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Apoptosis and proliferation are processes associated with the development and progression of breast cancer. The sensitivity of tumour cells to the induction of apoptosis depends on the balance between pro- and anti-apoptotic proteins. The expression of Bak and Bcl-2 was examined using an immunohistochemical method in 71 primary breast cancers. Furthermore, Bcl-2 and Bak were assessed in the normal mammary gland as well as in benign mammary dysplasia adjacent to breast cancer. Positive immunostaining for Bcl-2 was observed in 77.8% of cases of normal breast epithelium (NBE), 93% of benign dysplasia without intraductal proliferation (BBD) as well as in 94% of intraductal proliferative lesions of the breast (BIPL). Expression of Bak was detected in 39% of cases of NBE, 45% of BBD and in 67% of BIPL. In breast cancer Bcl-2 and Bak expression was found in 83% and 70% of the cases studied, respectively. Increased Bcl-2 expression in primary tumours significantly correlated with favourable prognostic factors, namely pT1, G2 and lack of metastases to the regional lymph nodes (p < 0.01, p < 0.03, p < 0.02, respectively). There were no relationships between Bak and the clinicopathological features studied, but our results indicate changes in the expression of Bak during breast cancer development and progression. It would appear to be important to assess and compare pro- and anti-apoptotic proteins between normal mammary gland, benign mammary dysplasia and the primary tumours of breast cancer. This knowledge should be helpful in understanding breast cancer development and progression.

Our study with animal models was designed to test the hypothesis that green tea protects against chronic (over 4 weeks) alcohol induced liver injury in rats. The research was conducted on Wistar male rats divided into 4 research groups: I - received the Libera-De Carli control diet (L-DC), II - received (L-DC) and green tea, III - received (L-DC) and ethanol and IV - received (L-DC), green tea and ethanol. When comparing groups I and II we saw less intensive steatosis in group II than in group I, which can suggest that green tea may affect the accumulation of fat in the hepatocytes and protect them against steatosis and disruption. In III, the ethanol group, the steatosis of the liver increased considerably and the green tea which was given with ethanol in group IV did not halt this, as in group IV we also observed intensive steatosis in the liver. From this data we conclude that green tea has an important, although not fully understood role in preventing liver injury.

Gap junctional intercellular communication (GJIC) plays a critical role in tissue development and differentiation and probably in carcinogenesis. The purpose of the study was to evaluate the expression and localisation of Cx43 in 40 cases of mammary dysplasia and 29 cases of breast cancer (without primary chemotherapy). The tissue sections were investigated for Cx43 expression by immunohistochemistry. In the normal mammary gland there was an intercellular, punctate staining pattern, mainly between myoepithelial cells, characteristic of functional gap junctions. In dysplasias there was mainly mixed (cytoplasmic and intercellular) staining and in most cases of breast cancer we observed diffuse or granular, but cytoplasmic, staining of Cx43. Our results demonstrated that expression of Cx43 in dysplasias and breast cancer is changed and GJIC is probably impaired because of disruption of functional gap junction formation especially between breast cancer cells.

Chordoma is one of rare intracranial neoplasms (0.2-0.5%). Apart from classic chordoma in 1973 r. Heffelfinger and al. separated chondroid chordoma which showed better prognosis. We studied 4 classic and 3 chondroid intracranial chordomas. All tumours contained chondroitine sulfate and keratan sulfate and showed positive immunohistochemical reactions to cytokeratin, S-100 protein and vimentin, supporting the concept of common origin of both types of chordomas. Immunohistochemical studies of PCNA and Ki-67 antigen and staining AgNOR's did not show significant differences in the proliferative activity between both types chordomas what attests to biological malignancy.