Pivotal role of myeloid-derived suppressor cells in infection-related tumor growth.

BACKGROUND: In this study, we investigated infection-related tumor growth, focusing on myeloid-derived suppressor cells (MDSCs) in clinical and experimental settings. PATIENTS AND METHODS: In the clinical study, a total 109 patients who underwent gastrectomy or esophagectomy were included. Blood samples were collected from a preoperative time point through 3 months after surgery, and MDSCs were analyzed using flow cytometry. In animal experiments, peritonitis model mice were created by CLP method. We investigated the number of splenic MDSCs in these mice using flow cytometry. Malignant melanoma cells (B16F10) were inoculated on the back of the mice, and tumor growth was monitored. We compared the level of MDSC infiltration around the tumor and the migration ability between CLP and sham-operated mice-derived MDSCs. Finally, we focused on PD-L1+ MDSCs to examine the effectiveness of anti-PD-L1 antibodies on tumor growth in CLP mice. RESULTS: In patients with postoperative infectious complication, MDSC number was found to remain elevated 3 months after surgery, when the inflammatory responses were normalized. CLP mice showed increased numbers of MDSCs, and following inoculation with B16F10 cells, this higher number of MDSCs was associated with significant tumor growth. CLP-mice-derived MDSCs had higher levels of accumulation around the tumor and had more enhanced migration ability. Finally, CLP mice had increased numbers of PD-L1+ MDSCs and showed more effective inhibition of tumor growth by anti-PD-L1 antibodies compared to sham-operated mice. CONCLUSION: Long-lasting enhanced MDSCs associated with infection may contribute to infection-related tumor progression.

Prognostic impact of postoperative infection after resection of biliary malignancy: A multicenter retrospective cohort study.

BACKGROUND: The aim of this study was to investigate the prognostic impact of postoperative infections in patients who underwent resection for biliary malignancy, including intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, gallbladder carcinoma, and carcinoma of the ampulla of Vater. METHODS: This study was conducted in an 11-center retrospective cohort study. Patients with biliary tract cancer who underwent curative resection between April 2013 and March 2015 at 11 institutions in Japan were enrolled. We analyzed the prevalence of postoperative infection, infection-related factors, and prognostic factors. RESULTS: Of the total 290 cases, 33 were intrahepatic cholangiocarcinoma, 60 were perihilar cholangiocarcinoma, 120 were distal cholangiocarcinoma, 55 were gallbladder carcinoma, and 22 were carcinoma of the ampulla of Vater. Postoperative infectious complications, including remote infection, were observed in 146 patients (50.3%), and Clavien-Dindo ≥III in 115 patients (39.7%). Postoperative infections occurred more commonly in the patients who received pancreaticoduodenectomy and bile duct resection. Patients with infectious complications had a significantly poorer prognosis than those without (median overall survival 38 months vs 62 months, P = .046). In a diagnosis-specific analysis, although there was no correlation between infectious complications and overall survival in intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, and carcinoma of the ampulla of Vater, infectious complications were a significantly poor prognostic factor in gallbladder carcinoma (P = .031). CONCLUSION: Postoperative infection after surgery for biliary tract cancer commonly occurred, especially in patients who underwent pancreaticoduodenectomy and bile duct resection. Postoperative infection is relatively associated with the prognosis of patients with biliary malignancy, especially gallbladder carcinoma.

Survival impact of surgical site infection in esophageal cancer surgery: A multicenter retrospective cohort study.

Aim: This study was performed to evaluate the oncological impact of surgical site infection (SSI) and pneumonia on long-term outcomes after esophagectomy. Methods: The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 407 patients with curative stage I/II/III esophageal cancer at 11 centers from April 2013 to March 2015. We investigated the association of SSI and postoperative pneumonia with oncological outcomes in terms of relapse-free survival (RFS) and overall survival (OS). Results: Ninety (22.1%), 65 (16.0%), and 22 (5.4%) patients had SSI, pneumonia, and both SSI and pneumonia, respectively. The univariate analysis demonstrated that SSI and pneumonia were associated with worse RFS and OS. In the multivariate analysis, however, only SSI had a significant negative impact on RFS (HR, 1.63; 95% confidence interval, 1.12-2.36; P = 0.010) and OS (HR, 2.06; 95% confidence interval, 1.41-3.01; P < 0.001). The presence of both SSI and pneumonia and the presence of severe SSI had profound negative oncological impacts. Diabetes mellitus and an American Society of Anesthesiologists score of III were independent predictive factors for both SSI and pneumonia. The subgroup analysis showed that three-field lymph node dissection and neoadjuvant therapy canceled out the negative oncological impact of SSI on RFS. Conclusion: Our study demonstrated that SSI, rather than pneumonia, after esophagectomy was associated with impaired oncological outcomes. Further progress in the development of strategies for SSI prevention may improve the quality of care and oncological outcomes in patients undergoing curative esophagectomy.

Prognostic impact of postoperative infection in patients with pancreatic cancer: A multicenter cohort study.

BACKGROUND: Postoperative infection after pancreatectomy in patients with pancreatic cancer often leads to poor prognosis. The aim of this study was to determine the prognostic effect of postoperative infection in patients with pancreatic cancer. METHODS: A multicenter cohort study was performed using a common database of patients with pancreatic cancer who underwent curative pancreatic resections between April 2013 and March 2015 at 15 high-volume centers in Japan. The rate of postoperative infection was determined, and patient demographic characteristics, clinicopathologic factors, and prognostic factors for overall survival were analyzed. RESULTS: Of the 462 eligible patients who underwent curative pancreatectomy, postoperative infection occurred in 141 patients (31%), including 114 surgical site infections (25%), 50 remote infections (11%), and 23 combined infections (5%). Risk factors for postoperative infection included high body mass index, nondiabetes, and longer operation time. In the survival analysis, patients with postoperative infection had significantly worse overall survival than patients without postoperative infection. The median survival times were 21.9 and 33.0 months (P = .023), respectively, for patients with and without postoperative infection. According to the multivariate analysis for overall survival, lack of adjuvant therapy (P = .002), but not postoperative infection (P = .829), predicted poor prognosis. The multivariate analysis revealed that postoperative infection (P < .001) was an independent risk factor for lack of adjuvant therapy. CONCLUSION: Postoperative infection in patients with pancreatic cancer may indirectly worsen the prognosis by preventing timely adjuvant therapy.

How has the COVID-19 pandemic affected gastrointestinal surgery for malignancies and surgical infections?

The coronavirus disease 2019 (COVID-19) pandemic has affected infection control and prevention measures. We investigated the impact of the COVID-19 pandemic on postoperative infections and infection control measures in patients underwent gastrointestinal surgery for malignancies. We retrospectively evaluated changes in clinicopathological features, frequency of alcohol-based hand sanitizer use, frequency of postoperative complications, and microbial findings among our patients in February-May in 2019 (Control group) and 2020 (Pandemic group), respectively. Surgical resection in pathological stage III or IV patients was more frequently performed in the Pandemic group than in the Control group (P = 0.02). The total length of hospitalization and preoperative hospitalization was significantly shorter in the Pandemic group (P = 0.01 and P = 0.008, respectively). During the pandemic, hand sanitizer was used by a patients for an average of 14.9±3.0 times/day during the pandemic as opposed to 9.6±3.0 times/day in 2019 (p<0.0001). Superficial surgical site infection and infectious colitis occurred less frequently during the pandemic (P = 0.04 and P = 0.0002, respectively). In Pandemic group, Enterobacter, Haemophilus, and Candida were significantly decreased in microbiological cultures (P < 0.05, P < 0.05, P = 0.02, respectively) compared with Control group. Furthermore, a significant decrease in Streptococcus from drainage cultures was observed in the Pandemic group (P < 0.05). During the COVID-19 pandemic, a decrease in nosocomial infections was observed in the presence of an increase in alcohol-based hand sanitizer use.

A Potential Mechanism of Tumor Progression during Systemic Infections Via the Hepatocyte Growth Factor (HGF)/c-Met Signaling Pathway.

BACKGROUND: Increasing evidence has demonstrated that postoperative infectious complications (PICs) after digestive surgery are significantly associated with negative long-term outcomes; however, precise mechanisms of how PICs affect the poor long-term survival remain unclear. Here, we focused on the hepatocyte growth factor (HGF)/c-Met signaling pathway as one of those mechanisms. Methods: In the clinical setting, serum HGF levels were measured in the patients with sepsis and those with PICs after undergoing esophagectomy. Using a liver metastasis mouse model with cecal ligation and puncture (CLP), expressions of HGF and the roles of the HGF/c-Met pathway in the progression of tumor cells were examined. Results: Serum HGF levels were very high in the patients with intra-abdominal infection on postoperative days (PODs) 1, 3, and 5; similarly, compared to the patients without PICs, those with PICs had significantly higher serum HGF levels on 1, 3, and 5 days after esophagectomy. The patients with PICs showed poorer overall survival than those without PICs, and the patients with high serum HGF levels on POD 3 showed poorer prognosis than those with low HGF levels. Similarly, at 24 and 72 h after operation, serum levels of HGF in CLP mice were significantly higher than those in sham-operated mice. Intraperitoneal injection of mouse recombinant HGF significantly promoted liver metastases in sham-operated mice on 14 days after surgery. Knocking down c-Met expression on NL17 tumor cells by RNAi technology significantly inhibited the promotion of CLP-induced liver metastases. Conclusions: Infections after surgery increased serum HGF levels in the clinical as well as experimental settings. Induction of high serum HGF levels by CLP promoted liver metastases in a murine liver metastasis model, suggesting the involvement of the HGF/c-Met signaling pathway in tumor promotion mechanisms. Thus, targeting the HGF/c-Met signaling pathway may be a promising approach for malignant tumors, particularly in the patients with PICs.

Association Between the Frequency of Glove Change and the Risk of Blood and Body Fluid Exposure in Gastrointestinal Surgery.

BACKGROUND: Surgical gloves are used to prevent the transmission of microorganisms from the surgeon's hands to the patient and vice versa. Little is known on the optimal frequency of glove changing. Therefore, we aimed to examine the optimal frequency of glove change during surgery by assessing the glove perforation rate in gastrointestinal surgery. METHODS: In this observational prospective cohort study, we investigated the incidence of perforation of 5,267 gloves during gastrointestinal surgeries. RESULTS: The overall glove perforation rate was 10.1%. There was no significant difference between single gloving (10.2%) and double gloving (10.0%; p = 0.8491). However, the perforation rate of the inner glove (5.7%) was found to be significantly lower than that of the outer glove (11.6%) (p < 0.0001). A significant difference in perforation rate was observed after wearing inner gloves for 240 min (< 240 min, 4.4%; ≤ 240 min, 7.2%; p = 0.0314), and outer gloves for 60 min (< 60 min, 7.1%; ≤ 60 min, 12.6%; p < 0.0001). We found cumulative perforation rate to rapidly increase until the wear time was 90 min. CONCLUSION: The inner gloves and outer gloves have a higher perforation rate as the wear time increased. To reduce the risk of intraoperative blood and fluid exposure and prevent healthcare-associated infection, gloves should be changed for approximately every 60-90 min for outer gloves and approximately every 240 min for inner gloves.

Risk factors for nonalcoholic fatty liver disease after gastrectomy for gastric cancer.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) refers to hepatic steatosis caused by something other than alcoholic liver injury, and often occurs after gastrointestinal surgeries such as pancreatoduodenectomy and gastrectomy. This study aimed to identify the risk factors for NAFLD after gastrectomy for gastric cancer. METHODS: A total of 721 patients who underwent gastrectomy for gastric cancer and plane abdominal computed tomography (CT) preoperatively and 1 year after surgery were included in this study. NAFLD was defined as having a mean hepatic CT attenuation value of < 40 Hounsfield units. We retrospectively examined the relationship between the onset of NAFLD and clinicopathological findings to identify the risk factors associated with the development of NAFLD after gastrectomy. RESULTS: The incidence of postoperative NAFLD was 4.85% (35/721). The univariate analysis identified the following factors as being significantly associated with the incidence of NAFLD: age, preoperative BMI ≥ 25 kg/m2, tumor depth of pT3 ≤, lymph node metastasis grade of pN2 ≤, cholecystectomy, D2 lymphadenectomy, adjuvant chemotherapy, high preoperative cholinesterase serum level, and low grade of preoperative FIB-4 index. Adjuvant chemotherapy (p < 0.001) and high preoperative cholinesterase serum level (p = 0.021) were identified as independent risk factors for NAFLD 1 year after gastrectomy. CONCLUSION: Our study showed that adjuvant chemotherapy with S-1 and high level of serum cholinesterase were considered as the risk factors for NAFLD occurring after gastrectomy for gastric cancer.

Impact of perioperative high mobility group box chromosomal protein 1 expression on long-term outcomes in patients with esophageal squamous cell carcinoma.

BACKGROUND AND AIM: High mobility group box chromosomal protein-1 (HMGB-1) is a potential late mediator of sepsis and a possible risk factor for postoperative pulmonary complications after esophagectomy. This study aimed to determine the relationship between HMGB-1 and clinicopathological factors and long-term prognosis after esophagectomy for esophageal cancer. METHODS: We measured perioperative serum HMGB-1 levels using ELISA and HMGB-1 protein by immunohistochemistry expression in resected specimens. RESULTS: Postoperative serum HMGB-1 levels were significantly higher than preoperative levels. Preoperative serum HMGB-1 levels were significantly higher in patients with more intraoperative bleeding, longer intensive care unit stays, and postoperative pneumonia. Postoperative serum HMGB-1 levels were significantly higher in older patients and those with longer operation time and more intraoperative bleeding. There were significant differences in long-term outcomes according to postoperative but not preoperative serum HMGB-1 levels. Multivariate analysis demonstrated that advanced pathological stage, postoperative pulmonary complications, and higher postoperative serum HMGB-1 levels were independently associated with relapse-free survival and overall survival. Preoperative serum HMGB-1 levels were significantly higher in patients with high HMGB-1 expression than those with low HMGB-1 expression by immunohistochemistry, whereas such statistical differences were not observed in postoperative serum HMGB-1. There were no differences in relapse-free survival and overall survival according to HMGB-1 expression by immunohistochemistry. Serum HMGB-1 levels were significantly increased after esophagectomy for esophageal cancer. CONCLUSION: Elevated postoperative serum HMGB-1, which was associated not only with poor long-term but also short-term outcomes such as postoperative complications, might serve as a potential marker for prognosis in esophageal cancer.

A case of pneumatosis intestinalis during neoadjuvant chemotherapy with cisplatin and 5-fluorouracil for esophageal cancer†.

Pneumatosis intestinalis (PI) is a relatively rare disease. A 70-year-old man with stage II squamous cell carcinoma of the middle thoracic esophagus was administered cisplatin plus 5-fluorouracil (CF) therapy as neoadjuvant chemotherapy. On Day 14 of the first course of CF therapy, he complained of acute abdominal pain. Computed tomography (CT) revealed PI of the entire colon and a small air bubble in the mesentery. A colonoscopy revealed that there was no finding suggestive of ischemia. Because there was no sign of peritoneal irritation, conservative treatment was selected. On Day 7 after PI diagnosis, CT indicated the disappearance of PI. The patient underwent a radical esophagectomy. Intraoperative laparoscopic findings showed the serosa of the colon to be intact. The patient was discharged without any complications. It is important to take into account that CF therapy may cause PI and that PI can be treated conservatively.

MET4 expression predicts poor prognosis of gastric cancers with Helicobacter pylori infection.

The role of HGF/SF-MET signaling is important in cancer progression, but its relation with Helicobacter pylori-positive gastric cancers remains to be elucidated. In total, 201 patients with primary gastric carcinoma who underwent curative or debulking resection without preoperative chemotherapy were studied. MET4 and anti-HGF/SF mAbs were used for immunohistochemical analysis. Survival of gastric cancer patients was estimated by Kaplan-Meier method and compared with log-rank. Cox proportional hazards models were fit to determine the independent association of MET-staining status with outcome. The effect of live H. pylori bacteria on cell signaling and biological behaviors was evaluated using gastric cancer cell lines. MET4-positive gastric cancers showed poorer prognosis than MET4-negative cases (overall survival, P = 0.02; relapse-free survival, P = 0.06). Positive staining for MET4 was also a statistically significant factor to predict poor prognosis in H. pylori-positive cases (overall survival, P < 0.01; relapse-free survival, P = 0.01) but not in H. pylori-negative cases. Gastric cancers positively stained with both HGF/SF and MET4 showed a tendency of the worst prognosis. Stimulation of MET-positive gastric cancer cells with live H. pylori bacteria directly upregulated MET phosphorylation and activated MET downstream signals such as p44/42MAPK and Akt, conferring cell proliferation and anti-apoptotic activity. In conclusion, positive staining for MET4 was useful for predicting poor prognosis of gastric cancers with H. pylori infection. Helicobacter pylori stimulated MET-positive gastric cancers and activated downstream signaling, thereby promoting cancer proliferation and anti-apoptotic activity. These results support the importance of H. pylori elimination from gastric epithelial surface in clinical therapy.

Acute gastric volvulus associated with wandering spleen in an adult treated laparoscopically after endoscopic reduction: a case report.

A 43-year-old female was referred to our hospital for sudden onset of abdominal pain, fullness, and vomiting. Physical examination revealed abdominal distension with mild epigastric tenderness. Abdominal radiography showed massive gastric distension and plain computed tomography (CT) a markedly enlarged stomach filled with gas and fluid. A large volume of gastric contents was suctioned out via a nasogastric (NG) tube. Contrast-enhanced CT showed a grossly distended stomach with displacement of the antrum above the gastroesophageal junction, and the spleen was dislocated inferiorly. Upper gastrointestinal (GI) series showed the greater curvature to be elevated and the gastric fundus to be lower than normal. Acute mesenteroaxial gastric volvulus was diagnosed. GI endoscopy showed a distortion of the gastric anatomy with difficulty intubating the pylorus. Various endoscopic maneuvers were required to reposition the stomach, and the symptoms showed immediate and complete solution. GI fluoroscopy was performed 3 days later. Initially, most of the contrast medium accumulated in the fundus, which was drawn prominently downward, and then began flowing into the duodenum with anteflexion. Elective laparoscopic surgery was performed 1 month later. The stomach was in its normal position, but the fundus was folded posteroinferiorly. The spleen attached to the fundus was normal in size but extremely mobile. We diagnosed a wandering spleen based on the operative findings. Gastropexy was performed for the treatment of gastric volvulus and wandering spleen. The patient remained asymptomatic, and there was no evidence of recurrence during a follow-up period of 24 months. This report describes a rare adult case of acute gastric volvulus associated with wandering spleen. Because delay in treatment can result in lethal complications, it is critical to provide a prompt and correct diagnosis and surgical intervention. We advocate laparoscopic surgery after endoscopic reduction because it is a safe and effective procedure with lower invasiveness.

Abdominal Infection Suppresses the Number and Activity of Intrahepatic Natural Killer Cells and Promotes Tumor Growth in a Murine Liver Metastasis Model.

BACKGROUND: Increasing evidence suggests that postoperative infection is associated with poorer long-term outcome in various malignancies. However, the mechanism of poor prognosis induced by postoperative infection has not been clearly explained. We sought to determine whether abdominal infection promotes cancer metastases in a murine liver metastasis model, and to investigate the role of liver natural killer (NK) cells on antitumor immunity during abdominal infection. METHODS: Female BALB/c (8-10 weeks old) mice were inoculated with NL-17 colon cancer cells into the spleen and then subjected to abdominal infection induced by cecal ligation and puncture (CLP) or sham treatment. The extent of liver metastases and cytokine production in the serum and liver were investigated. Cell fraction and cytotoxic activities of liver mononuclear cells (MNCs) were elucidated. RESULTS: CLP mice had poorer survival and their serum levels of IL-6, -10, and -12p70 were significantly elevated on day 1 compared with sham-treated and control mice. No obvious differences in cytokine levels of the liver homogenates were identified among the three groups, except IL-12p70 levels in CLP mice on day 7 significantly decreased. The cytotoxic activities of liver MNCs were significantly suppressed in CLP mice soon after tumor inoculation. Flow cytometry revealed a decrease in NK cells in the liver and perforin and granzyme B expression levels. CONCLUSIONS: Abdominal infection promoted liver metastases in a murine liver metastasis model, which may be partially caused by a decrease in the number and activity of NK cells during abdominal infection.

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. CD47(hi) gastric cancer cells showed significantly higher proliferation and spheroid colony formation than CD47(lo) , and CD44(hi) CD47(hi) 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.

Theranostic Photosensitive Nanoparticles for Lymph Node Metastasis of Gastric Cancer.

BACKGROUND: Preoperative 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. METHODS: In 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. RESULTS: In 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. CONCLUSIONS: ICGm presents a novel theranostic nanodevice for LN metastasis of gastric cancer.

Laparoscopic jejunostomy for obstructing upper gastrointestinal malignancies.

The aim of this study was to describe a minimally invasive laparoscopic jejunostomy (Lap-J) technique for obstruction due to upper gastrointestinal malignancies and evaluate the nutritional benefit of Lap-J during neoadjuvant chemotherapy (NAC) in cases with obstructing esophageal cancer. Under general anesthesia, the jejunum 20-30 cm distant from the Treitz ligament was pulled out through an extended umbilical laparoscopic incision and a jejunal tube was inserted to 30 cm. The loop of bowel was gently returned to the abdomen and the feeding tube was drawn through the abdominal wall via the left lower incision. The jejunum was then laparoscopically sutured to the anterior abdominal wall. Lap-J was performed in 26 cases. The median operative time was 82 min. The postoperative course was uneventful. Lap-J prior to NAC was not associated with a decrease in body weight or serum total protein during NAC, compared with patients who received NAC without Lap-J. This minimally invasive jejunostomy technique may be particularly useful in patients in whom endoscopic therapy is not feasible due to obstruction from upper gastrointestinal malignancies.

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.

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.

Distance between the esophageal tumor and the aorta measured by using the contrast-enhanced attenuation on computed tomography for predicting this tumor invading aorta.

BACKGROUND AND AIM: Despite remarkable advances in diagnostic modalities, preoperative assessment of the local tumor extent in esophageal cancer is still very difficult. The aim of this study was to evaluate the predictive value of the computed tomography (CT) attenuation value between the tumor and the aorta for esophageal cancer. METHODS: Consecutive CT values were determined between the center of the tumor and the center of the aorta. The distance between the intersection of the average CT attenuation value of the tumor using the lower CT attenuation value of the inclusion tissues (T-A distance) was determined. The minimal CT attenuation value and the overall circumference of contact area (Picus' angle) were also determined. This study included 101 patients suspected of having a tumor invading the adventitia and evaluated the capacity of these parameters for predicting the aortic invasion. RESULTS: The T-A distance in patients who were diagnosed without aortic invasion was significantly longer than patients who were pathologically confirmed to have invasion to the aortic wall [pT4(Ao)] (P < 0.05). The minimal CT attenuation value in patients without aortic invasion was significantly lower than pT4(Ao) patients (P < 0.05), although such a difference was not observed for the Picus' angle. The T-A distance (1.3 mm >) is the most reliable feature for predicting the aortic invasion, according to the results of the area under the receiver operating characteristic curve. CONCLUSIONS: The assessment of the T-A distance is simple and objective, and it can help prevent unnecessary surgery in patients with inoperable tumors.

Predictive value of pleural and serum interleukin-6 levels for pneumonia and hypo-oxygenations after esophagectomy.

OBJECTIVE: Pulmonary complications after esophagectomy continue to be a significant cause of morbidity and mortality. Although several factors have been implicated to be associated with pulmonary complications after esophagectomy, the prediction of pulmonary complications remains a challenge. The purpose of this study was to evaluate the predictive value of cytokine levels in sera and pleural drainage fluid for pneumonia and hypo-oxygenations following esophagectomy. METHODS: A total of 66 patients who underwent esophagectomy for esophageal cancer were retrospectively evaluated for preoperative status, surgical procedures, and postoperative systemic response and laboratory data up to postoperative day (POD) 7. Interleukin-6 (IL-6) and IL-8 levels were also examined in patient sera and pleural drainage fluid until POD 5. RESULTS: Eighteen patients (27.3%) had pneumonia following esophagectomy. Patients with pneumonia had significantly more frequent intraoperative blood transfusions, more frequent re-intubation, longer hospital stays, and higher hospital mortality than those without pulmonary complications. Patients with pneumonia had significantly higher levels of serum and pleural IL-6 immediately after surgery and on POD 1 than those without pneumonia. Univariate and multivariate analyses revealed higher pleural IL-6 levels were associated with postoperative minimum PaO2/FiO2 ratio. CONCLUSIONS: The elevation of pleural IL-6 levels immediately after surgery and on POD 1 may predict the incidence of pneumonia and the levels of postoperative impaired oxygenation following esophagectomy.