Characterization of an omega-class glutathione S-transferase in the stress response of the silkmoth.

The glutathione S-transferase (GST) superfamily is involved in detoxification of various xenobiotics. Using real-time PCR, mRNA encoding an omega-class GST of Bombyx mori (bmGSTO) was shown to be induced after exposure to various environmental stresses. A soluble form of recombinant protein (rbmGSTO) was functionally overexpressed in Escherichia coli cells and purified to homogeneity. Cys 38 and Pro 39 were found to be highly conserved in omega-class GSTs, and their roles were investigated by site-directed mutagenesis/kinetic analysis. Mutations of Cys 38 and Pro 39 residues affected the catalytic efficiency of enzymes, indicating that the presence of Cys 38 and Pro 39 residues is important for bmGSTO activity. Thus, bmGSTO could contribute to increasing the environmental stress resistance of lepidopteran insects.

Clinical effect of irinotecan in advanced and metastatic breast cancer patients previously treated with doxorubicin- and docetaxel-containing regimens.

BACKGROUND: Previous phase II trials in Japan suggested that irinotecan was a promising agent for advanced or metastatic breast cancer pretreated with anthracycline. However, irinotecan has not yet been evaluated in the salvage setting for breast cancer pretreated with both anthracycline and taxane, which are two active agents for breast cancer. METHODS: The efficacy and safety of irinotecan were retrospectively evaluated in patients with breast cancer who had previously been treated with both doxorubicin and docetaxel. From 1996 to 1999, irinotecan was administered to 20 patients, all with a performance status of <2. Irinotecan treatment was repeated in approximately 6 week cycles consisting of the administration of irinotecan once weekly for 4 weeks followed by a 2 week rest. The median dose of irinotecan administered was 100 mg/m(2) weekly. The median number of irinotecan cycles given was 1 (range: 1-8 cycles). The median total dose was 388 mg/m(2) (range: 50-2400 mg/m(2)). RESULTS: Performance status declined to >3 after treatment with irinotecan in four patients. Two patients had grade 3 leukopenia; three had grade 3 anemia and one had a creatinine elevation of grade 4. The objective response rate for all patients was 5.0% (95% CI: 0-15.5%). The median time to progression and overall survival were 35 days (range: 17-285 days) and 124 days (range: 17-667 days), respectively, since the start of the administration of irinotecan. CONCLUSIONS: Salvage chemotherapy with irinotecan may be inactive against advanced and metastatic breast cancer pretreated with doxorubicin and docetaxel. We will evaluate irinotecan for advanced and metastatic breast cancer patients as first- or second-line chemotherapy combined with anthracycline or taxane.

Treatable subsets in cancer of unknown primary origin.

The purpose of this study was to investigate the treatable subsets in cancer of unknown primary origin (CUP). Fifty patients (27 males and 23 females; median age, 53 years) with CUP diagnosed between April 1992 and June 1999 were analyzed retrospectively. Of the 50 patients, 39 received chemotherapy: platinum-based in 31, non-platinum-based in 4, and clinical trials of new agents in 4. Of the 39 patients, 13 (33.3%; 95% confidence interval: 19.1 - 50.2%) showed objective responses, with 4 complete responders. Patients with poorly differentiated carcinomas in whom beta-subunit of human chorionic gonadotropin (beta-HCG) was elevated more than 10 mIU / ml and female patients with peritoneal adenocarcinomatosis achieved high response rates (83.3% and 80%, respectively) with platinum-based chemotherapy, as compared with only a 15.3% response rate in the remaining patients. Platinum-based chemotherapy provided promising results in patients with poorly differentiated carcinomas and in female patients with peritoneal adenocarcinomatosis. Significantly elevated serum levels of beta-HCG in patients with poorly differentiated carcinoma might predict a better response to platinum-based chemotherapy. However, the investigation of novel chemotherapeutic approaches is warranted for other groups of patients with CUP.

Primary low-grade MALT lymphoma of the gallbladder.

We report a case of primary low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (low-grade MALT lymphoma) in the gallbladder. A 58-year-old woman suspected of gallbladder carcinoma underwent laparoscopic cholecystectomy. Microscopic examination of the gallbladder demonstrated lymphoid cell infiltration forming lymphoid follicles with hyperplastic secondary follicles. The surrounding monocytoid B cells and centrocyte-like cells selectively infiltrated the crypt epithelium forming lympho-epithelial lesions. Plasma cells were also noted beneath the mucosal epithelium. Bile culture revealed the Gram-negative bacilli Enterococcus faecalis and Morganella morganii. Immunoglobulin heavy chain gene rearrangement was confirmed using polymerase chain reaction (PCR) and oligoclonal lymphoid proliferations was detected. Because autoimmune diseases, or chronic inflammatory disorders, seem to correlate with the occurrence of MALT lymphoma, Gram-negative bacterial infection could also be considered as a prodrome of MALT lymphoma of the gallbladder.

[The occlusal force distribution on the dental arch restored with implants in uni-lateral molars missing].

The object of this study was to discuss the occlusal force distribution on the dental arch before and after wearing implant-supported prostheses. The occlusal force was measured on four patients missing uni-lateral molars restored with 14 dental implants. The occlusal force distribution was represented as the occlusal force bearing rate (B.R.) which is the percentage of occlusal force on each portion to the total occlusal force. B.R. of the implant portion, of the non-implant side molar portion and of the anterior portion were calculated on four patients. B.R. of the premolar implant portion and of the molar implant portion were calculated on two patients. The pressure sensitive sheets and the image scanner (Dental Prescale 50H type R and Occluzer FPD 703, Fuji Photo Film Co.) were used in this study. The results were as follows: 1. The corresponding occlusal force was also born with the implant portion. Therefore, the total occlusal force increased, and the occlusal force distribution was extended to the same degree as the natural dentition after wearing the implant-supported prostheses. 2. The occlusal force and B.R. on the molar implant portion were considerably large regardless of wearing premolar implants. 3. The occlusal force and B.R. on the most distal implant in any molar portion were almost constant. These results suggested that the implant restoration should be useful for recovering occlusal functions, and that the most distal implant on the dental arch should have the sufficient bearing potential.