Immunocytochemical detection of hMSH2 and hMLH1 expression in oral SCC

BACKGROUND

The loss of DNA mismatch repair system was reported in hereditary non-poliposis colon cancer and in other tumours. The aim of this study was to detect the protein expression pattern of hMSH2 and hMLH1 in oral squamous cell carcinoma (SCC) by immunohistochemistry in paraffin-embedded tissues.

MATERIALS AND METHODS

5 specimens, obtained from healthy oral mucosa, and 20 from oral SCC were tested with anti-hMSH2 and anti-hMLH1 monoclonal antibodies.

RESULTS

Six cases (30%) showed nuclear positivity in differentiated areas (G1) and cytoplasmic positivity in areas with a lower degree of differentiation, four cases (20%) showed only cytoplasmic positivity, and only one (5%) no staining. One case of oral SCC (5%) showed no hMLH1 staining in the tumoral cells, even if normal squamous epithelium available in this section showed a nuclear positivity; six cases (30%) showed nuclear positivity in differentiated areas (G1) and cytoplasmic positivity in areas with a lower degree of differentiation, three cases (15%) showed only cytoplasmic positivity.

CONCLUSIONS

These data suggest that examination of hMSH2 and hMLH1 protein expression by immunohistochemistry is important in oral SCC. The analysis of mismatches expression in these cases of oral SCC might suggest that an absent nuclear staining for both hMSH2 and hML1 could constitute a hallmark of potential phenotype mutator for this type of neoplasia.

Nevoid basal cell carcinoma syndrome. Clinical findings in 37 Italian affected individuals

Nevoid basal cell carcinoma syndrome (NBCCS) is a hereditary condition transmitted as an autosomal dominant trait with complete penetrance and variable expressivity. The syndrome is characterised by numerous basal cell carcinomas (BCCs), odontogenic keratocysts of the jaws, palmar and/or plantar pits, skeletal abnormalities and intracranial calcifications. In this paper, the clinical features of 37 Italian patients are reviewed. Jaw cysts and calcification of falx cerebri were the most frequently observed anomalies, followed by BCCs and palmar/plantar pits. Similar to the case of African Americans, the relatively low frequency of BCCs in the Italian population is probably due to protective skin pigmentation. A future search based on mutation screening might establish a possible genotype phenotype correlation in Italian patients.

[The role of oxytalan fibers in the stomatognathic system. A bibliographic review]

The authors review the oxytalan fibers, that belong to the elastic system fibers of the connective tissue. They are observed in many structures of the stomatognathic system, particularly in the periodontal ligament and TMJ disc.

Flavonoid Accumulation Is Correlated with Adventitious Roots Formation in Eucalyptus gunnii Hook Micropropagated through Axillary Bud Stimulation

Eucalyptus gunnii Hook microcuttings, obtained in vitro through axillary bud stimulation, show different rooting responses on the same rooting medium depending on the physiological state induced by cytokinins used in the previous multiplication medium. 6-Furfurylamino purine and 6-(4-hydroxy-3-methylbut-2-enylamino)purine induced a physiological state characterized by high sensitivity of microcuttings to the rooting stimulus exerted by the auxin 3-indolebutyric acid, but N(6)-benzyladenine did not produce the same effect. The former physiological state was characterized by an increased accumulation of two endogenous flavonoids (identified as quercetin glycosides) which may be markers of a well defined physiological state. They could have some direct influence on the rooting processes of the explants cultivated in vitro.