Pleomorphic Rhabdomyosarcoma of the Uterine Corpus in an Adult Who Underwent Multi-gene Panel Testing

Background/Aim

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children. Adult primary RMS of gynecological origin is a rare condition and uterine RMS is an aggressive malignancy with a poor prognosis. The genetic variants associated with uterine RMS in adults have yet to be fully elucidated, and there is no established therapeutic strategy for rare tumors.

Case Report

A 69-year-old Japanese woman was referred to our hospital with abdominal bloating. Imaging examination revealed a tumor with diameter of 85 mm located in the uterus and multiple regional lymph node metastases. Biopsy of the uterine corpus indicated possible uterine carcinosarcoma or RMS. Following debulking surgery, the patient was diagnosed with stage IVB pleomorphic RMS. The patient was treated with two courses of doxorubicin every three weeks and one course of combination chemotherapy with vincristine, actinomycin, and cyclophosphamide. Because of rapid progression of the disease, we decided to perform multi-gene panel testing to determine the most effective therapeutic strategy. However, no therapeutic plan based on genetic information was identified. The patient with chemotherapy-refractory RMS died 11 weeks after surgery.

Conclusion

Our patient had advanced uterine RMS with an unresectable tumor that was resistant to chemotherapy, resulting in poor outcomes. Despite conducting multi-gene panel testing, no tailored therapeutic approach based on genetic information was found. This case highlights the challenges in managing uterine RMS in adults and underscores the urgent need for further research to identify effective treatment modalities.

Clinical utility of comprehensive genomic profiling in Japan: Result of PROFILE-F study

Introduction

Clinical sequencing has provided molecular and therapeutic insights into the field of clinical oncology. However, despite its significance, its clinical utility in Japanese patients remains unknown. Here, we examined the clinical utility of tissue-based clinical sequencing with FoundationOne® CDx and FoundationOne® Heme. Between August 2018 and August 2019, 130 Japanese pretreated patients with advanced solid tumors were tested with FoundationOne® CDx or FoundationOne® Heme.

Results

The median age of 130 patients was 60.5 years (range: 3 to 84 years), and among them, 64 were males and 66 were females. Major cancer types were gastrointestinal cancer (23 cases) and hepatic, biliary, and pancreatic cancer (21 cases). A molecular tumor board had been completed on all 130 cases by October 31, 2019. The median number of gene alterations detected by Foundation testing, excluding variants of unknown significance (VUS) was 4 (ranged 0 to 21) per case. Of the 130 cases, one or more alterations were found in 123 cases (94.6%), and in 114 cases (87.7%), actionable alterations with candidates for therapeutic agents were found. In 29 (22.3%) of them, treatment corresponding to the gene alteration was performed. Regarding secondary findings, 13 cases (10%) had an alteration suspected of a hereditary tumor. Of the 13 cases, only one case received a definite diagnosis of hereditary tumor.

Conclusions

Our study showed that clinical sequencing might be useful for detecting gene alterations in various cancer types and exploring treatment options. However, many issues still need to be improved.

[A Case of Recurrent Breast Cancer with Improving Activities of Daily Living by Olaparib Treatment]

The patient is a 67-year-old woman who underwent surgery for left breast cancer in 1990 and right breast cancer in 2003. In 2013, local recurrence of right breast cancer was detected. Then she underwent removal of the local recurrence, axillary lymph node dissection, and post mastectomy irradiation. In 2017 lung metastasis appeared, and she underwent endocrine therapy and chemotherapy. BRCA1/2 analysis showed BRCA1 mutation, so olaparib was started in 2020. The metastatic lesions were reduced markedly, and the skin metastases were crusted over. Although it is necessary to decide when to use olaparib in each case, there is a possibility that olaparib may be effective even in the terminal stage, and it may be considered as one of the treatment options.

[A Case Report of Postoperative Chylous Ascites after Laparoscopic Sigmoidectomy]

A female in her 70s was diagnosed as sigmoid colon cancer. Laparoscopic sigmoidectomy was performed. Chylous ascites was observed after starting oral intake. As we changed the patient's diet to a low fat diet, the chylous ascites disappeared. There are certain numbers of reports of the cases improved by fasting or only fat decreased meal. It is important to prevent this complications using appropriate surgical devices.

A Pilot Study Analyzing the Clinical Utility of Comprehensive Genomic Profiling Using Plasma Cell-Free DNA for Solid Tumor Patients in Japan (PROFILE Study)

BACKGROUND

The clinical utility of plasma cell-free DNA in precision cancer medicine has not been established. A pilot study was conducted to investigate the clinical utility of comprehensive genomic profiling by liquid biopsy in a Japanese population.

METHODS

In this PROFILE study, 102 patients with advanced solid tumors who showed progression with standard systemic therapy underwent liquid biopsy between August 2017 and February 2020. Liquid biopsy was performed using Guardant360.

RESULTS

Of the 102 patients, 56 were women, and the median age was 65 years. Regarding the types of cancer, 31 were hepatobiliary and pancreatic cancer, 17 were gastrointestinal cancer, and 13 were breast cancer. Frequently altered genes were TP53 (53.9%, 46/102), KRAS (25.5%, 26/102), PIK3CA (19.6%, 20/102), and EGFR (17.6%, 18/102). At least one genetic aberration was detected in 92 patients (90.2%). Actionable mutation was discovered in 88 patients (86.3%), and 67 patients (65.7%) were clinical trial candidates. Of the 102 patients, 22 (21.6%) were able to receive biomarker-matched therapy. Their best responses were as follows: 1 complete response, 3 partial responses, 7 stable diseases, and 11 progressive diseases. Additionally, the treated patients were divided on the basis of matching scores (≥ 50% vs. < 50%). The patients were divided into high and low groups. The high group had a higher disease control rate (DCR) of 75% compared with 20% in the low group (P = 0.010).

CONCLUSIONS

The results indicate that liquid biopsy is useful for identifying actionable mutations associated with the clinical response of selected patients.

[A Case of Lynch Syndrome with Seven Cancers in Five Organs]

The case is a woman in her 70s with a history of colon and cervical cancer in her 40s. She had gastric cancer and breast cancer in her 70s. Her eldest son died of colon cancer in his 20s, and her eldest daughter had cervical cancer in her 40s. She was suspected to have Lynch syndrome and a genetic diagnosis was performed and then confirmed. Later she developed gastric cancer and ureteral cancer. We report a case of Lynch syndrome in which she developed seven cancers in five organs, all of which were early stage cancers.

Texture Analysis of Apparent Diffusion Coefficient Maps in Cervical Carcinoma: Correlation with Histopathologic Findings and Prognosis

Purpose

To determine the feasibility of texture analysis of apparent diffusion coefficient (ADC) maps and to assess the performance of texture analysis and ADC to predict histologic grade, parametrial invasion, lymph node metastasis, International Federation of Gynecology and Obstetrics (FIGO) stage, recurrence, and recurrence-free survival (RFS) in patients with cervical carcinoma.

Materials and Methods

This retrospective study included 58 patients with cervical carcinoma who were examined with a 1.5-T MRI system and diffusion-weighted imaging with b values of 0 and 1000 sec/mm². Software with volumes of interest on ADC maps was used to extract 45 texture features, including higher-order texture features. Receiver operating characteristic (ROC) analysis was performed to compare the diagnostic performance of ADC map random forest models and of ADC values. Dunnett test, Spearman rank correlation coefficient, Kaplan-Meier analyses, log-rank test, and Cox proportional hazards regression analyses were also used for statistical analyses.

Results

The ADC map random forest models showed a significantly larger area under the ROC curve (AUC) than the AUC of ADC values for predicting high-grade cervical carcinoma (P = .0036), but not for parametrial invasion, lymph node metastasis, stages III-IV, and recurrence (P = .0602, .3176, .0924, and .5633, respectively). The random forest models predicted that the mean RFS rates were significantly shorter for high-grade cervical carcinomas, parametrial invasion, lymph node metastasis, stages III-IV, and recurrence (P = .0405, < .0001, .0344, .0001, and .0015, respectively); the random forest models for parametrial invasion and stages III-IV were more useful than ADC values (P = .0018) for predicting RFS.

Conclusion

The ADC map random forest models were more useful for noninvasively evaluating histologic grade, parametrial invasion, lymph node metastasis, FIGO stage, and recurrence and for predicting RFS in patients with cervical carcinoma than were ADC values.Keywords: Comparative Studies, Genital/Reproductive, MR-Diffusion Weighted Imaging, MR-Imaging, Neoplasms-Primary, Pathology, Pelvis, Tissue Characterization, UterusSupplemental material is available for this article.© RSNA, 2020See also the commentary by Reinhold and Nougaret in this issue.

Clinical impact of hemizygous deletion detection and panel-size in comprehensive genomic profiling

e15671

Background: Comprehensive genomic profiling (CGP) identified single nucleotide variants (SNVs), copy number alteration (CNA), indels, and rearrangements in cancer-related genes. Only limited CGP detects hemizygous deletion. Also panel size differs among CGPs. Clinical impact of hemizygous deletion and panel-size are not well characterized. Methods: Formalin-fixed paraffin-embedded tissues from 10 cancer patients were analyzed by two CGPs: 1) test A (ACT Onc+) that interrogates SNVs, indels, rearrangement, and CNA including amplification, hemizygous and homozygous deletions in 440 genes, 2) test B that interrogates SNV, indels, rearrangement and CNA including amplification and homozygous deletion in 114 genes, but hemizygous deletion only in limited genes. Result was discussed in molecular tumor board and actionable genes and candidate drug were determined. Primary objective was the number of actionable genomic alterations. Secondary objectives are the number of candidate drugs, SNVs, CAN, and rearrangement. When there was difference of results in two tests, other validation test, such as PCR-based copy number evaluation, was performed. The difference of two tests was statistically evaluated using student t-test. Results: Median age of patients was 56 (range 48 – 70), and 50% were male. Tumor types were neuroendocrine tumor (60%), ovarian cancer (30%) and pancreatic cancer (10%). In 10 patients, actionable genes were found as follows: 39 in test A and 9 in test B (P = 0.0056). Total 64 genomic alterations were found in test A compared 12 in test B. SNV was not statistically different among two tests (10 in test A, 6 in test B; P = 0.269). However, the number of CNA was different: 54 in test A and 6 in test B (P = 0.007). Among CNA, hemizygous alteration explained majority of the difference (30 in test A and 1 in test B, P = 0.059), followed by amplification (24 in test A and 5 in test B, P = 0.201). The number of drug candidates was 38 in test A and 11 in test B (P = 0.014). Conclusions: Detection of hemizygous deletion and larger panel size resulted in more actionable genes and drug candidates, which might impact clinical practice. Future study of clinical utility of hemizygous deletion and panel size is warranted.

[A Case of Appendiceal Neuroendocrine Tumor Diagnosed after Appendectomy]

A 25-year-old woman visited our hospital with a complaint of right lower abdominal pain. As a result of the examination, she was diagnosed as having acute appendicitis. After conservative treatment, we planned an elective surgery. At 3 months after discharge, laparoscopic appendectomy was performed. We found a mass of 10mm in diameter at the body of the appendix. Histopathological examination revealed the proliferation of heteromorphic cells with small round nuclei. It was positive for chromogranin A and synaptophysin in immunostaining, so we made a diagnosis of NET G1. Tumor cells infiltrated beyond the intrinsic muscle layer, but no vascular invasion was observed, and the margin was negative. In accordance with the guidelines, we followed up the patient with imaging examination and did not find any signs of recurrence.

Endometrial Carcinoma: Texture Analysis of Apparent Diffusion Coefficient Maps and Its Correlation with Histopathologic Findings and Prognosis

PURPOSE

To determine the feasibility of texture analysis (TA) of apparent diffusion coefficient (ADC) maps for predicting histologic grade (HG) and recurrence-free survival (RFS) in patients with endometrial carcinoma (EMC).

MATERIALS AND METHODS

One hundred twenty-one patients with EMC were examined by using a 1.5-T MRI system and diffusion-weighted imaging (DWI) with b values of 0 and 1000 sec/mm². Software with volumes of interest on ADC maps was used to extract 45 texture features including higher-order texture features. Receiver operating characteristic analysis was performed to compare the diagnostic performance of the random forest (RF) model and ADC values for HG and recurrence.

RESULTS

Area under the curve (AUC) for predicting high-grade EMCs was significantly larger for RF model than for ADC values (0.967 vs 0.898; P = .0336). AUC for predicting recurrence was larger for the RF model than for ADC values (0.890 vs 0.875; P = .7248), although the difference was not significant. Mean RFS was significantly shorter for high-grade EMCs than for low-grade EMCs (P = .0002; hazard ratio, 4.9) and for ADC values less than or equal to 0.802 × 10^-3 mm²/sec than for ADC values greater than 0.802 × 10^-3 mm²/sec (P < .0001; hazard ratio, 32.9). RF model showed that the mean RFS was significantly shorter for the presence of recurrence than for its absence (P < .0001; hazard ratio, 94.7).

CONCLUSION

TA of ADC maps had significantly higher diagnostic performance than did ADC values for predicting HG and was a more useful indicator than HG and ADC values for predicting RFS in patients with EMC.Keywords: Comparative Studies, Genital/Reproductive, MR-Diffusion Weighted Imaging, MR-Imaging, Neoplasms-Primary, Pathology, Pelvis, Tissue Characterization, Uterus© RSNA, 2019.

[Clinical Utility of Comprehensive Genome Profiling Using FoundationOne CDx in Japanese Population(PROFILE-F Study)]

BACKGROUND

FoundationOne CDx is a cancer genome profiling test that has already been approved by the FDA, but its clinical utility in Japanese patients is unknown. In this study, we examined the clinical utility of FoundationOne CDx.

METHODS

46 samples from 43 Japanese pretreated patients with advanced solid tumors were tested with FoundationOne CDx between September 2018-January 2019.

RESULTS

The median age of 43 patients was 63 years(ranged 18 to 82 years), and among them 24 were males and 19 females. Major cancer types were hepato-biliary and pancreatic(8 cases)and other digestive organs(8 cases). All 27 cases in which genome cancer board had been completed by January 17, 2019 were analyzable, and the number of detected gene mutations(except VUS)was an average of 4.3(ranged 0 to 14)per case. Of the 27 cases, one or more mutations were found in 26 cases(96%), and in all such 26 cases actionable mutations with candidates for therapeutic agents were found. In 4(15%)of them, the treatment corresponding to the gene mutation was performed. Among the cases in which target disease matched and clinical trials of the drug were being conducted in Japan, only one case participated in the trial. The most common reason for not participating in the trial was disease deterioration and PS reduction (33%).

CONCLUSIONS

The FoundationOne CDx test showed that it can detect gene mutations in various cancer types in Japanese patients.

Port site recurrence and unusual diffuse subcutaneous metastases of unexpected early stage ovarian cancer after laparoscopic surgery: a case report

Port site recurrence is a rare but well-documented adverse event peculiar to laparoscopic surgery. We report an unusual outcome of unexpected early stage ovarian cancer in which port site recurrence occurred after laparoscopic surgery and was followed by diffuse subcutaneous metastases. A 31-year-old Japanese woman with a large tumor in her abdomen visited our hospital. Because no intratumoral solid component was detected on diagnostic imaging, the tumor was diagnosed as a benign ovarian tumor and the patient underwent left ovarian laparoscopic cystectomy. Contrary to our expectations, however, the ovarian tumor was a mucinous carcinoma. We performed additional surgery, but the tumor recurred in the umbilical area, and multiple subcutaneous metastases later appeared. The curative effect of chemotherapy and radiation was limited. This atypical metastatic distribution of an extremely small amount of cancer might have been caused by the laparoscopic procedure. Protection against tumor cell dissemination is necessary during all forms of laparoscopic surgery.

A high-quality and energy-tunable positronium beam system employing a trap-based positron beam

We constructed a new apparatus, built upon a trap-based slow positron beam, for the production of a collimated, energy-tunable positronium beam under ultra-high vacuum conditions employing the photodetachment of positronium negative ions. A slow positron generator consisting of a ²²Na radioisotope (20 mCi) combined with a buffer-gas positron trap is employed to generate high-quality, nano-second positron bursts with a repetition rate of 1 Hz-1 kHz. The positron bursts are focused onto an efficient positron-to-positronium negative ion converter, a Na-coated W thin film in a transmission geometry, using a magnetic lens system. The ions emitted from the opposite surface of the film are electrostatically accelerated to a given energy and photodetached by a pulsed infrared laser to form a mono-energetic positronium beam with kinetic energies of 0.2 keV-3.3 keV. The achieved detection rate of Ps atoms is 23 cps at the energy of 3.3 keV with a signal-to-background ratio as high as 300. The energy spread of the beam was evaluated by comparing the result of the time-of-flight measurements and particle-tracking simulations. With the use of a collimator of 1 mm diameter, a coherent beam with an angular divergence of less than 0.3° is obtained. The obtained Ps beam, having a much higher quality than those reported hitherto, will open up a new field of experimental investigations, such as Ps interacting with a variety of materials and fundamental studies on Ps spectroscopy.

Prevention of surgical site infection via antibiotic administration according to guidelines after gynecological surgery

AIM

We modified the antimicrobial prophylaxis of surgical site infection (SSI) according to the guidelines of the Japanese Society of Chemotherapy and Japan Society of Infectious Diseases (hereinafter referred to as optimization) and measured outcomes.

METHODS

From April 2016 to March 2017, we performed cesarean section and open hysterectomy with optimization, and compared the outcome to that of surgery performed without optimization between April 2014 and March 2016. We measured the rates of antibiotic discontinuation, appropriate antibiotic selection, SSI incidence, resumption of antibiotic therapy and fever incidence, as well as the length of postoperative hospital stay and medical expenses for antibiotics to evaluate the appropriateness and outcomes of antibiotic prophylaxis.

RESULTS

Optimization resulted in a change in the method of selecting antibiotics for cesarean section, but there was no change in SSI incidence rate (0.74% vs 0.0%, P = 0.36). Optimization reduced the use of antibiotics and medical expenses of hysterectomy (median reduction of 50% and 78% for hysterectomy without or with lymphadenectomy, respectively). However, there was no change in outcome regarding SSI incidence (5.7% vs 0.0%, P = 0.11 and 7.8% vs 9.5%, P = 0.77, respectively).

CONCLUSION

Appropriate use of antibiotics according to guidelines reduced antibiotic dose and medical expenses, but there was no change in outcome regarding SSI incidence rate. These findings suggested that implementation of dosing regimens according to the guidelines would be useful to reduce antibiotic medicine costs and prevent resistant bacteria and complications associated with antibiotics.

Exosomes of human placenta-derived mesenchymal stem cells stimulate angiogenesis

BACKGROUND

The therapeutic potential of mesenchymal stem cells (MSCs) may be attributed partly to humoral factors such as growth factors, cytokines, and chemokines. Human term placental tissue-derived MSCs (PlaMSCs), or conditioned medium left over from cultures of these cells, have been reported to enhance angiogenesis. Recently, the exosome, which can transport a diverse suite of macromolecules, has gained attention as a novel intercellular communication tool. However, the potential role of the exosome in PlaMSC therapeutic action is not well understood. The purpose of this study was to evaluate PlaMSC-derived exosome angiogenesis promotion in vitro and in vivo.

METHODS

MSCs were isolated from human term placental tissue by enzymatic digestion. Conditioned medium was collected after 48-h incubation in serum-free medium (PlaMSC-CM). Angiogenic factors present in PlaMSC-CM were screened by a growth factor array. Exosomes were prepared by ultracentrifugation of PlaMSC-CM, and confirmed by transmission electron microscopy, dynamic light scattering, and western blot analyses. The proangiogenic activity of PlaMSC-derived exosomes (PlaMSC-exo) was assessed using an endothelial tube formation assay, a cell migration assay, and reverse transcription-PCR analysis. The in-vivo angiogenic activity of PlaMSC-exo was evaluated using a murine auricle ischemic injury model.

RESULTS

PlaMSC-CM contained both angiogenic and angiostatic factors, which enhanced endothelial tube formation. PlaMSC-exo were incorporated into endothelial cells; these exosomes stimulated both endothelial tube formation and migration, and enhanced angiogenesis-related gene expression. Laser Doppler blood flow analysis showed that PlaMSC-exo infusion also enhanced angiogenesis in an in-vivo murine auricle ischemic injury model.

CONCLUSIONS

PlaMSC-exo enhanced angiogenesis in vitro and in vivo, suggesting that exosomes play a role in the proangiogenic activity of PlaMSCs. PlaMSC-exo may be a novel therapeutic approach for treating ischemic diseases.

Uric acid, indoxyl sulfate, and methylguanidine activate bulbospinal neurons in the RVLM via their specific transporters and by producing oxidative stress

Patients with chronic renal failure often have hypertension, but the cause of hypertension, other than an excess of body fluid, is not well known. We hypothesized that the bulbospinal neurons in the rostral ventrolateral medulla (RVLM) are stimulated by uremic toxins in patients with chronic renal failure. To investigate whether RVLM neurons are sensitive to uremic toxins, such as uric acid, indoxyl sulfate, or methylguanidine, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons of Wister rats using the whole-cell patch-clamp technique during superfusion with these toxins. A brainstem-spinal cord preparation that preserved the sympathetic nervous system was used for the experiments. During uric acid, indoxyl sulfate, or methylguanidine superfusion, almost all the RVLM neurons were depolarized. To examine the transporters for these toxins on RVLM neurons, histological examinations were performed. The uric acid-, indoxyl sulfate-, and methylguanidine-depolarized RVLM neurons showed the presence of urate transporter 1 (URAT 1), organic anion transporter (OAT)1 or OAT3, and organic cation transporter (OCT)3, respectively. Furthermore, the toxin-induced activities of the RVLM neurons were suppressed by the addition of an anti-oxidation drug (VAS2870, an NAD(P)H oxidase inhibitor), and a histological examination revealed the presence of NAD(P)H oxidase (nox)2 and nox4 in these RVLM neurons. The present results show that uric acid, indoxyl sulfate, and methylguanidine directly stimulate bulbospinal RVLM neurons via specific transporters on these neurons and by producing oxidative stress. These uremic toxins may cause hypertension by activating RVLM neurons.

Digitized detection of gamma-ray signals concentrated in narrow time windows for transient positron annihilation lifetime spectroscopy

A pulsed slow-positron beam generated by an electron linear accelerator was directly used for positron annihilation lifetime spectroscopy without any positron storage devices. A waveform digitizer was introduced to simultaneously capture multiple gamma-ray signals originating from positron annihilation events during a single accelerator pulse. The positron pulse was chopped and bunched with the chopper signals also sent to the waveform digitizer. Time differences between the annihilation gamma-ray and chopper peaks were calculated and accumulated as lifetime spectra in a computer. The developed technique indicated that positron annihilation lifetime spectroscopy can be performed in a 20 μs time window at a pulse repetition rate synchronous with the linear accelerator. Lifetime spectra of a Kapton sheet and a thermally grown SiO2 layer on Si were successfully measured. Synchronization of positron lifetime measurements with pulsed ion irradiation was demonstrated by this technique.

Trichostatin A, a potential drug for treatment of animal Babesia infections

In the present study, we evaluated the inhibitory effect of trichostatin A on the asexual growth of bovine, equine, and canine Babesia parasites in vitro as well as on the in vivo growth of Babesia microti (B.microti) in mice. The growth of Babesia bovis (B.bovis), Babesia bigemina (B.bigemina), Babesia caballi (B.caballi), Theileria equi (T.equi), and Babesia gibsoni (B.gibsoni) species was significantly inhibited (P < 0.05) by very low concentrations of trichostatin A (IC50 values = 2.6, 2.4, 2.3, 2.4, and 2.3 nM, respectively). Furthermore, in B.microti-infected mice, trichostatin A caused significant higher (P < 0.05) inhibition of the growth of B.microti at the dose of 2 mg/kg body weight than that in the control group. These results indicated the trichostatin A might be a chemotherapeutic agent for treatment of babesiosis. DOI: http://dx.doi.org/10.5564/mjas.v11i2.210 Mongolian Journal of Agricultural Sciences Vol.11(2) 2013 pp.24-26

Positron annihilation in cardo-based polymer membranes

Positron annihilation lifetime spectroscopy (PALS) is applied to a series of bis(aniline)fluorene and bis(xylidine)fluorene-based cardo polyimide and bis(phenol)fluorene-based polysulfone membranes. It was found that favorable amounts of positronium (Ps, the positron-electron bound state) form in cardo polyimides with the 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) moiety and bis(phenol)fluorene-based cardo polysulfone, but no Ps forms in most of the polyimides with pyromellitic dianhydride (PMDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (BTDA) moieties. A bis(xylidine)fluorene-based polyimide membrane containing PMDA and BTDA moieties exhibits a little Ps formation but the ortho-positronium (o-Ps, the triplet state of Ps) lifetime of this membrane anomalously shortens with increasing temperature, which we attribute to chemical reaction of o-Ps. Correlation between the hole size (V(h)) deduced from the o-Ps lifetime and diffusion coefficients of O2 and N2 for polyimides with the 6FDA moiety and cardo polysulfone showing favorable Ps formation is discussed based on free volume theory of gas diffusion. It is suggested that o-Ps has a strong tendency to probe larger holes in rigid chain polymers with wide hole size distributions such as those containing cardo moieties, resulting in deviations from the previously reported correlations for common polymers such as polystyrene, polycarbonate, polysulfone, and so forth.

[Marginal zone lymphoma of mucosa-associated lymphoid tissue of the parietal pleura; report of a case]

An 76-year-old man was referred to our hospital due to right hydrothorax. The diffuse thickening of parietal pleura with increased fluoro-2-deoxy-D-glucose (FDG) uptake was noted by computed tomography (CT) and positron emission tomography (PET). Surgical biopsy was performed and the tumor was diagnosed as mucosal associated lymphoid tissue (MALT) lymphomas of parietal pleura origin by pathology. Complete remission was achieved by postoperative chemotherapy (R-CHOP), and the patient is now alive without recurrence.

Simulations of slow positron production using a low-energy electron accelerator

Monte Carlo simulations of slow positron production via energetic electron interaction with a solid target have been performed. The aim of the simulations was to determine the expected slow positron beam intensity from a low-energy, high-current electron accelerator. By simulating (a) the fast positron production from a tantalum electron-positron converter and (b) the positron depth deposition profile in a tungsten moderator, the slow positron production probability per incident electron was estimated. Normalizing the calculated result to the measured slow positron yield at the present AIST linear accelerator, the expected slow positron yield as a function of energy was determined. For an electron beam energy of 5 MeV (10 MeV) and current 240 μA (30 μA), production of a slow positron beam of intensity 5 × 10(6) s(-1) is predicted. The simulation also calculates the average energy deposited in the converter per electron, allowing an estimate of the beam heating at a given electron energy and current. For low-energy, high-current operation the maximum obtainable positron beam intensity will be limited by this beam heating.

Prognostic value of duodenal invasion length in patients with gastric cancer

24

Background: Duodenal invasion (DI) has been considered as a poor prognostic factor of gastric cancer patients. Not all the patients would be able to undergo curative operation. Neoadjuvant chemotherapy (NAC) may improve the rate of curative operation of these patients. In this study, we investigated whether the length of duodenal invasion preoperative diagnosis can be one of factor to decide indication of NAC.

Methods: A total of 118 gastric cancer patients with clinically evident DI, who underwent laparotomy at our center, were enrolled in this study. 42 patients with DI length 20 mm or longer were categorized into long invasion group (LI), 76 patients with DI length shorter than 20 mm were categorized into short invasion group (SI). Clinicopathologic features, rate of direct invasion and lymph nodes involvement, R0 resection, and survival rate were compared between two groups.

Results: Resection rate was significantly different between two groups: SI group (85.5%; 65/76), LI group (69.0%; 29/42). Direct invasion to adjacent organs was significantly more frequently observed in LI group (21%; 6/29) than SI group (4 %; 3/65, p = 0.02). In LI group, pancreas invasion was observed in all patients except for one patient. Multivariate analysis to predict the adjacent organ invasion revealed that CT diagnosis (p = 0.005) and invasion length (p = 0.01) were selected as risk factors of direct invasion to adjacent organs. There was no significant difference of nodal involvement between LI group (83%; 24/29) and SI group (83%; 54/65 p = 0.99). The 5-year survival rate was 19% in LI group and 43% in SI group (p = 0.23). The number of patients who underwent R0 resection was more frequently in SI group (75.4%; 49/65) than SI group (69.1%; 16/29). The factors of R1 or R2 resection were metastasis of peritoneum or direct invasion to adjacent organs.

Conclusions: In patients with long duodenal invasion, direct invasion to the pancreas was more frequently observed, and resulted in low curative resection rate and poor survival. Preoperative chemotherapy may improve the curative resection rate and survival in these patients. Prospective study is warranted to evaluate the efficacy of NAC for these patients.

No significant financial relationships to disclose.

Down-regulation of single immunoglobulin interleukin-1R-related molecule (SIGIRR)/TIR8 expression in intestinal epithelial cells during inflammation

Single immunoglobulin (Ig) interleukin-1R-related molecule (SIGIRR) is an Ig-like membrane protein critical for negative regulation of Toll-like receptor (TLR)-4-mediated signalling. We investigated SIGIRR expression and its regulation mechanism in intestinal epithelial cells (IECs) during inflammation. Endoscopic biopsy specimens were obtained from active and inactive colonic mucosa of ulcerative colitis (UC) patients, then SIGIRR expression was examined using real-time polymerase chain reaction (PCR) and immunohistochemistry (IH). Mice experimental colitis models were established by administrations of sulphonic acid (TNBS) and dextran sodium sulphate (DSS), and epithelial expression of SIGIRR was examined using real-time PCR, IH and flow cytometry. The effects of lipopolysaccharide (LPS) and tumour necrosis factor (TNF)-α on SIGIRR expression were evaluated in vitro using cultured IECs. To elucidate SIGIRR expression regulation in IECs, binding ability of the transcription factor SP1 at the responsive element of the SIGIRR promoter was examined using gel-shift and chromatin immunoprecipitation (ChIP) assays. In human colonic samples, SIGIRR was expressed mainly in IECs at levels significantly higher in inactive compared to active mucosa. In the mice, SIGIRR colonic expression decreased rapidly after colitis development and returned gradually to basal levels. Experimental colitis-mediated down-regulation of SIGIRR in IECs was also confirmed by IH and flow cytometry results. Further, inflammatory conditions induced by TLR ligands and TNF-α caused significant down-regulation of SIGIRR expression in IECs, which was dependent upon decreased SP1 binding at the responsive element of the SIGIRR promoter. We found that SIGIRR is expressed in IECs and serves as a negative regulator to maintain gut innate immunity, which is down-regulated during inflammation by inhibition of an SP1-mediated pathway.

[Papillary fibroelastoma of the tricuspid valve with mitral regurgitation]

We report a 64-year-old male patient with papillary fibroelastoma of the tricuspid valve associated with moderate mitral regurgitation. Echocardiography had revealed a 10 x 10 mm tumor attaching to the anterior tricuspid leaflet 3 years before. Because the tumor was enlarged to 19 x 15 mm, we excised it with a part of the anterior tricuspid leaflet, and performed tricuspid and mitral valvoplasty. The histological findings suggested papillary fibroelastoma. The postoperative course was uneventful.

Mechanism of variable structural colour in the neon tetra: quantitative evaluation of the Venetian blind model

The structural colour of the neon tetra is distinguishable from those of, e.g., butterfly wings and bird feathers, because it can change in response to the light intensity of the surrounding environment. This fact clearly indicates the variability of the colour-producing microstructures. It has been known that an iridophore of the neon tetra contains a few stacks of periodically arranged light-reflecting platelets, which can cause multilayer optical interference phenomena. As a mechanism of the colour variability, the Venetian blind model has been proposed, in which the light-reflecting platelets are assumed to be tilted during colour change, resulting in a variation in the spacing between the platelets. In order to quantitatively evaluate the validity of this model, we have performed a detailed optical study of a single stack of platelets inside an iridophore. In particular, we have prepared a new optical system that can simultaneously measure both the spectrum and direction of the reflected light, which are expected to be closely related to each other in the Venetian blind model. The experimental results and detailed analysis are found to quantitatively verify the model.

[Histological complete response in a case of advanced gastric cancer treated by neo-adjuvant chemotherapy with S-1/CDDP]

A 59-year-old male was found to have advanced gastric cancer with multiple lymph node metastasis including para-aortic lymph nodes(cT3, cN3, cM0, cH0, cP0, cStage IV). Since curative surgery was deemed not feasible, we tried neoadjuvant chemotherapy expecting downstaging of the tumor. S-1(120 mg/body)was orally administered for three weeks followed by one week rest, and CDDP(60 mg/m2)was administered on day 8. Three courses of treatment resulted in a marked shrinkage of the primary lesion and a reduction of lymph nodes. He was judged as clinical PR by RECIST, and a radical resection was considered possible. Laparotomy revealed neither ascites nor peritoneal dissemination, and he underwent total gastrectomy, splenectomy and D2+para-aortic lymph node dissection with curative intent. The histological diagnosis revealed complete disappearance of cancer cells in the primary lesion of the stomach and lymph nodes, confirming a pathological complete response. The patient has been alive for six months without recurrence.

Direct measurement of the W boson width

We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.

A20 is an early responding negative regulator of Toll-like receptor 5 signalling in intestinal epithelial cells during inflammation

Several negative regulatory mechanisms control Toll-like receptor (TLR)-mediated inflammatory responses and restore immune system balance, including the zinc-finger protein A20, a negative regulator of TLR signalling that inhibits nuclear factor kappa B (NF-kappaB) activity. In the present study, we investigated TLR-5-mediated A20 expression and its role in intestinal epithelial cells (IECs) during inflammation. HCT-15 and HT-29 cells were stimulated with flagellin, then the expressions of A20, interleukin-1 receptor-associated kinase (IRAK-M) and Tollip were evaluated using RNase protection assay. Furthermore, experimental colitis was induced in tlr4-deficient CH3/HeJ mice by administration of dextran sodium sulphate (DSS), then flagellin was injected anally, and the colonic expression of A20 was examined by real-time polymerase chain reaction (PCR) and immunohistochemistry. To confirm flagellin-induced expression of A20, we employed an organ culture system. The role of A20 in flagellin-induced tolerance induction was evaluated in vitro, using a gene knock-down method targeting A20. A20 expression increased rapidly and peaked at 1 h after flagellin stimulation in cultured IECs, then declined gradually to the basal level. In vivo, anal injection of flagellin induced epithelial expression of A20 in injured colonic tissue, whereas flagellin did not cause a significant increase in A20 expression in non-injured normal tissue, which was also confirmed in vitro using the organ culture system. Gene knock-down using A20 siRNA did not influence tolerance induced by restimulation with flagellin. A20 is an early response negative regulator of TLR-5 signalling in IECs that functions during intestinal inflammation. Our results provide new insights into the negative feedback regulation of TLR-5 signalling that maintains the innate immune system in the gut.

Measurement of dijet angular distributions at square root(s) = 1.96 TeV and searches for quark compositeness and extra spatial dimensions

We present the first measurement of dijet angular distributions in pp collisions at square root(s) = 1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of 0.7 fb(-1) collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV(-1) scale extra dimensions. For all models considered, we set the most stringent direct limits to date.

Measurement of the WW production cross section with dilepton final states in pp collisions at square root(s) = 1.96 TeV and limits on anomalous trilinear gauge couplings

We provide the most precise measurement of the WW production cross section in pp collisions to date at a center of mass energy of 1.96 TeV, and set limits on the associated trilinear gauge couplings. The WW-->lnul'nu (l, l' = e, mu) decay channels are analyzed in 1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. The measured cross section is sigma(pp --> WW) = 11.5+/-2.1(stat+syst)+/-0.7(lumi) pb. One- and two-dimensional 95% C.L. limits on trilinear gauge couplings are provided.

Measurement of the W boson mass

We present a measurement of the W boson mass in W-->e(nu) decays using 1 fb-1 of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W-->e(nu) candidate events, we measure M(W)=80.401+/-0.043 GeV. This is the most precise measurement from a single experiment.

Direct measurement of the mass difference between top and antitop quarks

We present a measurement of the mass difference between t and t[over] quarks in lepton + jets final states of tt[over] events in 1 fb;{-1} of data collected with the D0 detector from Fermilab Tevatron Collider pp[over] collisions at sqrt[s] = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and t[over ] masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.

Observation of single top-quark production

We report observation of the electroweak production of single top quarks in pp[over ] collisions at sqrt[s]=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp[over ]--> tb + X, tqb + X) = 3.94 + or - 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10(-7), corresponding to a 5.0 standard deviation significance for the observation.

Search for dark photons from supersymmetric hidden valleys

We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to the lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.

Search for resonant pair production of neutral long-lived particles decaying to bb in pp collisions at square root(S)=1.96 TeV

We report on a first search for resonant pair production of neutral long-lived particles (NLLP) which each decay to a bb pair, using 3.6 fb(-1) of data recorded with the D0 detector at the Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6-20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.

Search for next-to-minimal supersymmetric Higgs bosons in the h --> aa --> micromicromicromicro, micromicrotautau channels using pp[over] collisions at sqrt[s] = 1.96 TeV

We report on a first search for production of the lightest neutral CP-even Higgs boson (h) in the next-to-minimal supersymmetric standard model, where h decays to a pair of neutral pseudoscalar Higgs bosons (a), using 4.2 fb;{-1} of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to micro;{+}micro;{-} or one to micro;{+}micro;{-} and the other to tau;{+}tau;{-}. No significant signal is observed, and we set limits on its production as functions of M_{a} and M_{h}.