Gastrospirillum hominis-associated gastritis: The first reported case in Japan

Tightly coiled spiral micro-organisms (Gastrospirillum hominis), distinct fromHelicobacter pylori, were found in the gastric mucosa of a 66-year-old man with a 4-month history of intermittent epigastric pain. The organisms were distributed in the antral mucosa, which showed erosive gastritis; histologically, the affected mucosa presented moderate to severe chronic gastritis with focal neutrophil infiltration. After a 2-week administration of cimetidine, his symptoms resolved and the active inflammation was reduced, both endoscopically and histologically, but the organisms still remained. Biopsy specimens taken 4 weeks after treatment with minocycline and cimetidine showed normal gastric mucosa without the spiral organisms. The above clinical course suggests the possible role ofGastrospirillum hominis in the pathogenesis of gastritis.     

The W9 peptide directly stimulates osteoblast differentiation via RANKL signaling

Objective

A RANKL-binding peptide, WP9QY (W9), is known to inhibit mouse osteoclastogenesis by stimulating the production of autocrine factors such as bone morphogenetic proteins (BMPs) to induce osteoblast differentiation. In the present study, we investigated whether osteoblastic differentiation is mediated by RANKL signaling.

Mediastinal Germ Cell Tumor Exhibiting a Discrepancy between Tumor Markers and Imaging: A Case Study

We report a mediastinal germ cell tumor (GCT) that exhibited a discrepancy between the time course of serum human chorionic gonadotropin (hCG) levels and clinical consequences. An otherwise healthy man, aged 34 years, was diagnosed with a nonseminomatous GCT, most likely embryonal carcinoma (EC), based on a mediastinal tumor biopsy. Standard chemotherapy resulted in an optimal decrease in serum hCG levels. However, multiple lesions in the liver continued to enlarge, which led to his death. Autopsy revealed few viable tumor cells in the liver, with the great majority of the tumor cells appearing to have undergone necrosis, suggesting that they responded to the chemotherapy. The residual tumor cells in the mediastinum and the liver were similar to syncytiotrophoblast cells, suggesting a cho-riocarcinoma (CC). On immunohistochemical analysis, the mediastinal tumor cells in the diagnostic biopsy specimen expressed both CD30 and hCG, whereas residual mediastinal and hepatic tumor cells in the autopsy specimen after chemotherapy also expressed hCG, but not CD30. These findings suggested that the patient suffered from a primary mixed GCT consisting of an EC and a CC. Both pre- and postchemotherapy tumors strongly expressed matrix metalloproteinase-2, supporting the aggressive and invasive features of the tumor phenotype. We speculate that the extremely invasive tumor destroyed normal liver structure, whereas chemotherapy and central necrosis reduced the number of viable cells themselves, causing a discordant decrease in serum hCG levels.Key Words: Nonseminomatous germ cell tumor, Serum human chorionic gonadotropin, Liver metastasis, Matrix metalloproteinase-2