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Biomedical subjects

J G Cowpe

Publications and source records attributed to J G Cowpe.

At least 19 recordsLinked to original sources
PubMed2001

Extraction of DNA from oral cytological samples by scraping and smear method suitable for restriction site mutation analysis: a pilot study.

The restriction site mutation assay (RSM) can be used to measure base changes which occur in the DNA coding for bacterial restriction enzymes. The aim of this study was to investigate whether DNA, of sufficient quantity and quality for analysis by RSM, could be extracted from cells collected from precancerous lesions using a cytological smear technique. Six smears were collected from each of five lesions of leukoplakia displaying a variety of clinical appearances. Three methods for the extraction of DNA were compared. The commercial extraction method was shown to be most convenient and reproducible, routinely providing 1-5 microg of DNA per sample. Cell populations collected by a cytological smear technique can provide DNA of sufficient quantity and quality for analysis of RSM.

DNA↗
PubMed2001

Quantitative cytomorphologic analyses of Papanicolaou-stained smears from oral lichen planus.

OBJECTIVE: To apply quantitative techniques to cytologic smears in order to improve the diagnostic sensitivity of cytology in the detection of malignant change in the oral cavity. STUDY DESIGN: Eighty-two patients with lesions of oral lichen planus were investigated. A total of 247 Papanicolaou-stained buccal smears underwent nuclear and cytoplasmic area measurements using a TV image analyzer. RESULTS: The cytomorphologic results of this study suggest that lesions of oral lichen planus contain smaller cells and nuclei than those observed in clinically normal oral mucosal smears. There was a statistically significant reduction in nuclear area (P < .001) and cytoplasmic area (P < .05) for the oral lichen planus smears. CONCLUSION: The TV image analysis system could provide a valuable method of quantifying cell changes in oral smears collected from oral mucosa as a method of monitoring lesions of oral lichen planus.

Analysis of Variance↗
PubMed2000

Sensitivity of Seescan TV image analysis in discriminating between normal, dysplastic and malignant oral smears.

OBJECTIVE: Smears from premalignant and malignant lesions may contain large proportions of normal cells together with atypical cells; that could reduce the sensitivity of cytologic diagnosis. The present study assessed the performance of the Seescan TV image analysis system (TVIAS) in distinguishing between normal, premalignant and malignant oral smears. The sensitivity of Seescan TVIAS was tested using both white and monochromatic light. STUDY DESIGN: Nuclear area (NA) and corrected integrated optical density (IOD) of 50 Feulgen-stained nuclei were measured in smears collected from normal oral mucosa (n = 6), lesions displaying epithelial dysplasia (n = 5) and invasive squamous cell carcinoma (n = 5) using a Seescan TVIAS with both white and monochromatic light. RESULTS: There was a significant increase (P < .001) in mean IOD for nuclei in smears from dysplastic lesions and carcinomas as compared with normal smears. For smears from carcinomas, the mean NA was significantly elevated as compared with dysplastic (P < .001) and normal smears (P < .01). Mean NA for dysplastic smears was significantly reduced as compared with normal smears. While all smears from premalignant and malignant lesions contained mostly normal nuclei, a significant proportion of abnormal nuclei was identified in each smear. CONCLUSION: Although oral smears contain large amounts of normal cells, the Seescan TVIAS could successfully identify dysplastic and malignant cells on the basis of both IOD and NA values with or without the use of a monochromatic filter.

Carcinoma, Squamous Cell↗
PubMed1999

Masseteric hypertrophy?: preliminary report.

We report radiological and histological investigations of a patient who presented with the masseteric hypertrophy. Sections of the patient's masseter muscles were also investigated using a series of histological techniques. The histological and morphometric analysis of the patient's masseter muscle showed numerous small fibres, which indicated that the masseteric enlargement was not the result of classic fibre hypertrophy. We suggest that the use of the term 'hypertrophy' in this condition may be misleading.

Adult↗
PubMed1999

Quantitative oral exfoliative cytology. Effect of alcohol on normal buccal mucosa.

OBJECTIVE: To assess the effect of chronic alcohol intake on the DNA distribution and cell area of normal oral mucosal cells. STUDY DESIGN: Smears were taken from clinically normal buccal mucosa of 50 patients attending an alcohol-problem service (i.e., chronic alcohol use) and average alcohol units per week recorded. DNA distribution histograms and total cell area values were then compared to those obtained from smears taken from a control group (which included social drinkers) of patients attending for routine dental treatment. Nuclear DNA content was assessed on 100 randomly selected, Feulgen-stained nuclei using a Seescan TV image analysis system, and total cell area was assessed on 50 Papanicolaou-stained cells using the Vids V image analysis system. RESULTS: The DNA distribution histograms were essentially diploid in appearance for the alcohol group, although there was an increase in nuclear DNA content in the occasional nucleus. A highly significant reduction in total cell area was found for the alcohol group when compared to the controls. CONCLUSION: The chronic ingestion of alcohol is associated with a reduction in total cell area but appears to have little effect on nuclear DNA content. Our previous research using the same technique showed that oral cancers are frequently nondiploid. Thus, a nondiploid DNA distribution histogram for smears taken from a clinically suspicious lesion in someone who consumes excessive amounts of alcohol is unlikely to be due to alcohol use alone and should indicate biopsy.

Adult↗
PubMed1998

The use of the PAPNET automated cytological screening system for the diagnosis of oral squamous carcinoma.

The automated PAPNET screening system has been developed to recognize abnormal cells in cervical smears. Given that the oral mucosa sheds cells resembling superficial and intermediate cells of the cervix, the aim of this study was to assess whether the PAPNET system could be used to detect dysplastic cells in oral mucosal smears. Sixty-two oral smears from 27 patients were examined by both light microscopy and using the PAPNET system from clinically abnormal and normal areas by two pathologists. The clinically abnormal sites were also biopsied for histological analysis. There was 100% correlation between the manual and PAPNET screening results. Cytological interpretation of oral smears by both manual and PAPNET screening methods correctly diagnosed squamous cell carcinoma in 14/23 (61%) of patients who had all been confirmed by biopsy. The nine patients with false-negative cases could be attributed to poor smear technique and preparation. The PAPNET system can be used to identify abnormal cells in oral smears and, as such, may have an application for screening those populations at high risk of oral cancer--provided that adequate tuition is given in smear technique.

Aged↗
PubMed1997

Oral exfoliative cytology: review of methods of assessment.

The use of oral exfoliative cytology in clinical practice declined due to the subjective nature of its interpretation and because there may be only a small number of abnormal cells identifiable in a smear. The more recent application of quantitative techniques, together with advances in immunocytochemistry, have refined the potential role of cytology, stimulating a reappraisal of its value in the diagnosis of oral cancer. This review considers the influence of the quantitative analysis of cytomorphology, DNA analysis and other tumour markers applied to oral exfoliative cytological samples. These studies indicate that oral cytology may provide an important adjunct in the assessment of the patient with a potentially cancerous oral lesion.

Biomarkers, Tumor↗
PubMed1996

A quantitative cytological study of lesional and non-lesional mucosa in oral lichen planus.

Smears of buccal mucosa, dorsal surface of the tongue and floor of mouth were taken from 10 patients with histologically confirmed oral lichen planus and 12 healthy age- and sex-matched controls. In buccal smears, no significant differences in cytoplasmic and nuclear areas were observed between lesional, adjacent non-lesional and control tissues. However, the cytoplasmic area in smears from lichen planus lesions on the dorsum of the tongue and adjacent clinically normal mucosa was reduced compared with healthy controls. The cytoplasmic: nuclear ratio in smears from clinically normal floor of mouth in oral lichen planus was similarly reduced. Papanicolaou-stained smears from buccal lichen planus showed increased keratinization compared with normal buccal mucosa. These findings demonstrate that quantitative cytology can detect both cytoplasmic and nuclear changes in oral lichen planus.

Adult↗
PubMed1996

Performance of a computer simulated neural network trained to categorise normal, premalignant and malignant oral smears.

The accurate detection of malignant neoplasms whilst they are still small is recognised as one of the main factors increasing chances of survival. Neural networks have many biomedical applications and they have been applied to neoplasia but their use in oral pathology has only recently been documented. The objectives of this study were to train networks to discriminate between normal and dysplastic mucosa. Each network was trained by back propagation, internal cross validation and tested on additional data. The data were derived by analysing 348 intra-oral smears and included mean nuclear and mean cytoplasmic areas of the smears measured by image analysis. A neural network differentiated between normal/non-dysplastic mucosa and dysplastic/malignant mucosa (specificity 0.82, sensitivity 0.76). These early results suggest that integrating neural networks and image analysis, as well as investigating additional criteria, could enhance automation and accuracy of smear techniques in diagnosing oral malignancy.

Automation↗
PubMed1996

Patient perceptions regarding the risks of morbidity and complications of lower third molar removal.

The risks associated with third molar surgery are well established. Current philosophy stresses co-development of treatment plans with patients, who need to understand the complications and risks of possible treatment. This understanding was therefore investigated at an initial outpatient appointment (n = 91) after a verbal explanation and immediately prior to surgery (n = 73), by means of visual analogue scales to assess patients' perceptions of the likelihood of each outcome. Most patients (98 percent) responding at an initial appointment (t1) felt that they had been given enough information regarding reasons for removal but the proportion was lower (88 percent) for patients responding at the time of surgery (t2). This reduction was also found for information regarding post operative pain, swelling, trismus and nerve damage. Patients estimated the likelihood of pain as t1 = 70 percent, t2 = 80 percent, swelling t1 = 76 percent, t2 = 75 percent, trismus t1 = 74, t2 = 73 percent, temporary nerve damage: transient labial t1 = 46 percent, t2 = 33 percent, transient lingual t1 = 51 percent, t2 = 41 percent, and permanent nerve damage: labial t1 = 13 percent, t2 = 7 percent, lingual t1 = 14 percent, t2 = 9 percent. At t1 and t2 the mean perceived likelihood for pain, swelling and trismus were significantly higher than the known prevalence of these sequelae. The mean values for temporary lingual and labial anaesthesia were considerably higher (P < 0.05) than the reported prevalence. It was concluded that patients overestimated the likelihood of post operative complications and that these estimates varied with time. The validity of patients' estimates might be improved by verbal explanation supplemented by provision of written information.

Appointments and Schedules↗
PubMed1995

Influence of temperature on long-term keratin immunoreactivity for oral exfoliative cytology.

We previously showed that keratin profiles can be of value in the diagnosis of oral cancer when using exfoliative cytology. In the future, they may form part of a screening program for oral cancer. This study evaluated the influence of long-term storage on keratin expression. Smears were collected from the clinically normal buccal mucosa and dorsal tongue of 22 patients. Half were stored in a refrigerator (5 degrees C) and half in a freezer (-70 degrees C). A total of 528 smears were collected. A panel of three antikeratin antibodies (LP34, AE8 and 1C7) was used to identify the preservation of keratin expression (graded as absent, few cells positive or many cells positive). The results for smears from dorsal tongue indicated that many cells were impermeable by the antikeratin antibodies. However, a satisfactory level of keratin immunoreactivity was observed in smears from buccal mucosa stored at -70 degrees C for over one year. Results for storage at 5 degrees C for both sites were inadequate after one month. Thus, smears from nonkeratinized oral sites may be stored at -70 degrees C for at least one year without a profound loss of keratin immunoreactivity, thus allowing examination of archival material.

Cold Temperature↗
PubMed1995

Comparison of nuclear area measurements carried out on normal and dysplastic oral smears.

We previously showed that quantitative cytology can help to detect oral cancer, not only at initial presentation but also in patients with unstable mucosa in whom recurrence has been detected prior to detection of a clinically obvious cancer. This has been due principally to the presence of a reduction in cytoplasmic area for Papanicolaou-stained cells and abnormal DNA distributions in Feulgen-stained nuclei collected from histologically confirmed dysplastic lesions. Furthermore, Feulgen-stained nuclei in oral smears that display abnormal DNA profiles appear to be larger than those in clinically normal smears, although an increase in nuclear area (NA) in Papanicolaou-stained smears is not always apparent. The aims of this study were to compare the mean NA values recorded for cells in Feulgen-stained smears with the values recorded for cells in Papanicolaou-stained smears collected from a selection of normal and abnormal sites to determine which of these smears produced mean NA values that correlated most closely with their DNA distributions. Forty patients with histologically confirmed epithelial dysplasia or invasive carcinoma and 20 patients with clinically normal mucosa were included in the study. NA values were obtained using image analysis. The mean NA values were obtained from the Feulgen-stained smears were significantly elevated when compared with mean NA values obtained from Papanicolaou-stained smears of dysplastic lesions and invasive carcinoma and for clinically normal smears collected from these patients. This elevation in mean nuclear size, for Feulgen-stained smears, correlated closely with DNA distribution.

Cell Nucleus↗