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Biomedical subjects

J G Cowpe

Publications and source records attributed to J G Cowpe.

At least 37 records · Page 2Linked to original sources

A new disposable bite gauge.

A simple method for assessing mouth opening by measuring interincisal distance with a disposable bite gauge is described. In a clinical study the technique has been proven to be both reproducible and reliable.

Calibration↗

DNA and keratin analysis of oral exfoliative cytology in the detection of oral cancer.

Refinements in oral exfoliative cytology may make it a suitable screening technique for the early diagnosis of oral cancer. In this study DNA range profiles were combined with keratin expression in an attempt to improve the diagnostic accuracy of oral exfoliative cytology. Smears were taken from 33 biopsy-proven oral cancers and the contralateral normal site. For DNA range profiles the smears underwent Feulgen hydrolysis, with DNA distribution being assessed using the Vickers M85 microdensitometer. For keratin expression a panel of antikeratin antibodies were applied. The smears for keratin expression were then graded on a three-point scale. Abnormal DNA range profiles were observed in 23 of 33 smears taken from oral cancers and in two smears from normal oral mucosa (sensitivity 70%, specificity 90%, positive predictive value 90%). The simple epithelial keratins 8 and 19 were identified in the majority of oral cancer smears. The sensitivity of keratin 19 was greater (90%). However, keratin 8 was the most useful keratin marker associated with malignancy (sensitivity 62%, specificity 100%, positive predictive value 100%). The combination of simple keratin expression and DNA content improved the cancer detection rate beyond that obtainable with DNA range profile alone.

Adult↗

p53 immunostaining as a marker for oral cancer in diagnostic cytopathology--preliminary report.

The expression of p53 in oral mucosal disorders is strongly associated with malignant disease. Smears from normal and malignant oral mucosa were investigated for the presence of p53 using CM1 polyclonal antibody against p53 protein. The expression of p53 in smears was compared with the expression of the marker in biopsies from these oral carcinomas. p53 was identified in eight smears from 12 biopsy positive oral cancers. It was not seen in smears from eight p53-negative oral cancers and 40 smears from normal oral mucosa. It is suggested that expression of p53 in smears from a clinically suspicious lesion may be of value in the diagnosis of oral carcinoma.

Biomarkers, Tumor↗

Nuclear DNA content and morphometric characteristics of normal, premalignant and malignant oral smears.

Three methods of DNA content assessment providing both rare-event and population features were applied to forty eight Feulgen-stained oral smears collected from twenty patients. The smears were collected from three sites and diagnosed either clinically as normal, or histologically as premalignant or malignant. Cell morphometry features were also measured from Papanicolaou-stained smears from each site. The three methods of DNA content assessment could distinguish clearly between normal and abnormal smears, but not between premalignant and malignant smears within the abnormal group. However discrimination could be obtained between these subgroups using cytoplasmic area. The results therefore suggest that a combination of DNA content and morphometric measurement of oral smears can give a useful method for detecting and localising premalignant and malignant conditions.

Cytodiagnosis↗

Comparison of planimetry and image analysis for the discrimination between normal and abnormal cells in cytological smears of suspicious lesions of the oral cavity.

Light microscope analysis of cytological smears of suspicious lesions of the oral cavity is used as a method for detecting early cancer in the oral cavity. The sensitivity of this approach can be improved by quantitative analysis of the cells in the cytological smears. We have compared the efficiency of planimetry and the Vids V system of image analysis, as quantitative methods for discriminating between normal and abnormal cells in cytological smears of suspicious lesions in the oral cavity. Both methods detected an increase in nuclear area and a decrease in cytoplasmic area in abnormal epithelial cells from dysplastic lesions of increasing severity. However, image analysis was better able to discriminate between benign and malignant cells on the basis of nuclear size. Thus the Vids V system of image analysis is more appropriate than planimetry for quantitative analysis of cytological smears from the oral cavity.

Cell Size↗

Detection of field change in oral cancer using oral exfoliative cytologic study.

Four smears were taken from the normal buccal mucosa of 55 oral cancer patients and 76 cancer-free patients. In each case, two were stained by the Papanicolaou method and two underwent Feulgen hydrolysis. Quantitative assessment of nuclear area (NA) and cytoplasmic area (CA) of the Papanicolaou smears was undertaken using a semiautomatic image analysis system. DNA profiles were assessed from the Feulgen smears using a Vickers M85 microdensitometer (Vickers Instruments, York, England) and were found to be diploid for all patients. Results were then analyzed with respect to those patients who took alcohol, tobacco, combination of alcohol and tobacco, and those who took neither. A significant reduction in CA for the oral cancer group (P equals 0.001) but no change in NA (P equals 0.74) was observed. A detailed analysis of alcohol and tobacco habits could identify no significant role for these two factors, in the reduction in cytoplasmic area. Such field change may prove to be of value in predicting the development of second malignant tumors.

Adult↗

Quantitative cytology of oral smears. A comparison of two methods of measurement.

Previous quantitative cytologic studies employing planimetry to assess oral smears established a "discriminant line" for separating normal and abnormal cases. The use of the Vids V semiautomatic image analysis system to make these measurements was analyzed to determine whether the results obtained by the two methods were comparable. In measuring the same cells by both methods, no significant variation in nuclear size was detected; however, there was a statistically significant variation in the measurements of cytoplasmic area. Further analysis suggested that the cytoplasmic areas differed by a constant amount, not a constant proportion, between the two methods; this may be due to the ability of the Vids V system to more clearly display the cell boundaries. The appropriateness of techniques for comparing different methods is discussed.

Cytodiagnosis↗

The effect of distant malignancy upon quantitative cytologic assessment of normal oral mucosa.

In 1962 Nieburgs et al. reported specific changes within cells taken from normal buccal mucosa, in those with malignant disease distant from the oral cavity. Few have attempted to confirm these findings. Given the potential application of the observations of Nieburgs et al., a quantitative investigation seemed necessary. Two groups were studied: 40 patients with malignant disease outside the oral cavity and 40 healthy patients attending for routine dental treatment. Both groups were matched for age and sex, with anemia excluded. Quantitative cytologic assessment of nuclear (NA) and cytoplasmic area (CA) and DNA distribution (using DNA cytophotometric study) were calculated from cells in normal buccal mucosal smears. No significant difference in NA (P = 0.28) was found between the two groups. However, a significant reduction in CA (P = 0.005) was found within the distant malignancy group. DNA distribution was invariably diploid. Previous studies on the effect of distant malignancy and nutritional deficiency have concentrated on examination of the nucleus, with exclusion of the cytoplasm. Important changes, such as the one reported, may therefore have gone unrecorded, particularly since oral smears have rarely been quantitatively assessed. The cause of this decrease in CA in distant malignancy patients is discussed with regard to the patients' nutritional state. The buccal smear may yet prove of value in assessing nutritional deficiency consequent to internal malignancy.

Cell Nucleus↗

Evidence of field change in oral cancer.

Evidence of field change in oral cancer was assessed using quantitative cytomorphometric analysis of smears taken from normal buccal mucosa in oral cancer and cancer-free patients. The nuclear areas (NA) and cytoplasmic areas (CA) were calculated using a semi-automatic image analysis system. A statistically significant reduction in CA (p = 0.002) but no change in NA was observed for the oral cancer group. This change occurred irrespective of tobacco and alcohol usage. We believe this to be the first evidence for true field change since Slaughter's original hypothesis in 1946.

Aged↗

Quantitative exfoliative cytology of normal buccal mucosa: effect of smoking.

The effect of cigarette smoking on the oral mucosa was assessed through the application of quantitative cytomorphometric analysis to smears obtained from clinically normal buccal mucosa. The nuclear (NA) and cytoplasmic (CA) area of cells within each smear were measured using a Vids V semi-automatic image analysis system. Mean values for NA (smokers--78.74 microns 2, non-smokers--72.28 microns 2 and for CA (smokers--3273.9 microns 2, non-smokers--3098.96 microns 2) were obtained. A two-sample t-test revealed a significant elevation in NA for smokers, but no significant variation in CA between the two groups. These results would suggest that for normal buccal mucosa smoking does appear to influence cytomorphology.

Aged↗

Quantitative assessment of various fixatives on nuclear and cytoplasmic areas in oral cytology.

Both nuclear and cytoplasmic areas are parameters known to be of significance in the diagnosis of malignancy. However, few studies have assessed the effect of fixation on exfoliative cytology and none has looked at such influences upon oral smears. Hence the method of fixation may influence directly diagnostic cytology. The effect of three methods of fixation upon the nuclear and cytoplasmic areas of cells removed from the buccal mucosa was quantitatively assessed. The three methods employed, prior to Papanicolaou staining, were: direct immersion in diethylether and ethanol (1:1 v/v), spray fixation (Vale Smear Fix) and air drying. Three smears from each of 21 patients were used, each slide being allocated randomly a method of fixation. After 24 h all smears were processed for Papanicolaou's stain. The nuclear and cytoplasmic areas were calculated using semi-automated image analysis. No significant differences were found in the two areas whichever method of fixation was used.

Adult↗

Effect of radiotherapy on oral mucosa assessed by quantitative exfoliative cytology.

The effect of radiotherapy on normal buccal mucosa was investigated using the quantitative techniques of cytomorphology (measurement of nuclear and cytoplasmic area) and DNA cytophotometry. These techniques were applied to smears obtained before, during, and after irradiation. Nuclear area and cytoplasmic area increased and DNA values were abnormal in most cases as a result of radiotherapy, returning to within normal limits one month after treatment. This contrasts strongly with the changes seen in smears from previously irradiated uterine cervices, where changes in cytomorphology may persist for several years.

Cell Nucleus↗

Are post-operative radiographs necessary in the management of simple fractures of the zygomatic complex?

Post-operative radiographs are usually requested, as an adjunct to clinical judgement, in the management of fractures of the facial skeleton. Unfortunately exposure to X-irradiation is not without risk. The request for radiographs should, therefore, be justified in every case. In this retrospective survey involving 183 simple fractures of the zygomatic complex, all treated via a Gillies temporal approach, only one required a further operation, under the criteria described. The findings in this study might be taken as evidence that clinical judgement alone is sufficient for post-operative evaluation and as such offers a challenge to the accepted protocol of requesting post-operative radiographs in such cases.

Humans↗