Risk of lymph node metastasis in mixed-type early gastric cancer determined by the extent of the poorly differentiated component

AIM: To predict the rate of lymph node(LN) metastasis in diffuse- and mixed-type early gastric cancers(EGC) for guidelines of the treatment.METHODS: We reviewed 550 cases of EGC withdiffuse- and mixed-type histology. We investigated the clinicopathological factors and histopathological components that influence the probability of LN metastasis, including sex, age, site, gross type, presence of ulceration, tumour size, depth of invasion, perineural invasion, lymphovascular invasion, and LN metastasis status. We reviewed all slides and estimated the proportions of each tumour component; pure diffuse type, mixed-predominantly diffuse type(diffuse > intestinal type), mixed-predominantly intestinal type(intestinal > diffuse type), and mixed diffuse = intestinal type. We calculated the extents of the respective components.RESULTS: LN metastasis was observed in 12.9%(71/550) of early gastric cancers cases [15/288 mucosal EGCs(5.2%) and 56/262 submucosal EGCs(21.4%)]. Of 550 cases, 302 were diffuse-type and 248 were mixed-type EGCs. Of 248 mixed-type EGCs, 163 were mixed-predominantly diffuse type, 82 were mixed-predominantly intestinal type, and 3 were mixed diffuse = intestinal type. Mixed-type cases with predominantly diffuse type histology showed a higher frequency of LN metastasis(20.2%) than cases of pure diffuse type(9.3%) and predominantly intestinal type(12.2%) histology. We measured the dimensions of each component(intestinal and diffuse type) to determine the association of the extent of each component with LN metastasis in mixed-type gastric carcinoma. The total tumour size and the extent of poorly differentiated components was associated with LN metastasis, while that of signet ring cell components was not.CONCLUSION: We recommend careful identification and quantitative evaluation of mixed-type early gastric cancer components after endoscopic resection to determine the intensity of the treatment.

Is it possible to differentiate gastric GISTs from gastric leiomyomas by EUS?

AIM: To evaluate the ultrasonog raphy (EUS) features of gastric gastrointestinal stromal tumors (GISTs) as compared with gastric leiomyomas and then to determine the EUS features that could predict malignant GISTs.METHODS: We evaluated the endoscopic EUS features in 53 patients with gastric mesenchymal tumors conf irmed by histopathologic diagnosis. The GISTs were classif ied into benign and malignant groups according to the histological risk classif ication.RESULTS: Immunohistochemical analyses demon-strated 7 leiomyomas and 46 GISTs. Inhomogenicity, hyperechogenic spots, a marginal halo and higher echogenicity as compared with the surrounding muscle layer appeared more frequently in the GISTs than in the leiomyomas (P < 0.05). The presence of at least two of these four features had a sensitivity of 89.1% and a specifi city of 85.7% for predicting GISTs. Except for tumor size and irregularity of the border, most of the EUS features were not helpful for predicting the malignant potential of GISTs. On multivariate analysis, only the maximal diameter of the GISTs was an independent predictor. The optimal size for predicting malignant GISTs was 35 mm. The sensitivity and specificity using this value were 92.3% and 78.8%, respectively.CONCLUSION: EUS may help to differentiate gastric GISTs from gastric leiomyomas. Once GISTs are suspected, surgery should be considered if the size is greater than 3.5 cm.

Effects of ciglitazone and troglitazone on the proliferation of human stomach cancer cells

AIM:To determine the cytological and molecular effects of peroxisome proliferation-activated receptor(PPAR)-γ and PPAR-γ agonists on stomach cancer cells.METHODS:To determine the proliferation-suppressive effects of troglitazone and ciglitazone,SNU-216 and SNU-668 stomach cancer cells were plated in media containing 40 μmol/L troglitazone and ciglitazone at a density of 1 × 104 cells/well.After 3,5 and 7 d,the cells were counted with a hemocytometer.To assess the appearance of PPAR-γ,a reverse-transcription polymerase chain reaction analysis was performed.On day 7,Western blotting was used to determine the effects of troglitazone and ciglitazone on the expression of p21 and phosphorylated-ERK(pERK) genes.Flow cytometry analysis was used to determine which portion of the cell cycle was delayed when troglitazone was used to suppress cell proliferation.In order to clarify the mechanism underlying the activity of troglitazone,microarray analysis was conducted.RESULTS:PPAR-γ was manifested in both SNU-216 and SNU-668 cells.Ciglitazone and troglitazone suppressed cell growth,and troglitazone was a stronger suppressor of stomach cancer cells than ciglitazone,an inducer of cell cycle arrest in the G1 phase.SNU-668 cells were also determined to be more sensitive to ciglitazone and troglitazone than SNU-216 cells.When troglitazone and ciglitazone were administered to stomach cancer cells,levels of p21 expression were increased,but ERK phosphorylation levels were reduced.When GW9662,an antagonist of PPAR-γ,was applied in conjunction with ciglitazone and troglitazone,the cell growth suppression effect was unaffected.The gene transcription program revealed a variety of alterations as the consequence of troglitazone treatment,and multiple troglitazone-associated pathways were detected.The genes whose expression was increased by troglitazone treatment were associated with cell development,differentiation,signal transmission between cells,and cell adhesion,and were also associated with reductions in cell proliferation,the cell cycle,nuclear metabolism,and phosphorylation.CONCLUSION:Troglitazone and ciglitazone suppress the proliferation of stomach cancer cells via a PPAR-γ-independent pathway.

Intracorporeal esophagojejunostomy using the double stapling technique after laparoscopic total gastrectomy:A retrospective case-series study

AIM:To introduce a simple and safe anvil insertion technique to esophagus during laparoscopic total gastrectomy(LTG).METHODS:Between July 2010 and December 2012,58 consecutive patients with early gastric cancer underwent LTG were enrolled.We performed a simple and safe Roux-en-Y esophagojejunostomy using the double stapling technique to all patients.Then patients’characteristics,perioperative outcome and histopathologic data were analyzed retrospectively.RESULTS:The mean age and body mass index were59.3±9.7 years and 22.7±2.6 kg/m2.The mean operation,reconstruction and anvil insertion times(from gastric incision to linear stapling)were 251.8±57.0,43.1±2.8 and 4.2±1.9 min,respectively.Intraoperative blood loss was 204.6±156.3 m L and there was no open conversion.The postoperative complications were in 8 cases(delayed gastric emptying in 4 cases,pulmonary complication in 2cases,pancreatitis in 1 case,anastomotic stricture in 1case).Anastomotic stricture occurred after discharge and was recovered by endoscopic intervention.The patients were discharged at a mean of 9.6±2.0 d after surgery.Neither leakage nor bleeding from the esophagojejunostomy occurred postoperatively.The mean proximal margin of specimen was 2.7±2.8 cm CONCLUSION:Roux-en Y esophagojejunostomy usingthe double stapling technique is simple and rapid,and it may offer a solid,alternative reconstruction method for LTG or proximal gastrectomy.

Solitary Peutz-Jeghers-type appendiceal hamartomatous polyp growing into the terminal ileum

Solitary Peutz-Jeghers type hamartomatous polyp is rare.It is considered to be related to a variant PeutzJeghers syndrome(PJS)and may be a separate disease entity.A 50-year-old man was referred to our hospital with a diagnosis of intussusception in the terminal ileum and underwent segmental ileal resection with appendectomy.We identified a 3.5-cm diameter polyp arising from the appendix with ingrowth into the terminal ileum.The polyp was confirmed to be a hamartomatous polyp of Peutz-Jeghers-type,histologically.However,the patient had no characteristic manifestations of PJS such as mucocutaneous pigmentation and family history.There are few reports of appendiceal hamartomatous polyp in PJS patients and solitary appendiceal hamartomatous polyp is even rarer.Also,rather than telescoping,ours is the first reported intussuscepted lesion,to the best of our knowledge.

Flammable carbon nanotube transistors on a nitrocellulose paper substrate for transient electronics

Transient electronics represent an emerging class of technology comprising materials that can vanish in a controlled manner in response to stimuli. In contrast to conventional electronic devices that are designed to operate over the longest possible period, transient electronics are defined by operation typically over a short and well-defined period; when no longer needed, transient electronics undergo self-deconstruction and disappear completely. In this work, we demonstrate the fabrication of thermally triggered transient electronic devices based on a paper substrate, specifically, a nitrocellulose paper. Nitrocellulose paper is frequently used in acts of magic because it consists of highly flammable components that are formed by nitratil^g cellulose by exposure to nitric acid. Therefore, a complete and rapid destruction of electronic devices fabricated on nitrocellulose paper is possible without producing any residue （i.e., ash）. The transience rates can be modified by controlling radio frequency signal-induced voltages that are applied to a silver （Ag） resistive heater, which is stamped on the backside of the nitrocellulose paper. The Ag resistive heater was prepared by a simple, low-cost stamping fabrication, which requires no harsh chemicals or complex thermal treatments. For the electronics on the nitrocellulose paper substrate, we employed semiconducting carbon nanotube （CNT） network channels in the transistor for superior electrical and mechanical properties.