Atypia Index Research Articles

The effect of derum (bark of Juglans regia tree) extract on oral mucosa: An in vivo study based on epithelial atypia in rabbit model

Background and objectivesDerum, the bark of walnut tree (Juglans regia) has been used as a traditional tooth cleanser and chewed for its ability to bestow purple color to oral mucosa, tongue and lips Studies have shown that derum extract could affect oral epithelium after long term exposure, causing dysplasia. The aim of this in-vivo study was to evaluate the degree of epithelial dysplasia caused by varying durations and frequencies of topical derum application on oral mucosa of rabbits. Materials and MethodsFollowing ethical approval, derum extract was applied to the buccal vestibule of New Zealand white rabbits over three different periods (60 days, 120 days, 180 days) and two different protocols were used (daily application and once every 3 days). Accordingly, the animals were divided into four groups (A – daily derum application/B – derum applied once in 3 days/C – Positive control and acetone applied every alternate day/D – negative control), and three batches (I – 60 days/II – 120 days/III – 180 days). The animals were sacrificed, and oral biopsies prepared and examined under light microscope. The magnitude of epithelial changes was evaluated using epithelial atypia index (EAI) based on Smith and Pindborg histological grading system (1969) for epithelial dysplasia. ResultsMild dysplastic changes were detected in animals treated with derum extract regardless of the period of application. Similar results were noted among positive control group, and highest score was recorded in group A followed by group B with high tendency towards long-term derum application. Moderate changes were encountered only in group A that received derum for 180 days. Statistically, long-term derum application (180 days / Batch III in groups A and B), irrespective of the frequency of application, resulted in significantly higher mean EAI scores than all other groups or batches. ConclusionBased on this study, prolonged and frequent use of derum can induce dysplastic changes in rabbit oral mucosa, ranging from mild to moderate dysplasia. Further studies with extended times of exposure of derum to oral mucosa are recommended to document these adverse effects as an evidence base.

Establishment of nuclear grade evaluation method for endometrial endometrioid carcinoma, and the significance of separately evaluating nuclear atypia of the glandular and solid structure parts

Aim: The objectives of this study were to: 1) establish a nuclear grade evaluation method for endometrioid carcinoma, and 2) evaluate the nuclear grade of each part in cases in which glandular and solid parts are present within the same tumor, and confirm its correlation with clinicopathological factors, through which the usefulness of this nuclear grade evaluation method was assessed. Material and Methods: Samples were 19 preparations of specimens (4 endometrium in proliferation phase, 8 endometrioid carcinoma G1 and 7 G3 cases) in HE-stained histological preparations (2-mm thin sections). The nuclear grade evaluation method for endometrioid carcinoma comprises 6 items of the nuclear atypia index and each item is scored 1-3. The nuclear grade (NG) was classified as follows based on the total score (6-18 points): NG-I, 6-10; II, 11-13; III, 14 -18. Then, in cases in which glandular and solid parts were present within the same tumor, the nuclear grades of these parts were separately evaluated. The nuclear grade pattern (glandular and solid part-nuclear grade score pattern: GS-NG pattern) was classified into 4 types: GS-NG patterns 1-4. The highest NG score in each case, designated as “ case nuclear grade (Case-NG) ”, was positively correlated with p53 expression, and two patients who died of primary disease were Case-NG III. Conclusion: Histological nuclear grade evaluation method for endometrioid carcinoma, and the significance of separately evaluating nuclear atypia of the glandular and solid structure parts, was a useful method. Keywords: Endometrium, Endometrioid carcinoma: EMC, Nuclear grade: NG, Case-nuclear grade: Case-NG Glandular and solid part-nuclear grade, score pattern: GS-NG

Localization of liposomal mTHPC formulations within normal epithelium, dysplastic tissue, and carcinoma of oral epithelium in the 4NQO‐carcinogenesis rat model

Foslip and Fospeg are liposomal formulations of the photosensitizer mTHPC (Foscan), which is used for photodynamic therapy (PDT) of malignancies. Literature suggests that liposomal mTHPC formulations have better properties and increased tumor uptake compared to Foscan. To investigate this, we used the 4NQO-induced carcinogen model to compare the localization of the different mTHPC formulations within normal, precancerous, and cancerous tissue. In contrast to xenograft models, the 4NQO model closely mimics the carcinogenesis of human oral dysplasia. Fifty-four rats drank water with the carcinogen 4NQO. When oral examination revealed tumor, the rats received 0.15 mg/kg mTHPC (Foscan, Foslip, or Fospeg). At 2, 4, 8, 24, 48, or 96 hours after injection the rats were sacrificed. Oral tissue was sectioned for HE slides and for fluorescence confocal microscopy. The HE slides were scored on the severity of dysplasia by the epithelial atypia index (EAI). The calibrated fluorescence intensity per formulation or time point was correlated to EAI. Fospeg showed higher mTHPC fluorescence in normal and tumor tissue compared to both Foscan and Foslip. Significant differences in fluorescence between tumor and normal tissue were found for all formulations. However, at 4, 8, and 24 hours only Fospeg showed a significant difference. The Pearson's correlation between EAI and mTHPC fluorescence proved weak for all formulations. In our induced carcinogenesis model, Fospeg exhibited a tendency for higher fluorescence in normal and tumor tissue compared to Foslip and Foscan. In contrast to Foscan and Foslip, Fospeg showed significantly higher fluorescence in tumor versus normal tissue at earlier time points, suggesting a possible clinical benefit compared to Foscan. Low correlation between grade of dysplasia and mTHPC fluorescence was found.

Definition of diethylnitrosamine-induced rat hepatic precancerous lesions with atypia index

Definition of diethylnitrosamine-induced rat hepatic precancerous lesions with atypia index

In vivo photo-detection of chemically induced premalignant lesions and squamous cell carcinoma of the rat palatal mucosa

Photo-detection using in vivo fluorescence was studied for different stages of chemically induced premalignant lesions and squamous cell carcinoma (SCC) of the Wistar rat palatal mucosa. It was found that the epithelial dysplasia (numerically expressed in the epithelial atypia index (EAI) of the rat palate, induced by repeated application of the carcinogen 4-nitroquinoline 1-oxide (4NQO), showed an increase approximately proportional to the duration of the application period. Photo-detection of the lesions using Photofrin-induced fluorescence was studied with dual-wavelength excitation and the subtraction of images, in an attempt to reduce the autofluorescence. The Photofrin dose was 2.5 mg kg −1. This was based on a dose-response study for normal tissue damage by photodynamic therapy (PDT) in this animal model, because the underlying rationale was to study photo-detection as a method of locating additional (early) malignancies in patients treated by PDT. Fluorescence intensities 24 and 48 h after injection of Photofrin were shown to increase with the duration of 4NQO application and with increasing EAI. For an EAI greater than 15, there was a statistically significant difference ( p < 0.01) between the fluorescence signals obtained with and without the injection of Photofrin. Fluorescence signals of these lesions without the use of Photofrin (autofluorescence) also showed an increase with increasing stages of epithelial dysplasia of the rat palate. However, the fluorescence signals obtained with Photofrin were always higher than those of the autofluorescence. From this study, we conclude that photo-detection with Photofrin has potential in distinguishing chemically induced premalignant lesions and squamous cell carcinomas from the normal rat palatal mucosa. Photofrin (2.5 mg per kg of body weight) certainly adds to the sensitivity of photo-detection, but autofluorescence alone also has promising features for detecting premalignant and malignant lesions of the oral mucosa.

Epithelial dysplasia and squamous cell carcinoma of the wistar rat palatal mucosa: 4NQO model

Background The carcinogen 4-nitroquinoline 1-oxide (4NQO) has been used in several studies concerning experimental oral carcinogenesis to induce squamous cell carcinoma in the palatal mucosa of rats, whereas limited attention has been paid to preceding premalignant mucosal changes. The aim of this study was to describe the macroscopic and microscopic changes of the rat palatal mucosa treated with 4NQO as a function of the application time of this carcinogen. Methods The carcinogen 4NQO was applied to the palatal mucosa of male Wistar rats three times a week for 2–26 weeks. The Epithelial Atypia Index (EAI) was used to quantify the degree of dysplasia induced by the application of 4NQO for various time intervals. Results This study shows that the EAI increases as a function of the application time. As soon as 2 weeks following application of the carcinogen, dysplastic alterations in the mucosa were observed. The extent and grade of the dysplastic changes increased with time. At week 26, squamous cell carcinoma developed. In rats in which the application of 4NQO was discontinued earlier, the application period appeared to be in inverse proportion to the latency period, ie, the period between the last application of the carcinogen and the first clinical sign of squamous cell carcinoma. This emphasizes the premalignant character of the induced epithelial changes, because in all the rats squamous cell carcinoma eventually developed. Conclusions From this study, we concluded that the 4NQO rat palate model is a proper model in which both premalignant epithelial lesions and squamous cell carcinoma of the oral mucosa can be studied. HEAD & NECK 1996;18:441–449 © 1996 John Wiley & Sons, Inc.

Epithelial dysplasia and squamous cell carcinoma of the Wistar rat palatal mucosa: 4NQO model.

The carcinogen 4-nitroquinoline 1-oxide (4NQO) has been used in several studies concerning experimental oral carcinogenesis to induce squamous cell carcinoma in the palatal mucosa of rats, whereas limited attention has been paid to preceding premalignant mucosal changes. The aim of this study was to describe the macroscopic and microscopic changes of the rat palatal mucosa treated with 4NQO as a function of the application time of this carcinogen. The carcinogen 4NQO was applied to the palatal mucosa of male Wistar rats three times a week for 2-26 weeks. The Epithelial Atypia Index (EAI) was used to quantify the degree of dysplasia induced by the application of 4NQO for various time intervals. This study shows that the EAI increases as a function of the application time. As soon as 2 weeks following application of the carcinogen, dysplastic alterations in the mucosa were observed. The extent and grade of the dysplastic changes increased with time. At week 26, squamous cell carcinoma developed. In rats in which the application of 4NQO was discontinued earlier, the application period appeared to be in inverse proportion to the latency period i.e., the period between the last application of the carcinogen and the first clinical sign of squamous cell carcinoma. This emphasizes the premalignant character of the induced epithelial changes, because in all the rats squamous cell carcinoma eventually developed. From this study, we concluded that the 4NQO rat palate model is a proper model in which both premalignant epithelial lesions and squamous cell carcinoma of the oral mucosa can be studied.

Atypia and Surface Structure of Superficial Neoplasms of the Colon Less Than 10 mm in Diameter

Histological specimens of 30 distinct adenomas and 30 distinct carcinomas were studied by image analysis to quantify nuclear size and shape. These data were used to derive a discriminant equation, which permitted the lesions to be classified into two groups based on nuclear atypia. Next, 50 superficial type tumors of the colon (34 IIa lesions, 9 IIc + IIa lesions, and 7 IIc lesions) <10 mm in longest diameter were similarly analyzed. These lesions were classified into a high atypia index group (HAI group, 14 lesions) and a low atypia index group (LAI group, 36 lesions) by the above discriminatory equation. Differences between these two groups in surface structure, marginal zone properties, and macroscopic type, assessed using a dissecting microscope, were studied. A hyperplastic shape of the tubular orifice was seen at the marginal zone in 10 lesions (27.7%) in the LAI group and 11 lesions (78.5%) in the HAI group. This difference was significant. Surface structure and macroscopic type were not correlated with the degree of atypia. The tubular density in lesions showing a hyperplastic pitted pattern at their border was 77.40, significantly higher than that for lesions without such a pattern (73.12). The contribution of various variables to surface structure, marginal zone properties, and macroscopic type was studied by discriminant analysis. A high correlation was found between marginal zone properties and tubular density. Since lesions with high nuclear atypia tend to have high tubular density, marginal zone properties were secondarily correlated with the level of nuclear atypia. Observation of the marginal zone properties of lesions was thus suggested to be helpful in the diagnosis of lesions with severe atypia.

Comparison of epithelial dysplasia—the 4NQO rat palate model and human oral mucosa

Epithelial dysplasia in the rat palatal mucosa was induced by application three times a week of the carcinogen 4-nitroquinoline 1-oxide (4NQO). With the Epithelial Atypia Index (EAI), the successive stages of 4NQO-induced epithelial dysplasia were compared with specimens of human oral epithelial dysplasia. It appeared that there was a close similarity between the histologic features of 4NQO-induced dysplasia in the rat palatal mucosa and human oral epithelial dysplaisa. Thus, the 4NQO rat palate model seems to be appropriate to study and assess new treatment modalities of premalignant epithelial lesions of the oral mucosa in man.

Scanning electron microscopy of oral epithelial cells Part II. Potentially malignant lesions (A computer-assisted study)

The technique described in Part I, has been extended to the examination of cells removed by scraping from 22 lesions of oral lichen planus and leukoplakia. It was concluded that the surface morphology of the cells from these lesions was intermediate between that of normal tissue and of malignant tissue. The observations have been quantified and subjected to computer analysis together with the data derived from the observations of normal and malignant tissue. This confirms the visual observation that a relationship exists between the modified surface characteristics of the cells from these lesions and their subjectively assessed histological appearances. A correlation has been found between the SEM appearances and an epithelial atypia index (EAI) derived according to the criteria of Smith and Pindborg (1969). In the case of lichen planus inflammatory changes appear to be associated with increased modification of surface characteristics. These changes are also reflected in an increased EAI. It is suggested that the present technique may be of value in the diagnosis and assessment of potentially malignant lesions.