Comparison of proliferative activity of epithelial cells between the follicles of impacted teeth / Comparación de la actividad proliferativa de las células epiteliales entre los folículos de dientes impactados

The aim of this comparative observational study was to compare the proliferative activity of dental follicles surrounding impacted maxillary canines and mandibular third molars. Following extraction, forty follicles of the impacted mandibular third molars and 40 follicles of the impacted maxillary canines were removed. Epithelial cell proliferative activity of these samples was assessed using immunohistochemical labeling for Ki-67, minichromosome maintenance 2 (MCM-2) protein and epithelial growth factor receptor (EGFR). Intensity and extent of Ki-67, MCM-2 and EGFR expressions were evaluated by a scoring formula. The lining epithelium of the maxillary canine follicles had mean scores of 4.65±0.27 for Ki-67, 1.25±0.33 for MCM-2 and 7.30±0.23 for EGFR which were not significantly different than those expressed in the mandibular third molar follicles (4.46±0.26 for Ki-67, 1.39±0.33 for MCM-2 and 7.21±0.20 for EGFR). The expression of Ki-67 and MCM-2 could not be detected in the epithelial remnants within the connective tissue in both groups. EGFR expression, detected in the epithelial remnants in both groups, was not significantly different (7.28±0.14 in the canine group as opposed to 7.21±0.16 in the third molar group). Based on these findings, it can be deduced that impacted mandibular third molars and maxillary canines carry similar risk of pathology development.

El objetivo fue comparar la actividad proliferativa de los folículos dentarios que rodean a dientes caninos maxilares y terceros molares mandibulares impactados. Luego de realizada la extracción dentaria, se removieron 40 folículos dentarios de los terceros molares mandibulares impactados y 40 de caninos maxilares impactados. Se evaluó la actividad proliferativa de las células epiteliales de estas muestras mediante marcaje inmunohistoquímico para Ki-67, para la proteína de mantenimiento minicromosoma 2 (MCM-2) y para el receptor del factor de crecimiento epitelial (EGFR). Se evaluó la intensidad y extensión de Ki-67, MCM-2 y las expresiones de EGFR mediante una fórmula de puntuación. El epitelio de revestimiento de los folículos correspondientes a los caninos maxilares presentaron valores promedios de 4,65±0,27 para Ki-67, 1,25±0,33 para MCM-2 y 7,30±0,23 para EGFR, que no fueron significativamente diferentes de los expresados en los folículos de terceros molares mandibulares (4,46±0,26 para Ki-67, 1,39±0,33 para MCM-2 y 7,21±0,20 para EGFR). La expresión de Ki-67 y MCM-2 no pudo ser detectada en los restos epiteliales dentro del tejido conectivo en ambos grupos. La expresión de EGFR, detectada en los restos epiteliales en ambos grupos, no fue significativamente diferente (7,28±0,14 en el grupo de los caninos, y 7,21±0,16 en el grupo de los terceros molares). Sobre la base de estos resultados, se puede deducir que la retención de terceros molares y caninos maxilares conlleva un riesgo similar para el desarrollo de patología.

Increased expression of COX-2 in recurrent basal cell carcinoma of the skin: A pilot study.

Introduction: Basal cell carcinoma (BCC) is the most frequent malignant skin tumor. BCC rarely metastasizes, but it is often locally aggressive. Cyclooxygenase-2 (COX-2) is critical for tumor formation, angiogenesis and metastasis. Matrix metalloproteinases (MMPs) are the members of the family of zinc (Zn)- and calcium-dependent endopeptidases that degrade the extracellular matrix. Materials and Methods: In our study, we used immunohistochemical methods for the evaluation of COX-2, MMP-2 and MMP-9 expression in tissue samples of 30 primary and 10 recurrent skin BCC cases. Results: Immunohistochemical COX-2 expression was significantly higher in the infiltrating pattern of BCC compared with the nodular (P = 0.005) and superficial (P = 0.041) subtypes in the primary BCC group. There was not a significant difference between nodular and superficial BCCs for COX-2 expression. In addition, COX-2 expression was significantly higher in the recurrent BCC group than in the primary BCC group (P = 0.030). There was no statistically significant difference between the histological subtypes of primary BCCs and between primary and recurrent BCCs for MMP-2 and MMP-9 expressions. Conclusions: Our data confirm previous findings that COX-2 and MMP-9 expressions are increased in BCC. Our results revealed an elevated COX-2 expression in recurrent BCCs. We suggest that COX-2 inhibition might have beneficial effects in BCCs, especially for the tumors with a higher level of COX-2 expression or aggressive phenotype.

Cyclooxygenase-2 expression in primary and recurrent pterygium.

BACKGROUND: Pterygia are common, benign, fibrovascular, and infiltrative processes of the corneo-conjunctival junction of unknown pathogenesis. Cyclooxygenase-2 (COX-2) mediates the rate-limiting step in arachidonic acid metabolism. Extensive evidence indicates that the COX-2 prostanoid pathway is involved in inflammation. The aim of the study was to document the immunohistochemical expression of COX-2 in primary and recurrent pterygia. MATERIALS AND METHODS: In this study, 21 primary pterygia and 12 recurrent pterygia from subjects undergoing pterygium surgery and six normal corneal-scleral tissue specimens were studied immunohistochemically for COX-2 expression. RESULTS: COX-2 was expressed in primary pterygia and recurrent pterygia specimens. There was a statistically significant difference in COX-2 expressions in fibroblasts between primary and recurrent pterygium cases ( P = 0.001). There were statistically significant differences in COX-2 expressions in surface epithelium ( P = 0.028) and stromal inflammatory cells ( P =0.000) between control tissues and primary pterygia tissues. We also detected statistically significant differences in COX-2 expressions in surface epithelium ( P =0.000), stromal fibroblasts P =0.000 (stromal fibroblasts and inflammatory cells), vessels ( P = 0.027) and inflammatory cells ( P =0.001) between control tissues and recurrent pterygia tissues. CONCLUSIONS: This is the first study to document the expression of COX-2 in primary and recurrent pterygia. In our opinion after excision of pterygia, fibroblastic proliferation continues and this contributes to recurrence.