Improvement of the anthropogenic emission rate estimate in Ulaanbaatar, Mongolia, for 2020-21 winter

Ulaanbaatar (UB), the fast-growing capital of Mongolia, is known for its world's worst level of particulate matter (PM) concentrations in winter. However, current anthropogenic emission inventories over the UB are based on data from more than fifteen years ago, and satellite observations are scarce because UB is in high latitudes. During the winter of 2020-21, the first period of the Fine Particle Research Initiative in East Asia considering the National Differences (FRIEND), several times higher concentrations of PM in UB compared to other urban sites in East Asia were observed but not reproduced with a chemical transport model mainly due to the underestimated anthropogenic emissions. Therefore, we devised a method for sequentially adjusting emissions based on the reactivity of PM precursors using ground observations. We scaled emission rates for the inert species (CO, elemental carbon (EC), and organic carbon (OC)) to reproduce their observed ambient concentrations, followed by SO2 to reproduce the concentration of SO42-, which was examined to have the least uncertainty based on the abundance of observed NH3, and finally NO and NH3 for NO3-, and NH4+. This improved estimation is compared to regional inventories for Asia and suggests more than an order of magnitude increase in anthropogenic emissions in UB. Using the improved emission inventory, we were able to successfully reproduce independent observation data on PM2.5 concentrations in UB in December 2021 from the U.S. Embassy. During the campaign period, we found more than 50% of the SO42-, NO3-, and NH4+ increased in UB due to the improvement could travel to Beijing, China (BJ), and about 20% of the SO42- could travel to Noto, Japan (NT), more than 3000 km away. Also, the anthropogenic emissions in UB can effectively increase OC, NO3-, and NH4+ concentrations in BJ when Gobi dust storms occur.

Rapid hydrolysis of NO2 at High Ionic Strengths of Deliquesced Aerosol Particles

Nitrogen dioxide (NO2) hydrolysis in deliquesced aerosol particles forms nitrous acid and nitrate and thus impacts air quality, climate, and the nitrogen cycle. Traditionally, it is considered to proceed far too slowly in the atmosphere. However, the significance of this process is highly uncertain because kinetic studies have only been made in dilute aqueous solutions but not under high ionic strength conditions of the aerosol particles. Here, we use laboratory experiments, air quality models, and field measurements to examine the effect of the ionic strength on the reaction kinetics of NO2 hydrolysis. We find that high ionic strengths (I) enhance the reaction rate constants (kI) by more than an order of magnitude compared to that at infinite dilution (kI=0), yielding log10(kI/kI=0) = 0.04I or rate enhancement factor = 100.04I. A state-of-the-art air quality model shows that the enhanced NO2 hydrolysis reduces the negative bias in the simulated concentrations of nitrous acid by 28% on average when compared to field observations over the North China Plain. Rapid NO2 hydrolysis also enhances the levels of nitrous acid in other polluted regions such as North India and further promotes atmospheric oxidation capacity. This study highlights the need to evaluate various reaction kinetics of atmospheric aerosols with high ionic strengths.

Solitary choroidal metastasis of distal cholangiocarcinoma: A case report

Metastatic choroidal carcinoma is rare and generally has a poor prognosis. The present case report describes a case of choroidal metastasis from distal cholangiocarcinoma, which was successfully managed using stereotactic radiotherapy (SRT). A 67-year-old Japanese man underwent pancreaticoduodenectomy for distal cholangiocarcinoma. The pathological stage was T2N0M0 stage IIA, according to the Union for International Cancer Control 8th edition. After surgery, the patient received adjuvant chemotherapy with oral TS-1® for 1 month. A total of 2 months after surgery, the patient was readmitted to hospital due to decreased visual acuity. Fundoscopy revealed a macular hole in the right eye that accounted for the decreased visual acuity. Additionally, Goldmann three-mirror contact lens examination revealed a 4-mm choroidal mass with a yellowish color situated at a considerable distance from the optic nerve. Magnetic resonance imaging revealed an enhanced choroidal mass. Based on the findings of ophthalmologic examinations and the patient's history of cholangiocarcinoma, they were diagnosed with choroidal metastasis from distal cholangiocarcinoma. SRT was administered at a total dose of 40 Gy divided into 8 Gy fractions. A total of 1 year after SRT, the patient achieved complete remission without decreased visual acuity. The patient remains alive and in good health without recurrence, 4 years after the diagnosis of choroidal metastasis. To the best of our knowledge, this is the second reported case of intraocular metastasis from cholangiocarcinoma. In conclusion, SRT may provide an opportunity to control metastatic choroidal carcinoma without decreasing visual acuity.

Predictive significance of surgery-induced lymphopenia on the survival after curative resection for locally advanced gastric cancer: a retrospective cohort analysis

BACKGROUND

Following the establishment of the anti-cancer effect of immune checkpoint inhibitors, lymphopenia has attracted attention as a parameter of preexisting cancer-related immune tolerance. Although the pretreatment absolute lymphocyte count (ALC) has been reported as a prognostic factor in gastric cancer patients, the impact of perioperative changes in the ALC remains unknown. The aim of the present study was to explore the relationship between surgery-induced lymphopenia and outcome.

METHODS

Database entries for 584 patients who underwent curative resections for pathological Stage IB-III gastric cancer were reviewed. We retrospectively compared clinicopathological factors including pretreatment ALC (pre-ALC) and ALC at first visit after discharge (post-ALC) with the survival. The low ALC was defined as < 1000/μL.

RESULTS

The ALC decreased significantly at 1 and 3 days after surgery and then recovered to the baseline value. A low pre-ALC (p < 0.001) and a low post-ALC (p < 0.001) were both correlated with a poor relapse-free survival (RFS). A multivariate analysis of RFS identified a low post-ALC (hazard ratio 1.875, 95% CI 1.156-3.402, p = 0.01), age, gender, BMI, T disease, N disease, severe vessel invasion, type of gastrectomy and postoperative morbidity as independent factors. The low post-ALC group had a poor RFS among patients with Stage II (p = 0.04) and Stage III (p = 0.04) disease, but not among patients with Stage IB disease (p = 0.13). Consistently, the overall survival (OS) rate was significantly lower among patients with a low post-ALC for all stage (p < 0.001), stage II (p = 0.02) and stage III (p = 0.01) disease, not for stage IB (p = 0.09). A low post-ALC was identified as an independent factor for predicting OS by multivariate analysis (hazard ratio: 2.275, 95% CI 1.373-3.769, p = 0.01).

CONCLUSIONS

A decrease in post-ALC was correlated with both of RFS and OS after curative resection in patients with locally advanced gastric cancer.

HIGHLIGHTS

Postoperative lymphopenia was a poor prognostic factor for gastric cancer.

Development of Quantitative Chemical Ionization Using Gas Chromatography/Mass Spectrometry and Gas Chromatography/Tandem Mass Spectrometry for Ambient Nitro- and Oxy-PAHs and Its Applications

The concentration of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere has been continually monitored since their toxicity became known, whereas nitro-PAHs (NPAHs) and oxy-PAHs (OPAHs), which are derivatives of PAHs by primary emissions or secondary formations in the atmosphere, have gained attention more recently. In this study, a method for the quantification of 18 NPAH and OPAH congeners in the atmosphere based on combined applications of gas chromatography coupled with chemical ionization mass spectrometry is presented. A high sensitivity and selectivity for the quantification of individual NPAH and OPAH congeners without sample preparations from the extract of aerosol samples were achieved using negative chemical ionization (NCI/MS) or positive chemical ionization tandem mass spectrometry (PCI-MS/MS). This analytical method was validated and applied to the aerosol samples collected from three regions in Northeast Asia-namely, Noto, Seoul, and Ulaanbaatar-from 15 December 2020 to 17 January 2021. The ranges of the method detection limits (MDLs) of the NPAHs and OPAHs for the analytical method were from 0.272 to 3.494 pg/m³ and 0.977 to 13.345 pg/m³, respectively. Among the three regions, Ulaanbaatar had the highest total mean concentration of NPAHs and OPAHs at 313.803 ± 176.349 ng/m³. The contribution of individual NPAHs and OPAHs in the total concentration differed according to the regional emission characteristics. As a result of the aerosol samples when the developed method was applied, the concentrations of NPAHs and OPAHs were quantified in the ranges of 0.016~3.659 ng/m³ and 0.002~201.704 ng/m³, respectively. It was concluded that the method could be utilized for the quantification of NPAHs and OPAHs over a wide concentration range.

Conversion surgery for stage IV gastric cancer: a multicenter retrospective study

Background

Recent improvements in systemic chemotherapy have provided an opportunity for patients with stage IV gastric cancer (GC) to undergo conversion surgery (CS). The aim of this study was to evaluate the long-term outcomes of patients who underwent CS and to elucidate the prognostic factors for CS in stage IV GC.

Methods

A total of 79 patients who underwent CS with the aim of R0 resection for stage IV GC at six institutions from January 2008 to July 2019 were enrolled. We retrospectively reviewed the clinicopathological data and prognosis.

Results

Of the 79 patients, 23 (31.1%) had initially resectable disease (IR) before chemotherapy, defined as positive for cancer on peritoneal cytology (CY1), resectable hepatic metastasis, or para-aortic lymph node No. 16a2/b1 metastasis. Of the 56 remaining patients with primary unresectable disease, 39 had peritoneal dissemination. R0 resection was accomplished in 63 patients (79.7%). The 3-year OS rates for patients with IR and unresectable disease were 78.3% and 44.5%, respectively. Multivariate analysis showed that IR (P = 0.014) and R0 (P = 0.014) were statistically significant independent prognostic factors for favorable OS. Among patients with peritoneal dissemination alone, OS was significantly better for patients with R0 resection than for patients with R1/2 resection, with the 3-year OS rates of 65.5% and 23.1%, respectively (P = 0.011).

Conclusions

CS is a treatment option for selected patients with stage IV GC. Patients with IR and patients who achieve R0 resection may obtain a survival benefit from CS.

Role of Dust and Iron Solubility in Sulfate Formation during the Long-Range Transport in East Asia Evidenced by 17O-Excess Signatures

Numerical models have been developed to elucidate air pollution caused by sulfate aerosols (SO₄^2-). However, typical models generally underestimate SO₄^2-, and oxidation processes have not been validated. This study improves the modeling of SO₄^2- formation processes using the mass-independent oxygen isotopic composition [¹⁷O-excess; Δ¹⁷O(SO₄^2-)], which reflects pathways from sulfur dioxide (SO₂) to SO₄^2-, at the background site in Japan throughout 2015. The standard setting in the Community Multiscale Air Quality (CMAQ) model captured SO₄^2- concentration, whereas Δ¹⁷O(SO₄^2-) was underestimated, suggesting that oxidation processes were not correctly represented. The dust inline calculation improved Δ¹⁷O(SO₄^2-) because dust-derived increases in cloud-water pH promoted acidity-driven SO₄^2- production, but Δ¹⁷O(SO₄^2-) was still overestimated during winter as a result. Increasing solubilities of the transition-metal ions, such as iron, which are a highly uncertain modeling parameter, decreased the overestimated Δ¹⁷O(SO₄^2-) in winter. Thus, dust and high metal solubility are essential factors for SO₄^2- formation in the region downstream of China. It was estimated that the remaining mismatch of Δ¹⁷O(SO₄^2-) between the observation and model can be explained by the proposed SO₄^2- formation mechanisms in Chinese pollution. These accurately modeled SO₄^2- formation mechanisms validated by Δ¹⁷O(SO₄^2-) will contribute to emission regulation strategies required for better air quality and precise climate change predictions over East Asia.

Long-range transport of airborne bacteria over East Asia: Asian dust events carry potentially nontuberculous Mycobacterium populations

The nontuberculous mycobacterial pulmonary disease (NTM-PD) caused by Mycobacterium species has increased in prevalence all over the world. The distributions of NTM-PD are possibly determined by the westerly wind traveling at high altitudes over East Asia. However, the long-range transport of Mycobacterium species has not been demonstrated by analyzing the bacterial communities in aerosols such as desert mineral particles and anthropogenic pollutants transported by the westerly wind. Here, airborne bacterial compositions were investigated including Mycobacterium species in high-elevation aerosols, which were captured in the snow cover at 2,450 m altitude on Mt. Tateyama. This was further compared to the ground-level or high-altitude aerosols collected at six sampling sites distributed from Asian-dust source region (Tsogt-Ovoo) to downwind areas in East Asia (Asian continental cities; Erenhot, Beijing, Yongin, Japanese cities; Yonago, Suzu, Noto Peninsula). The cell concentrations and taxonomic diversities of airborne bacteria decreased from the Asian continent to the Japan area. Terrestrial bacterial populations belonging to Firmicutes and Actinobacteria showed higher relative abundance at high-elevation and Japanese cities. Additionally, Mycobacterium species captured in the snow cover on Mt. Tateyama increased in relative abundance in correspondence to the increase of black carbon concentrations. The relative abundance of Mycobacterium sequences was higher in the aerosol samples of Asian continental cities and Japanese cities than in the desert area. Presumably, anthropogenic pollution over East Asia carries potential Mycobacterium species, which induce NTM-PD, thereby impacting upon the public health.

Development of spray-drying-based surface-enhanced Raman spectroscopy

We report a spray-drying method to fabricate silver nanoparticle (AgNP) aggregates for application in surface-enhanced Raman spectroscopy (SERS). A custom-built system was used to fabricate AgNP aggregates of four sizes, 48, 86, 151, and 218 nm, from drying droplets containing AgNPs atomized from an AgNP suspension. Sample solutions of Rhodamine B (RhB) at 10^-6, 10^-8, and 10^-10 M concentrations were dropped onto the AgNP aggregates as probe molecules to examine the enhancement of the Raman signals of the RhB. The ordering of the analytical enhancement factors (AEFs) by aggregate size at a 10^-6 M RhB was 86 nm > 218 nm > 151 nm > 48 nm. When RhB concentrations are below 10^-8 M, the 86 and 151 nm AgNP aggregates show clear RhB peaks. The AEFs of the 86 nm AgNP aggregates were the highest in all four aggregates and higher than those of the 218-nm aggregates, although the 218-nm aggregates had more hot spots where Raman enhancement occurred. This finding was attributable to the deformation and damping of the electron cloud in the highly aggregated AgNPs, reducing the sensitivity for Raman enhancement. When RhB was premixed with the AgNP suspension prior to atomization, the AEFs at 10^-8 M RhB rose ~ 100-fold compared to those in the earlier experiments (the post-dropping route). This significant enhancement was probably caused by the increased opportunity for the trapping of the probe molecules in the hot spots.

Calculating source contributions to urban atmospheric polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons using 1-nitropyrene and pyrene: An application to an Asian dust event

A method to calculate source contributions to atmospheric polycyclic aromatic hydrocarbons (PAHs) and their nitrated congeners (NPAHs) is proposed, using pyrene (Pyr) and 1-nitropyrene (1-NP), as respective representatives of PAHs and NPAHs. This is based on the known increases in NPAH to PAH ratios as combustion temperatures increase. The fractions of 1-NP and Pyr from high temperature combustion sources in total 1-NP and Pyr are respectively calculated as a (0 < a <1) and b (0 < b < 1). By using atmospheric concentrations of Pyr and 1-NP obtained at monitoring sites, contributions of high and low temperature combustion sources were calculated. Using this method, the contributions of automobiles and coal combustion facilities/industries to atmospheric Pyr and 1-NP concentrations were calculated for atmospheric samples collected in Kanazawa, Japan during a seasonal Asian dust event. The results show that Pyr was almost entirely emitted from industries in China and transported long-range to Japan. By contrast, 1-NP was emitted primarily from automobiles in Kanazawa and its surrounding areas, with a small amount of 1-NP possibly transported from China. The proposed method can provide greater clarity on source identification compared to the typically used PAH isomer pairs.

First X-ray Spectroscopic Observations of Atmospheric Titanium Species: Size Dependence and the Emission Source

Titanium dioxide (TiO2) in mineral dust is considered as one of the driving forces of photocatalytic reaction at the aerosol surface in the atmosphere. As a precursor of mineral dust, soil contains ilmenite (FeTiO3) and titanite (CaSiTiO5), which have lower photochemical reactivities than TiO2. However, Ti species other than TiO2 in aerosol particles are not well recognized due to the lack of observation in ambient samples. In this study, Ti species in size-fractionated aerosol samples collected in the Noto Peninsula, Japan, were determined by macroscopic and semi-microscopic X-ray absorption fine structure spectroscopy. Regardless of aerosol particle size, Ti species were primarily composed of rutile, anatase, ilmenite, and titanite. Semi-microscopic Ti speciation showed that Ti-poor spots associated with mineral dust were composed of a mixture of rutile, anatase, ilmenite, and titanite, and Ti-rich spots were primarily composed of TiO2 (rutile or anatase) derived from authigenic minerals or anthropogenic materials. Thus, the Ti species in aerosol particles, especially mineral dust, were not composed solely of TiO2 polymorphs. Therefore, the photochemical reactivities of Ti in aerosol particles may be overestimated when laboratory experiments or model studies employ TiO2 as the representative Ti species.

Efficacy and safety of ramucirumab plus paclitaxel therapy for advanced gastric cancer patients treated previously with docetaxel-containing chemotherapy

BACKGROUND

Ramucirumab (RAM) plus paclitaxel (PTX) therapy has shown promising results as a standard second-line treatment for advanced gastric cancer patients. Recently, combined docetaxel (DOC) plus S-1 (DS) therapy could be regarded as the new standard adjuvant chemotherapy for patients with curatively resected stage III gastric cancer. However, the efficacy and safety of RAM plus PTX therapy in patients treated previously with DOC-containing therapy remains unclear.

METHODS

This study assessed the clinical outcomes of RAM plus PTX therapy in advanced gastric cancer patients with or without a previous history of treatment with a DOC-containing regimen.

RESULTS

In a series of 107 consecutive patients enrolled for this study, the median PFS and OS were 4.2 and 6.2 months, respectively. Fifty-five patients had a history of prior therapy with DOC and 52 did not. There was no significant difference between with and without DOC groups in the ORR (22.2% vs. 23.5%), PFS (4.2 vs. 5.3 months), or OS (7.2 vs. 6.4 months). In a comparison taking into account the interval from the DOC-containing therapy to the RAM plus PTX therapy, the number of treatment courses was significantly smaller and the PFS significantly shorter in the patient group with an interval of ≤ 6 months (median, 2 vs 4.5 courses, P = 0.033; 3.4 months vs. 5.1 months, P = 0.043).

CONCLUSIONS

RAM plus PTX therapy in patients with advanced gastric cancer is effective even in patients who have previously received DOC-containing chemotherapy, especially if the interval is > 6 months.

Comparative Analysis of PM2.5-Bound Polycyclic Aromatic Hydrocarbons (PAHs), Nitro-PAHs (NPAHs), and Water-Soluble Inorganic Ions (WSIIs) at Two Background Sites in Japan

Daily PM2.5 (particulate matter with aerodynamic diameter ≤2.5 μm) samples were simultaneously collected at two background sites (Wajima Air Monitoring Station (WAMS) and Fukue-Jima Atmosphere and Aerosol Monitoring Station (FAMS)) in Japan in the East Asian winter and summer monsoon periods of 2017 and 2019, to compare the characteristics of air pollutants among different regions and to determine the possible variation during the long-range transport process. Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and water-soluble inorganic ions (WSIIs) were analyzed. Despite the PM2.5 concentrations at FAMS (8.90-78.5 µg/m3) being higher than those at WAMS (2.33-21.2 µg/m3) in the winter monsoon period, the average concentrations of ∑PAHs, ∑NPAHs, and ∑WSIIs were similar between the two sites. Diagnostic ratios indicated PAHs mainly originated from traffic emissions and mostly aged, whereas NPAHs were mostly secondarily formed during long-range transport. WSIIs at WAMS were mainly formed via the combustion process and secondary reactions, whereas those at FAMS mainly originated from sea salt and dust. Backward trajectories revealed the air masses could not only come from Asian continental coastal regions but also distant landlocked areas in the winter monsoon period, whereas most came from the ocean in the summer monsoon period. These findings can provide basic data for the establishment of prediction models of transboundary air pollutants in East Asia.

The impact of surgery induced immune-nutritional change on the outgrowth of micrometastasis after potentially curative resection for gastric cancer

e16581

Background: Whereas radical resection for gastric cancer is only life-saving option, resulting host response have been suggested to trigger the outgrowth of previously disseminated foci at distant anatomical sites via alteration of anti-tumor immunity. The prognostic nutrition index (PNI) which was calculated as 10 × serum Alb concentration (g/dL) + 0.005 × peripheral total lymphocyte count (/µL) is a surrogate marker of inflammation related nutritional decline and the imbalance of T lymphocyte differentiation. The aim of study was to evaluate the impact of perioperative change of PNI. Methods: The medical record of 567 gastric cancer patients who matched with the following inclusion criteria, R0 resection between 2006 and 2018, no preoperative anticancer treatment, pStage IB-IIIC according to UICC TNM classification and no other organ cancer at surgery, was identified from the prospectively maintained database. The postoperative laboratory data was routinely evaluated at POD 1, 3, 7 and first visit after discharge (AD). The PNI was compared through the perioperative course. Then the predictive value of low PNI-AD which defined as PNI < 40 on the relapse free survival (RFS) after surgery was estimated by COX proportional hazards analysis. Results: The median value of PNI at base line, 1, 3, 7 POD and AD was 51.0, 35.9, 34.0, 38.3 and 48.2, respectively. The PNI as significantly decreased at 1, 3 and 7 POD. Though the PNI at AD had a proclivity to recover, which was still significantly lower than that at base line. During observation period after surgery, the recurrence was encountered in 80 patients. The 5-year RFS rate in patients of pStage IB (n = 164), II (n = 228) and III (n = 175) was 97.4%, 88.9% and 64.7%, respectively. The multivariate analysis identified female gender (HR: 1.715, 95%CI; 1.018-2.890, p = 0.04), pT3-4 (HR:3.620, 95%CI; 2.011-6.518, p < 0.01), pN1-3 (HR:2.741, 95%CI; 1.428-5.263, p = 0.02), vessel invasion (+) (HR:2.666, 95%CI; 1.681-4.229, p < 0.01), PNI-AD < 40 (HR:1.833, 95%CI; 1.002-3.352, p = 0.04) were independent predictors of recurrence. The low PNI-AD was significantly related to the recurrence in the population of pStage III, but not in pStage IB and II. Conclusions: The retardation of postoperative recovery of PNI might evoke the distant metastasis.

Billroth-I vs Roux-en-Y after distal gastrectomy: A comparison of long-term nutritional status and survival rates from a large-scale multicenter cohort study

BACKGROUND

The optimal standard reconstruction procedure after distal gastrectomy is controversial. No large-scale persuasive clinical studies from long-term perspectives on this topic have yet been conducted.

STUDY DESIGN

This retrospective multicenter study analyzed a database of 2510 consecutive patients with clinical stage I gastric cancer who underwent distal gastrectomy followed by Billroth-I (B-I) or Roux-en-Y (R-Y) anastomosis from 2006 to 2012. After adjusting for 30 potential confounding factors using propensity score matching, we compared the body weight loss and other nutritional status for 5 years as primary outcomes between the two groups. We also investigated surgical outcomes, endoscopic findings, and long-term survival rates as secondary outcomes.

RESULTS

After matching the inclusion criteria, 940 patients (470 in each group) were enrolled. There was no marked difference in the body weight loss and other nutritional indicators. The incidence of grade ≥3 postoperative complications (Clavien-Dindo classification) or the incidence of gallstone formation was not markedly different between the two groups. The postoperative hospital stay after surgery was significantly longer, and the readmission rate was significantly higher in the R-Y group than in the B-I group. An endoscopic examination revealed no trends regarding the incidence and severity of gastritis or residual food in the remnant stomach. The 5-year overall survival rate was 92.6% in the B-I group and 91.8% in the R-Y group, with no significant difference (P = .379, log-rank test).

CONCLUSIONS

Roux-en-Y reconstruction may be nearly equal to Billroth-I with regard to the long-term nutritional perspectives.

Sources and Characteristics of Polycyclic Aromatic Hydrocarbons in Ambient Total Suspended Particles in Ulaanbaatar City, Mongolia

The purpose of this study was to identify pollution sources by characterizing polycyclic aromatic hydrocarbons from total suspended particles in Ulaanbaatar City. Fifteen polycyclic aromatic hydrocarbons were measured in total suspended particle samples collected from different sites, such as the urban center, industrial district and ger (Mongolian traditional house) areas, and residential areas both in heating (January, March), and non-heating (September) periods in 2017. Polycyclic aromatic hydrocarbon concentration ranged between 131 and 773 ng·m-3 in winter, 22.2 and 530.6 ng·m-3 in spring, and between 1.4 and 54.6 ng·m-3 in autumn. Concentrations of specific polycyclic aromatic hydrocarbons such as phenanthrene were higher in the ger area in winter and spring seasons, and the pyrene concentration was dominant in late summer in the residential area. Polycyclic aromatic hydrocarbons concentrations in the ger area were particularly higher than the other sites, especially in winter. Polycyclic aromatic hydrocarbon ratios indicated that vehicle emissions were likely the main source at the city center in the winter time. Mixed contributions from biomass, coal, and petroleum combustion were responsible for the particulate polycyclic aromatic hydrocarbon pollution at other sampling sites during the whole observation period. The lifetime inhalation cancer risk values in the ger area due to winter pollution were estimated to be 1.2 × 10-5 and 2.1 × 10-5 for child and adult exposures, respectively, which significantly exceed Environmental Protection Agency guidelines.

Oncological outcomes of function-preserving gastrectomy for early gastric cancer: a multicenter propensity score matched cohort analysis comparing pylorus-preserving gastrectomy versus conventional distal gastrectomy

OBJECTIVE

This study aimed to clarify the oncological safety of pylorus-preserving gastrectomy (PPG) compared with conventional distal gastrectomy (DG).

METHODS

From three institutions specializing in cancer, the medical records for a cohort of 2898 consecutive patients who had undergone DG (n = 2208) or PPG (n = 690) for clinical stage I gastric cancer between January 2006 and December 2012 were analyzed. A propensity score for each patient was estimated on the basis of 38 preoperative clinical and tumor-related factors. After propensity score matching had been done, 1004 patients (502 DG patients, 502 PPG patients) were included in the analysis. The overall survival, relapse-free survival, and occurrence of secondary gastric cancer were then compared. The median observation period was 48.6 months (range 1-109.8 months).

RESULTS

The 5-year overall survival rate was 98.4 % for the PPG group and 96.6 % for the DG group (hazard ratio 0.48, 95 % confidence interval 0.21-1.09, P = 0.07). The 3-year relapse-free survival rate was 99.5 % for the PPG group and 98.0 % for the DG group (hazard ratio 0.39, 95 % confidence interval 0.12-1.33, P = 0.12). Postoperative secondary gastric cancer was encountered in eight patients (1.6 %) in the PPG group and four patients (0.8 %) in the DG group. No significant differences in either overall survival, relapse-free survival, or the occurrence of secondary gastric cancer were observed between the two groups.

CONCLUSIONS

Given the adequate estimation of the clinical tumor stage, the oncological safety of PPG for clinical T1N0 gastric cancer in the middle portion of the stomach was comparable to that of DG.

Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Cloud condensation nuclei (CCN) number concentrations alongside with submicrometer particle number size distributions and particle chemical composition have been measured at atmospheric observatories of the Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS) as well as other international sites over multiple years. Here, harmonized data records from 11 observatories are summarized, spanning 98,677 instrument hours for CCN data, 157,880 for particle number size distributions, and 70,817 for chemical composition data. The observatories represent nine different environments, e.g., Arctic, Atlantic, Pacific and Mediterranean maritime, boreal forest, or high alpine atmospheric conditions. This is a unique collection of aerosol particle properties most relevant for studying aerosol-cloud interactions which constitute the largest uncertainty in anthropogenic radiative forcing of the climate. The dataset is appropriate for comprehensive aerosol characterization (e.g., closure studies of CCN), model-measurement intercomparison and satellite retrieval method evaluation, among others. Data have been acquired and processed following international recommendations for quality assurance and have undergone multiple stages of quality assessment.

[Long-Term Complete Response in Postoperative Multiple Lung and Mediastinal Lymph Node Metastases of Esophageal Cancer Using Systemic Chemotherapy with DCF Treatment - A Case Report]

A 59-year-old man was diagnosed with advanced thoracic esophageal cancer.He underwent neoadjuvant chemotherapy with cisplatin(CDDP), 5-fluorouracil(5-FU)(CF)followed by transthoracic esophagectomy with three-field lymphadenectomy. Histopathological examination revealed that the tumor was poorly differentiated squamous cell carcinoma invading the adventitia with 6 regional lymph node metastases.Four months after surgery, follow-up thoracic computed tomography (CT)showed multiple lung and mediastinal lymph node metastases.The patient's general condition was favorable, and he underwent systemic chemotherapy with docetaxel, CDDP, 5-FU(DCF).After 2 courses of DCF, chest CT revealed that the lung and mediastinal lymph node metastases had markedly decreased in size to the point of being unmeasurable.After receiving additional chemotherapy consisting of 2 courses of DCF and 8 courses of monthly docetaxel, the patient has been followed up without treatment.No tumor re-recurrence has occurred in the 6 years and 8 months since the first recurrence.In cases of recurrent or unresectable esophageal cancer, the rate of clinical response is reported to be higher for DCF than for CF. DCF is a tolerable regimen, even for postoperative patients, provided that monitoring is conducted for severe adverse events. In patients whose general conditions are favorable, DCF should be considered as a treatment option for recurrent esophageal cancer.

Thermal dissociation cavity attenuated phase shift spectroscopy for continuous measurement of total peroxy and organic nitrates in the clean atmosphere

A thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument was developed for measuring total peroxy nitrates (PNs) and organic nitrates (ONs) concentrations in the clean atmosphere. This instrument is easy to operate and can be applied to continuous measurement of PNs and ONs. A continuously measurable system is convenient to perform observations, especially in remote areas. Three lines (NO2, PNs, and ONs lines) were used for thermal dissociation. The NO2 line contains a quartz tube that is not heated, while the PN and ON lines contain quartz tubes that are heated at 433 K and 633 K, respectively. The concentrations of NO2, NO2 + PNs, and NO2 + PNs + ONs can be obtained from the NO2, PN, and ON lines, respectively. The lower limit values of the detection limit (3σ) for PNs and ONs were estimated to be 21 parts per trillion by volume with an integration time of 2 min. PNs were selectively thermally decomposed in the PNs line and formed NO2 quantitatively. In the ONs line, both PNs and ONs were thermally decomposed to produce NO2 quantitatively, but partial decomposition of HNO3 at 633 K interfered with the ONs measurement. Therefore, a HNO3 scrubber is required before the ONs line. Continuous observations were conducted with the TD-CAPS instrument in a remote area, and the instrument performed well for obtaining PNs and ONs concentrations.

Mineral dust aerosols promote the formation of toxic nitropolycyclic aromatic compounds

Atmospheric nitrated polycyclic aromatic hydrocarbons (NPAHs), which have been shown to have adverse health effects such as carcinogenicity, are formed in part through nitration reactions of their parent polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. However, little is known about heterogeneous nitration rates of PAHs by gaseous NO2 on natural mineral substrates, such as desert dust aerosols. Herein by employing kinetic experiments using a flow reactor and surface analysis by Fourier transform infrared spectroscopy with pyridine adsorption, we demonstrate that the reaction is accelerated on acidic surfaces of mineral dust, particularly on those of clay minerals. In support of this finding, we show that levels of ambient particle-associated NPAHs in Beijing, China, significantly increased during heavy dust storms. These results suggest that mineral dust surface reactions are an unrecognized source of toxic organic chemicals in the atmosphere and that they enhance the toxicity of mineral dust aerosols in urban environments.

[A Case of Abdominal Para-Aortic Lymph Node Recurrence of Gastric Cancer Treated with Radiotherapy, Surviving More Than 5 Years]

A 66-year-old man was diagnosed with advanced type 2 gastric cancer and underwent total gastrectomy. The pathological diagnosis was T3N2H0P0CY0M0, stage ⅢB gastric cancer. Consequently, the patient received adjuvant S-1 therapy for 12 months. Thirty months after the operation, para-aortic lymph node recurrence was evident by computed tomography (CT). As a result, combination chemotherapy with paclitaxel, 5-fluorouracil, and cisplatin was initiated. However, after three courses of chemotherapy, abdominal CT showed progressive disease of the recurrent lymph node. Thereafter, radiotherapy at a total dose of 56 Gy was performed. After the radiotherapy treatment, abdominal CT demonstrated a remarkable reduction of the recurrent lymph node. The patient remains alive, with no signs of relapse, 70 months later. Therefore, this case suggests that radiotherapy may represent an effective treatment for localized remote lymph node recurrence of gastric cancer.

Function of rayon fibers with metallophthalocyanine derivatives: potential of low-molecular weight polycyclic aromatic hydrocarbon removal and Bacillus sp. removal

Polycyclic aromatic hydrocarbons (PAHs) are known as carcinogenic and/or mutagenic substances, and are present at high concentration in polluted environments. It has recently been reported that spore-forming bacteria (e.g., Bacillus spp.) can be transported long distances alive in the atmosphere, which raises the possibility that some of the transported bacteria could have adverse effects on human health. There is thus a need for filters that can remove gaseous PAHs from the air that people breathe and that can inhibit bacterial growth on the filters. We focused on metallophthalocyanine derivatives (M-Pc) which are known to adsorb PAHs as well as to inhibit the growth of bacteria as a potential filtering agent. In this study, we developed different types of M-Pc-supported rayon fibers by changing central metals, functional groups, concentrations of M-Pc and rayon types, and evaluated their removal effects by measuring adsorption rates of 3- and 4-ring PAHs with a HPLC and growth curves of Bacillus sp. with a spectrophotometer. The results showed that both the effects depended on functional groups and concentrations of M-Pc, and rayon types. The most effective combination was observed in Fe-Pc with sulfo group supported on cationized rayon fiber at the concentration of 2 to 3.3 wt%. Central metal species of M-Pc were influenced only on the antibacterial properties. This fiber would be applicable to filtering agents and textiles.

Long-term outcomes of preoperative chemotherapy with modified DCS therapy for highly advanced gastric cancer with distant metastasis

193

Background: Among patients (pts) with advanced gastric cancer (AGC), the poor prognosis was exhibited and many pts died even after R0 resection. The aim of this study is to evaluate the preoperative chemotherapy with docetaxel, cisplatin and S-1 (modified DCS therapy) for treatment in highly AGC with distant metastasis. Methods: A retrospective analysis was performed in 58 pts (man/woman; 49/9, median age; 64.5-years) treated with preoperative modified DCS therapy in our hospital between 2009 and 2012. Eligibility criteria included StageIV AGC with distant metastasis (H1;14, P1;18,CY1;31, LYM;25, PUL;2, OTH;2), a Performance status of 0-2 and no prior chemotherapy. The regimen consisted of docetaxel and cisplatin infusion (35mg/m2, days 1 and 15) and oral administration of S-1 (80mg/m2, days 1-14) every 4 weeks. Surgery was planned 3 to 4 weeks after the chemotherapy. Pathological response was graded according to the JGCA criteria. Almost all pts were treated with S-1 as postoperative adjuvant chemotherapy. Results: The median cycles was 2 (1-13). The incidence of grade 3/4 toxicity was neutropenia 53.4%, anemia 8.6%, anorexia 15.5%, nausea 5.2%, and diarrhea 3.4%. All of these toxicities were well tolerable and there was no TRD. According to RECIST, The overall response rate was 79.3%. Forty-tree pts underwent gastrectomy (R0/R1/R2; 27/8/8), respectively. Postoperative morbidity rate was 20.9% and there was no mortality. Over all 5 years survival rate (5YSR) was 21.4 % and that of R0 was 44.8%, on the other hand 5YSR and MST of chemotherapy alone was 0% and 14.5 month. Pathological response rate (>=1b) was 60.5% and complete response was achieved 1 pts. 5YSR of pathological responders who underwent R0 resection was 81.4% and that of non-responders who underwent even R0 resection was 22.5% (P<0.05). Conclusions: Preoperative modified DCS therapy for AGC was tolerable, and survival benefit of pathological responders with R0 surgery was promising and warrants further investigation.

Surgical treatment in extremely aged patients with gastric cancer

163

Background: Average life expectancy is increased to 82.6-year-old nowadays in Japan, and there is the increase of the number of elderly patients diagnosed with gastric cancer. Methods: From 1991 to 2011, 5330 operations have been performed for patients diagnosed with gastric cancer in our hospital, and 78 patients (1.5%) were over 85-year-old (elder group). To analyze the problems of surgical treatment for the extremely aged patients, the clinic-pathological findings were investigated retrospectively and compared with those in 4494 patients under 75 years old (control group). Results: Median age of elderly group was 86 (85-95) and control group was 63 (19-75). Preoperative morbidity was higher in the elderly group than in control group (73.1% vs 23.2%,p<0.001). The operative prosedures such as local/proximal/distal/total were 9/0/49/20 in elderly group and 216/172/2983/1123 in control group. The ratio of D2/D3 nodal dissection was lower in elderly group than in control group (30.8/0% vs 48.1/5.4%). Operation-time/blood-loss was less invasive in elderly group (135min/70ml vs 165min/100ml,p<0.001), but the postoperative morbidity rate was higher in elderly group (24.4% vs 15.3%,p=0.029). Although the frequency of postoperative complications was similar in surgical field, (14.1% vs 13.1%), other morbidity such as pneumonia, cerebral infarction and renal impairment were more common in elderly group. There was no difference in postoperative hospital stay in two groups (15 days). The ratio of postoperative adjuvant chemotherapy was lower in elderly group (Stage II/III; 10.0/13.3% vs 54.2/67.9%). The best supportive care is highly selected in elderly group in case of recurrence (66.7% vs 11.9%). The overall 5-year survival rate of Stage I/II/III/IV was 70.6/70.0/30.3/0% in elderly group and 92.0/80.0/60.5/13.3% in control group. The ratio of non-cancer death was higher in elderly group (41% vs 14%,p<0.001). Conclusions: The postoperative morbidity and non-cancer death is higher in elderly group. With the restriction for treatment failure, appropriate surgical procedures such as minimally invasive surgery and attentive care for the morbidity would need for the extremely aged patients for their better quality of life.

Prognostic analysis of submucosa-invasive gastric cancer with lymph node metastasis

BACKGROUND

The aims of this study were to identify prognostic factors of patients with submucosa-invasive (T1b) gastric cancer and to verify the validity of adjuvant chemotherapy for this disease.

METHODS

We retrospectively examined the cases of 1,236 consecutive patients in our prospectively maintained database with T1b gastric cancer who underwent gastrectomy in 1995-2012. We used 11 clinicopathologic characteristics to identify prognostic factors by univariate and multivariate analyses. We compared the survival of the 160 node-positive T1b gastric cancer patients with that of 133 patients in the same database who had node-positive muscularis propria-invasive (T2) gastric cancer and had undergone gastrectomy without adjuvant chemotherapy during the same period, as a reference cohort.

RESULTS

The 5-year overall survival rate was 91.4% for all 1,236 patients. Advanced age (hazard ratio [HR] 4.51; 95% confidence interval [CI] 3.26-6.24; P < .01), male sex (HR 2.26; 95% CI 1.56-3.26; P < .01), and the presence of lymph node metastasis (HR 1.89; 95% CI 1.33-2.70; P < .01) were independent prognostic factors. The 5-year overall survival rates were 92.5% in node-negative patients, 84.5% in patients with 1 or 2 metastatic nodes, and 80.1% in patients with 3 or more metastatic nodes (P < .01). The 5-year overall survival rates of the node-positive T1b and T2 gastric cancer patients were 83.6% and 81.2%, respectively (P = .73).

CONCLUSION

The prognosis of node-positive T1b gastric cancer patients after curative gastrectomy was unsatisfactory. Adjuvant chemotherapy should be considered for these patients, especially those with 3 or more metastatic nodes.

Clinical benefit of surgical management for gastric cancer with synchronous liver metastasis

BACKGROUND/AIMS

The aim of this study was to evaluate the benefit of resection for liver metastasis from gastric cancer.

METHODOLOGY

Consecutive 74 patients of gastric cancer who undergone the gastrectomy for primary gastric cancer and simultaneous hepatic resection for synchronous liver metastasis were enrolled. The clinicopathological factors were retrospectively compared to the prognosis.

RESULTS

The median survival time and 5-year overall survival rate in 53 patients who accomplished microscopically negative margin resection was 27.4 months and 18.6%, respectively. In the multivariate survival analysis, the number of liver metastasis was identified as an independent prognostic factor (HR;2.232, 95%CI;1.036-4.808, p=0.04). When the patients undergone curative resection were subdivided into solitary and multiple liver metastasis, the median survival time and 5-year overall survival rate in a subgroup with solitary liver metastasis was 24.2 months and 27.2%, which was superior to the corresponding values of 12.6 months and 5.5% in another group with multiple liver metastasis (p=0.02).

CONCLUSIONS

The resection for liver metastasis might offer a chance for long-term survival in a carefully selected group of patients. The number of liver metastasis was a reliable criterion to discriminate the subgroup of patients who are most likely to benefit from hepatic resection.

Comparison of the surgical treatment strategies for Siewert type II squamous cell carcinoma in the same area as esophagogastric junction carcinoma: data from a single Japanese high-volume cancer center

Purpose

Siewert type II esophagogastric junction adenocarcinoma (ADC) and squamous cell carcinoma (SCC) existing in the same area have distinct clinicopathological characteristics. The objective of this study was to examine differences in the surgical treatment and survival data, according to the histological subtype, in a single high-volume cancer center.

Methods

We retrospectively examined data from a total of 123 patients. Seventy-two patients with Siewert type II ADC and 51 patients with SCC in the same area.

Results

In terms of the clinicopathological factors, the SCC patients had more advanced stage disease and thoracotomy was more frequently performed than in the ADC patients. The 5-year overall survival (OS) rates did not differ significantly between SCC and ADC, regardless of whether or not mediastinal, splenic hilum and para-aortic lymph node dissection was performed. Based on the calculated index for the frequency of nodal metastasis and the five-year OS rate for involvement at each level, only node nos. 1, 2, 3 and 7 had a high index (>5) in both groups. The multivariate Cox regression analysis showed that only age (<65), the pN category and residual tumor classification were independently associated with the outcome.

Conclusions

Differences in the histological type of esophagogastric junction cancer were not independent prognostic factors for survival, and there appears to be a benefit to dissecting the number 1, 2, 3 and 7 lymph nodes.

Significance of surgical treatment in multimodal therapy for stage IV highly advanced gastric cancer

BACKGROUND/AIMS

The purpose of this study was to evaluate the efficacy of surgical treatment following a response to chemotherapy to improve stage IV gastric cancer and to identify the factors contributing to survival benefit.

METHODOLOGY

In total, 148 patients with cStage IV gastric cancer were treated with S-1 and CDDP. We retrospectively evaluated the factors contributing to a survival benefit and the significance of surgical treatment.

RESULTS

The 148 cStage IV patients included 107 males with a median age of 61 years. The overall response rate was 54.7%. After chemotherapy, 97 patients underwent surgery. R0 resection was successfully performed in 51 (52.6%) patients. The overall median survival time (MST) of the patients was 16.8 months, with a 5YSR of 16.4%. The MST of patients who went on to receive surgery was 22.5 months, and the 5YSR was 19.6%. In the multivariate analysis of 97 patients who underwent surgery, R0 resection, lymph node dissection of D2/D3 and obtaining a CR/PR from chemotherapy were the only independently prognostic factors.

CONCLUSIONS

The use of multi-modal treatment, including surgical treatment, at an appropriate time was well tolerated and effective for patients with stage IV gastric cancer.

[Surgical treatment for curable and incurable recurrent gastric cancer]

Recurrent gastric cancer(RGC)after curative resection(R0)is difficult to treat and is often incurable. In such case, patients undergo palliative therapy. However, a small number of patients with RGC can be cured by multimodality therapy. The impact of surgical treatment on patient outcome was studied for each RGC pattern of recurrence. Dissection of GC in combination with lymphadenectomy is a promising treatment strategy for patients with P0CY1 or P1 GC. In contrast, there is no viable treatment option for patients with P2 or P3 GC. A clinical trial is currently ongoing in order to develop new treatment approaches for such patients. In patients presenting with metachronous liver metastasis or para-aortic lymph node(PAN) recurrence, liver resection or PAN dissection are good options and long-term survival is expected if the primary tumor is controlled, if there are no other remote metastases, and if the recurrent lesion is limited. Complete resectability of the tumor is the only significant prognostic factor. In cases where complete resection is not possible, palliative surgery and non-surgical approaches yield similar patient outcomes. In conclusion, RGC is commonly treated with systemic chemotherapy. However, surgery, as part of multimodality therapy, should be considered in cases where complete resection of RGC is achievable.

Ketamine and its isomers have equipotent relaxant effects on tracheal smooth muscle contracted by tachykinins

Recent studies indicate that not only inflammatory cells but also neural mechanisms by which tachykinins such as substance P (SP) and neurokinin A (NKA) are released from vagal afferent C-fiber contribute to asthma. Although ketamine (K) has been used in the anesthetic management of asthmatic patients, the mechanism by which K relaxes the airway smooth muscle is still uncertain, and no information exists on any differential effect of K and its isomers. We determined the spasmolytic effect of racemic [R(±)]K and its isomers S(+) K and R(-) K on SP and NKA-induced contraction of tracheal smooth muscle in guinea pigs. Strips of guinea pig trachea were mounted in an organ bath filled with Tyrode's solution at 37°C bubbled with 95% O2/5% CO2. Strip tension was measured isometrically with a force displacement transducer. Strip contraction was elicited with SP 10(-6) M or NKA 5×10(-7) M.R(±), R(-), or S(+) K (4.5-18.0×10(-4)M) was cumulatively administered into the bath. The calculated ED50 values (the concentration that relaxed the contraction by 50%) of R(±), R(-) and S(+) K were 7.6±0.5, 7.8±0.6, and 7.6±0.5 (10(-4)M), respectively, when the contraction was elicited with SP, and 8.0±1.0, 8.2±1.2, and 7.9±1.3 (10(-4)M), respectively, when NKA was used. We concluded that K and its isomers have equipotent spasmolytic effects on airway smooth muscle precontracted with tachykinins.

Evaluation of jejunal pouch interposition after proximal gastrectomy for early gastric cancer in the upper third of the stomach

BACKGROUND/AIMS

Proximal gastrectomy has two problems, reflux esophagitis and curability. This study evaluates postoperative outcomes focusing on reflux esophagitis and curability of proximal gastrectomy with jejunal pouch interposition for early gastric cancer in the upper third of the stomach.

METHODOLOGY

One hundred and thirty nine patients who underwent jejunal pouch interposition between 1996 and 2011, 10 esophago-gastrostomy and 20 jejunal interposition at our institution were compared retrospectively to examine heart burn and reflux esophagitis. Furthermore, we examined the remote outcomes of jejunal pouch interposition patients.

RESULTS

There were significantly fewer cases of heart burn; the numbers of cases of reflux esophagitis based on endoscopic findings were significantly small in jejunal pouch interposition. Carcinoma of the remnant stomach after jejunal pouch interposition was observed in 9 patients, curative treatment was possible with endoscopic therapy in 6 patients and surgical treatment in 3 patients. There are 119 survivals and 20 deaths at present Death caused primary disease is only 2 patients. Both recurrent patterns were peritoneal metastasis and the histopathological diagnosis was not indicated for proximal gastrectomy.

CONCLUSIONS

Jejunal pouch interposition after proximal gastrectomy for early upper third gastric cancer proves beneficial and favorable modality achieving prevention of reflux esophagitis and high curability.

[An 84-year-old man with highly advanced gastric cancer showing good response after chemotherapy with docetaxel, cisplatin and S-1 combination therapy]

An 84-year-old man had the wall thickness of his stomach accidentally detected by CT scan, and was diagnosed as type 2 advanced gastric cancer with liver and lung metastasis. Chemotherapy with docetaxel, cisplatin and S-1 combination therapy was adopted. Grade 4 neutropenia was revealed, but the treatment could be continued by G-CSF or by down dosing the anticancer agents. By maintaining CR of the primary lesion and PR of the liver and lung metastases, he has been kept at a PS 0 state and has been receiving regular outpatient treatment for 28 months now since the beginning of treatment.

Long-term clinical outcome and survival after pylorus-preserving gastrectomy

BACKGROUND/AIMS

Pylorus-preserving gastrectomy (PPG) was introduced as a function preserving and minimally-invasive surgery for early gastric cancer (ECG). We investigated the long-term clinical and oncological outcomes of the procedure.

METHODOLOGY

A total of 433 patients who underwent PPG between 1993 and 2009 were assessed retrospectively.

RESULTS

The accuracy of the preoperative diagnosis of EGC was 93.1%. The incidence of lymph node metastasis was 3.7%. The median follow-up period was 77 (9-201) months. The overall 5-year survival rate was 96.6%. Three patients with advanced cancer developed recurrence and died. Thirteen patients developed a second primary gastric cancer in the remnant stomach. Four patients were treated by endoscopic resection, and nine underwent gastrectomy all with curative intent. The incidence of regurgitation and gastric-fullness at 5 years after PPG were 6.1% and 1.5%. Endoscopic findings of residual food, gastritis, bile reflex and reflux esophagitis were 19.1%, 11.0%, 3.0%, 10.0%, respectively. The mean relative body weight recovered up to 94.0% of that prior to surgery after 1 year and maintained.

CONCLUSIONS

PPG is a safe operative procedure for patients with EGC. It is important to improve the accuracy of preoperative diagnosis, and patients should be carefully followed-up to detect remnant stomach cancer.

Atomic-resolution imaging in liquid by frequency modulation atomic force microscopy using small cantilevers with megahertz-order resonance frequencies

In this study, we have investigated the performance of liquid-environment FM-AFM with various cantilevers having different dimensions from theoretical and experimental aspects. The results show that reduction of the cantilever dimensions provides improvement in the minimum detectable force as long as the tip height is sufficiently long compared with the width of the cantilever. However, we also found two important issues to be overcome to achieve this theoretically expected performance. The stable photothermal excitation of a small cantilever requires much higher pointing stability of the exciting laser beam than that for a long cantilever. We present a way to satisfy this stringent requirement using a temperature controlled laser diode module and a polarization-maintaining optical fiber. Another issue is associated with the tip. While a small carbon tip formed by electron beam deposition (EBD) is desirable for small cantilevers, we found that an EBD tip is not suitable for atomic-scale applications due to the weak tip-sample interaction. Here we show that the tip-sample interaction can be greatly enhanced by coating the tip with Si. With these improvements, we demonstrate atomic-resolution imaging of mica in liquid using a small cantilever with a megahertz-order resonance frequency. In addition, we experimentally demonstrate the improvement in the minimum detectable force obtained by the small cantilever in measurements of oscillatory hydration forces.

[A case of advanced gastric cancer showing pathological CR after neoadjuvant chemotherapy with docetaxel, cisplatin and S-1 combination]

A 69-year-old man suffering from heart-burn was referred to our hospital, and diagnosed as type 3 advanced gastric cancer with lymph node metastasis. Neoadjuvant chemotherapy (NAC) with docetaxel, cisplatin and S-1 was attempted. After two courses of chemotherapy were completed, distal gastrectomy with D2 lymphadenectomy was performed. Pathologically, there were no viable cancer cells remaining in the primary lesion and lymph nodes. The pathological response of NAC was judged to be grade 3. The postoperative course was uneventful, and the patient is currently visiting our outpatient clinic for treatment with S-1 as postoperative adjuvant chemotherapy.

[Treatment strategy for marginally resectable gastric cancer]

It has been postulated that preoperative chemotherapy might promote tumor regression, eradicate nodal metastases, and improve resectability in patients with marginally resectable gastric cancer.For a marginally resectable tumor of gastric cancer, we selected the advanced gastric cancer patients with metastases and recurrences to the abdominal para-aortic lymph node (PAN), liver and invasion to the pancreas head and/or the duodenum.Patients with positive peritoneal cytology(P0, CY1)or localized peritoneal metastasis(P1), and Stage IV gastric cancer patients, were also considered candidates in this category. The strategy and results of surgical treatment for marginally resectable gastric cancer were explained as the dissection of PAN, hepatic resection, pancreaticoduodenectomy, perioperative chemotherapy for P0CY1 or P1, and neoadjuvant chemotherapy for Stage IV gastric cancer, which was still considered an experimental approach, although its use may be justified in unresectable or marginally resectable GC.The result of the resection of a marginally resectable gastric cancer is poor, but when there are no other non-curative factors, extended surgical resection should be performed because complete response is difficult at present with chemotherapy alone.In conclusion, there was no evidence suggesting that extended surgical procedures are effective, but a strategy of multidisciplinary treatment including extended surgical approach should be verified based on randomized controlled trials.

Pedunculated gastric tube interposition in an esophageal cancer patient with prepyloric adenocarcinoma

Gastric carcinoma is one of the malignancies that are most frequently associated with esophageal carcinoma. We describe herein our device for advanced esophageal cancer associated with early gastric cancer in the antrum. A 57-year-old man presenting with dysphagia and upper abdominal pain was admitted to our hospital. Preoperative examinations revealed locally advanced squamous cell carcinoma (SCC) of the middle thoracic esophagus (T3N0M0 Stage IIA) and mucosal signet-ring cell carcinoma of the gastric antrum (T1N0M0 Stage IA). Although the gastric tumor appeared to be an intramucosal carcinoma, its margin was obscure, so endoscopic en-bloc resection was considered inadequate. We chose surgical resection of the gastric tumor as well as the esophageal SCC after neoadjuvant chemotherapy with 5-fluorouracil and cisplatin for advanced esophageal cancer. Following transthoracic esophagectomy with three-field lymph node dissection, the gastric carcinoma was removed by gastric antrectomy, which preserved the right gastroepiploic vessels, and a pedunculated short gastric tube was used as the esophageal substitute. Twenty-eight months after the surgery, the patient is well with no evidence of cancer recurrence. Because it minimizes surgical stress and organ sacrifice, gastric tube interposition is a potentially useful technique for esophageal cancer associated with localized early gastric cancer.

Phase II study of weekly paclitaxel following fixed three cycles of S-1-based chemotherapy for advanced gastric cancer

BACKGROUND/AIMS

Awareness of the clinical importance of second-line chemotherapy for incurable gastric cancer has been increasing. To assess the clinical validity of the new concept that second-line chemotherapy following predetermined cycles of first-line chemotherapy would improve survival, we conducted a phase II study.

METHODOLOGY

Patients with pathologically proven incurable gastric adenocarcinoma and adequate organ functions were enrolled. S-1 or S-1 plus cisplatin was administered as first-line chemotherapy. The number of cycles of S-1-based chemotherapy was determined to be three as a maximum unless there was disease progression. The treatment was followed by weekly administration of paclitaxel. The primary endpoint was overall survival and the secondary endpoints were progression-free survival and safety.

RESULTS

Thirty-seven patients were eligible for enrollment. Twenty-eight patients (76%) underwent the second-line chemotherapy with paclitaxel after completion of S-1-based chemotherapy or disease progression. Treatment-related grade 3 or 4 toxicity was noted in 14 patients during S-1-based chemotherapy, and in 6 patients during paclitaxel treatment. The median survival time was 455 days and the median progression-free survival was 229 days.

CONCLUSIONS

Sequential set chemotherapy with three cycles of S-1-based chemotherapy followed by weekly paclitaxel is feasible. The survival results are equivalent to those of other current regimens using S-1.