Sensitivity analyses of factors influencing CMAQ performance for fine particulate nitrate.

UNLABELLED: Improvement of air quality models is required so that they can be utilized to design effective control strategies for fine particulate matter (PM2.5). The Community Multiscale Air Quality modeling system was applied to the Greater Tokyo Area of Japan in winter 2010 and summer 2011. The model results were compared with observed concentrations of PM2.5 sulfate (SO4(2-)), nitrate (NO3(-)) and ammonium, and gaseous nitric acid (HNO3) and ammonia (NH3). The model approximately reproduced PM2.5 SO4(2-) concentration, but clearly overestimated PM2.5 NO3(-) concentration, which was attributed to overestimation of production of ammonium nitrate (NH4NO3). This study conducted sensitivity analyses of factors associated with the model performance for PM2.5 NO3(-) concentration, including temperature and relative humidity, emission of nitrogen oxides, seasonal variation of NH3 emission, HNO3 and NH3 dry deposition velocities, and heterogeneous reaction probability of dinitrogen pentoxide. Change in NH3 emission directly affected NH3 concentration, and substantially affected NH4NO3 concentration. Higher dry deposition velocities of HNO3 and NH3 led to substantial reductions of concentrations of the gaseous species and NH4NO3. Because uncertainties in NH3 emission and dry deposition processes are probably large, these processes may be key factors for improvement of the model performance for PM2.5 NO3(-). IMPLICATIONS: The Community Multiscale Air Quality modeling system clearly overestimated the concentration of fine particulate nitrate in the Greater Tokyo Area of Japan, which was attributed to overestimation of production of ammonium nitrate. Sensitivity analyses were conducted for factors associated with the model performance for nitrate. Ammonia emission and dry deposition of nitric acid and ammonia may be key factors for improvement of the model performance.

Endoscopic diagnosis of early neoplasia of the esophagus with narrow band imaging: correlations among background coloration and iodine staining findings.

BACKGROUND AND AIM: It was previously reported that high-grade intraepithelial neoplasia of the esophagus turns pink within a few minutes after iodine staining (pink-color sign; PCS); however, iodine staining is uncomfortable. By using narrow band imaging (NBI), color change in the area between the intraepithelial papillary capillary loop (background coloration; BGC) is often observed within the brownish area. The diagnostic usefulness of BGC findings for differentiating high-grade intraepithelial neoplasia from low-grade intraepithelial neoplasia was evaluated. METHODS: In a prospective observational study from September 2010 to August 2012, 285 patients who were in a high-risk group for esophageal squamous cell carcinoma underwent endoscopic examination. Lesions with both endoscopic findings of dilated intraepithelial papillary capillary loop on NBI and iodine-unstained areas were studied, in which endoscopic biopsy or endoscopic resection was subsequently performed. The esophageal background mucosa was also evaluated on the basis of the iodine staining pattern (uniform type: Group U, scattered type: Group S). RESULTS: One hundred three esophageal lesions in 87 patients were studied. When BGC was used as the differentiation index, sensitivity was 93.8%, specificity was 88.2%, and accuracy was 91.3%. When PCS was used, sensitivity was 97.9%, specificity was 88.2%, and accuracy was 93.2% (P = 0.79). In Group U (n = 54), BGC had an accuracy of 93.8%, and PCS had an accuracy of 92.3% (P = 1.0). On the other hand, in Group S (n = 33), BGC had an accuracy of 86.8%, while PCS had an accuracy of 94.7% (P = 0.27). CONCLUSIONS: Diagnosis using BGC on NBI may substitute for diagnosis based on PCS in many patients.

Identification of a high risk gastric cancer group using serum pepsinogen after successful eradication of Helicobacter pylori.

BACKGROUND AND AIM: Pepsinogen (PG) method is widely used to identify high risk groups of gastric cancer. It is very useful before Helicobacter pylori eradication, but after eradication the method becomes useless because the PGI, PGII, PGI/II ratios change. Therefore, we aimed to identify a high risk group for gastric cancer using serum pepsinogen after successful eradication of H. pylori. METHODS: A total of 261 participants were enrolled after successful eradication of H. pylori in Hokkaido University Hospital from 1995 to 2010. Participants with renal failure, taking proton pump inhibitors, and those with advanced gastric cancer were excluded. Serum levels of PGI and II were measured using chemiluminescent immunoassay method. RESULTS: Receiver operating characteristic curves using cancerous and non-cancerous data in post-eradication determined the optimal cut-off value of PGI/II as 4.5. The sensitivity and the specificity were 65.9% and 79.3%, respectively. The usual PG method includes 48.9% of cancer cases, and the PGI/II ≤ 4.5 in post-eradication includes 65.9% of them, and it includes approximately half of the high risk group of diffuse type cancer. PGI/II ≤ 4.5 in post-eradication included many gastric cancer cases detected after eradication (12/16 = 75%). CONCLUSION: In the identification of a high risk group for gastric cancer, we suggest that the optimal cut-off value of PGI/II after successful eradication of H. pylori is 4.5. PGI/II ≤ 4.5 in post-eradication includes more gastric cancer cases compared with the traditional PG method, and 75% of gastric cancer cases detected after eradication.

Clinicopathological analysis of early-stage gastric cancers detected after successful eradication of Helicobacter pylori.

BACKGROUND AND AIMS: The results of a randomized controlled study and meta-analysis study have recently proved that Helicobacter pylori eradication has a preventive effect against the development of metachronous and primary gastric cancer. However, gastric cancer is sometimes detected after successful eradication. There is a lack of study about gastric cancers in eradicated patients. To clarify the characteristics of gastric cancers detected after H. pylori eradication, we analyzed the clinicopathological features of these cancers. METHODS: The subjects were 18 early-stage gastric cancer specimens resected from 17 patients who had received successful eradication of H. pylori from February 1995 to March 2009. The control group consisted of 36 specimens from noneradicated patients with persistent H. pylori infection who were matched with the subjects in age, sex, and depth of invasion. Clinicopathological features and mucin phenotypes of gastric cancer were clinically and immunohistologically evaluated. RESULTS: The average diameter of gastric cancer was smaller and Ki-67 index was lower in the eradication group. The morphological distribution of depression types was significantly lower in the control group. Immunohistochemical phenotyping revealed that 72.2% of the lesions in the eradicated group were complete gastric type or gastric predominant mixed type, whereas the percentages of gastric type and intestinal type in the control group were similar. CONCLUSION: Our findings indicate that the clinicopathological characteristics of gastric cancers detected after H. pylori eradication are different from those of gastric cancers in patients with persistent H. pylori infection. H. pylori eradication may suppress intestinalization during the development of gastric cancer.

[A case of diverticular form type of congenital choledochal dilatation with anomalous arrangement of pancreaticobiliary duct].

We report a case of diverticular form type of congenital choledochal dilatation with anomalous arrangement of pancreaticobiliary duct and bile duct stone. The patient was a 63-year-old woman with the chief complaint of epigastralgia. Abdominal CT showed low density area suggesting cystic lesion at the region of pancreatic head. MRCP and ERCP revealed dilatation of the common bile duct in the multiple diverticular form with anomalous arrangement of pancreaticobiliary duct. A 2.0cm sized stone was also recognized in the dilated common bile duct. The patient underwent resection of gall bladder and dilated common bile duct, followed by hepatico-jejunostomy. Histological findings did not revealed malignant changes in the mucosa of both gall bladder and dilated common bile duct.

Histologic results of EMR for esophageal lesions diagnosed as high-grade intraepithelial squamous neoplasia by endoscopic biopsy.

BACKGROUND: Biopsy specimens obtained from esophageal lesions detected in endoscopic screening with iodine staining have often been diagnosed as high-grade intraepithelial squamous neoplasia (WHO 2000). However, a management strategy for such lesions has not been established. The purpose of this study was to perform EMR for such lesions and to determine the actual tumor stage in patients with complete resection and the outcomes after EMR. PATIENTS: During the study period, 51 patients were found to have esophageal lesions diagnosed as high-grade intraepithelial squamous neoplasia by using endoscopic iodine staining in biopsy specimens. All of the patients underwent EMR, and resected specimens were reviewed microscopically. RESULTS: Histologic examination of totally resected specimens revealed that 12 (23.5%) of the 51 patients had tumor invasion of the lamina propria mucosae and that 4 (7.8%) had tumor invasion of the muscularis mucosae. The remaining 35 patients (68.6%) were confirmed to have high-grade intraepithelial squamous neoplasia. The invasive focus in all of the 16 lesions of invasive squamous-cell carcinoma was surrounded by high-grade intraepithelial squamous neoplasia. After a median of 23 months of follow-up, there were two recurrences, and those patients required second EMR. CONCLUSIONS: Histologic results suggested that high-grade intraepithelial squamous neoplasia of the esophagus has characteristics of carcinoma in the preinvasive stage. EMR should be performed for esophageal lesions diagnosed by endoscopic biopsy as high-grade intraepithelial squamous neoplasia, not only because of its probable malignant potential but also because more than 30% of such lesions are actually invasive carcinoma.

Simultaneous analysis of termiticides in indoor air by using gas chromatography mass spectrometry.

We have established a method for simultaneously analyzing termiticides (13 kinds) in indoor air based on collection by combination of quartz filter and C18 Empore extraction disks, and measurement using gas chromatography mass spectrometry (GC/MS). The lower limit of determination for each substance was 0.02 microg/m3 when 2 m3 of air was sampled. The recovery was 66-100%, and the relative standard deviation was 3.7-14.2%. In experiments using a model box with commercial termiticides, we verified that emissions of bis (2, 3, 3, 3-tetrachloropropyl) ether (S421) increased with a rise in temperature from 10 degrees C to 20 degrees C to 40 degrees C, whereas almost no etofenprox was released into the air regardless of temperature. In addition, decanal, nonanal and alkanes (C13 and C14), which are major components of termiticides, were detected in relatively high concentrations. In the present study, regardless of low vapor pressure of the termiticides, several compounds were detected with the model box experiment. The conclusion that can be drawn is that it is necessary to survey the indoor environmental pollution.

Tumor-promoting activity and mutagenicity of 5 termiticide compounds.

The tumor-promoting activities of 5 commercial compounds used in termiticides were measured by a cell-transformation assay employing Bhas 42 cells. Their initiating activities were also measured by the microsuspension assay employing S. typhimurium TA98 and TA100 strains. The results of the transformation assay confirmed the tumor-promoting activities of fenitrothion, silafluofen and bifenthrin. Furthermore, the mutagenicity of S-421 and fenitrothion were also confirmed. Consideration of 2-stage carcinogenesis suggests that concurrent use of and long-term exposure to these compounds that have tumor-promoting and initiator activity, and compounds exhibiting either type of activity individually should be avoided as much as possible.

Resection of hepatocellular carcinoma with tumor thrombus of the portal vein after neoadjuvant regional chemotherapy.

We report a successfully managed case of far-advanced hepatocellular carcinoma (HCC) by intraarterial infusion therapy. A 55-year-old man was admitted to our hospital with abdominal pain and subileus. Abdominal ultrasonography, computed tomography, and angiography revealed HCC with obstruction of the main portal vein due to tumor thrombus. Serum levels of alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) were elevated. Neoadjuvant chemotherapy was tried with a course of low-dose cisplatin (CDDP) +5-fluorouracil (5-FU) intrahepatic arterial infusion through the indwelling catheter via the subcutaneous reservoir port. After 7 weeks of administration (total dose CDDP 370 mg/5-FU 18.5 mg), the main tumor size was effectively reduced. Serum levels of AFP and PIVKA-II decreased markedly. Adverse effects were tolerated. Following the chemoinfusion therapy, posterior segmentectomy and thrombectomy were performed. Reconstruction of the portal vein was not necessary because we removed the tumor thrombus without resecting the portal vein. The postoperative course was uneventful, and the patient has been doing well more than 2 years after surgery, with no evidence of recurrence or metastasis. Preoperative low-dose CDDP +5-FU intrahepatic arterial infusion therapy in combination with hepatic resection may be an effective treatment for advanced HCC with portal vein tumor thrombus.