In previous work from this laboratory, extracts of noncancerous human gastric mucosa were studied by immunochemical and electrophoretic means ( 1 ). Gastric mucosal extracts obtained by homogenization at pH 8 were subjected to electrophoresis in agar at pH 8.2. Zones of proteolytic activity at pH 2 were developed directly on the agar by the technique of Uriel (2). Four electrophoretically distinct zones showing proteolytic activity maximal at or near pH 2.0 were found in each of 45 stomachs studied. Thirty-six stomachs were from patients with duodenal ulcer, seven from patients with gastric ulcer, and in two cases, were normal stomachs obtained at autopsy from patients dying of heart disease less than 24 hours before autopsy. These constituents were designated proteases (P) I, II, III, and IV in order of decreasing electrophoretic mobility.Immunoelectrophoretic studies of-gastric mucosal extracts, using antiserum to mucosal extracts, showed three of the proteolytic constituents, P II, III, and IV, to be antigenic and to differ immunochemically from one another (1). These antigens were found in all noncancerous stomachs studied. Preliminary studies of the noninvolved gastric mucosa of 10 patients with gastric carcinoma suggested that the proteolytic constituents were diminished or absent (3). It was thus of considerable interest to define more fully the nature of these gastric mucosal components.The activation of pepsinogen involves the splitting off of basic peptides, resulting in an increased electrophoretic mobility for pepsin.

Five different glomerular immunohistochemistry markers were evaluated and compared in four different acute and chronic rat kidney disease models. Progression of glomerular or podocyte damage was shown in the puromycin aminonucleoside nephrosis (PAN) and Zucker fatty/spontaneously hypertensive heart failure F1 hybrid (ZSF1) rat model. Progression and prevention of glomerular damage was demonstrated in the Zucker diabetic fatty (ZDF) and Dahl salt-sensitive (Dahl SS) rat. Immunohistochemistry was performed for desmin, vimentin, podocin, synaptopodin and Wilms tumor protein-1 (WT-1), and evaluation of glomerular immunohistochemistry markers was done by semiautomated quantitative image analysis. We found desmin and WT-1 as the most sensitive markers for podocyte damage in both acute and chronic glomerular damage followed by vimentin, podocin and synaptopodin. We were able to demonstrate that early podocyte damage as shown by increased desmin and vimentin staining together with either a phenotypic podocyte change or podocyte loss (reduced numbers of WT-1-stained podocytes) drives the progression of glomerular damage. This is followed by a reduction in podocyte-specific proteins such as podocin and synaptopodin. Our report describes the different sensitivity of glomerular or podocyte markers and gives future guidance for the selection of the most sensitive markers for efficacy testing of new drugs as well as for the selection of tissue-based toxicity markers for glomerular or podocyte injury. In addition to functional clinical chemistry markers, desmin and WT-1 immunohistochemistry offers reliable and valuable data on the morphologic state of podocytes.

By using an enzyme-bridge immunoperoxidase (PAP) technique, localization of so-called pregnancy-specific beta 1-glycoprotein (SP1) and placental-specific tissue proteins (PP5, PP10, PP11, PP12) was investigated in 19 cases of breast cancer, 24 cases of testicular malignant tumours, 12 cases of gastric cancer and some cases of other malignant tumours. These five glycoproteins isolated from human term placentae and characterized by Bohn are localised mainly in the cytoplasm, or nucleus of syncytiotrophoblast and appear to be specific for the trophoblast. But to a certain percentage these proteins could also be detected in the cytoplasma of malignant cells: In breast cancer, SP1 was present in 52.6% of cases, PP5 in 63.2%, PP10 in 68.4%, PP11 in 55.6% and PP12 in 31.6%. In testicular malignant tumours the detection rates of these proteins varied from 20.8 to 75.0% and in gastric cancer from 41.7 to 66.7%. In total 50% of the tumours tested were SP1-positive, 58.3% PP5-positive, 55.6% PP10-positive, 38.0% PP11-positive and 31.9% PP12-positive. In addition, it was found that mononuclear histiocytes showed a strong cytoplasmic staining for PP10 and PP12 and that a few other non-cancerous cells (i.e. striated cells in gastric metaplasia, gastric polyps etc.) stained for PP5, PP10, PP11 and/or PP12. All control sections were negative in malignant cells as well as in other tissue cells. This study confirms the reports that some kinds of malignant tumours produce SP1 and indicates that the ectopic production of proteins normally produced by the trophoblast is a common finding in malignant tumours. It furthermore suggests that such proteins may be useful as markers in monitoring patients with malignant diseases. The possible mechanisms of ectopic production of these inappropriate proteins in malignant tumours are discussed.

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