Matrix metalloproteinases 2 and 9 (MMP2 and MMP9) are proteolytic enzymes involved with extracellular matrix degradation. They play a role in tumor invasion and metastases. Be- cause of their ability to degrade signaling molecules presented in extracellular matrix, MMPs contribute to tumor proliferation and apoptosis. The aim of this study was to evaluate expression of MMP2 (latent and both active and latent forms) and MMP9 (active, latent, active and latent forms) in different subtypes of canine lymphomas and their relationship with proliferative (mi- totic index and percentage of Ki67-positive cells) and apoptotic (apoptotic index) markers. Ex- pression of MMPs was assessed immunohistochemically using an immunoreactive score system. Expression of both MMPs was found in all 20 examined lymphomas belonging to six subtypes. Most cases showed a moderate level of all analyzed forms of MMP2 and MMP9. High expres- sion of MMPs was found in single cases. Except for a positive correlation between the active form of MMP9 and the mitotic index for all lymphoma cases, no other correlations between any remaining forms of MMPs and neither proliferative nor apoptotic markers were found, irrespec- tive of whether the analysis encompassed all cases or the most numerous lymphoma subtypes i.e. centroblastic and Burkitt-like. Our results were not able to clearly confirm the influence of MMPs on the proliferation and apoptotic activity of canine lymphoma cells. However, further studies examining MMPs activity by zymography, expression of their inhibitors and other factors in- volved in activation of cell proliferation and apoptosis inhibition are needed to clarify the role of MMPs, especially the active form of MMP9, in the behavior of canine lymphoma cells.
The site at Orłowo Cliff was used to analyse the stratigraphic position and palaeogeographic interpretations of the properties and depositional conditions of two basal tills from the Late Pleistocene. A multi-proxy approach involved lithofacies, petrographic analysis of the fine gravel fraction, analyses of indicator erratics and till fabric. TL dating of intra-moraine deposits was used to determine depositional time frames of tills. The sediment profile at Orłowo Cliff shows a distinct reduction in number of Pleistocene units. Obtained dating results suggest the presence of Middle and Late Pleistocene fluvial units. The main issue discussed is the stratigraphic position of the older till (Unit O-4). It can be assumed that this till was deposited probably during the Middle Weichselian (MIS4). At Orłowo Horn the till of Unit O-4 reveals incorporation of the erratic material derived from an older till in the surrounded area (according to petrographic composition – probably from MIS 8). The younger till (Unit O-6) was deposited in the Late Weichselian (MIS 2). Moreover, the till of Unit O-6 is characterised by a significant shift towards the south-west in terms of the erratic origin in Unit O-4.