Beta-catenin is involved in both cell -cell adhesion and in transcriptional regulation by the Wingless/Wnt signalling pathway. Alterations of components of this pathway have been suggested to play a central role in tumorigenesis. The present study investigated, by immunohistochemistry and immunoblotting, the protein expression and localisation of b-catenin, adenomatous polyposis coli (APC), glycogen synthase kinase 3b (GSK3b) and lymphocyte enhancer factor-1 (Lef-1) in normal human ovaries and in epithelial ovarian tumours in vivo and in vitro. Immortalised human ovarian surface epithelium and ovarian cancer cell cells (OVCAR-3) expressed b-catenin, APC, GSK3b and Lef-1. Nuclear staining of b-catenin and Lef-1 were demonstrated only in OVCAR-3 cells. There were significant increases of b-catenin and GSK3b, while APC was reduced in ovarian cancer compared to the normal ovary. Beta-catenin and Lef-1 were coimmunoprecipitated in ovarian tumours, but not in the normal ovary. Nuclear localisation of b-catenin or Lef-1 could not be demonstrated in the normal ovary or in the ovarian tumours. The absence of nuclear localisation of b-catenin could be due to an increased binding to the cadherin -a-catenin cell adhesion complex. In fact, we have earlier reported an increased expression of E-cadherin in ovarian adenocarcinomas. In summary, this study demonstrates an increase in the expression of components of the Wingless/Wnt pathway in malignant ovarian tumours. The increase suggests a role for this signalling pathway in cell transformation and in tumour progression. However, it remains to be demonstrated whether it is an increased participation of b-catenin in transcriptional regulation, or in the stabilisation of cellular integrity, or both, that is the crucial event in ovarian tumorigenesis.

The ovarian surface epithelium (OSE) is the origin of the majority of human ovarian cancers. These adenocarcinomas are characterized by initial local growth followed by spreading into the peritoneal cavity at later stages of tumor progression. The cell-adhesion molecule E-cadherin (E-cad) plays an important role in maintaining tissue integrity. Disappearance or impaired function of E-cad have often been associated with tumor formation and invasion in vivo and in vitro. The cell-specific expression of E-cad was investigated in normal human ovaries (n 5 12), in benign (n 5 5) and borderline (n 5 4) ovarian epithelial tumors and in adenocarcinomas of different stages and histological grades (n 5 18), by immunohistochemistry and immunoblotting. An ovarian cancer cell line (NIH-OVCAR3) was used as a reference. The epithelial origin of the cells was confirmed with cytokeratin (AE1/AE3) staining. In normal ovaries, the expression of E-cad was limited to inclusion cysts or deep clefts lined with OSE, whereas no staining of the OSE could be demonstrated at the surface of the ovary. In contrast, benign and borderline tumors uniformly expressed E-cad. This was observed in malignant tumors of all stages despite their degree of differentiation. E-cad was also present in metastasis from such tumors. The cell-specific expression of E-cad in inclusion cysts of normal ovaries and in epithelial layers of borderline tumors indicates a role for E-cad in the early events of the progression to a malignant phenotype. E-cad was not downregulated in later stages of ovarian cancer progression. Int.

The distribution of blood flow in the rat kidney after 60 minutes of renal ischemia was studied by single-fiber laser-Doppler flowmetry. Blood flow in superficial cortex and inner medulla was measured with a probe directed towards the kidney surface and exposed papilla, respectively. Outer medullary blood flow was measured with a probe introduced through the renal core. After ischemia the blood flow decreased to 60% of the preischemic value (P less than 0.01) in superficial cortex and to 16% (P less than 0.01) in outer medulla, while inner medullary blood flow increased paradoxically to 125% (P less than 0.01). There was extensive trapping of red blood cells (RBC) in the outer medulla, but not in the inner medulla or cortex. The fractional RBC volume as measured by radiolabeled RBCs was 21% in the inner stripe of the outer medulla, but 2% in this area in a normal kidney. To investigate the influence of RBC trapping on intrarenal distribution of blood flow after ischemia, the hematocrit was reduced from 46% to 31% by isovolemic hemodilution. When performed before ischemia, this maneuver almost completely abolished RBC trapping. In this group blood flow in both outer and inner medulla was almost unchanged after ischemia, while superficial cortical blood flow decreased to 66% (P less than 0.01) of the pre-ischemic value. It is concluded that RBC trapping in the outer medulla causes a large decrease in blood flow in this area and, at the same time, shunting of blood to the inner medulla. In the absence of RBC trapping, blood flow of both outer and inner medulla is well preserved after ischemia.

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The influence of neutrophils on peritubular capillary permeability and intravascular red blood cell (RBC) aggregation after renal ischemia was studied in anesthetized Sprague-Dawley rats. Intraperitoneal administration of antineutrophil serum (ANS) reduced the number of neutrophils in the blood to 3% of normal. The control group received an equal volume of inactive serum. Renal macromolecular capillary permeability was studied from 1) extravasation of albumin and 2) plasma to lymph transport of plasma proteins and of neutral and negatively charged lactate dehydrogenase (LDH). The net driving force (NDF) for fluid transfer over the peritubular capillary membrane was determined by the micropuncture technique. The intrarenal distributions of neutrophils and RBC were measured by a histochemical method and 51Cr-labeled RBC, respectively. Under preischemic control conditions neither macromolecular permeability nor renal clearance of inulin was affected by ANS. However, the steep increase in the macromolecular transport from plasma to lymph resulting from 45 min of ischemia and reperfusion was blunted by ANS, and preischemic control values were restored after 1 h of recirculation. In the control group the mass transport of plasma proteins increased twofold and that of both neutral and negatively charged LDH fourfold. NDF was equal in the two groups. In the ANS-treated animals the intrarenal neutrophil content was only 2% of the control. Neutrophils were found mainly in the cortex, whereas RBC aggregation was observed only in the renal medulla. It is concluded that neutrophils mediate postischemic capillary leakage. It is suggested that this leakage underlies RBC aggregation and incomplete return of blood flow in the renal medulla after ischemia.