showed optimal growth but cells typically displayed only limited differentiation. By contrast, CT promoted considerably more cytodifferentiation but at the expense of proliferative capacity. Both factors together were complementary, resulting in maintenance of cells of a more mature phenotype of high proliferative capacity. Cytokeratins of normal oral epithelium in situ demonstrated characteristic changes in patterns of expression associated with differentiation. In culture, proliferative epithelial cells expressed keratins typical of the basal layer, whereas the most differentiated cells were identified by their strong reactivity with antibodies to epidermal keratins. Less mature cells showed expression of keratins associated with nonstratified epithelia. In cultures maintained with CT but no EGF, there was a tendency for weaker expression of basal type keratins, further suggesting that these cells were maintaining a more differentiated phenotype. Extracellular matrix components (fibronectin, laminin, collagen type IV) were not expressed by any epithelial cells in culture. Irrespective of medium composition, cultures did not survive beyond 100 days (5 or 6 subcultivations) before undergoing an irreversible 'crisis' of growth arrest and onset of degenerative changes.

Adolescent↗
PubMed1986

Onchocerciasis of the face and mouth.

Onchocerciasis is characterized by the presence of numerous microfilariae in the skin, by the formation of subcutaneous nodules, and by eye lesions that frequently lead to blindness. The organisms' life cycle and the clinical symptoms and histologic features of the disease are described, together with three case reports from Nigeria. One of the cases involved a rare intraoral lesion.

Adolescent↗
PubMed1984

Advanced central myxoma of the jaws in Nigeria. Clinical features, treatment and pathogenesis.

18 advanced cases of myxoma of the jaws are described. These had a typical age, sex and site distribution and characteristic clinical and radiographic features. Surgical treatment was radical as benefits large, poorly defined tumours, but there was no evidence that these were aggressive lesions. It is argued that the designation of myxoma as an odontogenic tumour is uncertain though not excluded. Attention is drawn to evidence that many myxomas of the jaws may be examples of myxomatous degeneration in other neoplasms.

Adolescent↗