Cell kinetics of hamster ventral tongue epithelium in iron deficiency

Histological and ultrastructural aspects of the tongue in undernourished rats

There are few published studies on the effects of protein-caloric undernourishment on the oral mucosa.

Objectives

The objective of this study is to verify the histological and ultrastructural aspects of the tongue mucosa in protein-caloric undernourished adult rats.

Material and Methods

A clinical experimental study was done in thirty Wistar rats, 15 controls and 15 with protein-caloric undernourishment. The last group received ration in small amounts, with a reduced casein content, during 45 days. Rats were weighed every 3 days, from the first (90 days of life) to the last day of a 45-day dietary period, when they were sacrificed. Plasma was used for protein electrophoresis and their tongues were prepared for light and scanning electron microscopy. Analysus of variance and Student's t-test were used for statistical analysis.

Results

A significant decrease in weight and in plasma proteins was found in protein-caloric undernourished rats compared to the control group. Histological findings revealed no differences between the two groups and there were no statistically significant differences in the filiform papilla count under the scanning electron microscopy.

Conclusion

Protein-caloric undernourishment does not cause alterations in the tongue mucosa of adult rats.

Aspectos histológicos e ultraestruturais da língua em ratos desnutridos

Poucos estudos sobre os efeitos da desnutrição protéico-calórica na mucosa oral são encontrados na literatura. OBJETIVOS: O objetivo deste trabalho é verificar os efeitos da desnutrição protéico-calórica na mucosa da língua de ratos adultos, envolvendo microscopia óptica e eletrônica de varredura. MATERIAIS E MÉTODOS: Um estudo experimental foi realizado em trinta ratos Wistar, 15 controles e 15 com desnutrição protéico-calórica. O último grupo recebeu ração em pequena quantidade, com menor conteúdo de caseína, durante 45 dias. Os ratos foram pesados a cada 3 dias, do primeiro (90 dias de vida) ao último dia (45 dias de dieta), quando foram sacrificados. Foi realizada eletroforese de proteínas plasmáticas e as línguas foram preparadas para microscopia óptica comum e eletrônica. Para análise estatística utilizou-se análise de variância e teste T de Student. RESULTADOS: Foi observada uma significante diminuição no peso e nas proteínas plasmáticas dos ratos com desnutrição protéico-calórica em relação ao grupo controle. A análise histológica não mostrou diferenças entre os dois grupos, e os resultados, com respeito à contagem das papilas filiformes da mucosa lingual pela microscopia eletrônica, não revelou diferenças estatisticamente significantes entre os grupos. CONCLUSÃO: A desnutrição protéico-calórica não causa alterações na mucosa da língua de ratos adultos.

A comparison of the management of potentially malignant oral mucosal lesions by oral medicine practitioners and oral & maxillofacial surgeons in the UK

This study describes the results of a survey undertaken to assess the management of potentially malignant oral mucosal lesions by oral medicine practitioners and compares their approach with that of oral & maxillofacial surgeons that we have previously described. Significant differences were noted between the two groups in the use of photography to document the lesions and in the use of certain special investigations, which included measurement of serum iron, serum ferritin, serum Vit B12, red cell folate and candidal isolation. The groups also varied in the perceived importance of the age of the patient and anatomical site of the lesion when deciding on the need for further biopsy. There was also significant variation in the use of certain treatment modalities, including excising non-dysplastic and severely dysplastic/carcinoma in-situ lesions and eliminating trauma when treating mild/moderately dysplastic and severely dysplastic/carcinoma in-situ lesions. Significant differences in the frequency and duration of follow-up were noted for non-dysplastic lesions. Finally, the two groups differed significantly when asked to rank the perceived importance of certain factors (the histopathology of the most recent biopsy and the anatomical site of the lesion) when deciding the need to follow-up. Possible reasons for the variation are discussed.

Unit length as the denominator for quantitation of cell proliferation in nasal epithelia

Cell proliferation data, generally based on a labeling index (LI), provide a valuable endpoint for assessment of toxic and potentially carcinogenic responses in laboratory animals. Measurement of the LI is time consuming because of the large number of cells that need to be counted to determine the denominator. In respiratory mucosa, the total cell count of the surface epithelia may be altered in response to treatment, either through cell loss or increases in cell number (e.g., hyperplasia). As an alternative to the more conventional LI, the present studies were carried out to assess the value of expressing cell proliferation in nasal epithelia as a unit length labeling index (ULLI), defined as labeled cells per mm of basement membrane. Rats were exposed by inhalation to formaldehyde or methyl bromide, and changes in cell proliferation were determined in the respiratory and olfactory epithelia, respectively, using both total cell count and basement membrane length as denominators. Total cell counts were clearly influenced by treatment, while basement membrane length was not. Both methods revealed similar treatment-induced effects on cell proliferation, and in fact were highly correlated (R greater than or equal to 0.92, p less than 0.001). It was concluded that the ULLI method provides an effective alternative to total cell counts and the LI method. This approach is not influenced by alterations in the total cell population, and has the benefit of being less labor intensive than LI determinations.

Iron deficiency depresses cell proliferation in hamster cheek pouch epithelium

Iron deficiency anaemia was induced in hamsters by feeding a low iron diet coupled with weekly bleeding. To assess cell proliferation, the stathmokinetic agent vinblastine sulphate was administered and cell birth rates were calculated from cumulative mitotic indices. The rate was significantly reduced in epithelium from iron-deficient animals. The uptake of tritiated thymidine [( 3H]TdR) was also significantly reduced in these animals. Results of both stathmokinetic and labelling experiments indicate that cell production in the cheek pouch epithelium of iron-deficient animals is impaired.

Pathological changes induced by formaldehyde in open-ended rat tracheal implants preexposed to benzo(a)pyrene

The promotion effects of 0.1% formaldehyde (HCHO) in phosphate-buffered saline (PBS) were tested in rat tracheal implants preexposed to a minimal carcinogenic dose of 468 micrograms benzo(a)pyrene (BAP) released over one month from 865 micrograms BAP-beeswax pellets. At the time of pellet removal, the tracheas were made into open-ended, flow-through, tracheal implants (FTTI), and exposed twice/week to HCHO for 30 weeks. Morphological alterations in the FTTI were monitored biweekly by collection of exfoliated cells from the luminal washings for cytopathologic diagnosis, and periodically by sacrificing animals for histopathology. FTTI exposed to the BAP followed by 30 weeks of HCHO had extensive squamous metaplasia, a high proliferation index of 7.87 [3H]thymidine-labeled cells/mm basement membrane, and foci of moderate and marked atypia. Clear diagnosis of some of the lesions was difficult because of the acute toxic effects of the repeated exposures to HCHO. These effects were seen in the tissues as well as in the exfoliated cells, which attest to the latter as an efficient, non-destructive, method for determining the responses of the tracheas to exposure to toxic and carcinogenic agents. FTTI exposed to BAP followed by twice weekly PBS, had a mostly flattened epithelium, and a low proliferation index (0.39). FTTI exposed to beeswax pellets, followed by the HCHO had a relatively high proliferation index (4.20) in a mucociliary epithelium exhibiting some basal cell hyperplasia. Control FTTI had a normal mucociliary epithelium with a proliferation index of 1.52 [3H]thymidine labeled cells/mm basement membrane.

Morphometric analysis of atrophic changes in human lingual epithelium in iron deficiency anaemia

A stereological analysis of epithelial structure at the lateral surface of the tongue showed that iron deficiency anaemia was associated with reduced epithelial thickness despite the absence of overt mucosal abnormalities. The epithelial atrophy was entirely due to a reduction in the size and number of cells in the maturation compartment. By contrast, the progenitor cell compartment was increased in thickness due to an increase in the number of cells. This hyperplastic reaction may be a trophic response to the overall loss of epithelium in this condition.