A38 INVESTIGATION OF POST-TRANSLATIONAL MODIFICATIONS IN SERUM OF CROHN’S DISEASE PATIENTS USING A PROTEOMICS APPROACH

Background

Canada has one of the highest prevalences of Crohn’s disease (CD) worldwide. More specifically, fibrostenotic CD is a phenotype with prolonged chronic inflammation and fibrotic strictures often resistant to anti-inflammatory therapies and characterized by luminal narrowing that ultimately requires surgery. Proteins play an essential role in disease pathogenesis, and post-translational modifications (PTMs) can alter their properties. PTMs have been frequently implicated in human diseases. However, they have yet to be explored in the context of CD, which could lead to new avenues for a better understanding of disease mechanisms and the discovery of biomarkers.

Purpose

Identify post-translational modifications in serum proteins of CD patients.

Method

Serum samples from patients with strictures or inflammatory phenotype (without strictures) (n=4 per group), as diagnosed by intestinal ultrasound, were analyzed using a shotgun-proteomics approach. Protein identification and PTM prediction were performed with FragPipe. Identified mass shifts determined by an open search in FragPipe were mapped to possible PTMs and confirmed via unimod.org. Statistical significance analysis was performed with MSstatsPTM.

Result(s)

The prediction analysis identified 363 potential modification sites, including artifacts and chemical derivatives. The addition of all potential PTMs in the analysis would lead to false positives; therefore, it was selected five of the most abundant mass shifts mapped to true PTMs: cysteine oxidation, serine methylation, and three modifications of the protein n-termini (formaldehyde adduct, carbamylation, and formylation). Standard proteomics analysis identified 3635 unique peptides and 317 unique proteins. The addition of the predicted PTMs increased the number of peptides by 9.8%, reaching 3994 unique sequences. Interestingly, a very subtle increase was observed on the protein level, where only two additional proteins were identified. Of the PTMs identified, methylation of a serine residue on the variable chain of immunoglobulin (IGLV1-47) was statistically enriched in inflammatory samples (5.74 fold change, adj. p-value = 0.041). The variable chain participates in the antigen recognition process, and modification of its amino acids could impact antibody specificity. Additionally, structuring patients showed two modifications on thrombin: oxidation of cysteine and methylation of serine. Thrombin was previously shown to be elevated in CD patients compared to healthy controls. As both modifications were not present in inflammatory patients, they constitute potential biomarkers for specific diagnosis of the structuring disease.

Conclusion(s)

The observed gain in peptide identification demonstrates the diversification promoted by PTMs and exhibits their importance in proteomics studies. Even though the identified modifications require further validation, they can shed light on new players of CD pathogenesis and suggest novel biomarkers for disease diagnosis.

Disclosure of Interest

None Declared

The skill qualification system for portal hypertension in Japan

Objectives

The diverse treatments available for portal hypertension require specialized knowledge of hemodynamics and include endoscopic treatments, interventional radiology (IVR), and surgery. The Japan Society for Portal Hypertension has developed the skill qualification system (SQS) for portal hypertension and began examination in 2014. Here, the status and validity of the judgment of the SQS examination were evaluated.

Methods

From 2014 to 2020, 79 applicants were evaluated by the SQS for portal hypertension. Each unedited video submitted as a candidate procedure was evaluated by two judges, and a grade of greater than 70% for the scoring items assessed by the judges was required to pass the examination. Inter‐rater agreement of success/failure between the two judges was investigated by the AC₁ coefficient.

Results

The results of two judges differed for 11 of the 79 videos (13.9%), and five applicants (6.3%) ultimately failed the examination. The percentages of total points received by the applicants with endoscopic treatments, IVR, and surgery were 87.3%, 79.4%, and 80.8%, respectively. There were significant differences in the percentages between endoscopic treatments and IVR (P = 0.0015). The AC₁ coefficients were 0.84 for the applicants overall, 0.93 for endoscopic treatments, 0.66 for IVR, and 0.72 for surgery. Similarly, there were significant differences in the AC₁ coefficient between endoscopic treatments and IVR (P = 0.021).

Conclusions

The SQS for portal hypertension of the Japan Society for Portal Hypertension showed high reliability for video assessments by the judges. This system may contribute to the spread and further development of safe and effective treatments for portal hypertension in Japan.

The accuracy and interobserver variability in the assessment of coronary atherosclerotic plaques by optical frequency domain imaging: involving five observers with different levels of coronary imaging

Background

Whether optical frequency domain imaging (OFDI) images can realize pathological diagnosis of coronary atherosclerotic plaques, and whether its diagnostic accuracy of lesion types varies depending on the personal experience of the clinician caring for coronary intervention have not been elucidated.

Purpose

This study investigated the interobserver variability in characterizing atherosclerotic plaque types by OFDI for multiple OFDI observers with levels of different experience.

Methods

Three-hundred-thirty-three histological cross-sections from 21 autopsy hearts were co-registered with the corresponding OFDI images. Histological cross-sections were classified into the following 7 lesion types according to the modified AHA atherosclerosis classification by a single experienced pathologist blinded for OCT findings: adaptive intimal thickening (AIT), intimal xanthoma (IX), pathological intimal thickening (PIT), fibrous cap atheroma (FA), fibrocalcific plaque (FC), calcified nodule (CN), and healed erosion/rupture (HER). The five OFDI observers, unaware of the histological diagnosis, provided a single diagnosis for each corresponding OFDI image. The OFDI observer 1 was an expert interventional cardiologist with sufficient experience in OFDI imaging, followed by the OFDI observer 2, 3, and 4 as middle career interventional cardiologists who had completed training ten, seven, and four years. The OFDI observer 5 was a young career interventional cardiologist. The diagnostic accuracy of lesion types for each OFDI observer was determined taking histology as a gold standard.

Results

On histological analysis, 13% of histological cross-sections were diagnosed as AIT, 5% as IX, 23% as PIT, 25% as FA, 27% as FC, 2% as CN, and 5% as HER. The overall agreement between OFDI diagnosis and histopathologic diagnosis for OFDI observer 1 to 5 was 77%, 62%, 61%, 56%, and 46% (k values of 0.71, 0.54, 0.54, 0.45, and 0.33), respectively. Although the performance for characterizing AIT and FC was excellent and comparable among all OFDI observers, the sensitivity and positive predictive value for characterizing IX, PIT and FA varied depending on the OFDI observers' years of experience (Table). The main causes of false-positive or -negative diagnosis of FA were IX and PIT for all OFDI observers.

Conclusion

The diagnostic accuracy of atherosclerotic tissue properties from OFDI images correlated with the observers' years of experience, subspecialty training in coronary imaging, which suggests that the interpretation of OFDI images requires expertise and can be challenging to a less experienced reader.

Table 1

Funding Acknowledgement

Type of funding source: None

Successful Transcatheter Arterial Embolisation for a Traumatic Iliacus Hematoma: A Case Report

A traumatic iliacus hematoma is rare and usually occurs in patients after a fall involving a lower back injury. Although the hematoma may compress the femoral nerve causing femoral nerve palsy, the gold standard treatment for this condition has not been established. Here we report transcatheter arterial embolisation as a useful treatment strategy for a traumatic iliacus hematoma.

3284Quantification of macrophage presence and identification of thin-cap fibroatheroma by optical coherence tomography image: histopathological validation study

Background

Intracoronary optical coherence tomography (OCT) is thought to be capable of identifying a vulnerable, rupture-prone plaque based on the presence of a thin-cap fibroatheroma (TCFA). Moreover, recent studies have reported that OCT may be able to identify macrophage infiltration of the fibrous cap, a key characteristic of vulnerable plaque.

Purpose

This study evaluated the accuracy of OCT image for characterizing TCFA and identifying macrophage infiltration in comparison with histopathology.

Methods

A total of 924 focal plaques in 206 coronary arteries from 78 autopsy hearts were examined to compare OCT and histological images. By histology, 16 plaques (1.7%) were classified as TCFAsthat contained a large necrotic core covered by a thin (<65μm) fibrous-cap. Correlating OCT-histological sections were identified and OCT-derived tissue property indexes named normalized standard deviation (NSD) and signal attenuation ratio were applied on the fibrous-cap to identify inflamed fibrous-cap defined as a macrophage percentage >10% by histology.

Results

With histology as standard, the sensitivity, specificity, and negative-predictive-value of TCFAs were extremely high (more than 90%). However, the positive-predictive-value of TCFAs was only 32%, which indicated a high proportion of false-positives. Most false-positive diagnoses of OCT for TCFAs contained large amounts of foam cell accumulations on luminal surface without necrotic core. Twelve of 16 fibrous-caps were considered as inflamed and the remaining 4 were non-inflamed on histology. However, no significant difference in NSD and signal attenuation ratio were identified between them. There was moderate correlation of the fibrous-cap thickness between OCT and histology (r2 = 0.41 and p<0.01).

Conclusions

OCT is a promising intracoronary imaging modality for differentiating tissue characteristics (fibrous, calcified, or lipid-rich plaque) and identifying TCFA. However, it is still challenging to precisely identify inflammation, fibrous-cap thickness, and necrotic core in the native coronary artery. Therefore, careful interpretation is required to assess coronary vulnerable plaque by OCT.

Acknowledgement/Funding

None

107Diagnostic accuracy of optical coherence tomography for the identification of in-stent fibroatheroma following stent implantation: an ex-vivo histological validation study

Background

Previous histopathological studies have demonstrated that new atherosclerotic formation within the neointima, called neoatherosclerosis, is one of the most important mechanisms leading to both very late in-stent restenosis and stent thrombosis after stent implantation. Therefore, to distinguish lipid-containing atherosclerotic neointima from other tissues using intracoronary imaging modalities is clinically important to prevent late stent failures.

Purpose

This study evaluated the diagnostic performance of optical coherence tomography (OCT) for the detection of “in-stent fibroatheroma” following stent implantation by comparing cross-sections of the model with the corresponding histological images.

Methods

Fifty stented coronary arteries from the 31 autopsy hearts were imaged by OCT. Coronary arterial histopathological specimens, all of which included more than 30% of %neointimal hyperplasia, were compared with the corresponding OCT cross-sections. Histological in-stent fibroatheroma was defined as neointima containing large necrotic core and inflammatory cells. OCT-derived in-stent fibroatheroma comprised a low-intensity tissue containing a poorly delineated region with invisible stent strut behind low signal intensity.

Results

A total of 122 OCT cross-sections were compared with histological images. OCT examination revealed that 24 images (20%) contained low-intensity tissue inside the neointima. Of those, 5 images, in which stent strut behind low signal intensity was invisible, were diagnosed as OCT-derived in-stent fibroatheroma (4%) (Figure A). By histological analysis, only 4 images were classified as in-stent fibroatheroma (3%) (Figure B). With histology as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for OCT-derived in-stent fibroatheroma were 100%, 99%, 80%, 100%, and 99%, respectively. The only histological finding underlying the false-positive-diagnosis of OCT-derived in-stent fibroatheroma was foam cells accumulation without necrotic core on the neointimal surface (Figure C and D). Most tissue that showed low-intensity tissue with visible stent strut by OCT contained proteoglycan matrix and organized thrombus in the absence of an underlying necrotic core.

Coregistration of OCT with histology

Conclusion

This study showed the potential capability of OCT based on the visualization of stent struts behind low-intensity regions for discriminating in-stent fibroatheroma from other neointimal tissues following stent implantation.

11C-Choline positive but 18F-FDG negative pancreatic metastasis from renal cell carcinoma on PET

Choline is a new PET tracer, which uptake may occur via a choline-specific transporter protein and be accelerated during the proliferation of tumor cells. We report a 61-year-old woman with a metastatic pancreatic tumor from renal cell carcinoma, measuring 35×40 mm. PET scans demonstrated accumulation of ¹¹C-choline in the metastatic pancreatic tumor, but no accumulation of ¹⁸F-FDG. Choline PET/CT may play a useful and complementary imaging modality, especially when FDG-PET/CT does not show expected findings or when the evaluation of tumor viability is needed, in patients with renal cell carcinoma.

Diagnostic performance of 11C-choline PET/CT and bone scintigraphy in the detection of bone metastases in patients with prostate cancer

The aim of this study was to compare 11C-choline PET/CT and bone scintigraphy (BS) for detection of bone metastases in patients with prostate cancer. Twenty-one patients with histologically proven prostate cancer underwent 11C-choline PET/CT and BS before (n = 4) or after (n = 17) treatment. Patient-, region-, and lesion-based diagnostic performances of bone metastasis of both 11C-choline PET/CT and BS were evaluated using a five-point scale by two experienced readers. Bone metastases were present in 11 (52.4%) of 21 patients and 48 (32.7%) of 147 regions; 111 lesions were found to have bone metastases. Region-based analysis showed that the sensitivity, specificity, accuracy, and area under the receiver-operating-characteristic curves (AUC) of 11C-choline PET/CT were 97.9%, 99.0%, 98.6%, and 0.9989, respectively; those of BS were 72.9%, 99.0%, 90.5%, and 0.8386, respectively. Sensitivity, accuracy, and AUC significantly differed between the two methods (McNemar test, p = 0.0015, p = 0.0015, and p < 0.0001, respectively). 11C-choline PET/CT detected 110/111 metastatic lesions (99.1%); BS detected 85 (76.6%) (p < 0.0001). According to the CT morphological type, the visualization rates of 11C-choline-PET/BS were 100%/90.3% for the blastic type, 91.7%/8.3% for the lytic type, 100%/100% for the mixed type, and 100%/53.3% for the invisible type, respectively. Significant differences in blastic, lytic, and invisible types were observed between the two methods (p = 0.013, p = 0.0044, and p = 0.023, respectively). In conclusion, 11C-choline PET/CT had greater sensitivity and accuracy than BS for detection of bone involvement in patients with prostate cancer.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.

Structural basis of the redox switches in the NAD+-reducing soluble [NiFe]-hydrogenase

NAD⁺ (oxidized form of NAD:nicotinamide adenine dinucleotide)-reducing soluble [NiFe]-hydrogenase (SH) is phylogenetically related to NADH (reduced form of NAD⁺):quinone oxidoreductase (complex I), but the geometrical arrangements of the subunits and Fe-S clusters are unclear. Here, we describe the crystal structures of SH in the oxidized and reduced states. The cluster arrangement is similar to that of complex I, but the subunits orientation is not, which supports the hypothesis that subunits evolved as prebuilt modules. The oxidized active site includes a six-coordinate Ni, which is unprecedented for hydrogenases, whose coordination geometry would prevent O₂ from approaching. In the reduced state showing the normal active site structure without a physiological electron acceptor, the flavin mononucleotide cofactor is dissociated, which may be caused by the oxidation state change of nearby Fe-S clusters and may suppress production of reactive oxygen species.

Antithrombin III for portal vein thrombosis in patients with liver disease: A randomized, double-blind, controlled trial

AIM

Portal vein thrombosis (PVT) is one of the most critical disorders in liver disease patients. These patients have the imbalance of coagulation and coagulation inhibition resulting from decreased levels of coagulation inhibitory factors, such as protein C, protein S, and antithrombin III (AT-III). We designed this randomized, double-blind, placebo-controlled trial comparing the safety and efficacy of AT-III for PVT in liver disease patients with those who received no treatment.

METHODS

Eligible patients were diagnosed with the association of thrombus, without tumor thrombus, and thrombus in more than 50% of the cross-sectional lumen of the portal vein. Patients with 70% or less serum level of AT-III were included. The study drug was given up to three times in a 5-day consecutive infusion interval if the thrombus decreased in size. Efficacy was evaluated by contrast enhanced computed tomography using a five-grade scale (complete response, partial response, slight response, no response, and progression). From October 2014 through to March 2016, 36 patients were randomly assigned to the AT-III group and 37 patients to the placebo group.

RESULTS

The proportion of patients with complete response or partial response of PVT was significantly higher in the AT-III group (55.6%; 20/36 patients; 95% confidence interval, 38.1-72.1) than in the placebo group (19.4%; 7/36 patients, 95% confidence interval, 8.2-36.0) (P = 0.003). The overall incidence of adverse events and adverse drug reactions did not differ significantly between the two groups.

CONCLUSION

Antithrombin III is one of the essential therapies for patients with PVT in cases with lower concentration levels of AT-III.

Balloon-occluded retrograde transvenous obliteration of varices: focusing on the portal hemodynamics and the recent techniques

PURPOSE

To evaluate the recent topics of Ballloon-occluded retrograde trasnvenous obliteration(B-RTO).

METHOD

We overviewed the recent scientific papers regarding B-RTO.

RESULT

B-RTO is a treatment method for occluding varices retrogradely using a sclerosing agent under balloon occlusion of a major draining vein. It has been recognized as an effective treatment method for gastric varices. Hepatic function reserve is improved and liver volume is increased after B-RTO. In recent years, various technical options, such as plug-assisted retrograde transvenous obliteration, coil-assisted retrograde transvenous obliteration, or foam B-RTO, have also been reported. In performing B-RTO, portal hemodynamics must be thoroughly examined radiologically. Judging the classification of the grade of collateral venous hemodynamics is important to select the appropriate embolization technique of B-RTO and to successfully occlude varices. Finally, the word "portosystemic shunt syndrome" has been proposed and the condition should be considered while selecting a treatment for gastric varices.

CONCLUSION

B-RTO is effective for gastrointestinal varices and portosystemic shunts.

Prevalence of Gastric Motility Disorders in Patients with Functional Dyspepsia

Background/Aims

Gastric motility abnormalities have been considered to be pathophysiological features of functional dyspepsia (FD) that are closely related to dyspepsia symptoms, especially postprandial distress syndrome (PDS). The aims of this study are to (1) investigate the prevalence of gastric motility disorders and (2) evaluate the association between gastric motility abnormalities and dyspeptic symptoms using gastric scintigraphy in the PDS type of FD.

Methods

Forty healthy subjects and 94 PDS type FD patients were enrolled in the study. The volunteers and patients ingested a radiolabeled (technetium-99m) solid test meal, and scintigraphic images were recorded. Gastric accommodation and emptying were assessed by scintigraphic imaging. The patients’ dyspeptic symptoms were also explored using self-completed symptom questionnaires with 10 variables (4 scales, 0–3 points) at the same time.

Results

In 94 Japanese FD patients, the prevalence of impaired gastric accommodation and delayed emptying were 14.9% (14/94) and 10.6% (10/94), respectively. Gastric motility abnormalities were seen in 25.5% (24/94) of FD patients. There was no association between gastric motility abnormalities and dyspeptic symptoms.

Conclusions

Gastric motility abnormalities were seen in 25.5% of Japanese PDS type FD patients. However, there was no association between gastric motility abnormalities and dyspeptic symptoms on gastric scintigraphy.

Phase II trial of sorafenib combined with on-demand transarterial chemoembolization for advanced stage hepatocellular carcinoma (Barcelona Clinic Liver Cancer stage C): STAB study

e15648

Background: Sorafenib has been acknowledged as a standard treatment for advanced stage hepatocellular carcinoma (HCC). This study was conducted to evaluate the safety and efficacy of combination therapy of sorafenib and on-demand transarterial chemoembolization (TACE) for advanced stage HCC. Methods: Inclusion criteria were advanced stage HCC (Barcelona Clinic Liver Cancer stage C), a systemic chemotherapy native status, an Eastern Cooperative Oncology Group performance status 0–1, and a Child-Pugh grade-A. Sorafenib therapy (800 mg daily) was started 4–28 days after TACE. On-demand TACE was allowed. The primary endpoint was the completion rate of protocol treatment, which was defined as sorafenib administration at least for 2 months from initial TACE. Secondary endpoints were objective response rate (ORR), disease control rate (DCR) based on modified Response Evaluation Criteria in Solid Tumors, overall survival (OS), progression-free survival (PFS), and the incidence of adverse events. Results: From July 2013 to September 2015, a total of 32 patients were registered from 9 institutions, but one patient was excluded because his tumor turned out to be combined hepatocellular carcinoma and cholangiocarcinoma. The protocol treatment was completed in 28 of 31 enrolled patients (90.3%, 28/31). The median treatment duration was 7.0 months (range 0.5–30) with the median number of TACE was 1 (range 1–4) and the median sorafenib dosage of 400 mg daily (range 154-800). The ORR and DCR were 77% and 90%, respectively. Median OS and PFS were 17.3 months [95% confidence interval (CI), 11.9–22.6] and 5.4 months (95% CI, 4.6–6.2), respectively. The most common grade-3 or -4 adverse events were increased aspartate aminotransferase (55%, 17/31), increased alanine aminotransferase (45% 14/31), and hypertension (23%, 7/31). Conclusions: Combination therapy of sorafenib and on-demand TACE was well tolerated and safe. Furthermore, this combination treatment may provide a survival benefit to patients with advanced stage HCC. Clinical trial information: UMIN000014213.

A double-blind placebo controlled study of acotiamide hydrochloride for efficacy on gastrointestinal motility of patients with functional dyspepsia

BACKGROUND

Acotiamide is widely used to improve symptoms in patients with functional dyspepsia (FD) in multiple large-scale clinical studies, but there are few reports about the drug's mechanism of action. The aim of this study was to assess the effects of acotiamide on gastric accommodation and gastric emptying, gastrointestinal symptoms, and health-related quality of life (HR-QOL) in a placebo-controlled study.

METHODS

We conducted a randomized, double-blind placebo-controlled study. Fifty Japanese FD patients were randomly assigned to either placebo (n = 25) or acotiamide 100 mg × 3/day for 2 weeks (n = 25). At baseline and at 2 weeks of treatment, we evaluated the patients' gastric motility using scintigraphy to determine the accommodation and emptying values, gastrointestinal symptom rating scale (GSRS), HR-QOL (SF-8), and anxiety and depression scale (HADS).

RESULTS

Four patients failed to complete the medication regimen and were omitted from analysis; data from 24 placebo patients and 22 acotiamide patients were analyzed. Acotiamide significantly increased gastric accommodation compared to the placebo (p = 0.04 vs. p = 0.08; respectively). Acotiamide significantly accelerated gastric emptying (50 % half-emptying time) (p = 0.02 vs. p = 0.59). Acotiamide significantly improved the total GSRS scores compared to placebo (p = 0.0007 vs. p = 0.14). HR-QOL did not differ significantly between the two groups, but acotiamide significantly improved the HADS anxiety score compared to placebo (p = 0.04 vs. p = 0.20).

CONCLUSIONS

Our placebo-controlled study demonstrated that acotiamide significantly increased both gastric accommodation and gastric emptying in Japanese FD patients. Acotiamide also improved the patients' dyspeptic symptoms and anxiety score. Clinical Trials Registry no: UMIN000013544.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Pravastatin reduces radiation-induced damage in normal tissues

Pravastatin is an inhibitor of 3-hydroxy-3-methyl- glutaryl-coenzyme A reductase that has been reported to have therapeutic applications in a range of inflammatory conditions. The aim of the present study was to assess the radioprotective effects of pravastatin in an experimental animal model. Mice were divided into two groups: The control group received ionizing radiation with no prior medication, while the pravastatin group received pravastatin prior to ionizing radiation. Pravastatin was administered orally at 30 mg/kg body weight in drinking water at 24 and 4 h before irradiation. Intestinal crypt epithelial cell survival and the incidence of apoptosis in the intestine and lung were measured post-irradiation. The effect of pravastatin on intestinal DNA damage was determined by immunohistochemistry. Finally, the effect of pravastatin on tumor response to radiotherapy was examined in a mouse mesothelioma xenograft model. Pravastatin increased the number of viable intestinal crypts and this effect was statistically significant in the ileum (P<0.0001). The pravastatin group showed significantly lower apoptotic indices in all examined parts of the intestine (P<0.0001) and tended to show reduced apoptosis in the lung. Pravastatin reduced the intestinal expression of ataxia-telangiectasia mutated and gamma-H2AX after irradiation. No apparent pravastatin-related differences were observed in the response of xenograft tumors to irradiation. In conclusion, pravastatin had radioprotective effects on the intestine and lung and reduced radiation-induced DNA double-strand breaks. Pravastatin may increase the therapeutic index of radiotherapy.

11C-Choline-Avid but 18F-FDG-Nonavid Prostate Cancer with Lymph Node Metastases on Positron Emission Tomography

Choline is a new positron emission tomography (PET) tracer useful for detection of prostate cancer and metastatic lesions. We report a 70-year-old man with prostate cancer and multiple abdominal, pelvic, and inguinal node metastases. PET scans demonstrated accumulation of ¹¹C-choline in the primary tumor and lymph node metastases but no accumulation of ¹⁸F-FDG. Choline PET/computed tomography may be useful for diagnosis of advanced prostate cancer with suspected metastatic lesions and treatment planning.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Changes in liver stiffness on real-time tissue elastography before and after occlusion of spontaneous portosystemic shunts

PURPOSE

This study was conducted to evaluate changes in liver stiffness, volume, and function before and after occlusion of spontaneous portosystemic shunt.

MATERIALS & METHODS

Twenty-four patients (13 men and 11 women) with a mean age of 68.2 years±10.1 (SD) (age range, 49-82 years) underwent percutaneous occlusion of spontaneous portosystemic shunt because of gastric varices (n=17) or hepatic encephalopathy (n=7) from March 2011 to June 2013. The liver fibrosis index indicating liver stiffness was calculated by using ultrasound elastography before and after shunt occlusion. Liver volume and liver profile were also evaluated.

RESULTS

Spontaneous portosystemic shunt occlusion was uneventfully performed in all patients. The mean liver fibrosis index was significantly decreased from 2.7±1.0 before shunt occlusion to 2.0±0.9 (P<0.001) at 1 month, 2.2±1.0 at 3 months (P=0.004), and 1.6±0.7 at 6 months (P=0.001) afterwards. A significant increase in the liver volume was observed from 1035.3±340.1mL before shunt occlusion to 1116.8±298.4mL (P=0.006) at 1 month and 1174.2±354.1mL (P<0.001) at 3 months afterwards. Significant improvement in the Child-Pugh score was also found at 1 month (6.2±1.4, P<0.001), 3 months (6.5±1.1, P=0.022), and 6 months (6.0±0.9, P=0.004) after shunt occlusion as compared with that (7.2±1.9) before.

CONCLUSION

The liver stiffness decreases along with an increase in liver volume and improvement in liver function after spontaneous portosystemic shunt occlusion.

Polaprezinc protects normal intestinal epithelium against exposure to ionizing radiation in mice

Polaprezinc (PZ), an antiulcer drug, has been reported to have antioxidant effects. The purpose of the present study was to assess the radioprotective effects of PZ in the normal intestine of C57BL/6J mice. PZ was orally administered at 100 mg/kg body weight in the drinking water. Firstly, the present study compared the survival of normal intestinal crypt epithelial cells with mice that received PZ prior to or following irradiation. Next, the present study examined the sequential changes of the incidence of apoptosis in the normal intestine of mice that received irradiation. The mice that received PZ prior to irradiation demonstrated a stronger protective effect on the normal intestine compared with those that received PZ after irradiation. The present study therefore administrated PZ 2 h before irradiation in the subsequent experiments. The mice receiving PZ developed fewer apoptotic cells in the duodenum, jejunum and ileum. Radiation-induced cell death occurred with a peak at position 10 or lower from the base of the crypt axis, and was subsequently reduced by PZ treatment. Pretreatment with PZ protected the normal intestinal tissues from radiation-induced apoptosis.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

SUVmax on FDG-PET is a predictor of prognosis in patients with maxillary sinus cancer

PURPOSE

Our aim was to determine whether the maximum standardized uptake value (SUVmax) of the primary lesion demonstrated by [(18)F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is associated with the prognosis of maxillary sinus cancer.

MATERIALS AND METHODS

The relationships of clinicopathological factors including age, T stage, N stage, histologic type, treatment strategy, and primary tumor SUVmax with progression-free (PFS) and overall (OS) survival were evaluated using the log-rank test and Cox method in 31 patients with maxillary sinus cancer before combined superselective intra-arterial chemotherapy using high-dose cisplatin with concurrent radiotherapy, or radiotherapy alone.

RESULTS

The median duration of follow-up was 55.4 (range 9.7-72.6) months. PFS and OS of patients exhibiting a high SUVmax (≥16 and ≥17, respectively) for the primary tumor were significantly lower than those of patients for whom the primary tumor SUVmax was low (p = 0.0010 and p = 0.033, respectively). Multivariate analyses showed that T stage (p = 0.0049) and primary tumor SUVmax (p = 0.026) were independently prognostic of poorer PFS and that only primary tumor SUVmax (p = 0.049) was independently prognostic of poorer OS.

CONCLUSION

SUVmax of the primary tumor determined by FDG-PET/CT before treatment could be a good surrogate marker for prognostication of maxillary sinus cancer.

Correlation of the SUVmax of FDG-PET and ADC values of diffusion-weighted MR imaging with pathologic prognostic factors in breast carcinoma

PURPOSE

To correlate both primary lesion maximum standardized uptake values (SUVmax) of FDG-PET/CT, and apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) with clinicopathologic prognostic factors in patients with breast carcinoma.

MATERIALS AND METHODS

214 patients with 216 mass-type invasive breast carcinomas underwent whole-body FDG-PET/CT and 3-Tesla breast MRI including DWI before initial therapy. The primary tumor's SUVmax and ADC values were measured using FDG-PET/CT and DWI, respectively. Histologic analysis parameters included tumor size, expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67, nuclear grade, histology subtype, and axillary lymph node (LN) metastasis. The relationships among SUVmax, ADC values, and pathologic prognostic factors were evaluated.

RESULTS

The mean SUVmax and ADCmean were 5.63±3.79 (range, 1.2-24.17) and 894±204×10(-6)mm(2)/s (range, 452-1550×10(-6)), respectively. There was a significant but weak inverse correlation between the SUVmax and ADCmean values (correlation coefficient r=-0.30, p<0.0001). SUVmax was associated with numerous prognostic factors such as tumor size (p<0.0001), expression levels of ER (p=0.00041), PR (p=0.00028), HER2 (p=0.00021), and Ki-67 (p<0.0001), nuclear grade (p<0.0001), histology subtype (p=0.00061), axillary LN metastasis (p<0.0001), and TNM staging (p<0.0001). Meanwhile, ADCmean value was associated with tumor size (p=0.013), expression of Ki-67 (p=0.0010), histology subtype (p=0.00013), axillary LN metastasis (p=0.00059), and TNM staging (p=0.0011).

CONCLUSIONS

Primary tumor SUVmax on FDG-PET/CT has a stronger relationship with known prognostic parameters and may be a more useful for predicting the prognosis of breast carcinoma than ADC values.

Diagnostic and prognostic value of (18)F-FDG PET/CT for axillary lymph node staging in patients with breast cancer

PURPOSE

To investigate the diagnostic and prognostic value of (18)F-FDG-PET/CT for axillary lymph node (LN) staging in breast cancer patients, employing histologic evaluation as the reference.

METHODS

Among 196 patients with biopsy-proven breast cancer who had undergone (18)F-FDG-PET/CT before mastectomy or breast-conserving surgery with sentinel LN biopsy and/or axillary LN dissection, 200 axillae were retrospectively analyzed by visual assessment and quantitatively using SUVmax. LN SUVmax as well as other clinicopathological features were assessed for their prognostic value using the log-rank test and Cox method.

RESULTS

Metastasis was diagnosed histopathologically in 56 (28 %) axillae. The sensitivity, specificity, and accuracy of visual PET/CT for diagnosing node metastasis were 55.4, 95.8, and 84.5 %, respectively. When the optimal discriminative SUVmax cutoff was 1.5, these figures were 51.8, 97.2, and 84.5 %, respectively. Fourteen of 55 patients (25.5 %) with LN metastases suffered a recurrence during follow-up (median 39 months). Patients with a high nodal SUVmax (≥1.7) had a significantly lower progression-free survival rate than those with a low SUVmax (p = 0.0499). Axillary nodal and primary tumor SUVmax as well as estrogen receptor status were significantly associated with recurrence.

CONCLUSION

Axillary nodal SUVmax may be a prognostic indicator of disease recurrence in patients with axillary LN metastases.

Sub-classification of intermediate-stage (Barcelona Clinic Liver Cancer stage-B) hepatocellular carcinomas

Hepatocellular carcinoma (HCC), the fifth most common cancer in the world, shows increasing incidence worldwide. Curative treatments such as hepatectomy, liver transplantation, and radiofrequency ablation are applied in only 30%-60% of cases. Most remaining patients receive transarterial chemoembolization (TACE). Patients with intermediate-stage HCCs are regarded as good candidates for TACE. However, the intermediate stage includes non-homogeneous patients. Some movements are underway to stratify patients using prognostic factors to identify patient groups exhibiting greater benefit from TACE than other patient groups. This review describes two substaging systems that subclassify intermediate-stage HCCs and discusses the importance of dividing intermediate-stage patients.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment

Search results for nucleon decays p→e^{+}X, p→μ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→μ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of  273.4  kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→μ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32}  yr, τ_{np→μ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.

Diffusion-weighted magnetic resonance imaging for prediction of tumor response to neoadjuvant chemoradiotherapy using irinotecan plus S-1 for rectal cancer

The purpose of this study was to investigate the clinical value of diffusion-weighted (DW) magnetic resonance imaging (MRI) as a predictor of tumor response in patients receiving neoadjuvant chemoradiotherapy (NA-CRT) for rectal cancer (RC) through measurement of the apparent diffusion coefficient (ADC) value in each tumor. Neoadjuvant radiotherapy with a total dose of 45 Gy in 25 fractions was performed in all 16 patients with RC, combined with irinotecan and S-1. MRI was performed before and after NA-CRT. Multiple factors were assessed to predict the pathological response to NA-CRT. The pathological response rate was determined in 9 patients (56.3%). Statistical analyses indicated that the ADC value prior to NA-CRT was significantly lower in patients with a better response to NA-CRT (P=0.023). A cut-off value of 0.750×10^-3 mm²/sec obtained by a receiver operating characteristic curve analysis indicated a sensitivity of 77.8% and specificity of 85.7% for pathological responders to NA-CRT. In addition, the patients with lower ADC values exhibited a greater pathological response to NA-CRT (P=0.041). In conclusion, the ADC value of MRI of RC patients treated with NA-CRT followed by surgery may provide valuable information to predict the response to NA-CRT.

The threshold of hypothyroidism after radiation therapy for head and neck cancer: a retrospective analysis of 116 cases

The purpose of the present study was to determine the risk factors for developing thyroid disorders based on a dose-volume histograms (DVHs) analysis. Data from a total of 116 consecutive patients undergoing 3D conformal radiation therapy for head and neck cancers was retrospectively evaluated. Radiation therapy was performed between April 2007 and December 2010. There were 108 males and 8 females included in the study. The median follow-up term was 24 months (range, 1-62 months). The thyroid function was evaluated by measuring thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels. The mean thyroid dose, and the volume of thyroid gland spared from doses ≥10, 20, 30 and 40 Gy (VS10, VS20, VS30 and VS40) were calculated for all patients. The thyroid dose and volume were calculated by the radiotherapy planning system (RTPS). The cumulative incidences of hypothyroidism were 21.1% and 36.4% at one year and two years, respectively, after the end of radiation therapy. In the DVH analyses, the patients who received a mean thyroid dose <30 Gy had a significantly lower incidence of hypothyroidism. The univariate analyses showed that the VS10, VS20, VS30 and VS40 were associated with the risk of hypothyroidism. Hypothyroidism was a relatively common type of late radiation-induced toxicity. A mean thyroid dose of 30 Gy may be a useful threshold for predicting the development of hypothyroidism after radiation therapy for head and neck cancers.