Generation of Rat Monoclonal Antibodies Against Human Pancreatic Ductal Adenocarcinoma Cells.

Pancreatic ductal adenocarcinoma is an aggressive tumor with a poor prognosis. Biomarkers that can detect the tumor in its early stages when it may be amenable to curative resection might improve prognosis. To discover novel markers expressed in primary pancreatic cancer, we generated a panel of monoclonal antibodies against pancreatic ductal adenocarcinoma cell line BxPC3 using a rat medial iliac lymph node method. The antigen recognized by 1B5A5 was expressed on the cell surface and secreted into the conditioned medium of BxPC3 cells, and characterized as glycoproteins with molecular mass between 60 and 90 kDa. A wide range of molecular weights of 1B5A5 antigen in several pancreatic cancer cell lines were observed. Immunohistochemistry using a human multiple organ tumor tissue array showed an enhanced expression of 1B5A5 antigen in pancreas, lung, stomach, breast, urinary bladder, colon, and cervix uteri cancers. Immunoprecipitation followed by proteomic analyses identified CEACAM6 as a 1B5A5 antigen. In addition, western blot analysis results indicated that the 1B5A5 epitope is located within an amino-terminal domain of CEACAM6. These results raised the possibility that our approach could lead to discovery of novel biomarkers for the early stage of cancers in a relatively short period of time.

[A case of advanced gastric cancer found to be remaining by gastrectomy after a clinically complete response to chemotherapy].

The patient was a 72-year-old woman diagnosed with advanced gastric cancer, hepatic portal lymph node and para-aortic lymph node metastases. After five courses of S-1/CDDP combination therapy, both the primary tumor and lymph node metastases disappeared clinically. She wished to continue chemotherapy instead of having a resection. After three more courses of S-1/CDDP therapy, gastric cancer and lymph node metastases were still completely regressed, but complications of carcinoma of the gallbladder were suspected. Gastrectomy was performed with cholecystectomy, and a histopathological examination revealed cancer cells remaining in the gastric submucosa and xanthogranulomatous cholecystitis. We consider surgical therapy for clinically completely disappearing advanced gastric cancer by chemotherapy, in addition to case report.

Effects of light intensity distribution on growth of Rhodobacter capsulatus.

For cultivation of photosynthetic cells under defined light intensity distributions, the repeated batch culture, in which a part of culture broth containing grown cells was repeatedly replaced at predetermined time intervals with a fresh medium to keep the cell concentration constant at an initial value, was employed. By use of this method the effects of the light intensity distribution on the growth characteristics of Rhodobacter capsulatus were studied. Unexpected decreases in the specific growth rate were observed in culture of R. capsulatus at high cell concentrations and a long light path length. Big differences in the light intensities of lightly and darkly illuminated portions in photobioreactors, which reflects the light intensity distribution, seemed to cause this phenomenon, which must be taken into consideration for stable growth of photosynthetic cells.