[A case of advanced gastric cancer with peritoneal dissemination effectively treated by combined chemotherapy of paclitaxel (TXL) and TS-1].

The patient was a 49-year-old woman. Chemotherapy was conducted combining paclitaxel (TXL) and TS-1 under the diagnosis of non-resectable advanced gastric cancer with peritoneal dissemination. The administration schedule was as follows: 60 mg/m2 of TXL on days 1, 8 and 15 intravenously and 120 mg/day of TS-1/on days 1 5, 8-12, and 15-19 orally. One cycle lasted for 5 weeks. Grade 1 peripheral neuropathy was noted, but no other serious adverse reaction occurred. Ascites fluid was reduced after completion of the 1st cycle, and the therapeutic efficacy was rated as PR. Abdominal fullness was relieved shortly after starting the treatment, making it possible to conduct treatment on an ambulatory basis in the 2nd and subsequent cycles. At present, 6 months after starting chemotherapy, there is no evidence of relapse or adverse reactions that require intervention. Chemotherapy is being continued on an ambulatory basis. Combination of TXL and TS-1 is expected to show good therapeutic efficacy and improve patients' QOL in patients with gastric cancer associated with peritoneal dissemination.

Contribution of light chain rearrangement in peripheral B cells to the generation of high-affinity antibodies.

Recently, peripheral B cells have been shown to undergo secondary V(D)J rearrangement of immunoglobulin genes, but the physiological role of this event has not been fully elucidated. To investigate whether rearrangement of L chain genes in the periphery is involved in the generation of high-affinity antibodies (Ab), we used the 17.2.25 rearranged VHDJH gene (VHT)-knockin mouse whose B cell diversity is limited due to the expression of the site-directed transgene. Immunization of the mouse with p-nitrophenylacetyl (pNP)-conjugated chicken gamma-globulin preferentially led to the production of anti-pNP IgG Ab comprised of non-VHT-encoded H chains and lambda chains. lambda(+) IgG constituted a majority of high-affinity Ab to this hapten. RAG-2 mRNA and the recombination signal sequence break of the lambda1 gene increased in the draining lymph node of immunized mice, but not of nonimmunized animals. There was a close correlation between the levels of these parameters implicating lambda gene rearrangement and the production of lambda(+ )high-affinity anti-pNP IgG. These observations were reproduced in RAG-1-deficient mice that were reconstituted with the spleen cells ofthe knockin mouse. Thus, our findings suggest that L chain rearrangement that occurs in the periphery can contribute to affinity maturation of Ab.