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Biomedical subjects

C Scully

Publications and source records attributed to C Scully.

At least 541 records · Page 30Linked to original sources

Characterization of malignant rat keratinocytes in culture following the induction of oral squamous cell carcinomas in vivo.

An in vivo model of oral epithelial carcinogenesis in rats has been established successfully in cell culture. Oral carcinomas of the tongue and palate were induced in Sprague-Dawley male rats by painting their palates three times weekly for 7-8 months with 0.5% (w/v) 4-nitroquinoline-N-oxide. Oral keratinocytes from malignant and untreated control tissues were cultivated using 3T3 fibroblast support. Both the normal and malignant cells stained positively with an anti-human keratin polyclonal antibody but malignant keratinocytes were heterogeneous with regard to cell size, shape and intercellular packing, unlike the regular organization of the normal cultures. Malignant keratinocyte cultures differed markedly from their normal counterparts by an increase in their growth rate, the capacity for serial cultivation to the 25th passage (to date) and independence of 3T3 fibroblast support. In contrast, cultures established from healthy tissue showed signs of senescence usually by passage 4 and were totally reliant on 3T3 fibroblast support for growth. Malignant keratinocytes expressed anchorage independence when cultured in a semi-solid medium and gave rise to tumour formation in athymic mice. The development of this specialized cell culture system substantially increases the potential of the rat 4NQO model to investigate the pathogenesis of oral squamous cell carcinomas.

Animals↗

Association between HLA-A9 and rapidly progressive periodontitis.

HLA-A, B, C, DR antigen frequencies and Properdin factor B (Bf) allotypes were studied in a group of 44 patients with rapidly progressive periodontitis. HLA-A9 (A24) was the only antigen with a frequency statistically significantly different from the control population. An increased frequency of HLA-A9 was previously reported in periodontal diseases. Our results in a well characterised group of patients adds to the evidence that HLA-A9 plays a role in the susceptibility to severe periodontitis.

Complement Factor B↗

Site-specific distribution of epithelial cell-surface carbohydrates in rat oral mucosa.

The binding of two fluorescein-labelled lectins to epithelial cell surfaces was examined microspectrofluorimetrically in rat oral mucosa. Griffonia simplicifolia (GS-I-B4), which is specific for alpha-D-galactosyl end groups, labelled only basal cells, while Ulex europaeus (UEA-I), which is specific for alpha-L-fucosyl groups, labelled only spinous cells. The degree of binding of the lectins was dependent on the lectin concentration and the lectin pH. Different sites were examined. The labelling of basal cells by GS-I-B4 was maximal on the lateral borders of the tongue, and the fluorescence diminished medially; in contrast, the UEA-I labelling of the corresponding spinous cells was of undiminished intensity in the mediolateral direction across the entire lingual epithelium. There was a gradual increase in the binding of GS-I-B4 and UEA-I towards the posterior aspect of the tongue. In the mid-palate, there was stronger staining both of basal cells by GS-I-B4 and of spinous cells by UEA-I in the gingivae as compared to the centre of the palate. In anteroposterior sections of the fore- and mid-palate, the fluorescence intensity of basal cells was inversely related to that of spinous cells, with maximal labelling of basal cells by GS-I-B4 and corresponding minimal binding of spinous cells by UEA-I being evident at the crests of the transverse rugae, and the opposite pattern of staining by both lectins being noted at the bases of the rugae.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Use of panoramic radiographs in general dental practice in England.

The rapid growth in the use of panoramic radiographs provoked this survey of the reasons why general dental practitioners in Avon take such views. Of the 193 dentists who responded, 42 (22%) took one or more panoramic radiographs during a specified week. A total of 195 patients, 8% of those x-rayed, had a panoramic radiograph taken either alone or in combination with other views. Panoramic radiographs were stated to have been taken primarily for the diagnosis of caries (48%) and surgical (24%), periodontal (20%), orthodontic (20%) and endodontic/apical assessment. These findings are discussed with respect to published guidelines on the use of panoramic radiographs and the teaching of radiology in dental schools.

Adolescent↗

Reasons for taking radiographs in general dental practice.

This survey investigated the reasons why general dental practitioners take radiographs. 179 (54%) dentists responded and provided information for 2359 patients who were radiographed during a specified week. Of those patients aged less than 15 yr, 62% were radiographed primarily for orthodontic purposes and 22% for caries. In older age groups, caries was the predominant reason for taking radiographs but endodontic assessment assumed increasing importance with age and accounted for 37% of radiographs in patients aged more than 45 yr. Only 8% of patients were radiographed for periodontal reasons. These findings are discussed with respect to the changing pattern of disease and treatment provided in general dental practice.

Adolescent↗

Oral epithelial atypia and acantholytic dyskeratosis in rats painted with 4-nitroquinoline N-oxide.

Oral epithelial atypia and foci of acantholytic dyskeratosis (FAD) were investigated in 54 rats treated with the carcinogen 0.5% (w/v) 4-nitroquinoline-N-oxide in propylene glycol and in 18 rats treated with propylene glycol only. The palate of each animal was painted 3 times weekly for up to 9 months and rats were killed at monthly intervals. A gradual significant increase in the epithelial atypia indices of the palatal and lingual tissues (anterior and posterior of the intermolar tubercle) was observed with a maximum value of 17-22 of a possible 75 at 28-32 weeks. No significant differences were noted between the atypia indices of the palatal and lingual tissues. FAD were not evident in the palate or lingual tissues before 12 weeks and 16-24 weeks, respectively, and although the palate consistently showed more FAD compared with the lingual tissues the differences were not significant. Features of epithelial atypia and FAD were absent in the 18 control rats treated with propylene glycol only and in 8 untreated control animals. At 28 weeks of 4NQO treatment 2 of 5 rats, at 32 weeks 3 of 4 rats and at 36 weeks 3 of 3 rats had developed infiltrating squamous cell carcinomas in either/both the palate or tongue. The results suggest that epithelial dysplasia and acantholytic dyskeratosis may be late morphological features of a more fundamental change occurring earlier in the process of tumour development.

4-Nitroquinoline-1-oxide↗

Identification of immunoreactive membrane antigens of Brucella ovis by ELISA profiling.

Enzyme-linked immunosorbent assay (ELISA) profiling was used to identify the immunoreactive membrane antigens of Brucella ovis. Immunoreactive membrane antigens obtained after detergent extraction of the bacterial membrane complex (inner and outer membranes) were resolved into five peaks (A, B, B1, C and D) by gel permeation chromatography. Aliquots from each of the chromatographed fractions were coupled to 96-well microtitre plates and immunoreactive fractions identified with sera from two rams. Serum from ram 1 which had been vaccinated with a single injection of formalin-killed B ovis emulsified in incomplete Freund's adjuvant identified A and B as the major immunoreactive peaks. Serum from ram 2, which had been successfully infected with B ovis, reacted mainly against peaks A, B1, C and D. This observation facilitated the use of A, B, B1, C and D peak antigens as test reagents to examine the serological response of 12 other rams exposed to B ovis by vaccination or intraconjunctival or intravenous inoculation. Sera from rams which developed productive infections reacted strongly against peaks A, B1, C and D while vaccinated rams had preferential antibody activity against peaks A and B.

Animals↗

Monoclonal antibodies against ovine IgA purified from lung lavage fluid.

Ovine secretory IgA (sIgA) has been purified to relative homogeneity by ammonium sulphate precipitation (to 40 per cent w/v) of lung lavage fluid from 3- or 12-month-old lambs, followed by molecular sieve chromatography on a Sephacryl S300 matrix. Three peaks A, B and C with molecular sizes corresponding to 550,000, 400,000 and 165,000 respectively were eluted from the column. Immunoelectrophoresis, radial immunodiffusion and enzyme-linked immunosorbent assays (ELISAs) with class specific antiserum confirmed that peak B contained only IgA. Polyacrylamide gel electrophoresis of peak B under reducing conditions resolved three subunits corresponding to secretory component, heavy and light chains. Hybridomas generated by fusing spleen cells from IgA-primed Balb/C mice with murine myeloma (Sp2/0) were screened for IgA-specific monoclonal antibodies against a panel of ovine IgG2, IgG1, IgA and IgM. One particular clone, F3-4B4, identified as murine IgG1, was monospecific against ovine IgA with no cross reactivity against bovine immunoglobulins. This hybridoma was successfully tested as a serological probe by ELISA profiling to locate IgA containing fractions in the course of immunoglobulin purification from biological fluids.

Animals↗

The use of the lectin Ulex europeus to study epithelial cell differentiation in neoplastic and non-neoplastic oral white lesions.

Ulex europeus (Ulex 1) has been used to study the expression of cell surface alpha-L-fucose on oral epithelial cells of normal human mucosa, white lesions and carcinomas. In normal tissue and in 11 of 12 specimens of non-specific keratoses (leukoplakia), Ulex 1 stained epithelial spinous cells only. In 16 specimens of oral lichen planus, Ulex 1 labelled spinous epithelial cells, and in 12 there was also staining of the basal epithelial cells. Two specimens of white sponge naevus showed a total absence of epithelial staining with Ulex 1. Squamous carcinomas showed a loss of staining in the invading epithelial islands in six of eight specimens, but normal labelling of the surfaces of spinous cells at sites distant from the areas of epithelial invasion. When the severity of epithelial dysplasia, as assessed by the index of epithelial atypia, was compared with the pattern of staining of Ulex 1 in normal mucosa and white lesions there was no correlation. The results show that failure of Ulex 1 to stain cell surface carbohydrates may not be attributable to malignant transformation. The staining of cells not normally stained may be related to hitherto masked residues revealed by cell damage or altered differentiation.

Carcinoma, Squamous Cell↗

Ulcerative stomatitis, gingivitis, and skin lesions. An unusual case of primary herpes simplex infection.

A 2-year-old white girl had acute oral ulceration, gingivitis, pyrexia, cervical lymph node enlargement, and a generalized, initially macular and later purpuric rash. None of the common oral viral infections, with the exception of chickenpox, is usually associated with a rash. This presented a diagnostic dilemma that appears not previously to have been reported in the dental literature.

Child, Preschool↗