Erythropoietin stimulates proliferation of rat-cultured gastric mucosal cells.

Most anemic patients with chronic renal failure have gastric mucosal lesions. However, these gastric lesions are often improved after the administration of recombinant human erythropoietin (rHuEPO). We have used the rat gastric mucosal cell line RGM-1, to examine the possibility that rHuEPO might directly stimulate the growth of gastric mucosal cells in vitro. Our results show that rHuEPO dose-dependently increased [3H]thymidine incorporation into RGM-1 cells and their expression of c-myc gene. In addition, 125I-rHuEPO specifically bound to RGM-1 cells, and moreover, erythropoietin receptor gene expression was detected by RT-PCR. We conclude that rHuEPO has a direct growth-promoting effect on RGM-1 cells, suggesting possible usefulness of rHuEPO administration for the treatment of gastric mucosal damage in patients with chronic renal failure.

Systemic capillary leak syndrome associated with multiple myeloma of IgG kappa type.

A case of systemic capillary leak syndrome in a 67-year-old woman is reported. The patient suddenly presented with severe edema and hypotension associated with an increased hematocrit and a decreased level of serum albumin, suggesting capillary hyperpermeability. The patient had IgG kappa monoclonal gammopathy in association with not only a slight increase in plasma cells in the bone marrow but also several punched out lesions in the skull, indicating multiple myeloma. Although most of the cases of systemic capillary leak syndrome reported previously were accompanied by monoclonal gammopathy, this appears to be the first case in which capillary leak syndrome developed in a patient with multiple myeloma.

Gastrin receptor genes are expressed in gastric parietal and enterochromaffin-like cells of Mastomys natalensis.

Although gastric enterochromaffin-like (ECL) carcinoid tumors are known to develop in patients with long-standing hypergastrinemia, the expression of the gastrin receptor gene in ECL cells has not yet been demonstrated. Therefore, this study was designed to examine gastrin receptor gene expression in ECL cells. Mastomys gastric mucosal cells isolated by enzyme dispersion were separated into 10 fractions (F1-10) by centrifugal elutriation. Each fraction was examined histologically to determine whether they contained ECL and/or parietal cells and Northern blot analysis was used to confirm the presence of histidine decarboxylase and H+, K(+)-ATPase gene expression. ECL cells were found only in fractions 1 and 2, whereas parietal cells were detected in fractions 6-10. Gastrin receptor gene expression was demonstrated in both parietal cell-rich and ECL cell-rich fractions. In addition, the gastrin receptor cDNA sequences obtained from the two of the fractions (F1 and 8) were identical. These results suggest that gastrin receptor genes are expressed in ECL cells as well as in parietal cells and that these receptors are identical.

Gastrin receptor gene expression in several human carcinomas.

Gastrin has been shown to enhance the growth of various human tumors. The present study was designed to examine the gastrin receptor gene expression in various human carcinoma cell lines and in surgically resected carcinoma tissues. By Northern blot analysis, gastrin receptor mRNA was detected in 3 out of 7 small cell lung carcinoma cell lines. Gastrin receptor mRNA was also expressed in one out of 8 colon carcinoma cell lines and 2 out of 10 colon carcinoma tissues. Moreover, one of two small cell carcinoma cell lines of the stomach clearly expressed gastrin receptor mRNA. However, none of the gastric adenocarcinoma cell lines or surgically resected gastric adenocarcinomas tested had any detectable expression of gastrin receptor gene. These findings may suggest a role of gastrin receptor in the growth and differentiation of certain human carcinomas.

Sarcoidosis with hypercalcemia--successful treatment of renal insufficiency and renal calcification with prednisolone.

A case of muscular sarcoidosis accompanied by severe hypercalcemia (serum calcium 15.5 mg/dl), renal insufficiency and renal calcification is reported. Sarcoid granulomas were found in the biopsy specimens of the lung and the muscle. The administration of prednisolone effectively improved not only muscle weakness but also hypercalcemia, renal insufficiency and renal calcification. This is a rare case of sarcoidosis in which renal calcification remitted after treatment with prednisolone. It is thus suggested that prednisolone treatment should be considered not only for hypercalcemia, but also for renal insufficiency caused by renal calcification in patients with sarcoidosis.

Cloning and characterization of gastrin receptor from ECL carcinoid tumor of Mastomys natalensis.

We report here the cDNA cloning of a putative gastrin receptor from enterochromaffin-like (ECL) carcinoid tumor of Mastomys natalensis. For this study, we used the polymerase chain reaction technique to amplify transmembrane domain sequences related to rat pancreatic cholecystokinin (CCK)-A receptor from the ECL tumor cDNA library. The amino acid sequence deduced from the cloned cDNA showed 85.7% and 49.0% identity to canine parietal cell gastrin receptor and rat pancreatic CCK-A receptor, respectively. Ligand binding studies using COS-7 cells transfected with the cDNA showed the same binding specificity for gastrin and CCK-8 as the gastrin receptor on the Mastomys carcinoid tumor membrane. Both gastrin and CCK-8 elevated free cytosolic calcium concentration in COS-7 cells expressing the cloned receptor. RNA blot analysis revealed the expression of the gastrin receptor in both Mastomys stomach and brain.