Hydrogen bonds of the imidazolium rings of ionic liquids with DMSO studied by NMR, soft X-ray spectroscopy, and SANS.

The hydrogen bonds of the imidazolium-ring H atoms of ionic liquids (ILs), 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amides ([Cnmim][TFSA], n = 2 to 12 where n represents the alkyl chain length), with the O atom of dimethyl sulfoxide (DMSO) have been elucidated using 1H, 13C, and 15N NMR spectroscopy and soft X-ray absorption and emission spectroscopy (XAS and XES). Density functional theory (DFT) calculations have been performed on an isolated DMSO molecule and two cluster models of [Cnmim]+-DMSO by hydrogen bonding to interpret the XES spectra for the [Cnmim][TFSA]-DMSO solutions. The 1H and 13C NMR chemical shifts of the imidazolium ring showed that deshielding of the ring H and C atoms is moderate as the DMSO mole fraction xDMSO increases to ∼0.8; however, it becomes more significant with further increase of xDMSO. This finding suggests that the hydrogen bonds of the three ring H atoms with the DMSO O atoms are saturated in solutions with xDMSO increased to ∼0.8. The 1H and 13C chemical shifts of the alkyl chains revealed that the electron densities of the chain H and C atoms gradually decrease with increasing xDMSO, except for the N1-bound carbon atom C7 of the chain. The 15N NMR chemical shifts showed that the imidazolium-ring N1 atom which is bound to the alkyl chain is shielded with increasing xDMSO in the range from 0 to 0.8 and is then deshielded with further increase of xDMSO. In contrast, the imidazolium ring N3 atom is simply deshielded with increasing xDMSO. Thus, the electron densities of the alkyl chain may be condensed at the C7 and N1 atoms of [Cnmim]+ by the hydrogen bonding of the ring H atoms with DMSO. The hydrogen bonding of DMSO with the ring results in low-energy shifts of the XES peaks of the O K-edge of DMSO. Small-angle neutron scattering experiments showed that [Cnmim][TFSA] and DMSO are homogeneously mixed with each other on the mesoscopic scale. This results from the strong hydrogen bonds of DMSO with the imidazolium-ring H atoms.

Feasibility and functional efficacy of distal gastrectomy with jejunal interposition for gastric cancer: a case series.

INTRODUCTION: Distal gastrectomy with jejunal interposition (DGJI) has been used in our institution for selected patients with gastric cancer as a function-preserving gastrectomy. The aim of this retrospective study was to clarify the feasibility and functional efficacy of DGJI. METHODS: A retrospective analysis was performed in 61 patients who underwent DGJI between 2002 and 2011. RESULTS: Mean operation time was 393.8 min and blood loss was 463.3 ml. Postoperative early major complications developed in 2 (3.3%) patients. The most common complication was gastric stasis, occurring in 7 (11.5%) patients. All patients with complications recovered with conservative treatment, and no operative mortality occurred. Endoscopy 1 year after operation revealed reflux gastritis in 1 patient. Reflux esophagitis was not found in any patient. However, anastomotic ulcer was found in 12 (22.2%) patients over the 1-year period after operation. No patient reported symptoms of early and late dumping syndrome, and 1 (1.9%) patient self-reported diarrhea. CONCLUSIONS: DGJI was a feasible and safe procedure with several advantages in terms of less incidence of reflux gastritis and esophagitis, dumping syndrome and diarrhea. However, this procedure is complicated and time-consuming, and it is necessary to be aware of the potential occurrence of an anastomotic ulcer at the site of the gastrojejunostomy after DGJI.

Five-year survival after surgery for invasive micropapillary carcinoma of the stomach.

Invasive micropapillary carcinoma (IMPC) of the breast, urinary bladder, ovary, and colon has been reported. However, few reports have described IMPC of the stomach. In addition, IMPC has been described as a histological indicator for lymphatic invasion and nodal metastasis, resulting in poor prognosis. We report a case of 5-year survival after surgery for IPMC of the stomach. A 69-year-old woman was admitted to our hospital with symptoms of upper abdominal pain. Upper gastrointestinal endoscopy revealed a tumor at the antrum of the stomach. Histological examination of the biopsy specimen indicated poorly differentiated adenocarcinoma. The patient underwent distal gastrectomy with lymph node dissection. Microscopic examination of the specimen revealed that the tumor consisted of an invasive micropapillary component. Carcinoma cell clusters were floating in the clear spaces. The patient recovered uneventfully and remains alive without recurrence 5 years after surgery.

Decreased growth rate of lung metastatic lesions after splenectomy in mice.

BACKGROUND: The effect of splenectomy on hematogenous metastases of malignant tumors remains controversial. The aim of this study was to clarify the effect of splenectomy on hematogenous metastases in an animal model. METHODS: Colon 26 cancer cells were inoculated into the lateral tail vein of 90 mice. The mice were then assigned to a splenectomy group or a control group. Lung weight, number of lung metastases, size of metastatic nodules, and serum vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) levels after the surgical procedure were measured and compared between the two groups. RESULTS: The lung nodules were significantly smaller in the splenectomy group than in the control group. In both groups, the serum VEGF levels increased on day 1 and then decreased. The serum VEGF levels on day 5 were significantly lower in the splenectomy group than in the control group. The serum bFGF levels were significantly lower in the splenectomy group than in the control group on days 1 and 5. Immunohistochemical study showed that bFGF was produced by reticuloendothelial cells of the spleen. CONCLUSION: The growth rate of hematogenous metastatic lesions appears to decrease after splenectomy and may be associated with decreases in serum levels of VEGF and bFGF induced by splenectomy.

Suppression of tumor growth in human gastric cancer with HER2 overexpression by an anti-HER2 antibody in a murine model.

New modalities are necessary for the treatment of patients with unresectable gastric cancer. The aim of this study was to investigate whether or not anti-HER2 antibody could suppress the growth of human gastric cancer cells with HER2 overexpression in vitro and in vivo. Four human gastric cancer cell lines, NCI-N87, MKN-45P, Kato-III, and MKN-1, were used in this study. The suppression of cell proliferation in vitro and of subcutaneous tumor growth in a nude mouse model after treatment with trastuzumab was examined. The expression of HER2 protein was investigated by Western blot analysis. The effect of trastuzumab on the survival rate of nude mice with peritoneal dissemination was examined. Trastuzumab significantly reduced proliferative activity in NCI-N87, a HER2-overexpressing human gastric cancer cell line, in vitro. In the nude mouse model with transplanted subcutaneous tumor, trastuzumab significantly suppressed the tumor growth of NCI-N87 cells, and then HER2 expression was reduced. Trastuzumab improved the survival rate of mice with peritoneal dissemination of MKN-45P cells. Trastuzumab therapy is a potential candidate for a novel treatment of HER2-overexpressing gastric cancer.

Hyaluronic acid stimulates tumor-cell proliferation at wound sites.

BACKGROUND: For EMR, the submucosal injection of sodium hyaluronate has become popular, because this substance creates a more prominent and longer-lasting mucosal protrusion than normal saline solution. However, the effects of sodium hyaluronate on tumor growth at wound sites remain unclear. METHODS: For these experiments, a murine model with artificial wounds was used. Forty mice were randomly divided into two groups according to the substance to be injected into a wound: a sodium hyaluronate group and a control group. Tumors were created by inoculation of transplantable adenocarcinoma cell line colon 26. Two weeks later, the size, weight, proliferating cell nuclear antigen-labeling index, and CD44 expression of the subcutaneous tumors were compared between the two groups of mice. RESULTS: There were significantly greater increases in the growth and the weight of subcutaneous tumors in the sodium hyaluronate group compared with the control group. The PCNA-labeling index of cancer cells also was higher in the sodium hyaluronate group. Immunohistochemistry and Western blot analysis demonstrated that the CD44 protein expression of cancer cells was higher in the sodium hyaluronate group vs. the control group. CONCLUSIONS: In this study, sodium hyaluronate enhanced both tumor growth and CD44 expression of cancer cells at wound sites, suggesting that the use of sodium hyaluronate for EMR might stimulate the growth of residual tumor cells.

A convenient murine model for the study of intra-abdominal lymph node metastasis.

Lymph node metastasis is one of the most important prognostic factors for cancer patients. There are few animal models of lymph node metastasis. The purpose of this study was to develop a simple animal model without surgical trauma. B16F10 melanoma (1 x 10(6) cells in 0.1 ml phosphate-buffered saline) were slowly injected into the retroperitoneal space followed by direct puncture at the position between the anus and tail of 50 female C57BL6 mice. At 1-week intervals for 4 weeks after the procedure, we examined the retroperitoneal tumor and intra-abdominal lymph nodes. There was no morbidity and no mortality. At 2 weeks after inoculation, the retroperitoneal tumor was visible macroscopically at the position between the rectum and the sacrum, and histological examination showed the occurrence of intra-abdominal lymph node metastasis in all mice. The number of positive nodules was increased and was affected by the amount of cancer cells inoculated and the interval from inoculation to lymph node metastasis. A convenient murine model for the study of lymph node metastasis has been developed. Our animal model does not involve surgical trauma and may be useful in the analysis of the association between surgical stress and lymph node metastasis and in the elucidation of the mechanism and prevention of lymph node metastasis.

Less impaired cell-mediated immune response in the murine peritoneal cavity after CO(2) pneumoperitoneum.

PURPOSE: We compared changes in the populations of peritoneal T lymphocytes and natural killer (NK) cells after CO(2) pneumoperitoneum and laparotomy to clarify whether pneumoperitoneum affects cell-mediated immune responses in the peritoneal cavity. METHODS: We analyzed and compared populations of T lymphocytes and NK cells among peritoneal exudative cells (PECs) collected from 185 female mice subjected to pneumoperitoneum, laparotomy, or anesthesia only. PECs were collected postoperatively, and the populations of T lymphocytes and NK cell subsets were analyzed by flow cytometry. The NK cell cytotoxicity (NKCC) of PECs and splenocytes was measured. RESULTS: The populations of CD3(+), CD4(+), and CD8(+) lymphocytes in the PECs continued to increase up until postoperative day (POD) 7 after laparotomy. The CD4/8 ratio on POD 3 was significantly lower after laparotomy than after pneumoperitoneum. The percentages of NK cells in the pneumoperitoneum group were significantly lower than those in the laparotomy group. On POD 1, the NKCC of splenocytes was less impaired in the pneumoperitoneum group than in the laparotomy group (10.3% vs 5.0%, P << 0.05). CONCLUSION: Laparoscopic surgery is preferable to open surgery because it results in less impairment of systemic and intraperitoneal cell-mediated immune responses.

Multiple gastric ruptures caused by blunt abdominal trauma: report of a case.

We report a rare case of four separate gastric ruptures resulting from blunt abdominal trauma that were successfully repaired by primary closure. A 22-year-old man injured in a motorcycle accident was admitted to our hospital where physical and radiological examinations confirmed the need for abdominal exploration. Laparotomy revealed four full-thickness lacerations in the anterior wall of the stomach. The lacerations were repaired primarily by a two-layer closure. The patient recovered gradually, and was discharged on hospital day 41, since when he has remained well. Although there has been no previous report of as many gastric lacerations following blunt abdominal trauma, surgeons should be aware of the possibility of multiple ruptures, which can be managed by simple closures.