Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisation

The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology.

Angiogenesis and vasodilation in skin warts. Association with HPV infection

BACKGROUND

Angiogenesis is required for tumour growth. Since human papillomavirus (HPV) infection is associated with the development of neoplastic lesions, the aim of this study was to determine the possible association between HPV infection and angiogenesis in benign tumours.

MATERIALS AND METHODS

Specimens of skin warts which were either negative for HPV types 1, 2, 3 and 4 (HPV-ve; n = 15), or positive for HPV2 (HPV+ve; n = 19) were compared with normal skin (NS, n = 10). Vascularity and inflammation were assessed in consecutive sections. vWF-positive blood vessels were classified as small or large using a cut-off value of 50 microns diameter.

RESULTS

Vascularity values for small vessels increased significantly from NS to HPV-ve warts and from HPV-ve to HPV+ve warts. Large vessels were found only in warts and their abundance was not related to HPV status. No significant association was found between vascularity and inflammation or between vascularity values for small and large vessels.

CONCLUSIONS

The development of skin warts is accompanied by angiogenesis and vasodilation and these two processes may be independently regulated. Further increased angiogenesis, but not vasodilation, is associated with the presence of HPV type 2 DNA.

Apoptosis, proliferation, and angiogenesis in oral tissues. Possible relevance to tumour progression

Experimental animal models have demonstrated that angiogenesis is essential for tumour progression, whilst sustained tumour growth requires a positive balance between tumour cell proliferation and cell death (apoptosis). The aim of this study was to determine the relative contribution of apoptosis, proliferation, and angiogenesis to disease progression in the oral mucosa. Histological sections of 47 archival specimens were examined; these included four groups of oral tissues: normal mucosa (n=12), moderate dysplasia (n=11) severe dysplasia (n=6), and squamous cell carcinoma (n=18). Apoptotic cells were visualized by in-situ end-labelling of DNA, proliferative cells by staining with Ki-67 antibody, and blood vessels with von Willebrand factor (vWF) antibody. One-way analysis of variance showed that indices of apoptosis (AI), proliferation (PI), and angiogenesis (vascularity) increased significantly with disease progression from normal oral mucosa, through dysplasia, to carcinoma (p<0.0001 for every index). The increase from normal mucosa to moderate dysplasia was significant for PI and vascularity, but not for AI. In contrast, the increase from dysplasia to carcinoma was significant for AI and vascularity, but not for PI. These data suggest that disease progression in the oral mucosa is accompanied by angiogenesis and increases in both epithelial proliferation and apoptosis. Net epithelial growth results from proliferation starting earlier and proceeding at a higher rate than apoptosis.

The presence of pericytes and transitional cells in the vasculature of the human dental pulp: an ultrastructural study

The aim of this study was to determine the ultrastructural characteristics of the microvasculature of healthy human dental pulp, with particular reference to pericytes. Pulp tissue was taken from healthy impacted third molars following extraction. Eight teeth were obtained from 17- to 25-year-old patients and pulp tissue was processed for examination using standard techniques for transmission electron microscopy. The pulp was rich in capillaries composed of endothelial and peri-endothelial cells in a 4: 1 ratio. Endothelial cells contained typical and abundant Weibel-Palade bodies. Three types of peri-endothelial cells were identified: pericytes, transitional cells and fibroblasts. Pericytes were embedded within the capillary basement membrane. Transitional cells were partly surrounded by basement membrane, but separated from the endothelium by collagen fibrils; fibroblasts were outside, but adjacent to the basement membrane and closely associated with collagen fibrils. Pericytes and transitional cells, but not peri-endothelial fibroblasts, contained low numbers of dense bodies similar to the endothelial Weibel-Palade bodies. Our observations are consistent with the hypothesis that, during normal tissue turnover, some pericytes may originate from endothelium and migrate away from the vessel wall to undergo transition to a fibroblastic phenotype.

The association between epithelial proliferation and disease progression in the oral mucosa

The purpose of this study was to examine the possible association between epithelial proliferation and disease progression in the oral mucosa. Archival specimens of normal oral mucosa (n = 12), dysplasia (n = 17) and squamous cell carcinoma (n = 18) were sectioned and proliferating cells visualised by staining with Ki-67 antibody. The proliferative index of the epithelium (PI) was determined by total cell counts and point counting. Similar results were obtained using either method. Comparison of the three groups of tissues by one-way analysis of variance showed a significant increase in PI with increasing lesion severity (p < 0.001). The PI of both dysplasia and carcinoma groups was significantly higher than that of normal oral mucosa (p < 0.001). However, the difference between dysplasia and carcinoma groups was not significant. PI was not associated with tobacco or alcohol consumption. We therefore conclude that Ki-67 expression is an early marker of disease progression in the oral mucosa but, on its own, is not a good indicator of neoplastic transformation.

Plasma cell mucositis: a review and case report

The simultaneous involvement of the mucous membranes of the oral cavity and upper aerodigestive tract by lesions characterised clinically by an intensely erythematous, lobulated surface and histologically by a dense connective tissue infiltrate composed of non-neoplastic plasma cells may be called plasma cell mucositis. We present a review of the literature, consisting of 14 cases, outlining the multifocal site distribution, chronicity and systemic background that distinguish this entity and report a single case with confirmation of the polyclonal nature of the plasma cell infiltrate using gene rearrangement studies.

Assessment of vascularity in histological sections: effects of methodology and value as an index of angiogenesis in breast tumours

The aims of this study were to (a) determine how the quantification of blood vessels in histological sections (vascularity) is affected by the methodology used and (b) assess the value of vascularity as an index of angiogenesis by comparing tumour and normal breast tissue. Archival specimens of breast, lung and oral carcinoma, oral dysplasia and normal breast tissue were used to test the effects of the following experimental variables on vascularity: pretreatment of the sections (enzymatic digestion, heating), endothelial markers (von Willebrand factor and CD31 antibodies), method of quantification (highest microvascular density, average microvascular density and microvascular volume) and interobserver variations. All the variables examined significantly affected the estimated vascularity; this depended on the type of tissue and method used. The pretreatment of the sections before staining was the most important variable, altering the vascularity ranking of the tumours. Vascularity in breast tumours was similar to that of the normal breast intralobular stroma, suggesting that an area of high microvascular density in the tumour does not necessarily represent tumour-induced angiogenesis. Contradictory results have been published regarding the value of vascularity as a tumour prognostic factor. Our results suggest that statistically significant differences in vascularity values are most likely to arise from failure to optimize the staining protocol and from the method used to assess vascularity.

Relationships between different measurements of vascularity and clinico-pathological parameters in breast cancer

Microvascular density has been put forward as an independent prognostic factor in breast cancer, with high levels indicating poorer prognosis. However, various studies have failed to confirm its prognostic value. The reasons for the contradictory results are not known, but it is believed that methodological differences are responsible. To test this hypothesis, we have used four different methods of assessing vascularity (average and highest microvascular density, microvascular volume and image analysis of vascular area) and related them to known prognostic factors in 51 cases of breast cancer NOS. All four methods showed a significant correlation with each other, with the exception of image analysis vs microvascular volume. The average microvascular density was significantly lower in p53 positive compared to negative tumours (median 38.4 and 66.2; IQR 31.1 and 49.4, respectively, p < 0.05). Vascularity, measured by the four methods, was not associated with nodal status or any other parameter examined.

The association between tumour progression and vascularity in the oral mucosa

Tumourigenesis in experimental models is associated with the formation of new blood vessels (angiogenesis). Recent studies have suggested that tumour angiogenic activity may be inferred in histological sections by measuring the density of the vasculature. The purpose of this study was to determine whether the transition from normal to dysplastic and neoplastic tissue in the oral mucosa is accompanied by quantitative or qualitative changes in the vascularity of the tissue, and how the estimate of vascularity is influenced by the vessel marker and method of assessment. A total of 100 specimens of normal oral mucosa, dysplastic lesions, and squamous cell carcinomas were examined. Sections were immunostained with the pan-endothelial antibodies to von Willebrand Factor (vWF) and CD31, or with an antibody to the alpha v beta 3 integrin, previously reported to be a marker of angiogenic vessels. Vascularity was quantitated by two different methods: highest microvascular density (h-MVD) and microvascular volume, as determined by point counting (MVV). The results showed that vascularity, measured by the MVV method using antibodies to either vWF or CD31, increased significantly (P < 0.0001) with disease progression from normal oral mucosa, through mild, moderate, and severe dysplasia to early and late carcinoma (76 paraffin-embedded tissues examined). In contrast, h-MVD did not discriminate between dysplastic lesions and carcinoma. A similar percentage of the total vessel volume (MVV) and density (h-MVD) were positive for alpha v beta 3 in 24 frozen tissues examined, including normal oral mucosa. It is concluded that there is a close association between vascularity and tumour progression in the oral mucosa. Morphometric analysis reflecting microvascular volume is more informative than the currently popular analysis of microvascular density. The expression of alpha v beta 3 in the vasculature of oral tissues does not necessarily reflect the presence of angiogenic vessels.

Overexpression of p53 in normal oral mucosa of oral cancer patients does not necessarily predict further malignant disease

Recent reports of p53 positivity in the normal mucosa of some head and neck cancer patients have been taken as evidence for field cancerization and hence a likelihood of the development of further tumours, yet few papers report the clinical significance of this finding through long-term follow-up. The immunohistochemical detection of p53 expression in clinically and histopathologically normal oral mucosa taken from the wound margin following excision of oral cancer was assessed using the polyclonal antibody CM1. Fresh frozen biopsies of normal oral mucosa and the corresponding tumour from 21 oral cancer patients and of normal mucosa from 25 non-cancer patients were assessed for p53 overexpression. The 'normal' mucosa was positive in 12 of the oral cancer patients and one of the non-cancer patients. Second malignant tumours were seen in patients from whom p53-positive 'normals' and p53-negative 'normals' were recorded. In five of the p53-positive 'normals', the corresponding cancer was p53-negative. In one case, where 'normal' mucosa was available from more than one site, one region was positive, whilst the other was negative. No obvious difference in age, tobacco use, or recurrence rate was seen between positive and negative cases. All patients who were still alive were reviewed for a minimum of 5 years. Using Fisher's exact test, no statistically significant difference was found for the rate of second malignant tumours occurring in patients with p53-positive compared with p53-negative normal mucosa. Thus, the detection of p53 in normal mucosa did not necessarily predict a further tumour.

Relationship between vascularity, age and survival in non-small-cell lung cancer

Lung tumours in the elderly show reduced growth potential; impaired angiogenesis may contribute to this phenomenon. Recent studies have suggested that the angiogenic potential of a tumour may be inferred by the vascularity measured in histological sections. The purpose of this study has been to determine whether vascularity is related to age, survival or other clinical parameters in resected non-small-cell lung cancer (NSCLC). A group of 88 consecutive patients with a follow-up period of at least 5 years was selected. The group exhibited a wide age range (37-78 years) and similar survival characteristics to those of the general NSCLC population. Tumour sections were stained with a pan-endothelial antibody (vWF) and vascularity was quantitated, without knowledge of the clinical details, by three methods: highest microvascular density; average microvascular density; and average microvascular volume. The results were analysed by non-parametric statistical tests. A correlation was found between all three methods of quantitation. Vascularity was not associated with age, sex, tumour type, stage, volume, size (TNM-T) nodal status (TNM-N) or survival. However, survival time was generally longer for patients with higher vascularity, reaching borderline significance (P = 0.06) for the average microvascular density values. Higher tumour volume (P = 0.02) and stage (P = 0.05) were associated with lower survival times. Using multivariate survival analysis, tumour volume was the only factor related to survival. We conclude that vascularity is not associated with age and has no significant prognostic value in NSCLC.

The utility of cytokeratin profiles for detecting oral cancer using exfoliative cytology

It is generally agreed that there is a need for a routine, non-invasive screening procedure for oral cancer particularly of high risk groups. Refinements in oral exfoliative cytology now make this technique worthy of consideration for such screening. This study assesses the utility of monitoring cytokeratin expression in smears of oral cancer in comparison with assessing the keratin expression in corresponding biopsies. Smears and biopsies were taken from 34 patients with oral cancer. A panel of antibodies, CAM5.2, LH1, AE8, LP2K and LH8 recognising keratins 8, 10, 13, 19 and a basal cell marker respectively were employed. Keratins were identified using a standard immunocytochemical technique (Vectastain) and assessed on a 3 point scale, for both smears and biopsies. The vast majority of tumours were well differentiated. No particular keratin profile scen within the smear was associated with any particular state of differentiation. Although the sensitivity of K19 was greatest, its specificity was poor. The keratin antibodies with the best positive predictive value were CAM5.2 (K8) and the marker of the basal cell phenotype, LH8. The combination of down regulation of the secondary differentiation markers (K13, K10) coupled with 'simple' keratin expression (K8, K19) would seem to be the most consistent profile. We conclude that for exfoliative cytological screening to be of value as a diagnostic test it remains necessary to employ assays using more than one antikeratin antibody.

Exfoliative cytology of normal oral mucosa. Assessing the basal cell keratin phenotype

OBJECTIVE

To attempt to evaluate the likelihood that normal keratin (antibody LH8) expression might contribute to a false positive diagnosis when sampling a lesion affecting the oral mucosa.

STUDY DESIGN

Smears were taken from four oral sites (buccal mucosa, hard palate, dorsal tongue, ventral tongue) in 28 patients using the Axibrush. These were processed using a standard avidin-biotin technique, and the number of brown "positive" cells was assessed.

RESULTS

None of the smears contained cells that were LH8 positive.

CONCLUSION

While the results of this study suggest that exfoliative cytology is poor at sampling the basal cells of intact oral epithelium, it does indicate that the identification of LH8-positive cells in a smear from a clinically suspicious lesion is unlikely to be due to harvesting of normal basal cells.

Subpopulations of fetal-like gingival fibroblasts: characterisation and potential significance for wound healing and the progression of periodontal disease

Wound healing in the adult is commonly compromised by excessive scar formation. In contrast, fetal wound healing is a regenerative process characterised by the conspicuous absence of scarring. Available evidence suggests that phenotypic differences between fetal and adult fibroblasts are important determinants of these distinct modes of tissue repair. In this context, a number of groups (including our own) have documented differences between fetal and adult fibroblasts with respect to such potentially relevant characteristics as migratory activity, motogenic response to cytokines and the synthesis of motility factors, cytokines and matrix macromolecules. The oral mucosa appears to be a privileged site in the adult in that it continues to display a fetal-like mode of wound healing. Data are presented in this review indicating that a subpopulation of gingival fibroblasts expresses several 'fetal-like' phenotypic characteristics. These observations are discussed in terms of both the continued expression of a fetal-like mode of wound healing in the oral mucosa and the possible differential involvement of distinct fibroblast subpopulations in the progression of periodontal disease.

A histological, lectin and S-100 histochemical study of the developing prenatal human sublingual salivary gland

Lectin and S-100 protein histochemistry during fetal growth and development (10-38th gestational weeks) of these glands was studied. The histological development of glandular structures followed the known pattern for other salivary glands. Using biotinylated lectins Ulex europeus-I, Dolichos biflorus, Glycine maximus (soyabean), Helix pomatia, Arachis hypogaea (peanut) and Triticum vulgare (wheatgerm), the binding level and, by implication, the concentration of associated specific oligosaccharide available for binding was low at 10 to 19 weeks and generally higher as maturity increased through the middle and late stages of development. S-100 protein reactivity was demonstrated in the cytoplasm of basophil acinar cells of the gland primordia from their origin. Stereological analysis of these developing salivary glands showed a highly significant progressive increase in proportional gland volume occupied by acini from 25% at 20 weeks to 60% at 38 weeks (p < 0.0001), and a comparable halving of the relative gland volume occupied by connective tissue in the same period (p < 0.0001). The extent of these changes depended upon the stage of differentiation and maturation of the glands but by the late stage of fetal development, histochemical reactions were similar to known adult patterns.

Cell deletion by apoptosis during regression of rat parotid sialadenosis

Enlargement of the rat parotid salivary glands was induced by repeated administration of isoproterenol. Mean wet weights of the treated glands increased steadily to 240% of control values. Following withdrawal of the drug, quantitative histological techniques were used to investigate the balance between hypertrophy, hyperplasia and apoptosis. The volume occupied by acinar cells relative to the total gland volume together with cytoplasmic magnitude of nuclear area ratios as measures of hypertrophy increased during the early experimental period. Similarly, serous acinar cell mitotic counts increased, indicating that hyperplasia had occurred. Apoptosis was demonstrated at light microscopical level to be the main mechanism for cell deletion as the glands returned to normal size and weight. The results indicate that hypertrophy and hyperplasia of serous acinar cells contribute to isoproterenol-induced sialadenosis. The experimental animal model demonstrates that these proliferative changes are completed by 48 h and thereafter are balanced by apoptosis as the glands recover their normal size and weight.

Cell proliferation and apoptosis in isoprenaline-induced sialosis in the rat submandibular glands

Regression of submandibular acinar cell hyperplasia after withdrawal of the mitogenic stimulus induced by isoprenaline was studied in male Wistar rats. Intraperitoneal administration of 39 mg of isoprenaline, in divided doses over a 9-day period, resulted in a marked increase in gland size and weight. The proportional volume occupied by acinar cells increased. These changes were associated with acinar cell proliferation and an increase in the mitotic index and cytoplasmic: nuclear ratio. Thus, both hyperplasia and hypertrophy clearly contributed to gland enlargement. Granular and other duct cells appeared to be unaffected by isoprenaline administration. Following cessation of the drug, the mitotic index reached a peak value by the second day but thereafter declined rapidly. This change was matched by a marked rise in the apoptotic cell index, the latter reaching a maximum by the fourth day. By the end of the second week, glands had returned to normal with respect to size and weight and neither hyperplasia nor apoptosis could be detected histologically. These results confirm that apoptosis is involved in the regulation of submandibular salivary gland size.

Histochemical study of lectin binding in the human fetal minor salivary glands

The emerging synthesis of glycoconjugates containing specific oligosaccharides in developing human fetal labial and lingual salivary glands has been investigated by lectin histochemistry. An avidin-biotin technique was used to study the binding of lectins from Ulex europeus I (UEA-I), Dolichos biflorus (DBA), Glycine maximus (SBA), Helix pomatia (HPA), Arachis hypogaea (PNA) and Triticum vulgare (WGA) to specific sugars on sections of tissue from labial glands, glands of Blandin and Nuhn, glands of von Ebner and the dorsoposterior lingual salivary glands. Incipient synthesis of glycoconjugates in early glands and their presence in the cells and ducts of the later glands was shown. The study also showed a time-related increase in both staining intensity and binding sites of serous acinar cells from all glands and for all lectins used. For mucous cells, peak intensity of staining was reached by the middle phase of development. During later gland development this intensity was maintained in dorsoposterior lingual glands but tended to decline in labial glands. The various lectins showed different degrees of binding but UEA-I lectin generally bound the L-fucose sugar group in all salivary glands at all gestational ages. The results showed that lectins appear to bind to the oligosaccharides on epithelial cell surfaces of fetal salivary glands at all stages of development. The degree of change depends upon the stage of differentiation and maturation of the glands.

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.

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.

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.

Stereological and immunohistochemical study of development of human fetal labial salivary glands and their S-100 protein reactivity

Stereological and certain histochemical aspects of fetal growth and development of human labial salivary glands are reported. Stereological analysis showed a highly significant progressive increase in proportional gland volume occupied by acini from 27% at 20 weeks to 56% at 38 weeks (P < 0.0001), and a comparable having of the relative gland volume occupied by connective tissue in the same period (P < 0.0001). Linear regression fitted the data well (r2 = 0.59 and 0.47 respectively, n = 46). The change in relative volume occupied by ducts or by vascular tissue was small and did not reach significance. S-100 protein reactivity was demonstrated in the cytoplasm of cells of the labial gland primordia from their origin. As gland differentiation progressed, the S-100 reactivity became localized in basophil acinar cells and in proximal (intercalated and intralobular), but not in distal, duct cells. A gradual increase in intensity of S-100 protein activity at these sites during salivary gland development was observed. Morphological maturity seems to be complete before 29 weeks but myoepithelial cells could not be identified with certainty.

Evidence for field change in oral cancer based on cytokeratin expression

It was hypothesised that one may be able to visualise field changes, which are proposed to exist around tumours, as alterations in keratin intermediate filament protein expression. Standard immunohistochemical analysis using a panel of monoclonal anti-keratin antibodies was applied to fresh tissue sections to look for subtle changes in epithelial differentiation not visible in H&E sections. Such changes were observed in clinically normal epithelium from oral cancer patients, involving primarily substantial expression of keratins K8/K7 (using CAM 5.2) in the basal cells of 12 out of 34 biopsies, and also a trend towards a reduction in the complexity of keratin differentiation. Monitoring such changes may prove to be a valuable adjunct to conventional H&E staining if found to have prognostic and diagnostic significance.

Keratin profiles of normal and malignant oral mucosa using exfoliative cytology

AIMS

To assess keratin profiles from smears of malignant and contralateral normal oral mucosa as part of the development of a screening procedure for oral cancer based on exfoliative cytology.

METHODS

Smears were taken from oral cancers (confirmed by biopsy) and from the contralateral site of 20 patients. Using a panel of antikeratin antibodies, the keratins expressed by these cells were identified using a standard immunocytochemical technique (Vectastain) and assessed on a 3 point scale.

RESULTS

Using chi 2 analysis, noticeable differences between the keratin profiles for malignant mucosal smears compared with the contralateral mucosal smears were found. This was particularly evident for the simple epithelial keratins.

CONCLUSION

Individual keratins can be identified in smears from oral cancers. The identification of simple epithelial keratins seem to be the best keratin markers associated with malignancy. Their detection within smears from oral lesions could be valuable in the early diagnosis of oral cancer.

Cytokeratin expression in oral cancer and its relationship to tumor differentiation

Although cytokeratin expression is said to alter with the state of tumor differentiation, few studies appear to have confirmed this in fresh tissue biopsies from oral squamous cell carcinomas. Previous studies have been limited by the number of antibodies utilized, small sample size, or lack of information regarding tumor differentiation. A panel of 8 antikeratin antibodies (of which five recognised the simple epithelial keratins, 8, 18 and 19) were applied to fresh tissue biopsies from 24 oral cancer and 15 normal oral mucosal biopsies. A standard immunocytochemical technique was followed (Vectastain ABC method), with keratin expression graded on a 3 point scale. Our analysis indicated that simple epithelial keratins (K8, K18, K19) were not confined to the more poorly differentiated tumors. This may be relevant to tumor prognosis.

p53 expression in dyskeratosis congenita: a marker for oral premalignancy?

As p53 expression has been associated with malignant disease its presence was assessed in biopsy specimens from dorsal lingual hyperkeratosis, taken over a five year period. p53 expression, using CM1, was assessed using a standard immunoperoxidase technique. p53 was not identified in the first biopsy specimen in 1986 but was identified in all subsequent ones. Only in the latest biopsy specimen was there evidence for dysplasia in haematoxylin and eosin stained sections. It is suggested that p53 expression may be a reliable marker for predicting premalignant change in keratoses occurring in dyskeratosis congenita.

p53 protein in odontogenic cysts: increased expression in some odontogenic keratocysts

AIMS

To assess p53 protein expression in a range of odontogenic cysts arising in the mouth, including those of developmental and inflammatory origin.

METHODS

p53 protein was identified using the polyclonal antibody CM-1, together with a standard immunoperoxidase technique. A total of 36 cystic lesions were examined, all of which were histologically benign.

RESULTS

Expression of p53 protein was identified within the lining of five of 12 odontogenic keratocysts but was not detected in the other cystic lesions in the series.

CONCLUSIONS

This is believed to be the first report that identifies increased expression of p53 protein in benign cystic epithelium. The increased expression of p53 protein in the nucleus is usually associated with malignant disease. These findings are relevant to the management of odontogenic keratocysts which have a tendency to recur, and also to Gorlin Goltz syndrome in which keratocysts and multiple basal cell carcinomas are features.

Cytokeratin profiles in dyskeratosis congenita: an immunocytochemical investigation of lingual hyperkeratosis

In dyskeratosis congenita, the hyperkeratotic lesions affecting the mucous membranes have a propensity to undergo malignant change. Unfortunately there is presently no reliable method for predicting such an outcome. Oral mucosal biopsies were obtained from a case of dyskeratosis congenita and keratin expression identified using a panel of antikeratin antibodies. Marked changes were found from keratin profiles established for normal oral mucosa. In particular coexpression of three separate type 1 keratins (K16, K10 and K13) were observed in the ventral tongue lesion. The keratin pattern found in the tissue biopsies examined is suggestive of an unusually immature or disturbed state of tissue differentiation, and as such may be indicative of future malignant change.

Cytokeratin expression in oral exfoliative cytology: effect of temperature and fixation

The identification of keratin expression within oral cytology may be useful in the diagnosis of clinically suspicious oral mucosal lesions. There may be wide variation in the temperature at which such smears are stored, prior to processing. Conventionally, rapid fixation or storage at low temperatures is recommended to preserve kertin expression within tissue biopsies. No previous study has assessed whether this is true for oral cytology. Smears were taken from clinically normal buccal mucosa. For each temperature assessed (-70, -40, -22, +5, +20 and +26 degrees C), one smear was spray-fixed (Vale Smear Fix) and one air-dried, prior to storage for 4 days, and then staining with the pan-epithelial antikeratin antibody, LP34. Preservation of keratin expression was assessed as either weak (zero to few positive cells) or strong (most cells positive). The results were analysed using logistic regression with the statistical modelling package, GLIM. Over the range of temperatures studied, spray fixation did not appear to improve the identification of keratin expression. Although the best preservation was obtained at lower temperatures, keratin expression was still adequate after 4 days at 20 degrees C. Hence, a delay in processing of 4 days would still allow detectable expression in oral exfoliative cytology even at room temperature.

Preservation of keratin expression in oral mucosa using a novel transport medium

Cellular expression of keratins (intermediate filaments) can be demonstrated by immunocytochemistry using unfixed tissue. However, for practical reasons, provision of fresh tissue to the laboratory is often difficult. Recently a fresh tissue transport medium (Patent applied for) has been developed which allows keratin immunocytochemistry to be performed up to 4 days after biopsy. In this study oral mucosal biopsies from 10 patients were hemisected, half placed in the new transport medium at 4 degrees C and the other half immediately frozen in liquid nitrogen. After 4 days frozen sections of both halves of the biopsies were stained by immunocytochemistry using various antikeratin antibodies. The morphology and staining characteristics of the two halves of the biopsies were then assessed. No significant difference could be found in either morphology or preservation of keratin expression in specimens stored in transport medium, as compared to those in liquid nitrogen. This new transport medium may offer considerable advantage for the provision of a histologic and immunocytochemical diagnostic service.

Lingual hyperkeratosis in dyskeratosis congenita: ultrastructural findings

The first ultrastructural description of the mucosal lesions of lingual hyperkeratosis in dyskeratosis congenita is reported. The histology described may help explain the high incidence, later in life, of cancerous change in these leukoplakic patches.

An analysis of mandibular fractures in Dundee, Scotland (1977 to 1985)

A retrospective study was undertaken to assess mandibular fractures presenting over the period 1977-1985 in Dundee, Scotland. The data collected included age, sex, aetiology, month in which injury occurred, anatomical site of fracture, associated maxillofacial trauma and treatment modalities. The majority of fractures were sustained by males in the age group 20 to 29 years. Assault was the major cause of trauma followed by falls and road traffic accidents. The posterior body region was found to be the most common fracture site in the mandible. The level of such trauma has more than doubled, since a similar study was undertaken between the years 1961 to 1970.

Langerhans cells in human chronic gingivitis and phenytoin-induced gingival hyperplasia

Langerhans cell numbers in oral epithelium increase as dental plaque accumulates. The anti-convulsant drug phenytoin predisposes to gingival hyperplasia in certain patients who take this medication for epilepsy and who also have poor oral hygiene. In this study 7 patients with phenytoin-induced gingival hyperplasia were compared with 5 subjects with chronic marginal gingivitis. On initial examination and on completion of the hygiene phase of periodontal therapy (a period ranging from 3.0 to 4.25 months), clinical indices of plaque and gingivitis were recorded and biopsies were taken from the lower anterior labial gingiva. Frozen sections were stained by an immunoperoxidase technique using the monoclonal antibody OKT6, and the number of Langerhans cells in a defined cross-sectional area was counted. In phenytoin-induced gingival hyperplasia there was a marked increase in Langerhans cells (13.8 +/- 0.45) when compared with chronic gingivitis (7.7 +/- 0.31; p less than 0.05). Both groups showed marked reductions in their plaque and gingival indices and numbers of Langerhans cells once treatment had been completed. However, levels of Langerhans cells in the drug-induced hyperplasia remained significantly higher (3.5 +/- 0.26) than in chronic gingivitis (1.5 +/- 0.22; p less than 0.05).

Dyskeratosis congenita: report of a case and review of the literature

A case of dyskeratosis congenita in a 10-year-old white boy is reported. The triad of oral leukoplakia, nail dystrophy, and skin pigmentation was present. Other associated anomalies included dysphagia and varied immunoglobulin levels, although there was no evidence of anemia, pancytopenia, and ocular involvement. Since it may be associated with future malignant change, dyskeratosis congenita should be considered in all cases in which an obscure white lesion exists in the mouth.

Models of protein lateral arrangements in lipid bilayer membranes. Application to electron spin resonance studies of cytochrome c oxidase

We consider the situation of integral membrane proteins in a lipid bilayer matrix where the size of the polar group of the protein is important in determining the lateral packing of the proteins. We represent the cross-section of the protein hydrophobic core as a hexagon moving on a lattice, and represent the projection of the polar group onto the plane of the bilayer as a shape, parts of which overlap the hexagon. Lattice sites represent lipid molecules. We calculate the fraction of lipid molecules which are adjacent to the hydrophobic core of at least one protein. We use this data to consider the "motion restricted" spectrum observed in electron spin resonance (ESR) probe studies, and compute the dependence of the "motion restricted" fraction upon protein concentration. The resulting curves can be used to analyse ESR data in order to deduce the size and shape of the proteins' polar segment. We have used the range of models examined to study the dependence upon protein concentration of the particular case of the "motion restricted" spectrum of a spin-labelled lipid freely diffusing or, alternatively, covalently bound to cytochrome c oxidase. We find that our calculations are in accord with a model where approximately 60 lipid molecules can fit around an isolated such protein in both halves of the bilayer, and where the polar segment is substantially anisotropic and extends laterally beyond the limits of the hydrophobic core. The latter is in accord with what is known about the structure of cytochrome c oxidase. We indicate further measurements that should be performed in order to establish more definitively the dependence of the "motion restricted" component upon protein concentration, giving the lipid protein ratios at which they should be performed, and we make predictions concerning the results. Finally we argue for a particular unified way of plotting experimental data.

The relationship between localization of Na+, K+-ATPase and cellular fine structure in the rat parotid gland

A method for the ultrastructural localization of the Na+-pump enzyme, Na+, K+-ATPase has been applied to the rat parotid gland. A ouabain-sensitive final reaction product, dependent on the presence of K+ and Mg2+, was found to be evenly distributed along the basal and basolateral plasma membranes of acinar and striated duct cells. In both cases, it was localized predominantly in the cytoplasm of the extensive foldings of these membranes. It is concluded that the reaction product meets the criteria for valid localization of this enzyme and that potential Na+-pump sites have been demonstrated. This study supports previous findings in salivary glands and contributes to an increasing body of evidence that contraluminal Na+-pumps are common to both reabsorbing and secreting epithelial cells.

A qualitative and quantitative study of the ageing human labial salivary glands

A series of 36 post-mortem labial salivary glands from both male and female subjects with ages ranging from 25 to 80 yr were examined histologically. Features such as acinar atrophy, fibrous replacement and ductal aberrations were noted in the aged glands. By the stereological method of point counting, the volume proportions of various defined gland constituents were calculated for individual glands in the series. An age-related decrease in acinar volume proportion and an increase in ductal and connective tissue volume proportion is recorded. These changes should be considered when diseased glands are studied.

Blood lymphocytes surface markers and clinical findings in chronic lympoproliferative disorders

Surface receptors on peripheral blood lymphocytes have been studied in 43 cases with chronic lymphocytic leukaemia (CLL), and five cases with lymphoma and overspill. One quarter of the cases with CLL had lymphocytes with no detectable surface immunoglobulin (SIg) by direct fluorescent antibody staining. The remainder had SIgM, which was associated with SIgD in one third of the cases. 70% of the SIg negative group had extensive extramedullary involvement (EMI) compared with 35% of the SIg positive group at presentation; correspondingly more of the SIg negative group were treated. 46% of the SIg negative group were CLL patients of more than 3 years standing compared with 9% of the SIgM+D group and 32% of the SIgM group. Some explanations for this pattern are discussed.

Sarcoidosis with salivary gland involvement: biochemical studies on parotid saliva

Parotid saliva from a patient suffering from sarcoidosis with salivary gland involvement has been shown to have a decreased level of alpha-amylase but increased levels of albumin and lysozyme. These observations suggest that in addition to impaired gland function, gland damage as a result of inflammation had occurred which permitted increased passage of constituents from serum into the gland secretion.

A qualitative and quantitative electronmicroscopic study of the structure of the adenoid cystic carcinoma of human minor salivary glands

The fine structural characteristics of five adenoid cystic carcinomas of human minor salivary galnds and a quantitative assessment of the relative volumes occupied by morphologically defined cell types in these tumors are reported. We observed that the cyst-like spaces which give the characteristic cribriform pattern to the adenoid cystic carcinoma contain replicated basement membrane-like materail. Material comprisimg aggregates of fine tubules having a median diameter of 270 A, and rounded, electron dense bodies were noted within duct-like lumena of one tumor. In addition, dilatation of the intercellular spaces and squamous metaplasia were noted. From 500 electronmicrographs obtained by standardized techniques and used for the morphological part of the study, 175 were selected by a random sampling method and analyzed by the stereological technique of point counting. This method demonstrated that duct type cells occupied 75% by volume of the tumor in these glands; myoepithelial cells occupied 3%, acinar cells occupied 2%, and other tissues occupied 22% of the tumors. These proportions differ significantly (P less than 0.001) from our previously published figures for normal specimens of these glands.