Summary Urokinase plasminogen activator (uPA) is a serine proteinase that has been suggested to play an important role in cancer invasion and metastasis. It binds to a specific membrane receptor denominated uPA receptor (uPAR Pancreatic cancer has one of the poorest prognoses of all gastrointestinal malignancies, being the fourth or fifth leading cause of cancer-related deaths in Western industrialized countries (Bomman et al, 1994). Gudjonsson (1987), in his classical review of 37 000 patients with pancreatic cancer, demonstrated an overall survival rate of 0.4% and a median survival time of 5 months after the diagnosis was established. Once pancreatic cancer is clinically evident, it progresses at a rapid rate, and metastasis has usually occurred at the time of diagnosis. Consequently, many patients are not resectable at presentation, and the overall resection rate is often less than 30% (Gudjonsson 1987;Bomman et al, 1994). The mechanisms that regulate this aggressive growth behaviour in pancreatic cancer are not at all clear. Recently, it has been shown in pancreatic cancer that the concomitant overexpression of the epidermal growth factor (EGF) receptor and its ligands EGF-, TGF-alpha (Korc et al, 1992;Yamanaka et al, 1993a) and/or amphiregulin (Ebert et al, 1994a; Yokoyama et al., 1995a) is associated with shorter post-operative survival following tumour resection. In addition, enhanced expression of c-erbB-3 (Friess et al, 1995), TGF-fs and basic fibroblast growth

Abstract. The flagellum of the parasitic hemoflagellate Trypanosoma brucei contains two major structures: (a) the microtubule axoneme, and (b) a highly ordered, filamentous array, the paraflagellar rod (PFR). This is a complex, three-dimensional structure, of yet unknown function , that extends along most of the axoneme and is closely linked to it. Its major structural component is a single protein of 600 amino acids. This PFR protein can assume two different conformations, resulting in two distinct bands of apparent molecular masses of 73 and 69 kD in SDS-gel electrophoresis. Secondary structure predictions indicate a very high helix content. Despite its biochemical similarity to the intermediate filament proteins (solubility properties, amino acid composition, and high degree of helicity), the PFR protein does not belong in this class of cytoskeletal proteins. The PFR protein is coded for by two tandemly linked genes of identical nucleotide sequence. Both genes are transcribed into stable mRNAs of very similar length that carry the mini-exon sequence at their 5' termini.

We examined the altered expression of transforming growth factor-beta s in chronic renal rejection in humans, including transforming growth factor beta-1 (TGF-beta 1), TGF-beta 2, TGF-beta 3 and their receptors, transforming growth factor beta receptor type I (T beta R-I) and T beta R-II. Using Northern blot analysis and immunohistochemistry, 10 specimens of chronically rejected and 8 normal kidney samples were analyzed. By Northern blot analysis the expression of mRNA encoding TGF-beta 1, TGF-beta 2, TGF-beta 3 (P < 0.02), T beta R-I and T beta R-II (P < 0.02) was decreased in chronically rejected renal cortex samples, compared to normal controls. Immunohistochemical analysis of the normal renal cortex showed strong immunostaining for TGF-beta 1 and TGF-beta 3, and mild immunostaining for TGF-beta 2 in the proximal and distal tubulointerstitium, but no signal for any of the TGF-beta isoforms in the glomeruli or in the cortical vessels. In sharp contrast, the glomeruli and the cortical vessels of the rejected kidney specimens exhibited strong immunostaining for TGF-beta 1 and TGF-beta 3, whereas the tubules revealed a decrease in immunoreactivity. T beta RI and T beta RII immunostaining showed similar changes as observed with TGF-beta 1 and TGF-beta 3 antibodies. There was a concomitant increase in B-cell accumulation in the glomeruli, while T-cells and macrophages were diffusely abundant in the rejected samples. Since TGF-beta S are potent inducers of extracellular matrix proteins and have been shown to be involved in fibrotic disease, the increase in TGF-beta 1 and TGF-beta 3 immunoreactivity in the glomeruli suggests that there is a redistribution in TGF-beta expression in chronic renal allograft rejection. Together with changes affected by B-cell mediated immunity, the above alterations might contribute to the histopathological changes that occur in this disorder, such as intimal fibrosis, arteriosclerosis and glomerular and tubular sclerosis.