Reconstruction after Laparoscopic Distal Gastrectomy

Laparoscopy-assisted distal gastrectomy (LADG) has advanced much in the past 10 years in the eastern countries, due to the high gastric cancer incidences. Reconstruction is the major hurdle for perfect laparoscopic distal gastrectomy (LDG). Initially, hand-associated or small incisional open laparotomy reconstruction, the so-called associated operation, was performed. A full laparoscopic operation is much better for the patient—small wound, less pain, and quick recovery. Several reconstruction methods have been developed by experts during more than 10 years. The question of what method is the best after distal gastrectomy is still controversial. This chapter focuses on the reconstruction methods in the total laparoscopy distal gastrectomy (LDG) operation, explains the merits and demerits of several methods, and introduces our original method, named augmented rectangle technique (ART)

A base pair at the bottom of the anticodon stem is reciprocally preferred for discrimination of cognate tRNAs by Escherichia coli lysyl- and glutaminyl-tRNA synthetases

Although the yeast amber suppressor tRNA(Tyr) is a good candidate for a carrier of unnatural amino acids into proteins, slight misacylation with lysine was found to occur in an Escherichia coli protein synthesis system. Although it was possible to restrain the mislysylation by genetically engineering the anticodon stem region of the amber suppressor tRNA(Tyr), the mutant tRNA showing the lowest acceptance of lysine was found to accept a trace level of glutamine instead. Moreover, the glutamine-acceptance of various tRNA(Tyr) transcripts substituted at the anticodon stem region varied in reverse proportion to the lysine-acceptance, similar to a ‘seesaw’. The introduction of a C31–G39 base pair at the site was most effective for decreasing the lysine-acceptance and increasing the glutamine-acceptance. When the same substitution was introduced into E.coli tRNA(Lys) transcripts, the lysine-accepting activity was decreased by 100-fold and faint acceptance of glutamine was observed. These results may support the idea that there are some structural element(s) in the anticodon stem of tRNA, which are not shared by aminoacyl-tRNA synthetases that have similar recognition sites in the anticodon, such as E.coli lysyl- and glutaminyl-tRNA synthetases

日本及び米国の承認医薬品の薬効評価に影響を与える治験デザイン要素に関する探索的研究

学位の種別: 課程博士審査委員会委員 : （主査）東京大学准教授 小野 俊介, 東京大学教授 新井 洋由, 東京大学教授 清水 敏之, 東京大学教授 楠原 洋之, 東京大学特任教授 木村 廣道, 筑波大学教授 荒川 義弘, 東京有明医療大学特任教授 津谷 喜一郎University of Tokyo(東京大学

N-methyl-D-aspartate receptors play important roles in acquisition and expression of the eyeblink conditioned response in glutamate receptor subunit delta2 mutant mice.

Classical eyeblink conditioning has been known to depend critically on the cerebellum. Apparently consistent with this, glutamate receptor subunit delta2 null mutant mice, which have serious morphological and functional deficiencies in the cerebellar cortex, are severely impaired in delay paradigm. However, these mutant mice successfully learn in trace paradigm, even in \u270-trace paradigm,\u27 in which the unconditioned stimulus starts just after the conditioned stimulus terminates. Our previous studies revealed that the hippocampus and the muscarinic acetylcholine receptors play crucial roles in 0-trace paradigm in glutamate receptor subunit delta2 null mutant mice unlike in wild-type mice, suggesting a large contribution of the forebrain to 0-trace conditioning in this type of mutant mice. In the present study, we investigated the role of N-methyl-D-aspartate receptors in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice. Mice were injected intraperitoneally with the noncompetitive N-methyl-d-aspartate receptor antagonist (+)MK-801 (0.1mg/kg) or saline, and conditioned with 350-ms tone conditioned stimulus followed by 100-ms periorbital shock unconditioned stimulus. Glutamate receptor subunit delta2 null mutant mice that received (+)MK-801 injection exhibited a severe impairment in acquisition of the conditioned response, compared with the saline-injected glutamate receptor subunit delta2 null mutant mice. In contrast, wild-type mice were not impaired in acquisition of 0-trace conditioned response by (+)MK-801 injection. After the injection solution was changed from (+)MK-801 to saline, glutamate receptor subunit delta2 null mutant mice showed a rapid and partial recovery of performance of the conditioned response. On the other hand, when the injection solution was changed from saline to (+)MK-801, glutamate receptor subunit delta2 null mutant mice showed a marked impairment in expression of the pre-acquired conditioned response, whereas impairment of the expression was small in wild-type mice. Injection of (+)MK-801 had no significant effects on spontaneous eyeblink frequency or startle eyeblink frequency to the tone conditioned stimulus in either glutamate receptor subunit delta2 null mutant mice or wild-type mice. These results suggest that N-methyl-D-aspartate receptors play critical roles both in acquisition and expression of the conditioned response in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice

The hippocampus plays an important role in eyeblink conditioning with a short trace interval in glutamate receptor subunit delta 2 mutant mice.

Mutant mice lacking the glutamate receptor subunit delta2 exhibit changes in the structure and function of the cerebellar cortex. The most prominent functional feature is a deficiency in the long-term depression (LTD) at parallel fiber-Purkinje cell synapses. These mutant mice exhibit severe impairment during delay eyeblink conditioning but learn normally during trace eyeblink conditioning without the cerebellar LTD, even with a 0 trace interval. We investigated the hippocampal contribution to this cerebellar LTD-independent "0 trace interval" learning. The mutant mice whose dorsal hippocampi were aspirated exhibited severe impairment in learning, whereas those that received post-training hippocampal lesions retained the memory. The wild-type mice showed no impairment in either case. These results suggest that the hippocampal component of the eyeblink conditioning task becomes dominant when cerebellar LTD is impaired

Signal transduction mechanism of interleukin 6 in cultured rat mesangial cells

AbstractInterleukin 6 (IL-6) is one of the potent autocrine growth factors for mesangial cells. We investigated the signal transduction mechanism or IL-6 in cultured rat mesangial cells. IL-6 induced a transient increase of inositol 1,4,5-trisphosphate (Ins 1,4,5-P3) followed by a transient and sustained increase of intracellular calcium concentration, suggesting that IL-6 stimulates phosphoinositide turnover. IL-6 also stimulated prostaglandin E2 (PGE2) production. The IL-6-concentration dependency in PGE2 production was similar to that in Ins 1,4,5-P3 production. We concluded that the action of IL-6 on mesangial cells is exerted at least partially through the enhancement of phosphoinositide turnover and PGE2 production

Reduction in Flux Loss of an Nd-Fe-B Bonded Ring Magnet for an SPM Motor

We have previously proposed a simulation method of an initial flux loss in permanent magnets using finite element method, and confirmed that predicted flux loss of an Nd-Fe-B boned ring magnet showed good agreement with measured flux loss. In this paper, we applied our proposed method to an Nd-Fe-B boned ring magnet in an SPM motor. We modeled a rotor composed of an Nd-Fe-B bonded ring magnet and a soft magnetic core made from silicon steels, and carried out the simulations for magnetizing process and prediction process of the flux loss. From the simulation results, we found that the inner side of the ring magnet has large flux loss. In order to reduce in flux loss, we enhanced the coercivity in the inner side of the ring magnet by partial replacement with another bonded magnet with high coercivity. Consequently, we found that the ring magnet with locally enhanced coercivity is effective to reduce in the flux loss

The significance of extended lymphadenectomy for colorectal cancer with isolated synchronous extraregional lymph node metastasis

SummaryBackground/ObjectiveThe significance of extended lymphadenectomy for colorectal cancer with extraregional lymph node metastasis, such as para-aortic lymph node metastasis, has not been established. The purpose of this study was to evaluate the significance of extended lymphadenectomy for colorectal cancer with synchronous isolated extraregional lymph node metastasis.MethodsBetween July 2004 and December 2013, 16 patients with synchronous extraregional lymph node metastasis without other organ metastases underwent curative resection and extended lymphadenectomy (R0 group). The clinical characteristics and survival outcomes of the R0 group were compared with those of 12 patients with extraregional lymph node metastasis who underwent palliative surgery (control group).ResultsIn the R0 group, the 5-year cancer-specific survival (CSS) rate was 70.3% and the 5-year relapse-free survival (RFS) rate was 60.5%. The 5-year CSS differed significantly between the R0 and control groups (70.3% vs. 12.5%; p = 0.0003). Univariate analyses revealed that the total numbers of metastatic lymph nodes and metastatic regional lymph nodes present were significantly associated with RFS (p = 0.019 for both).ConclusionFindings from our study suggest that extended lymphadenectomy for colorectal cancer with synchronous isolated extraregional lymph node metastasis might be effective in carefully selected patients

Epithelial EP4 plays an essential role in maintaining homeostasis in colon

Colonic epithelial cells comprise the mucosal barrier, and their dysfunction promotes microbial invasion from the gut lumen and induces the development of intestinal inflammation. The EP4 receptor is known to mediate the protective effect of prostaglandin (PG) E2 in the gastrointestinal tract; however, the exact role of epithelial EP4 in intestinal pathophysiology remains unknown. In the present study, we aimed to investigate the role of epithelial EP4 in maintaining colonic homeostasis by characterizing the intestinal epithelial cell-specific EP4 knockout (EP4 cKO) mice. Mice harboring the epithelial EP4 deletion showed significantly lower colonic crypt depth and lower numbers of secretory cell lineages, as well as impaired epithelial cells in the colon. Interestingly, EP4-deficient colon epithelia showed a higher number of apoptotic cells. Consistent with the defect in mucosal barrier function of colonic epithelia and secretory cell lineages, EP4 cKO colon stroma showed enhanced immune cell infiltration, which was accompanied by increased production of inflammatory cytokines. Furthermore, EP4-deficient colons were susceptible to dextran sulfate sodium (DSS)-induced colitis. Our study is the first to demonstrate that epithelial EP4 loss resulted in potential "inflammatory" status under physiological conditions. These findings provided insights into the crucial role of epithelial PGE2/EP4 axis in maintaining intestinal homeostasis