[A Case of Synchronous and Solitary Gallbladder Metastasis from Gastric Cancer].

A 60s woman was found to have wall thickening of the gastric body and gallbladder in the follow-up CT scan after surgery for cervical carcinoma. An endoscopic examination revealed a type 3 tumor, located in the lesser curvature of the middle stomach. Abdominal CT showed lymphadenopathy at the lesser curvature. An enhanced thickened wall was also noted in the fundus of the gallbladder. FDG-PET/CT showed negative uptake in the gallbladder lesion. Distal gastrectomy and cholecystectomy were performed under the preoperative diagnosis of gastric cancer and adenomyomatosis. Histopathologically, the gastric lesion was a poorly differentiated adenocarcinoma, SE, ly1c, v1b. Moreover, the gallbladder lesion was a poorly differentiated adenocarcinoma proliferating mainly in the muscularis propria and subserosa, which had similar histological features as those in the adenocarcinoma part of gastric cancer. From these findings, the patient was diagnosed with gallbladder metastasis from gastric cancer. Gastric cancer rarely metastasizes to the gallbladder, and only 16 cases have been reported in Japan. We present the clinicopathological features with a review of the literature.

[A case of hepatocellular carcinoma showed the usefulness of endoscopic ultrasound-guided fine needle aspiration cytology using the cell block technique for differential diagnosis of gastric submucosal tumor].

A mass lesion presenting difficulty in differential diagnosis between a tumor in the lateral segment of the liver and a gastric submucosal tumor (SMT) was found in a 59-year-old man with chronic hepatitis B. For differential diagnosis between the 2 lesions, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed. EUS showed a tumor exhibiting a mosaic pattern with a halo derived from the lateral segment of the hepatic left lobe in contact with the stomach. FNA using the cell block technique revealed findings consistent with HCC. No examination-associated complications developed. In patients with HCC that is in contact with the stomach and shows extrahepatically protruding growth, which is difficult to differentiate from gastric SMT, EUS-FNA is a method worthy of trying.

Emergence of macrolide-resistant Mycoplasma pneumoniae with a 23S rRNA gene mutation.

A total of 195 Mycoplasma pneumoniae strains were isolated from 2,462 clinical specimens collected between April 2002 and March 2004 from pediatric outpatients with respiratory tract infections. Susceptibilities to six macrolide antibiotics (ML), telithromycin, minocycline, levofloxacin, and sitafloxacin were determined by the microdilution method using PPLO broth. A total of 183 M. pneumoniae isolates were susceptible to all agents and had excellent MIC90s in the following order: 0.00195 microg/ml for azithromycin and telithromycin, 0.0078 microg/ml for clarithromycin, 0.0156 microg/ml for erythromycin, 0.0625 microg/ml for sitafloxacin, 0.5 microg/ml for minocycline, and 1 microg/ml for levofloxacin. Notably, 12 ML-resistant M. pneumoniae strains were isolated from patients with pneumonia (10 strains) or acute bronchitis (2 strains). These strains showed resistance to ML with MICs of >or=1 microg/ml, except to rokitamycin. Transition mutations of A2063G or A2064G, which correspond to A2058 and A2059 in Escherichia coli, in domain V on the 23S rRNA gene in 11 ML-resistant strains were identified. By pulsed-field gel electrophoresis typing, these strains were classified into groups I and IIb [corrected] as described previously (A. Cousin-Allery, A. Charron, B. D. Barbeyrac, G. Fremy, J. S. Jensen, H. Renaudin, and C. Bebear, Epidemiol. Infect. 124:103-111, 2000). These findings suggest that excessive usage of MLs acts as a trigger to select mutations on the corresponding 23S rRNA gene with the resultant occurrence of ML-resistant M. pneumoniae. Monitoring ML susceptibilities for M. pneumoniae is necessary in the future.

[Preparation of NK-enriched LAK cells--their potential cytotoxic and ADCC activities].

We examined several culture methods to induce proliferation of natural killer (NK) cells from peripheral blood mononuclear cells (PBMC). In the presence of IL-2, a remarkable proliferation of NK cells was observed when PBMC were co-cultured with MMC-treated K562, which is known as a highly sensitive in vitro target cell for the NK assay. Addition of OK-432 or TNF-alpha and IL-1 beta also induced marked NK proliferation in a dose dependent manner. These NK-enriched lymphokine activated killer (LAK) cells showed highly cytotoxic activities against various MHC class I positive or negative tumor cells. They also showed potent ADCC activities against Herceptin-coated SK-BR-3, a HER2/neu positive breast cancer cell line. These results indicated that NK-enriched LAK cells are potent effector cells, and suggested novel therapeutic strategies for nonspecific immunotherapy as well as target immunotherapy in combination with anticancer antibodies, such as Herceptin.

[Phenotypical analysis of effector cells on nonspecific cancer cell therapy].

In the present study, we examined the contributions of lymphocyte subpopulations in lymphokine activated killer (LAK) activity. LAK cells prepared from peripheral blood mononuclear cells (PBMC) of healthy donors showed highly cytotoxic activities against target tumor cells. When CD16 and CD56 positive cells in LAK cells were depleted by magnetic cell sorting, their cytotoxic activities were dramatically decreased. In contrast, little change was observed by the depletion of CD3 positive cells, suggesting that CD16 and/or CD56 positive populations, but not CD3 positive populations, including natural killer (NK) cells are the major cell types involved in LAK activity. Indeed, NK-enriched LAK cells prepared by culturing PBMC with IL-2 and OK-432 showed a more potent LAK activity than conventional LAK cells and CD3-activated T cells. These results suggest that selective expansion and activation of CD16 and CD56 positive cells in LAK cells is a useful strategies to improve their anti-tumor potential in nonspecific immunotherapy, and possibly in combination therapy with other target immunotherapies as well.

Clathrin sheets on the protoplasmic surface of ventral membranes of osteoclasts in culture.

Physical cell-shearing resulted in various degrees of disruption of the basolateral (upper) membranes, cytoskeletons or cell organelles and exposed the protoplasmic surface of ventral (adhesion) membranes of osteoclasts that were attached to the underlying substratum, such as coverslips, mica or synthetic apatite plates. Freeze-dried replicas of the ventral membranes left behind on the substratum after cell-shearing provided three-dimensional information on the ultrastructure of the protoplasmic membrane surface of cultured osteoclasts. An extensive area of the protoplasmic surface and various amounts of cytoskeletal structures attached to the adherent ventral surface of the plasma membrane were visible. In particular, the most characteristic finding of the present study is that numerous clathrin sheets displaying various sizes, shapes and curvature were revealed on the ventral membrane. The polygon substructures of the clathrin lattices appeared to be composed of hexagons with a few pentagons interspersed. They were seen at the peripheral membranes where they were situated at the sites of close contact with the underlying substratum. In addition, clathrin lattices were never observed on the basolateral (upper) membranes. In favourable stereo views, most cytoskeletons were not in direct contact with the clathrin sheets. However, a few observations indicated possible remnants of cytoskeletons attached to clathrin lattices. Podosomes did not have a direct structural relationship to clathrin lattices. Although it is generally accepted that cytoskeletal podosomes in motile cells, such as osteoclasts, play a major role in cell adhesion, the present study indicates that membrane-associated clathrin might also function during attachment to the substrate. In this regard, clathrin is thought to be required for receptor-mediated endocytosis, but whether it might also function in cell attachment is still a matter for debate. This type of clathrin-related adhesion appears to be a previously unrecognized site of cell/substrate adhesion in osteoclasts. To assess this possible function, we focused on clathrin and related cytoskeletal elements on the ventral membranes of cultured osteoclasts.

Regeneration of small intestinal mucosa after acute ischemia-reperfusion injury.

To determine whether c-Fos and c-Jun are involved in the repair of small intestinal mucosa after ischemia-reperfusion (I/R), we investigated the mechanism of regeneration following acute I/R injury in rats by evaluating changes in DNA synthesis, fractional synthesis rate (FSR) of proteins, and alkaline phosphatase (ALP) activity. Furthermore, we examined the sequential expression of c-Fos and c-Jun using western blot analysis and immunohistochemical staining. Proliferating cell nuclear antigen (PCNA) labeling index (LI) demonstrated that the LI of the I/R group at 2 and 6 hr after reperfusion was significantly higher than that of the controls. Statistically significant differences were found between the FSRs of the I/R group and the corresponding conventional group at 2, 6, and 12 hr. The expression of c-Fos and c-Jun proteins increased markedly after I/R and these proteins decreased with time. The levels of ALP in the I/R group were significantly decreased at 2 and 6 hr after reperfusion compared to controls. These results indicate that c-Fos and c-Jun play a central role in the repair process that results in complete restoration of intestinal mucosal function after I/R.