Secure Robotic Transthoracic Valvuloplastic Esophagogastrostomy by Double Flap Technique in Esophagogastric Junctional Cancer Surgery

Valvuloplastic esophagogastrostomy by the double flap technique (VPEG-DFT) after proximal gastrectomy for early proximal gastric cancer or esophagogastric junctional cancer (EGJC) is a promising procedure to prevent reflux. However, the transhiatal procedure alone for alimentary reconstruction is sometimes too complex because of the short esophageal remnant. Therefore, additional transthoracic procedures are needed in some patients with EGJC. Although additional thoracoscopic surgery has been reported, no reports to date have described robotic transthoracic VPEG-DFT after excision of EGJC. We herein describe the secure robotic techniques of transthoracic VPEG-DFT performed in 3 patients with EGJC. After completion of the abdominal procedures by robotic and extracorporeal creation of H -shaped flaps on the gastric remnant, robotic VPEG-DFT through the right thoracic approach was performed in the prone position. To accomplish VPEG-DFT in the thorax of patients in the prone position, fixation of the esophagus and stomach was performed before the rotation of the 2 organs to expose the planned anastomotic aspect. In addition, the final abdominal phase was required again to prevent a postoperative hiatal hernia. Secure techniques of right transthoracic VPEG-DFT by robotic surgery could contribute to the successful treatment of EGJC when the remnant esophagus is too short.

Disturbed passage of jejunal limb near esophageal hiatus after overlapped esophagojejunostomy following laparoscopic total gastrectomy

BACKGROUND

Overlapped esophagojejunostomy (OEJ) is a secure purely laparoscopic reconstruction after laparoscopic total gastrectomy (LTG). However, long-term surgical results have not been documented well.

AIM

In this paper, we report unusual patients who manifested jejunal limb stricture near the esophageal hiatus without anastomotic stenosis during long-term observation after surgery.

METHODS

From April 2009 until May 2020, we retrospectively reviewed 211 patients underwent LTG following by OEJ for gastric carcinoma and took a standard surveillance program. We aimed to characterize a novel complicated disorder observed in these patients to assist treatment and prevention.

RESULTS

Five patients (2.4%) had unusual jejunal limb stricture after LTG and OEJ, occurring at a mean of 10 mo after initial radical LTG. All five patients had disturbed oral intake and marked weight loss, and two had aspiration pneumonia. Various diagnostic modalities and intraoperative findings in each patient revealed an intact anastomosis, bent or tortuous jejunal limb resulting from loose fibrous adhesions on the left crus at the esophageal hiatus and no cancer recurrence. All five patients were successfully treated by reoperation for adhesiolysis, division of the left crus and rearrangement of the jejunal limb.

CONCLUSION

Disturbed passage through the jejunal limb near the hiatus can occur after some types of OEJ following LTG. We speculate that it may result from a short remnant esophagus, excessive mobilization of the jejunal limb that permits bending or tortuosity and adhesions on the left crus at the hiatus. Prevention for this complication is possible during the original LTG procedure.

Initial Learning Curve and Stereotypical Use of Extra Arm During da Vinci Chest Procedures of McKeown Esophagectomy

Objective: McKeown esophagectomy facilitates extensive lymphadenectomy for the optimal management of esophageal cancer. Robot-assisted esophagectomy (RAE) was introduced in an attempt to reduce the incidence of postoperative complications. The da Vinci System has 3 active robotic arms in addition to the camera scope, and an extra robotic arm (ERA) is generally used to maintain a fine and stable operative field. However, the optimal use of an ERA has not been documented. In addition, the learning curve of the RAE using the da Vinci System remains controversial. In this study, we aimed to determine the optimal use of an ERA in association with the initial learning curve of robotic McKeown esophagectomy with extremely extensive lymphadenectomy. Methods: We reviewed 81 consecutive patients who underwent RAE. To determine whether stereotypical use of an ERA after establishment of its optimal use accounted for the learning curve, we measured the duration of 14 steps and the duration when performed with optimal use of an ERA in the corresponding step by reviewing video-recorded procedures. We then calculated the ratio as the degree of stereotypical use of the ERA during the da Vinci chest procedures. Results: The cumulative sum method showed that the learning curve required 27 cases of RAE. In addition, stereotypical use of the ERA was significantly associated with the learning curve of RAE. Conclusions: Establishment of optimal use of an ERA could help to accelerate the learning curve in da Vinci chest procedures during McKeown esophagectomy with extensive lymphadenectomy.

Safe implementation of robotic gastrectomy for gastric cancer under the requirements for universal health insurance coverage: a retrospective cohort study using a nationwide registry database in Japan

BACKGROUND

Robotic gastrectomy (RG) has increased since being covered by universal health insurance in 2018. However, to ensure patient safety the operating surgeon and facility must meet specific requirements. We aimed to determine whether RG has been safely implemented under the requirements for universal health insurance in Japan.

METHODS

Data of consecutive patients with primary gastric cancer who underwent minimally invasive total or distal gastrectomy-performed by a surgeon certified by the Japan Society for Endoscopic Surgery (JSES) endoscopic surgical skill qualification system (ESSQS) between October 2018 and December 2019-were extracted from the gastrointestinal surgery section of the National Clinical Database (NCD). The primary outcome was morbidity over Clavien-Dindo classification grade IIIa. Patient demographics and hospital volume were matched between RG and laparoscopic gastrectomy (LG) using propensity score-matched analysis (PSM), and the short-term outcomes of RG and LG were compared.

RESULTS

After PSM, 2671 patients who underwent RG and 2671 who underwent LG were retrieved (from a total of 9881), and the standardized difference of all the confounding factors reduced to 0.07 or less. Morbidity rates did not differ between the RG and LG patients (RG, 4.9% vs. LG, 3.9%; p = 0.084). No difference was observed in 30-day mortality (RG, 0.2% vs. LG, 0.1%; p = 0.754). The reoperation rate was greater following RG (RG, 2.2% vs. LG, 1.2%; p = 0.004); however, the duration of postoperative hospitalization was shorter (RG, 10 [8-13] days vs. LG, 11 [9-14] days; p < 0.001).

CONCLUSIONS

Insurance-covered RG has been safely implemented nationwide.

Low-dose DNA demethylating therapy induces reprogramming of diverse cancer-related pathways at the single-cell level

BACKGROUND

Epigenetic reprogramming using DNA demethylating drugs is a promising approach for cancer therapy, but its efficacy is highly dependent on the dosing regimen. Low-dose treatment for a prolonged period shows a remarkable therapeutic efficacy, despite its small demethylating effect. Here, we aimed to explore the mechanisms of how such low-dose treatment shows this remarkable efficacy by focusing on epigenetic reprograming at the single-cell level.

METHODS

Expression profiles in HCT116 cells treated with decitabine (DAC) were analyzed by single-cell RNA-sequencing (scRNA-seq). Functional consequences and DNA demethylation at the single-cell level were analyzed using cloned HCT116 cells after DAC treatment.

RESULTS

scRNA-seq revealed that DAC-treated cells had highly diverse expression profiles at the single-cell level, and tumor-suppressor genes, endogenous retroviruses, and interferon-stimulated genes were upregulated in random fractions of cells. DNA methylation analysis of cloned HCT116 cells revealed that, while only partial reduction of DNA methylation levels was observed in bulk cells, complete demethylation of specific cancer-related genes, such as cell cycle regulation, WNT pathway, p53 pathway, and TGF-β pathway, was observed, depending upon clones. Functionally, a clone with complete demethylation of CDKN2A (p16) had a larger fraction of cells with tetraploid than parental cells, indicating induction of cellular senescence due to normalization of cell cycle regulation.

CONCLUSIONS

Epigenetic reprogramming of specific cancer-related pathways at the single-cell level is likely to underlie the remarkable efficacy of low-dose DNA demethylating therapy.

Postoperative hiatal hernia after minimally invasive esophagectomy for esophageal cancer

Background

Minimally invasive esophagectomy (MIE) can reduce various complications compared with conventional thoracotomic esophagectomy. However, several reports suggested that MIE promoted incidence of post-operative hiatal hernia (HH). In current reports, we retrospectively analyzed incidence and risk factors of HH development after MIE.

Methods

A total of 113 patients undergoing MIE (McKeown esophagectomy) at our institute from April 2009 to December 2015 were included in this study. Patients with clinical stage II and III received neoadjuvant chemotherapy (NAC).

Results

Eleven of 113 patients (9.7%) undergoing MIE developed HH. Four of them were female and the ratio of female among the patient with HH was higher than that among the patient without HH after MIE (36.4% vs. 13.7%, P=0.05). Sixty-six patients (58.4%) during the study period were administered NAC and 10 of 11 patients with HH (90.9%) received NAC according to the clinical stage, which was significantly more than in the non-HH group (P=0.02). Type and route of graft organ were not related to HH development. Moreover, the fixation of the conduit organ at the hiatus does not contribute to post-operative HH.

Conclusions

In the current study, we showed that NAC was a major risk factor of HH development after MIE.

Abstract 838: Epigenetic reprogramming of different cancer-related pathways at the single cell level after low-dose DNA demethylation therapy

The efficacy of DNA demethylation therapy is highly dependent on the dosing regimen. Administration of a drug at a dose much lower than the maximum tolerated dose (MTD) for a prolonged period shows a high therapeutic efficacy, despite its small demethylating effect. However, the mechanisms underlying the high therapeutic efficacy of low-dose treatment are still unclear. In this study, we aimed to reveal the mechanisms by analyzing decitabine (DAC)-treated individual cancer cells. To reveal the epigenetic reprogramming at the single cell level and its functional consequences, individual DAC-treated HCT116 cells (H3 clones) were cloned from DAC-treated bulk HCT116 cells. Genome-wide DNA methylation was analyzed using InfiniumHuman450 beadChip. In bulk cells, only partial reduction of DNA methylation levels was observed, and no genes were completely demethylated. In contrast, in cloned cells, a much larger reduction of DNA methylation levels was observed, depending upon genes. Promoter CpG islands of 233-470 genes of 1,188 hypermethylated genes in HCT116 were completely demethylated (Δβ ≥ 0.6) in some of the clones analyzed. Demethylated genes were highly variable among individual clones, and different cancer-related genes, such as those involved in the p53 pathway, WNT pathway, and cell cycle regulation, were completely demethylated, depending upon clones. For example, CDKN2A (p16) was completely demethylated only in a H3-32 clone, and this clone showed slower cell growth rate (14.6% of untreated cells), and aneuploid cells were detected possibly due to cellular senescence. These results showed that epigenetic reprogramming at the single cell level involves diverse cancer-related pathways, and this mechanism is likely to underlie the high efficacy of low-dose DNA demethylation therapy.

Citation Format: Hideyuki Takeshima, Yukie Yoda, Naoko Watanabe, Mika Wakabayashi, Toshikazu Ushijima. Epigenetic reprogramming of different cancer-related pathways at the single cell level after low-dose DNA demethylation therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 838.

Erratum: Structural and Valence Changes of Europium Hydride Induced by Application of High-Pressure H_{2} [Phys. Rev. Lett. 107, 025501 (2011)]

This corrects the article DOI: 10.1103/PhysRevLett.107.025501.

Formalin fixation on HER-2 and PD-L1 expression in gastric cancer: A pilot analysis using the same surgical specimens with different fixation times

BACKGROUND

The needs for human epidermal growth factor receptor 2 (HER-2) and/or programmed death-ligand 1 (PD-L1) evaluations in gastric cancer are dramatically increasing. Although the importance of standardization of sample fixation has been widely recognized, most of the evidence regarding the fixation duration or type of fixing solution are based on breast cancer.

AIM

To investigate the real effects of fixation conditions on HER-2 testing or PD-L1 testing for gastric cancer using gastrectomy specimens.

METHODS

Thirty-two patients who underwent gastrectomy for gastric cancer were enrolled. Their resected specimens were each divided into four pieces and fixed in four strictly controlled different durations (6 h, 24 h, and 48 h, and 1 wk) by 10% formalin (n = 22) or 10% neutral buffered formalin (NBF) (n = 10). Immunohistochemistry (IHC) of HER-2 and PD-1 was performed, and a pathology examination was conducted. In the HER-2-immunoreactive cases, all four specimens were subjected to dual-color in situ hybridization (DISH). Five cases were assessed as HER-2-positive by IHC and DISH. We used the cut-off values of 1%, 10%, and 50% to assess the IHC findings of PD-L1.

RESULTS

No significant difference was observed in comparisons between the shorter fixation period groups (6 h, 24 h, and 48 h) and the prolonged fixation period (1 wk) group in the HER-2 and PD-L1 analyses. Although no significant difference was observed between 10% formalin and 10% NBF within 1 wk of fixation, the superiority of 10% NBF was confirmed in a long-term (> 3 mo) fixation in both the HER-2 and PD-L1 analyses.

CONCLUSION

In this small-numbered pilot study, prolonged fixation within 1 wk showed no inferiority in HER-2 or PD-L1 testing. However, a large-numbered prospective study is needed to obtain conclusive results.

Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city

Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM_2.5 ) and coarse (PM_10-2.5 ) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM_2.5 than in PM_10-2.5 . In both PM_2.5 and PM_10-2.5 , indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R² =0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM_2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM_10-2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations.

Fast x-ray detector system with simultaneous measurement of timing and energy for a single photon

We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The system is able to acquire both timing and energy of a single X-ray photon simultaneously in a high rate condition, 10⁶ counts per second for one Si-APD. The performance of the system was investigated in SPring-8, a synchrotron radiation facility in Japan. Good time resolution of 120 ps (FWHM) was achieved with a slight tail distribution in the time spectrum by a level of 10^-9 at 1 ns apart from the peak. Using this system, we successfully observed the NRS from the 26.27-keV level of mercury-201, which has a half-life of 630(50) ps. We also demonstrated the reduction of background events caused by radioactive decays in a radioactive sample by discriminating photon energy.

Survival outcomes of 220 consecutive patients with three-staged thoracoscopic esophagectomy

Patients with thoracic esophageal cancer are often treated by minimally invasive esophagectomy. However, the long-term survival benefits of minimally invasive esophagectomy remain unclear. Two approaches are available for thoracoscopic surgery: one with the patient in the left lateral decubitus position (LLDP), and the other with the patient in the prone position (PP). We investigated the survival benefit of thoracoscopic esophagectomy according to the tumor stage and patient position during the thoracoscopic procedure. We reviewed the records of 220 consecutive patients with esophageal cancer treated from 1998 to 2012. In total, 146 and 74 patients were treated with thoracoscopic esophagectomy in the LLDP and PP, respectively. No patients were initially proposed to be candidates for esophagectomy by thoracotomy during the study period. Data collection was performed with a focus on survival and recurrent disease. Among all the 220 patients, the overall 5-year survival rates were 83.7%, 74.1%, 45.5%, 78.6%, 44.2%, 29.4% and 24.3% in the patients with pStage IA, IB, IIA, IIB, IIIA, IIIB and IIIC disease, respectively. Despite the greater number of dissected mediastinal lymph nodes in the PP procedure, there were no significant differences in the survival curves between the LLDP and PP procedures. The long-term results of thoracoscopic esophagectomy are comparable and acceptable. The PP procedure was not confirmed to offer a superior survival benefit to the LLDP procedure in this retrospective study.

Repeated changes of the molecular subtype in gastric metastasis from breast cancer: A case report

Gastric metastasis from breast cancer is clinically diagnosed rarely. The present study described an interesting and valuable case of gastric metastasis from breast cancer, which showed repeated changes of the molecular subtype with an impact on the choice of treatment. A 42-year-old woman underwent mastectomy with axillary lymph node dissection for an invasive lobular carcinoma of the left breast. The patient received gastroscopy due to an epigastric pain during the adjuvant chemotherapy. The endoscopic examination revealed an erosive lesion at the posterior wall of the gastric body. The gastric lesion was immunohistochemically diagnosed as a metastatic disease from the breast cancer. The patient initially received hormone therapy, according to the subtype of the primary and the metastatic diseases. The gastric lesion initially disappeared; however, a relapsed lesion transformed into luminal human epidermal growth factor receptor 2 type from luminal type. Subsequently, the metastatic lesions underwent repeated subtype changing, which created difficultly when deciding the treatment strategy. The molecular profile of breast cancer can change during the treatment, resulting in the treatment resistance observed in certain cases. Therefore, the optimal treatment must be selected, according to the changed subtype.

Relationship between fibrinopeptide a (FPA) level and fibrinogen kinetics in patients with malignant disease

The relationship between FPA level and fibrinogen turnover rate as well as fibrinolytic activity was studied in 18 patients with malignant diseases. It was found that the FPA levels were significantly elevated and were correlated with fibrinogen turnover rate (r = 0.74, p less than 0.001) and FDP (r = 0.58, p less than 0.02). The estimated FPA turnover rate was also correlated with fibrinogen turnover rate (r = 0.70, p less than 0.001). These results suggest that fibrinogen catabolism in patients with malignant disease is related to thrombin proteolysis. However, ratios of 1/2 FPA turnover rate to fibrinogen turnover rate suggest that intravascular thrombin proteolysis is not the major determinant of fibrinogen catabolism. It is suspected that extravascular thrombin proteolysis is responsible for the elevation of plasma FPA level which is correlated with acceleration of fibrinogen catabolism.

Stroboscopic detection of nuclear resonance in an arbitrary scattering channel

The theory of heterodyne/stroboscopic detection of nuclear resonance scattering is developed, starting from the total scattering matrix as a product of the matrix of the reference sample and the sample under study. This general approach holds for all dynamical scattering channels. In the forward channel, which has been discussed in detail in the literature, the electronic scattering manifests itself only in an energy-independent diminution of the scattered intensity. In all other channels, complex resonance line shapes of the heterodyne/stroboscopic spectra are encountered, as a result of the interference of electronic and nuclear scattering. The grazing-incidence case will be evaluated and described in detail. Experimental data of classical X-ray reflectivity and their stroboscopically detected resonant counterpart spectra on the [(nat)Fe/(57)Fe]10 isotope periodic multilayer and antiferromagnetic [(57)Fe/Cr]20 superlattice are fitted simultaneously.

Integrated analysis of cancer-related pathways affected by genetic and epigenetic alterations in gastric cancer

BACKGROUND

The profiles of genetic and epigenetic alterations in cancer-related pathways are considered to be useful for selection of patients likely to respond to specific drugs, including molecular-targeted and epigenetic drugs. In this study, we aimed to characterize such profiles in gastric cancers (GCs).

METHODS

Genetic alterations of 55 cancer-related genes were analyzed by a benchtop next-generation sequencer. DNA methylation statuses were analyzed by a bead array with 485,512 probes.

RESULTS

The WNT pathway was activated by mutations of CTNNB1 in 2 GCs and potentially by aberrant methylation of its negative regulators, such as DKK3, NKD1, and SFRP1, in 49 GCs. The AKT/mTOR pathway was activated by mutations of PIK3CA and PTPN11 in 4 GCs. The MAPK pathway was activated by mutations and gene amplifications of ERBB2, FLT3, and KRAS in 11 GCs. Cell-cycle regulation was affected by aberrant methylation of CDKN2A and CHFR in 13 GCs. Mismatch repair was affected by a mutation of MLH1 in 1 GC and by aberrant methylation of MLH1 in 2 GCs. The p53 pathway was inactivated by mutations of TP53 in 19 GCs and potentially by aberrant methylation of its downstream genes in 38 GCs. Cell adhesion was affected by mutations of CDH1 in 2 GCs.

CONCLUSIONS

Genes involved in cancer-related pathways were more frequently affected by epigenetic alterations than by genetic alterations. The profiles of genetic and epigenetic alterations are expected to be useful for selection of the patients who are likely to benefit from specific drugs.

Nuclear resonant scattering measurements on (57)Fe by multichannel scaling with a 64-pixel silicon avalanche photodiode linear-array detector

We developed a silicon avalanche photodiode (Si-APD) linear-array detector for use in nuclear resonant scattering experiments using synchrotron X-rays. The Si-APD linear array consists of 64 pixels (pixel size: 100 × 200 μm(2)) with a pixel pitch of 150 μm and depletion depth of 10 μm. An ultrafast frontend circuit allows the X-ray detector to obtain a high output rate of >10(7) cps per pixel. High-performance integrated circuits achieve multichannel scaling over 1024 continuous time bins with a 1 ns resolution for each pixel without dead time. The multichannel scaling method enabled us to record a time spectrum of the 14.4 keV nuclear radiation at each pixel with a time resolution of 1.4 ns (FWHM). This method was successfully applied to nuclear forward scattering and nuclear small-angle scattering on (57)Fe.

Oxidation states and quality of upper interfaces in magnetic tunnel junctions: oxygen effect on crystallization of interfaces

In this study, we have deposited an 57Fe sensor layer at the upper interface, i.e. the interface between the oxide barrier and the upper electrode in selected magnetic tunnel junctions (MTJs), in order to perform nuclear resonant scattering with the aim of obtaining direct information on the magnetic properties and quality of this interface. This is a unique approach as it makes use of this powerful technique to give information at the atomic level, and specifically from the interface where the sensor layer is deposited. By varying sample tunnel barrier thicknesses and oxidation times in the preparation of this barrier, we have observed that longer oxidation time results in not only an increase of the magnetic hyperfine fields, but also causes an interesting crystallization and smoothing of the interface. We also observed that boron atoms diffuse away from the lower part of the upper FeCoB electrode toward the capping layer. An important observation, which has a crucial effect in tunnel magnetoresistance values, is the absence of any magnetically dead FeO layer at the interface. Another finding is that the deposition of Fe on MgO is much smoother than the deposition of MgO on Fe.

Relationship between psychological factors and arthralgia in patients with rheumatoid arthritis

Abstract Various factors were assessed in terms of their contribution to arthralgia in a rheumatoid arthritis patient. Eighty-two outpatients (62 women and 20 men) with rheumatoid arthritis (RA) were examined with respect to the subjective degree of arthralgia, age, disease duration, dysfunction, steroid dose, steroid period, depression, anxiety, extroversion, neurotic disorder, and number of caretakers. The results were explained on the basis of stepwise regression analysis and psychological and clinical data. We analyzed results of a correlation coefficient test on the mutual relationship between variables. Stepwise regression analysis was performed to assess factors of arthralgia in terms of "depression," "mean activity," "morning stiffness," and "steroid dose." Depression is a factor of arthralgia as shown in this study, but it is clear that other factors are also involved. Anxiety was a factor distinct from the activity of RA. The factor contributing most to arthralgia was found to be depression, whereas anxiety had no effect.

Radial incision and cutting method for refractory stricture after nonsurgical treatment of esophageal cancer

Strictures remaining after nonsurgical treatment for esophageal cancer are generally more refractory to endoscopic balloon dilation (EBD) when compared with anastomotic strictures. The aim of the present study was to evaluate the efficacy and safety of a radial incision and cutting (RIC) method for the treatment of refractory strictures after nonsurgical treatment of esophageal cancer. All subjects complained of grade 2 or worse dysphagia, even after at least 10 sessions of EBD. Between August 2009 and May 2012, eight consecutive patients with refractory esophageal stricture after nonsurgical treatments, including chemoradiotherapy (CRT) alone (n = 3), CRT followed by salvage endoscopic treatment (n = 3), or endoscopic submucosal dissection (ESD; n = 2), underwent the RIC procedure. After the RIC procedure, dysphagia in all the patients dramatically improved to grade 1 or 0 without any major complications; however, the long-term efficacy was unfavorable as only 37.5 % (3 /8) demonstrated adequate lumen patency at 3 months, and re-intervention was necessary in six patients (75 %).

Oxidation states and the quality of lower interfaces in magnetic tunnel junctions: oxygen effect on crystallization of interfaces

Lower interfaces in magnetic tunnel junctions (MTJs), which are the basic components in many spintronic devices such as magnetoresistive random access memories, have crucial effects on the performance of these devices. To obtain more insight into such interfaces, we have introduced an ultrathin sensor layer of (57)Fe at the interface between the lower electrode and the oxide barrier in selected MTJs. This allowed us to perform nuclear resonant scattering measurements, which provide direct information on the magnetic properties and quality of the interfaces. The application of nuclear resonant scattering to study interfaces in MTJs is a unique approach in the sense that it gives information at the atomic level, and specifically from the interface where the sensor layer is deposited. Samples with different tunnel barrier thicknesses and varied oxidation times in the preparation of this barrier have been studied. These show that oxidation can not only increase the magnetic hyperfine fields but also cause an interesting smoothing and crystallizing of the interface. Another interesting finding is the observation of boron diffusion into the lower part of the FeCoB lower electrode towards the Ta seed layer.

Comprehensive DNA methylation and extensive mutation analyses reveal an association between the CpG island methylator phenotype and oncogenic mutations in gastric cancers

Recent development of personal sequencers for extensive mutation analysis and bead array technology for comprehensive DNA methylation analysis have made it possible to obtain integrated pictures of genetic and epigenetic alterations on the same set of cancer samples. Here, we aimed to establish such pictures of gastric cancers (GCs). Comprehensive methylation analysis of 30 GCs revealed that the number of aberrantly methylated genes was highly variable among individual GCs. Extensive mutation analysis of 55 known cancer-related genes revealed that 19 of the 30 GCs had 24 somatic mutations of eight different genes (CDH1, CTNNB1, ERBB2, KRAS, MLH1, PIK3CA, SMARCB1, and TP53). Integration of information on the genetic and epigenetic alterations revealed that the GCs with the CpG island methylator phenotype (CIMP) tended to have mutations of oncogenes, CTNNB1, ERBB2, KRAS, and PIK3CA. This is one of the first studies in which both genetic and epigenetic alterations were extensively analyzed in the same set of samples. It was also demonstrated for the first time in GCs that the CIMP was associated with oncogene mutations.

Structural and valence changes of europium hydride induced by application of high-pressure H₂

Europium hydride EuH(x), when exposed to high-pressure H₂, has been found to exhibit the following structural and valence changes: Pnma(x = 2, divalent) → P6₃/mmc(x = 2, 7.2-8.7 GPa) → I4/m(x > 2, 8.7-9.7 GPa) → I4/mmm(x > 2, 9.7 GPa-,trivalent). With a trivalent character and a distorted cubic fcc structure, the I4/mmm structure is the β phase commonly observed for other rare-earth metal hydrides. Our study clearly demonstrates that EuH(x) is no longer an irregular member of the rare-earth metal hydrides.

Prevention by lansoprazole, a proton pump inhibitor, of indomethacin -induced small intestinal ulceration in rats through induction of heme oxygenase-1

The effect of lansoprazole, a proton pump inhibitor (PPI), on indomethacin-induced small intestinal ulceration was examined in rats, particularly in relation to heme oxygenase (HO)-1. The animals were administered indomethacin (10 mg/kg, p.o.) and killed 24 h later. Lansoprazole (30-100 mg/kg, p.o.) and omeprazole (30-100 mg/kg, p.o.) were given 30 min before the administration of indomethacin, while tin-protoporphyrin IX (SnPP: 30 mg/kg, i.v.), an inhibitor of HO-1, was injected 10 min before indomethacin or lansoprazole. Indomethacin produced hemorrhagic lesions in the small intestine, accompanied with an increase of mucosal invasion of enterobacteria, inducible nitric oxide synthase (iNOS) expression, and myeloperoxidase (MPO) activity in the mucosa. Pretreatment with lansoprazole dose- dependently reduced the severity of the indomethacin-induced intestinal lesions, with suppression of the increased MPO activity, while omeprazole had no effect. Pretreatment with SnPP significantly exacerbated these intestinal lesions and almost totally abolished the protective effect of lansoprazole. The up-regulation of iNOS mRNA expression following indomethacin was suppressed by lansoprazole in a SnPP-inhibitable manner, although the enhanced enterobacterial invasion remained unaffected. The amount of HO-1 protein in the intestinal mucosa was significantly increased by lansoprazole but not by omeprazole. Prior administration of carbon monoxide (CO)-releasing molecule-2 (CORM-2; 10 mg/kg, i.p.) significantly reduced the severity of these lesions and the enhancement of mucosal iNOS mRNA expression induced in the small intestine by indomethacin. These results suggest that lansoprazole prevents indomethacin-induced small intestinal ulceration, and this effect is associated with inhibition of iNOS expression, through up-regulation of HO-1/CO production in the mucosa.

Endoscopic submucosal dissection allows less-invasive curative resection for gastric tube cancer after esophagectomy - a case series

Detection of early gastric tube cancers (GTCs) has increased with more detailed surveillance endoscopy using indigo carmine dye following esophagectomy. This retrospective study clarified the clinicopathological features and application of endoscopic submucosal dissection (ESD) for GTCs. Data collected for eight GTCs treated by ESD included clinical and pathological features and outcomes following ESD. Overall, eight GTCs were identified in seven (6.3 %) of 112 patients who underwent esophagectomy and gastric tube reconstruction. Almost all lesions were macroscopically type 0-IIa with mucosal to submucosal invasion, and seven GTCs were successfully resected en bloc by ESD. Submucosal invasion to > 500 microm was observed in one case with associated delayed perforation that was treated conservatively. No local recurrences of GTCs were observed. Detailed surveillance endoscopy using indigo carmine dye appears useful for diagnosing early-stage GTC. Furthermore ESD represents a feasible alternative to conventional endoscopic mucosal resection as a minimally invasive therapy for early-stage GTC.

Ethanol injection for ablation of an intractable digestive tract fistula: report of a case

We successfully occluded an intractable digestive tract fistula by injecting it with absolute ethanol after all other treatments failed. A 48-year-old man suffered from a complex and relapsing digestive tract fistula after curative surgery for advanced colon cancer invading the pancreas and duodenum. After conservative management by fasting, drainage, and irrigation failed, fibrin glue infusion achieved only transient occlusion. We performed surgical repair and he was discharged from hospital, at which time fistulography showed no fistula. However, 1 month later fistulography showed that the fistula had recurred and involved the transverse colon, stomach, and intrahepatic bile duct via the jejunum. Finally, we gave five injections of absolute ethanol into the fistula, which resulted in complete occlusion within 6 months. Considering its clinical efficacy, safety, and cost efficiency, we think that ethanol sclerotherapy is a feasible treatment for intractable digestive tract fistula when conservative therapy fails.

Iliac lymph node metastasis of an unknown primary tumor: report of a case

Metastasis to the lymph nodes around the iliac vessels from cancer of an unknown primary (CUP) tumor has not yet been reported in either the English or Japanese literature and it is therefore described herein for the first time. The patient was a 70-year-old woman with persistent right leg edema. Computed tomography (CT) displayed a mass around the iliac vessels while physical, laboratory, and other imaging examination did not show any other tumor. Preoperatively diagnosed as a retroperitoneal tumor, the patient underwent a tumor resection, but a histopathological examination revealed the tumor to be poorly differentiated squamous cell carcinoma. Only residual lymph nodes in the pelvis were detected by postoperative fluorine-18 fluorodeoxyglucose-positron emission tomography. Neither a primary lesion nor any signs of recurrence were demonstrated for 13 months after radiotherapy for the residual nodes. We herein discuss the diagnosis, treatment, and follow-up of this less common CUP.

Normal Mode Analysis of Pyrococcus furiosus Rubredoxin via Nuclear Resonance Vibrational Spectroscopy (NRVS) and Resonance Raman Spectroscopy

We have used (57)Fe nuclear resonance vibrational spectroscopy (NRVS) to study the Fe(S(cys))(4) site in reduced and oxidized rubredoxin (Rd) from Pyrococcus furiosus (Pf). The oxidized form has also been investigated by resonance Raman spectroscopy. In the oxidized Rd NRVS, strong asymmetric Fe-S stretching modes are observed between 355 and 375 cm(-1); upon reduction these modes shift to 300-320 cm(-1). This is the first observation of Fe-S stretching modes in a reduced Rd. The peak in S-Fe-S bend mode intensity is at approximately 150 cm(-1) for the oxidized protein and only slightly lower in the reduced case. A third band occurs near 70 cm(-1) for both samples; this is assigned primarily as a collective motion of entire cysteine residues with respect to the central Fe. The (57)Fe partial vibrational density of states (PVDOS) were interpreted by normal mode analysis with optimization of Urey-Bradley force fields. The three main bands were qualitatively reproduced using a D(2)(d) Fe(SC)(4) model. A C(1) Fe(SCC)(4) model based on crystallographic coordinates was then used to simulate the splitting of the asymmetric stretching band into at least 3 components. Finally, a model employing complete cysteines and 2 additional neighboring atoms was used to reproduce the detailed structure of the PVDOS in the Fe-S stretch region. These results confirm the delocalization of the dynamic properties of the redox-active Fe site. Depending on the molecular model employed, the force constant K(Fe-S) for Fe-S stretching modes ranged from 1.24 to 1.32 mdyn/A. K(Fe-S) is clearly diminished in reduced Rd; values from approximately 0.89 to 1.00 mdyn/A were derived from different models. In contrast, in the final models the force constants for S-Fe-S bending motion, H(S-Fe-S), were 0.18 mdyn/A for oxidized Rd and 0.15 mdyn/A for reduced Rd. The NRVS technique demonstrates great promise for the observation and quantitative interpretation of the dynamical properties of Fe-S proteins.

The targeted inactivation of polyketide synthase mycAV in the mycinamicin producer, Micromonospora griseorubida, and a complementation study

Mycinamicin is a 16-membered macrolide antibiotic produced by Micromonospora griseorubida A11725, which shows strong antimicrobial activity against gram-positive bacteria. Recently, the nucleotide sequences of the mycinamicn biosynthetic gene cluster in M. griseorubida have been completely determined. Mycinamicin non-producer M7A21 was isolated by mycAV inactivation, which encodes the module 7 of mycinamicin polyketide synthase (PKS) required for the biosynthesis of the mycinamicin biosynthetic intermediate protomycinolide-IV (PML-IV). When the bioconversion to mycinamicin II (M-II) from PML-IV was performed using M7A21 and the feeding culture method, the productivity of M-II was the same as that of M-II in wild-type strain A11725. p446M7 containing mycAV was constructed using the Escherichia coli-Streptomyces shuttle vector pGM446. The mycinamicin productivity of M7A21 was restored by the introduction of p446M7 into the M7A21 cell, but almost all p446M7 was integrated into the chromosome of M7A21 because the plasmid was unstable in M7A21. The feeding culture and the introduction of the complement gene for M7A21 would be powerful tools to perform combinatorial biosynthesis for the production of new macrolide antibiotics.

Expression of vascular endothelial growth factor by synovial fluid neutrophils in rheumatoid arthritis (RA)

Most of the leucocytes infiltrating rheumatoid synovial fluid (SF) are neutrophils capable of producing a variety of inflammatory mediators known to contribute significantly to the disease process during active RA. In the present study, we investigated the contribution made by SF neutrophils to the elevated levels of vascular endothelial growth factor (VEGF) seen in rheumatoid SF. Rheumatoid SF neutrophils were found to contain significantly larger amounts of both VEGF protein and its mRNA than peripheral blood neutrophils from either RA patients or healthy controls. Levels of cell-associated VEGF were well correlated with free VEGF in SF, which was significantly higher than in SF from osteoarthritis patients. Levels of SF neutrophil-associated VEGF also correlated with RA disease activity and cell surface integrin expression. Thus, SF neutrophil-associated VEGF may be considered an indicator of both local and systemic inflammation of RA, contributing to the neovascularization seen during RA synovitis.

Observation of nuclear excitation by electron transition in 197Au with synchrotron X rays and an avalanche photodiode

We have succeeded in observing nuclear excitation by electron transition (NEET) in 197Au by a new method. Monochromatic x-rays of synchrotron radiation were used to ionize the K shell of gold atoms in a target foil. The internal-conversion electrons emitted from excited nuclei were detected with a silicon avalanche photodiode. At a photon energy of 80.989 keV, the NEET probability in 197Au was determined to be (5.0+/-0.6)x10(-8) from a comparison of the event number per photon between NEET and the nuclear resonance at 77.351 keV.

Vascular endothelial growth factor expression and regulation of murine collagen-induced arthritis

We have examined the expression and function of the angiogenic factor, vascular endothelial growth factor (VEGF) during the evolution of type II collagen-induced arthritis (CIA). Biologically active VEGF was expressed along a time course that paralleled the expression of two specific VEGF receptors, Flk-1 and Flt-1, and the progression of joint disease. Moreover, levels of VEGF expression correlated with the degree of neovascularization, as defined by vWF levels, and arthritis severity. Macrophage- and fibroblast-like cells, which infiltrated inflamed sites and were then activated by other inflammatory mediators, are probably important sources of VEGF and may thus regulate angiogenesis during the development of CIA. Administration of anti-VEGF antiserum to CIA mice before the onset of arthritis delayed the onset, reduced the severity, and diminished the vWF content of arthritic joints. By contrast, administration of anti-VEGF antiserum after the onset of the disease had no effect on the progression or ultimate severity of the arthritis. These data suggest that VEGF plays a crucial role during an early stage of arthritis development, affecting both neovascularization and the progression of experimentally induced synovitis.

Precision wavelength measurement of the 14.4 keV Mössbauer photon

The wavelength of the 14.4 keV Mössbauer photon has been determined by using undulator radiation and diffraction of FZ silicon crystals. For the wavelength determination a goniometer equipped with a laser rotary encoder and a sine-bar angle optical interferometer was developed; a temperature-monitoring system and X-ray optics related to the experiment were also developed. The mean wavelength was 0.08602557 nm with an uncertainty of 0.6 p.p.m., derived from 16 measurements of three pieces of FZ Si(840) crystals.