Risa Takahata

Neutralization of interleukin-10 or transforming growth factor-β decreases the percentages of CD4+ CD25+ Foxp3+ regulatory T cells in septic mice, thereby leading to an improved survival.

OBJECTIVES To investigate the role of CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in septic conditions, and to examine the potential of targeting them for the treatment of sepsis. BACKGROUND Sepsis-induced immunosuppression has long been considered a factor in late mortality of patients with sepsis. Although Tregs are central to the maintenance of immunologic homeostasis and tolerance, little is known about Treg-mediated immunosuppression in the late stages of sepsis. METHODS Peripheral blood mononuclear cells (MNCs) in septic patients and liver or spleen MNCs collected after a cecal ligation and puncture (CLP) model in C57BL/6 mice were examined to evaluate the roles of Tregs and the correlation of transforming growth factor (TGF)-β or interleukin (IL)-10 with their activity. We next examined the effects of neutralization of TGF-β or IL-10 on the percentages of Tregs in CD4+ T cells and the survival rates of septic mice. RESULTS The percentages of Tregs in peripheral blood lymphocytes were significantly increased in patients with sepsis, and there was a significantly positive correlation between serum IL-10 levels and the percentage of Tregs. CLP injury increases the percentages of Tregs in the CD4+ T cells in the spleen, and there was a significantly positive correlation between the percentages of Tregs and the serum IL-10 or TGF-β levels. The neutralization of TGF-β or IL-10 decreased the percentages of Tregs in CD4+ T cells, restored the percentages of CD4+ T cells in spleen MNCs, and improved survival rates in septic mice. CONCLUSION We found an increase in the percentages of Tregs in peripheral blood circulating CD4+ T cells from patients with sepsis, and in splenic MNCs from septic mice, and observed that regulation of Tregs by neutralizing IL-10 or TGF-β might represent a novel strategy for treating the immunosuppressive conditions in sepsis.

CD47 is an adverse prognostic factor and a therapeutic target in gastric cancer.

CD47 is an antiphagocytic molecule that acts via ligation to signal regulatory protein alpha on phagocytes; its enhanced expression and therapeutic targeting have recently been reported for several malignancies. However, CD47 expression in gastric cancer is not well documented. Immunohistochemical expression of CD47 in surgical specimens was investigated. Expression of CD47 and CD44, a known gastric cancer stem cell marker, were investigated in gastric cancer cell lines by flow cytometry. MKN45 and MKN74 gastric cancer cells were sorted by fluorescence‐activated cell sorting according to CD44 and CD47 expression levels, and their in vitro proliferation, spheroid‐forming capacity, and in vivo tumorigenicity were studied. In vitro phagocytosis of cancer cells by human macrophages in the presence of a CD47 blocking monoclonal antibody (B6H12) and the survival of immunodeficient mice intraperitoneally engrafted with MKN45 cells and B6H12 were compared to experiments using control antibodies. Immunohistochemistry of the clinical specimens indicated that CD47 was positive in 57 out of 115 cases, and its positivity was an independent adverse prognostic factor. Approximately 90% of the MKN45 and MKN74 cells expressed CD47 and CD44. CD47hi gastric cancer cells showed significantly higher proliferation and spheroid colony formation than CD47lo, and CD44hiCD47hi cells showed the highest proliferation in vitro and tumorigenicity in vivo. B6H12 significantly enhanced in vitro phagocytosis of cancer cells by human macrophages and prolonged the survival of intraperitoneal cancer dissemination in mice compared to control antibodies. In conclusion, CD47 is an adverse prognostic factor and promising therapeutic target in gastric cancer.

Removal of increased circulating CD4+CD25+Foxp3+ regulatory T cells in patients with septic shock using hemoperfusion with polymyxin B-immobilized fibers.

BACKGROUND Although sepsis-induced immunosuppression has long been considered to be a factor in the late mortality of patients with sepsis, little is known about regulatory T cell (Treg)-mediated immunosuppression and the effect of polymyxin B-immobilized fiber (PMX-F) on sepsis-induced immunosuppression. We sought to investigate the role of CD4(+)CD25(+)Foxp3(+) Tregs in septic patients, and to evaluate the effect of hemoperfusion with PMX-F on the recovery from immunosuppression owing to septic shock. METHODS Thirty-two septic patients who had an identified focus of infection in the abdominal cavity were enrolled in this study. Peripheral blood mononuclear cells in the septic patients were examined to evaluate the roles of Tregs and the serum cytokine levels. We also examined the effects of PMX-F therapy on CD4(+) T cells, especially Tregs and serum cytokine levels in patients with septic shock. RESULTS The percentage of Tregs in the CD4(+) T-cell population, and the serum IL-6 and IL-10 levels, were significantly higher among patients with septic shock compared with those without septic shock, and PMX-F therapy significantly decreased the number of Tregs, as well as the serum IL-6 and IL-10 levels. Furthermore, a significant increase in the number of CD4(+) T cells, a significant decrease in the percentage of Tregs in the CD4(+) T-cell population, and a significant decrease in the serum IL-6 and IL-10 levels 24 hours after PMX-F therapy were observed in septic shock survivors compared with nonsurvivors. CONCLUSION We found a major increase in the percentage of Tregs in peripheral blood circulating CD4(+) T cells from patients with septic shock, and observed that the removal of Tregs by hemoperfusion with PMX-F might represent a novel strategy for inducing recovery from the immunosuppression associated with sepsis.

Photodynamic therapy using nanoparticle loaded with indocyanine green for experimental peritoneal dissemination of gastric cancer

Although there have been multiple advances in the development of novel anticancer agents and operative procedures, prognosis of patients with advanced gastric cancer remains poor, especially in patients with peritoneal metastasis. In this study, we established nanoparticles loaded with indocyanine green (ICG) derivatives: ICG loaded lactosomes (ICGm) and investigated the diagnostic and therapeutic value of photodynamic therapy (PDT) using ICGm for experimental peritoneal dissemination of gastric cancer. Experimental peritoneal disseminated xenografts of human gastric cancer were established in nude mice. Three weeks after intraperitoneal injection of the cancer cells, either ICGm (ICGm‐treated mice) or ICG solution (ICG‐treated mice) was injected through the tail vein. Forty‐eight hours after injection of the photosensitizer, in vivo and ex vivo imaging was carried out. For PDT, 48 h after injection of the photosensitizer, other mice were irradiated through the abdominal wall, and the body weight and survival rate were monitored. In vivo imaging revealed that peritoneal tumors were visualized through the abdominal wall in ICGm‐treated mice, whereas only non‐specific fluorescence was observed in ICG‐treated mice. The PDT reduced the total weight of the disseminated nodules and significantly improved weight loss and survival rate in ICGm‐treated mice. In conclusion, ICGm can be used as a novel diagnostic and therapeutic nanodevice in peritoneal dissemination of gastric cancer.

Postoperative serum concentrations of high mobility group box chromosomal protein-1 correlates to the duration of SIRS and pulmonary dysfunction following gastrointestinal surgery.

OBJECTIVE To clarify the time course of changes in the serum HMGB-1 concentrations in patients undergoing major gastrointestinal surgery, and to investigate whether the serum HMGB-1 levels correlate with the postoperative clinical course of the patients. METHODS Twenty-eight patients with alimentary tract carcinoma who underwent elective gastrointestinal surgery were enrolled in this study. The correlation between the serum HMGB-1 levels and the postoperative clinical course were evaluated. RESULTS Serum HMGB-1 concentrations in patients who underwent surgery for gastrointestinal cancer increased gradually during postoperative days, and reached peak concentrations on postoperative day 3 (POD3). There was a statistically significant positive correlation between the serum HMGB-1 levels on POD3 or POD5 and the duration of SIRS (r = 0.68, P < 0.001, r = 0.45, P < 0.05, respectively). A significantly positive correlation was found between the serum HMGB-1 levels on POD3 or POD5 and the heart rates on POD3 or POD5. Furthermore, there was a negative correlation between the serum HMGB-1 levels and PaO2/FiO2 ratio on POD3. CONCLUSIONS Serum HMGB-1 levels increase after major gastrointestinal surgery, and the serum peak HMGB-1 levels correlate with the duration of SIRS and postoperative pulmonary dysfunction.

Neutralization of IL-10 restores the downregulation of IL-18 receptor on natural killer cells and interferon-γ production in septic mice, thus leading to an improved survival.

ABSTRACT The objective of the study was to investigate the mechanisms of insufficient interferon-&ggr; (IFN-&ggr;) response to interleukin 18 (IL-18) and the treatment for the insufficient response in septic mice. Interleukin 18 stimulation does not restore IFN-&ggr; production by blood mononuclear cells in septic patients but does restore its production in postoperative patients. Although sepsis impairs the IFN-&ggr; response to IL-18, little is known about why the IL-18/IFN-&ggr;–mediated immune response is ineffective in patients with sepsis. A cecal ligation and puncture was made in C57BL/6 mice following a sublethal lipopolysaccharide challenge to examine their IFN-&ggr; response to IL-18, focusing on natural killer (NK) cells and cytokines. We next examined the effect of neutralization of IL-10 on the NK cell and survival in septic mice. Interleukin 18 injection did not restore IFN-&ggr; production in septic (cecal ligation and puncture) mice. Despite an increase in the numbers of liver NK cells, the IL-18 receptor (IL-18R) expression was decreased in the septic mice compared with sham mice. Serum IL-10 levels were positively correlated with the percentage of liver NK cells, but negatively with their IL-18R expression. Neutralization of IL-10 restored the IL-18R expression on liver NK cells and restored the IFN-&ggr; response in the septic mice, improving their survival. Sepsis might impair IL-18R expression on liver and spleen NK cells and impair the IL-18–mediated IFN-&ggr; response. Neutralization of IL-10 may restore this response in septic hosts, thereby improving survival.

Systemic inflammatory response syndrome as a predictor of anastomotic leakage after esophagectomy

PurposeEsophageal anastomotic leakage is still a major cause of morbidity and mortality after esophagectomy. We conducted this study to elucidate how anastomotic leakage affects the systemic inflammatory response syndrome (SIRS) criteria.MethodsThe subjects of this retrospective study were 61 patients who underwent esophagectomy. We evaluated their preoperative status, the surgical procedures, and postoperative systemic response, including white blood cell count, heart rate, respiratory rate, body temperature, and laboratory data up to postoperative day (POD) 4.ResultsAnastomotic leakage developed in nine patients (14.8%) and was found on POD 7 on average. These patients had a significantly longer hospital stay than those without leakage. Although no difference was observed in postoperative changes of any of the SIRS criteria, the postoperative incidence of SIRS was significantly higher in the patients with anastomotic leakage on POD 4. The number of positive criteria for SIRS was also significantly higher in patients with anastomotic leakage than in those without leakage on PODs 3 and 4.ConclusionsThe SIRS scoring system is valuable for evaluating the severity of systemic inflammatory response caused by anastomosis leakage, and may serve as an indicator for prompt management.

Computed tomography lymphography for the detection of sentinel nodes in patients with gastric carcinoma

The sentinel node (SN) concept has been found to be feasible in gastric cancer. However, the lymphatic network of gastric cancer may be more complex, and it may be difficult to visualize all the SN distributed in unexpected areas by conventional modalities. In this study, we evaluate the feasibility and efficacy of CT lymphography for the detection of SN in gastric cancer. A total 24 patients with early gastric cancer were enrolled in the study. Three modalities (CT lymphography, dye and radioisotope [RI] methods) were used for the detection of SN. The images of CT lymphography were obtained at 10 min after injection of contrast agents. The SN were successfully identified by CT lymphography in 83.3% of patients; detection rates by the dye and RI methods were 95% and 100%, respectively. Most patients, in whom SN were successfully detected by CT lymphography, had positive results at 5 min after injection of the contrast material. The SN stations detected by CT lymphography were consistent with or included those detected by dye and/or RI methods. In conclusion, CT lymphography for the detection of SN in gastric cancer is feasible and has several advantages. However, based on this initial experience, CT lymphography had a relatively low detection rate compared with conventional methods, and further efforts will be necessary to improve the detection rate and widen the clinical application of CT lymphography for the detection of SN in gastric cancer. (Cancer Sci 2010; 101: 2586–2590)

Theranostic Photosensitive Nanoparticles for Lymph Node Metastasis of Gastric Cancer

BackgroundPreoperative and intraoperative diagnoses of lymph node (LN) metastasis in patients with gastric cancer is essential to determine the extent of LN dissection in order to establish individualized treatment strategies. We investigated the theranostic value of a newly developed drug delivery system employing nanoparticles loaded with the indocyanine green (ICG) derivative ICG-loaded lactosome (ICGm) using a murine draining LN metastasis model of gastric cancer.MethodsIn the experimental draining LN metastasis model of human gastric cancer, the right hind footpads of nude mice were injected with cancer cells. Three weeks later, either ICGm or ICG solution was injected through the tail vein. Forty-eight hours after the administration of a photosensitizer, in vivo and ex vivo imaging and photodynamic therapy (PDT) were performed, and size of the LNs was measured.ResultsIn vivo imaging revealed metastatic LNs in the ICGm-treated mice but not in the ICG-treated mice. PDT using ICGm induced apoptosis and significantly inhibited the growth of metastatic LNs.ConclusionsICGm presents a novel theranostic nanodevice for LN metastasis of gastric cancer.

Laparoscopic gastrectomy after incomplete endoscopic resection for early gastric cancer

Endoscopic submucosal dissection (ESD) utilizes electrical coagulation, which can cause burns, fibrosis and adhesion of the stomach and surrounding tissue; these complications might increase the surgical difficulties for subsequent laparoscopy-assisted gastrectomy (LAG) and the risk of complications. However, scarce data are available on the influence of previous ESD on LAG. The purpose of this study was to evaluate the feasibility and safety of LAG following incomplete ESD in patients with early gastric cancer. Ninety-seven patients who underwent LAG were analyzed retrospectively; 17 patients had undergone ESD previously and the remaining 80 patients had no history of ESD. Clinicopathological data and surgical outcomes were compared between the two groups. No differences were observed in surgical outcomes of LAG after ESD in terms of operation time, intraoperative blood loss, total number of harvested lymph nodes, time until start of flatus, and postoperative hospital stay. These results were not influenced by tumor location and operative procedures. In conclusion, in terms of surgical outcomes, LAG is a safe and feasible procedure for the treatment of early gastric cancer regardless of previous endoscopic treatment. LAG may be the first-choice radical treatment after incomplete ESD for early gastric cancer.