Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

AI-based Virtual Synthesis of Methionine PET from Contrast-enhanced MRI: Development and External Validation Study

Background Carbon 11 (¹¹C)-methionine is a useful PET radiotracer for the management of patients with glioma, but radiation exposure and lack of molecular imaging facilities limit its use. Purpose To generate synthetic methionine PET images from contrast-enhanced (CE) MRI through an artificial intelligence (AI)-based image-to-image translation model and to compare its performance for grading and prognosis of gliomas with that of real PET. Materials and Methods An AI-based model to generate synthetic methionine PET images from CE MRI was developed and validated from patients who underwent both methionine PET and CE MRI at a university hospital from January 2007 to December 2018 (institutional data set). Pearson correlation coefficients for the maximum and mean tumor to background ratio (TBR_max and TBR_mean, respectively) of methionine uptake and the lesion volume between synthetic and real PET were calculated. Two additional open-source glioma databases of preoperative CE MRI without methionine PET were used as the external test set. Using the TBRs, the area under the receiver operating characteristic curve (AUC) for classifying high-grade and low-grade gliomas and overall survival were evaluated. Results The institutional data set included 362 patients (mean age, 49 years ± 19 [SD]; 195 female, 167 male; training, n = 294; validation, n = 34; test, n = 34). In the internal test set, Pearson correlation coefficients were 0.68 (95% CI: 0.47, 0.81), 0.76 (95% CI: 0.59, 0.86), and 0.92 (95% CI: 0.85, 0.95) for TBR_max, TBR_mean, and lesion volume, respectively. The external test set included 344 patients with gliomas (mean age, 53 years ± 15; 192 male, 152 female; high grade, n = 269). The AUC for TBR_max was 0.81 (95% CI: 0.75, 0.86) and the overall survival analysis showed a significant difference between the high (2-year survival rate, 27%) and low (2-year survival rate, 71%; P < .001) TBR_max groups. Conclusion The AI-based model-generated synthetic methionine PET images strongly correlated with real PET images and showed good performance for glioma grading and prognostication. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Correction: The role of ion solvation in lithium mediated nitrogen reduction

[This corrects the article DOI: 10.1039/D2TA07686A.].

The role of ion solvation in lithium mediated nitrogen reduction

Since its verification in 2019, there have been numerous high-profile papers reporting improved efficiency of lithium-mediated electrochemical nitrogen reduction to make ammonia. However, the literature lacks any coherent investigation systematically linking bulk electrolyte properties to electrochemical performance and Solid Electrolyte Interphase (SEI) properties. In this study, we discover that the salt concentration has a remarkable effect on electrolyte stability: at concentrations of 0.6 M LiClO₄ and above the electrode potential is stable for at least 12 hours at an applied current density of -2 mA cm^-2 at ambient temperature and pressure. Conversely, at the lower concentrations explored in prior studies, the potential required to maintain a given N₂ reduction current increased by 8 V within a period of 1 hour under the same conditions. The behaviour is linked more coordination of the salt anion and cation with increasing salt concentration in the electrolyte observed via Raman spectroscopy. Time of flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy reveal a more inorganic, and therefore more stable, SEI layer is formed with increasing salt concentration. A drop in faradaic efficiency for nitrogen reduction is seen at concentrations higher than 0.6 M LiClO₄, which is attributed to a combination of a decrease in nitrogen solubility and diffusivity as well as increased SEI conductivity as measured by electrochemical impedance spectroscopy.

[Development of Dose Management Software Using Visual Basic for Applications and Dose Evaluation in the Field of Nuclear Medicine]

PURPOSE

The purpose of this study was to develop software for smooth dose management based on the Japan diagnostic reference levels (DRLs 2020) in the field of nuclear medicine.

METHOD

Using the programming language Visual Basic for Applications (VBA), we implemented a function for calculating actual doses, a function for comparing doses at one's own facility with those of DRLs 2020, a function for calculating appropriate doses for pediatric nuclear medicine examinations, and so on. In addition, we evaluated actual doses before and after the software implementation.

RESULT

The software enabled easy calculation of actual doses and comparison with DRLs 2020 for smooth dose management. Furthermore, we were able to use the results of dose evaluation to determine the dosage at our facility and to use them as a reference for optimization.

CONCLUSION

In the field of nuclear medicine, it is possible to manage doses in accordance with DRLs 2020 by introducing own software into our clinical practice.

Visual and quantitative evaluation of microcalcifications in mammograms with deep learning-based super-resolution

PURPOSE

To evaluate visually and quantitatively the performance of a deep-learning-based super-resolution (SR) model for microcalcifications in digital mammography.

METHOD

Mammograms were consecutively collected from 5080 patients who underwent breast cancer screening from January 2015 to March 2017. Of these, 93 patients (136 breasts, mean age, 50 ± 7 years) had microcalcifications in their breasts on mammograms. We applied an artificial intelligence model known as a fast SR convolutional neural network to the mammograms. SR and original mammograms were visually evaluated by four breast radiologists using a 5-point scale (1: original mammograms are strongly preferred, 5: SR mammograms are strongly preferred) for the detection, diagnostic quality, contrast, sharpness, and noise of microcalcifications. Mammograms were quantitatively evaluated using a perception-based image-quality evaluator (PIQE).

RESULTS

All radiologists rated the SR mammograms better than the original ones in terms of detection, diagnostic quality, contrast, and sharpness of microcalcifications. These ratings were significantly different according to the Wilcoxon signed-rank test (p <.001), while the noise score of the three radiologists was significantly lower (p <.001). According to PIQE, SR mammograms were rated better than the original mammograms, showing a significant difference by paired t-test (p <.001).

CONCLUSION

An SR model based on deep learning can improve the visibility of microcalcifications in mammography and help detect and diagnose them in mammograms.

POS0728 ASSOCIATION BETWEEN TREATMENT GOAL ACHIEVEMENT AND GRIT PERSONALITY CHARACTERISTICS OF ATTENDING PHYSICIAN IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A MULTICENTER CROSS-SECTIONAL STUDY

Background

In clinical practice for systemic lupus erythematosus (SLE), the concept of “treat to target” has been introduced with an established goal of reducing glucocorticoid dose as much as possible while controlling disease activity. Although it has been shown that various personality characteristics of patients with SLE affect their disease activity and damage, it is not clear whether the personality characteristics of attending physicians affect the outcomes of patients with SLE. Grit is a personality trait characterized by perseverance and passion for achieving long-term goals.

Objectives

This study aims to evaluate the relationship between attending physicians’ grit personality characteristics and treatment goal achievements in patients with SLE.

Methods

A cross-sectional study was conducted on 386 patients with SLE in five referral hospitals in Japan. The main exposure was the “perseverance” and “consistency” (scores 1-5) of the attending physicians, as measured by the Short Grit Scale, and the primary outcome was the achievement of the Lupus Low Disease Activity Score (LLDAS). Considering the clustering of achievement of LLDAS by each attending physician, the association between attending physician’s personality and LLDAS was analyzed by logistic regression with cluster robust variance estimation. Odds ratios to assess the relationship between perseverance and consistency and LLDAS were estimated with adjustment for confounders (age, sex, disease duration, hydroxychloroquine use, immunosuppressant use, and Systemic Lupus International Collaborating Clinics-Damage Index). We used multiple imputation to handle the uncertainty caused by missing values of potential confounders on the assumption of missing at random.

Results

The median age of the patients was 45 years (interquartile range[IQR],36-56), 88% were female, and the median disease duration was 152 months(IQR, 80-240). Thirty-seven doctors were in charge of the patients (1-79 patients/each doctor). The median age of the attending physicians was 40 years (IQR, 35-43), and 19% were female. The median perseverance and consistency scores of attending physicians were 3.1 (IQR, 3.0-3.5) and 3.3 (IQR, 2.8-3.8), respectively. Of the enrolled patients, 154 (40%) had achieved LLDAS. The attending physicians with a lower consistency score of <3 were more frequent in the patients who achieved LLDAS (40% vs. 29%, p=0.026). The lower consistency score of attending physicians was still related to LLDAS independently (adjusted odds ratio 1.63, 95% confidential interval 1.17-2.27). There was no association between the achievement of LLDAS and perseverance.

Conclusion

The grit personality characteristics of the attending physician may affect the achievement of treatment goals in patients with SLE.

Disclosure of Interests

KEN-EI SADA Speakers bureau: I received speaker’s fees from Glaxo Smith Kline K.K., Grant/research support from: I received a research grant from Pfizer Inc., Yoshia Miyawaki: None declared, Kenta Shidahara: None declared, Shoichi Nawachi: None declared, Yu Katayama: None declared, Yosuke ASANO: None declared, Keigo Hayashi: None declared, Keiji Ohashi: None declared, Eri Katsuyama: None declared, Takayuki Katsuyama: None declared, Mariko Narazaki: None declared, Yoshinori Matsumoto: None declared, Nao Oguro: None declared, Yuichi Ishikawa: None declared, Natsuki Sakurai: None declared, Chiharu Hidekawa: None declared, Ryusuke Yoshimi: None declared, Takanori Ichikawa: None declared, Dai Kishida: None declared, Yasuhiro Shimojima: None declared, Noriaki Kurita: None declared, Nobuyuki Yajima: None declared

POS1475-HPR THE MINIMALLY IMPORTANT DIFFERENCE AS THE INTERPRETABILITY OF EMOTIONAL HEALTH DOMAIN IN JAPANESE VERSION OF LupusPRO FOR SLE PATIENTS; PRELIMINARY RESULTS OF A PROSPECTIVE COHORT STUDY

Background

The minimally important difference (MID) required to interpret the magnitude of changes in lupus patient-reported outcome (LupusPRO), which is a widely used outcome measure of quality of life in SLE patients, remains unclear.

Objectives

We report preliminary results of an ongoing prospective observational study that assesses the MID as the interpretability of emotional health (EH) domain in Japanese version of LupusPRO.

Methods

We recruited subjects at three university hospitals in Japan participating in an ongoing multidisciplinary cohort study (the Lupus registry of Nationwide institutions (LUNA). Of a total of 210 SLE patients enrolled during the 17-month recruitment period, patients with low disease activity, defined as SLE Disease Activity Index 2000 (SLEDAI-2K) ≤ 4, and who were seen at least twice of three months’ duration and responded to both the LupusPRO and health status change questions were included in this subcohort. The second questionnaire was given an allowance period of 30 days before or after the ​three months from starting date. Descriptive statistics were presented as means and standard deviations (SD) or counts and percentages (%). The emotional health score ranges from 0 to 100; a higher score indicates less frequent presence of symptoms. The change in health status was assessed using the 7-point Global Rating of Change 1), and the score = 0 and the score ≥ +1 were considered in the ‘unchanged’ and the minimal ‘improved’ category, respectively. MID was mainly estimated using the mean change of the groups with the score ≥ +1 as the anchor-based method, and the area under the curve (AUC) was also calculated as a sensitivity analysis to estimate MID thresholds 2) and 95% confidence intervals (CI) were constructed using 1000 bootstrapping.

Results

The mean age of the 24 eligible patients was 48 (SD 14), and 88% were female. The glucocorticoid dose, SLEDAI-2K, and Systemic Lupus International Collaborating Clinics /American College of Rheumatology Damage Index were 3.4 (2.1) mg, 1.0 (1.1) and 1.1 (1.9), respectively. The mean EH score was 67.5 (30.3), five patients (21%) had the maximum EH score at baseline, 73.4 (25.0) after three months, 7.2 (18.0) for the change in EH. The correlation coefficient and the AUC for the change in health status and the EH were 0.23 and 0.60. The mean changes were 4.1 (18.4) of the groups with ‘unchanged’ health status and 12.3 (17.1) of the groups with ‘improved’ health status. The MID for improvement was estimated at 12.3 using the anchor-based method, and the cutoff point corresponded to 9.3 [95%CI -6.7 to 25.3]) of the EH change score by the receiver operating curve method.

Conclusion

In this study, the MID (3 months) for the EH domain in the Japanese version of LupusPRO was estimated to be between 9 and 12, which was similar to the results of the previous cross-sectional study 3). The challenge in estimating the MID in our setting was the low correlation with external anchors, even though the study population was limited to patients with low disease activity, because disease activity at baseline can generally influence ‘improved’ health status.

References

[1]Kamper SJ, Maher CG, Mackay G. Global rating of change scales: a review of strengths and weaknesses and considerations for design. J Man Manip Ther. 2009;17(3):163.

[2]Froud R, Abel G. Using ROC curves to choose minimally important change thresholds when sensitivity and specificity are valued equally: the forgotten lesson of pythagoras. theoretical considerations and an example application of change in health status. PLoS One. 2014;9(12):e114468.

[3]Miyawaki Y, Shimizu S, Ogawa Y, et al. Association of glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS): a cross-sectional study. Arthritis Res Ther. 2021;23(1):79.

Acknowledgements

The authors thank Yuka Nakanou for her significant assistance in data management and Kikuko Miyazaki for her expert assistance on this topic.

Disclosure of Interests

Yoshia Miyawaki: None declared, Kenta Shidahara: None declared, Shoichi Nawachi: None declared, Yosuke ASANO: None declared, Yu Katayama: None declared, Keiji Ohashi: None declared, Eri Katsuyama: None declared, Takayuki Katsuyama: None declared, Mariko Narazaki: None declared, Yoshinori Matsumoto Speakers bureau: I received speaker’s fees from Glaxo Smith Kline K.K., KEN-EI SADA Speakers bureau: I received speaker’s fees from Glaxo Smith Kline K.K., Ryo Yanai: None declared, Nobuyuki Yajima: None declared, Ayuko Takatani: None declared, Kunihiro Ichinose: None declared, Jun Wada Speakers bureau: Jun Wada receives speaker honoraria from Astra Zeneca, Daiichi Sankyo, Novartis, Novo Nordisk Pharma, Tanabe Mitsubishi and receives grant support from Astellas, Baxter, Bayer, Chugai, Dainippon Sumitomo, Kyowa Kirin, Novo Nordisk Pharma, Ono, Otsuka, Tanabe Mitsubishi, and Teijin.

Deep learning-based detection of parathyroid adenoma by 99mTc-MIBI scintigraphy in patients with primary hyperparathyroidism

OBJECTIVE

It is important to detect parathyroid adenomas by parathyroid scintigraphy with 99m-technetium sestamibi (^99mTc-MIBI) before surgery. This study aimed to develop and validate deep learning (DL)-based models to detect parathyroid adenoma in patients with primary hyperparathyroidism, from parathyroid scintigrams with ^99mTc-MIBI.

METHODS

DL-based models for detecting parathyroid adenoma in early- and late-phase parathyroid scintigrams were, respectively, developed and evaluated. The training dataset used to train the models was collected from 192 patients (165 adenoma cases, mean age: 64 years ± 13, 145 women) and the validation dataset used to tune the models was collected from 45 patients (30 adenoma cases, mean age: 67 years ± 12, 37 women). The images were collected from patients who were pathologically diagnosed with parathyroid adenomas or in whom no lesions could be detected by either parathyroid scintigraphy or ultrasonography at our institution from June 2010 to March 2019. The models were tested on a dataset collected from 44 patients (30 adenoma cases, mean age: 67 years ± 12, 38 women) who took scintigraphy from April 2019 to March 2020. The models' lesion-based sensitivity and mean false positive indications per image (mFPI) were assessed with the test dataset.

RESULTS

The sensitivity was 82% [95% confidence interval 72-92%] with mFPI of 0.44 for the scintigrams of the early-phase model and 83% [73-92%] with mFPI of 0.31 for the scintigrams of the delayed-phase model in the test dataset, respectively.

CONCLUSIONS

The DL-based models were able to detect parathyroid adenomas with a high sensitivity using parathyroid scintigraphy with 99m-technetium sestamibi.

Diagnostic Accuracy of Diastolic Fractional Flow Reserve for Functional Evaluation of Coronary Stenosis

Background

In the resting conditions, narrowing the window of coronary pressure measurements from the whole cardiac cycle to diastole improves diagnostic performance of coronary pressure–derived physiological index. However, whether this also applies to the hyperemic conditions has not yet been thoroughly evaluated.

Objectives

The purpose of this study was to assess whether diastolic fractional flow reserve (diastolic FFR) has better diagnostic performance in identifying ischemia-causing coronary lesions than conventional FFR in a prospective, multicenter, and independent core laboratory–based environment.

Methods

In this prospective multicenter registry at 29 Japanese centers, we compared the diagnostic performance of FFR, diastolic FFR, resting distal to aortic coronary pressure (Pd/Pa), and diastolic pressure ratio (dPR) using myocardial perfusion scintigraphy (MPS) as the reference standard in 378 patients with single-vessel coronary disease.

Results

Inducible myocardial ischemia was found on MPS in the relevant myocardial territory of the target vessel in 85 patients (22%). In the receiver-operating curve analyses, diastolic FFR had comparable area under the curve (AUC) compared with FFR (AUC_{diastolic FFR}: 0.66; 95% confidence interval [CI]: 0.58-0.73, vs AUC_FFR: 0.66; 95% CI: 0.58-0.74, P = 0.624). FFR and diastolic FFR showed significantly larger AUCs than resting Pd/Pa (0.62; 95% CI: 0.54-0.70; P = 0.033 and P = 0.046) but did not show significantly larger AUCs than dPR (0.62; 95% CI: 0.55-0.70; P = 0.102 and P = 0.113).

Conclusions

Diastolic FFR showed a similar diagnostic performance to FFR as compared with MPS. This result reaffirms the use of FFR as the most accurate invasive physiological lesion assessment. (Diagnostic accuracy of diastolic fractional flow reserve (d-FFR) for functional evaluation of coronary stenosis; UMIN000015906)

Deep Learning-based Angiogram Generation Model for Cerebral Angiography without Misregistration Artifacts

Background Digital subtraction angiography (DSA) generates an image by subtracting a mask image from a dynamic angiogram. However, patient movement-caused misregistration artifacts can result in unclear DSA images that interrupt procedures. Purpose To train and to validate a deep learning (DL)-based model to produce DSA-like cerebral angiograms directly from dynamic angiograms and then quantitatively and visually evaluate these angiograms for clinical usefulness. Materials and Methods A retrospective model development and validation study was conducted on dynamic and DSA image pairs consecutively collected from January 2019 through April 2019. Angiograms showing misregistration were first separated per patient by two radiologists and sorted into the misregistration test data set. Nonmisregistration angiograms were divided into development and external test data sets at a ratio of 8:1 per patient. The development data set was divided into training and validation data sets at ratio of 3:1 per patient. The DL model was created by using the training data set, tuned with the validation data set, and then evaluated quantitatively with the external test data set and visually with the misregistration test data set. Quantitative evaluations used the peak signal-to-noise ratio (PSNR) and the structural similarity (SSIM) with mixed liner models. Visual evaluation was conducted by using a numerical rating scale. Results The training, validation, nonmisregistration test, and misregistration test data sets included 10 751, 2784, 1346, and 711 paired images collected from 40 patients (mean age, 62 years ± 11 [standard deviation]; 33 women). In the quantitative evaluation, DL-generated angiograms showed a mean PSNR value of 40.2 dB ± 4.05 and a mean SSIM value of 0.97 ± 0.02, indicating high coincidence with the paired DSA images. In the visual evaluation, the median ratings of the DL-generated angiograms were similar to or better than those of the original DSA images for all 24 sequences. Conclusion The deep learning-based model provided clinically useful cerebral angiograms free from clinically significant artifacts directly from dynamic angiograms. Published under a CC BY 4.0 license. Supplemental material is available for this article.

AB0387 TREATMENT STATUS FOR OSTEOPOROSIS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: CROSS-SECTIONAL ANALYSIS FROM A LUPUS REGISTRY OF NATIONWIDE INSTITUTIONS (LUNA)

Background:

Osteoporosis is one of the most important adverse effects of glucocorticoids in patients with systemic lupus erythematosus (SLE). Because osteoporosis is accelerated by chronic kidney disease (CKD), more attention should be paid to the treatment for osteoporosis in SLE patients with CKD. Many treatment options for osteoporosis have emerged recently, but treatment status in patients with SLE is not elucidated.

Objectives:

The purpose of this study is to elucidate the treatment status for osteoporosis in patients with SLE among the CKD stages.

Methods:

Using data from lupus registry of nationwide institutions (LUNA), a cross-sectional analysis was performed. We firstly described treatment status for osteoporosis in all enrolled patients. Secondary, treatment status for osteoporosis was compared among CKD stages. Finally, bone damage in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) was compared among CKD stages.

Results:

The median age (interquartile range [IQR]) of enrolled 917 patients was 44 (34- 57) years and 809 patients (88%) were female. CKD stages were follows: CKD stage 1, 234 (26%); CKD stage 2, 465 (51%); CKD stage 3, 189 (21%); CKD stage 4, 9 (1%); CKD stage 5, 16 (2%). Median (IQR) age, female sex, and median (IQR) previous maximum dose of prednisolone in patients with and without CKD (≥CKD stage 3) were 56 (46.5-66) and 41 (32-50), 191 (89%) and 615 (88%), and 40 (30-60) and 40 (30-55) mg/day, respectively. Bisphosphonate was administered in 388 (42%) patients, vitamin D supplements in 448 (49%), Ca supplements in 36 (4%), denosumab in 20 (2%) and teriparatide in 14 (2%), respectively. Of enrolled patients, any treatment for osteoporosis was not administered in 226 (25%) patients. In spite of more frequent bone damage in patients with CKD compared to those without CKD (15% vs 10%, p=0.036), treatment status did not differ between patients with and without CKD (bisphosphonate: 41% vs 46%, p=0.29; vitamin D supplements: 50% vs 44%, p=0.14).

Conclusion:

About a quarter of patients with SLE did not take any treatment for osteoporosis. Treatment for osteoporosis might be strengthened to prevent bone damage in SLE patients with CKD.

Disclosure of Interests:

KEN-EI SADA Speakers bureau: I received speaker’s fee from GSK and Astra Zeneca K.K., Keigo Hayashi: None declared, Yosuke ASANO: None declared, Yu Katayama: None declared, Sumie Hiramatsu Asano: None declared, Keiji Ohashi: None declared, Michiko Morishita: None declared, Haruki Watanabe: None declared, Mariko Narazaki: None declared, Yoshinori Matsumoto: None declared, Nobuyuki Yajima: None declared, Ryusuke Yoshimi: None declared, Yasuhiro Shimojima: None declared, Shigeru Ono: None declared, Hiroshi Kajiyama: None declared, Kunihiro Ichinose: None declared, Shuzo Sato: None declared, Michio Fujiwara: None declared, Jun Wada: None declared

P3576Histopathological validation of optical coherence tomography assessment for cholesterol crystals

Background

Cholesterol crystals (CCs) are well recognized as one of important components of advanced atherosclerotic plaques. Whilethe consensus document for intravascular optical coherence tomography (OCT) has proposed that CCs are appeared as thin, linear regions of high-signal intensity within a plaque, no study has validated CCs assessment by OCT in comparison with histopathology.

Purpose

Thepurpose of this study was to validate OCT assessments of CCs with histopathology.

Methods

A total of 27 diseased coronary artery samples (10–20 mm length) were resected from 7 randomly selected cadavers. OCT imaging was performed for the samples. Then, arterial samples were fixed in 10% formalin for ≥48 hours, decalcified and processed for standard paraffin embedding. Sections 5μm thick were sliced at the ink-marked imaging sites and stained with hematoxylin and eosin, and Masson's Trichrome. An independent pathologist blinded to the OCT results diagnosed all of the plaques. Subsequently, the OCT images were interpreted by an observer blinded to the histological results. In the OCT assessment, CCs were defined as thin, linear regions of high-signal intensity within a plaque.

Results

We obtained 27 pairs of OCT/ histopathology. CCs were diagnosed by histology in 10 (37%) of the 27 pairs. The sensitivity and specificity of OCT for detecting CCs were 60% and 94%, respectively.

Conclusion

OCT has a high specificity but modest sensitivity for detection of CCs in comparison with histopathology. CCs diagnosed with OCT would help the identification of advanced atherosclerotic plaques.

Acknowledgement/Funding

JSPS KAKENHI 17K09557

P3387Cholesterol crystals in superficial plaque layer detected by optical coherence tomography as a new morphological feature for plaque rupture

Background

While plaque rupture (PR) is the leading cause of acute myocardial infarction (AMI), other etiologies are also involved in the onset of AMI. Cholesterol crystals (CCs) are usually present abundantly in atherosclerotic plaques, especially in the culprit site of AMI. However, the relationship between in vivo CCs and PR is unclear. Optical coherence tomography (OCT) is a high-resolution imaging technique that allows for the in vivo identification of various plaque characteristics including PR and CCs.

Purpose

The aim of this study was to investigate prevalence and distribution of CCs between patients with AMI with PR, AMI without PR, and SAP.

Method

This study consisted of 146 patients with coronary artery disease (AMI with PR; n=64, AMI without PR; n=41, and SAP; n=41) who underwent OCT prior to percutaneous coronary intervention. Plaque characteristics in OCT images were assessed according to the consensus document. We classified the distribution of CCs as follows; superficial type CCs were defined by any of the CCs invading the fibrous cap and remaining CCs as deep type CCs.

Result

There was no statistical difference in clinical characteristics among the three groups. The % diameter stenosis was significantly smaller in the SAP group than others (AMI with PR 91±12% vs. AMI without PR 86±13% vs. SAP 65±9%, p<0.001). The prevalence of CCs was significantly higher in the AMI with PR group than others (AMI with PR 78% vs. AMI without PR 41% vs. SAP 39%, p<0.001). The prevalence of superficial type CCs was significantly different among the groups (AMI with PR 72% vs. AMI without PR 24% vs. SAP 7%, p<0.001). Multivariable logistic analysis demonstrated that lipid plaque (OR 84.5, 95% CI [6.30–11332.33], p<0.001) and superficial type CC (OR 9.5, 95% CI [2.61–34.89], p<0.001) were independent predictors of PR.

Conclusion

Plaque with CCs invading the fibrous cap is frequently associated with PR in patients with AMI, suggesting. In vivo CC detection is a new morphological feature for plaque rupture.

Acknowledgement/Funding

This study was supported by a grant from JSPS KAKENHI (17K09557).

102Diagnosis of coronary plaque rupture, plaque erosion, and calcified nodule by using near-infrared spectroscopy intravascular ultrasound

Objectives

This study sought to investigate the ability of near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) to differentiate among plaque rupture (PR), plaque erosion (PE), and calcified nodule (CN) in acute myocardial infarction (AMI) using an optical coherence tomography (OCT) diagnosis as a reference standard.

Background

In vivo, precise differentiation among PR, PE and CN is a major challenge for intravascular imaging.

Methods

The study enrolled 156 AMI patients who had a de novo culprit lesion in a native coronary artery. The culprit lesions were assessed by both NIRS-IVUS and OCT.

Results

OCT identified 112 PR, 29 PE, and 15 CN. IVUS-detected plaque ulceration showed a high specificity (100%) to identify OCT-PR although the sensitivity (62%) was intermediate. IVUS-detected convex calcium showed a high sensitivity (93%) and specificity (100%) to identify OCT-CN. In NIRS, the maximum lipid core burden index in 4 mm (maxLCBI4mm) was greatest in OCT-PR (values are median [interquartile range]) (671 [530 to 853]), followed by OCT-CN (355 [303 to 432]) and OCT-PE (283 [89 to 357]) (p<0.001). MaxLCBI4mm of <422 was the best cut-off to discriminate OCT-PE from OCT-PR and OCT-CN. The NIRS-IVUS classification algorithm using plaque ulceration, convex calcium, and maxLCBI4mm <422 showed a sensitivity and specificity of 96% and 95% for identifying OCT-PR, 93% and 95% for OCT-PE, and 93% and 100% for OCT-CN, respectively.

NIRS-IVUS classification algorism

Conclusion

Lipid component assessed by NIRS-IVUS was different among OCT-PR, OCT-PE and OCT-CN. The NIRS-IVUS classification algorism was highly sensitive and specific for differentiating these unstable lesion types in AMI.

Acknowledgement/Funding

None

Two Cases of Equine Multinodular Pulmonary Fibrosis in Japan

Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with equine herpesvirus type 5 (EHV-5). This disease has been reported in North and South America, Europe and Oceania but not, to our knowledge, in horses in Japan. We diagnosed EMPF in two Thoroughbred horses in Japan on the basis of gross and histopathological findings. In both cases, significant gross lesions, restricted to the lungs, consisted of numerous firm and coalescing nodules widely distributed throughout the lung. The nodules were <3 cm in diameter and pale white to tan in colour. Microscopically, they showed severe interstitial fibrosis and infiltration of macrophages, neutrophils, lymphocytes and a few eosinophils. The residual alveoli were lined by cuboidal epithelial cells (type II pneumocytes) and filled with many macrophages, which rarely displayed oval eosinophilic to amphophilic intranuclear inclusion bodies. Polymerase chain reaction and sequence analyses identified the glycoprotein H gene of EHV-5, and in-situ hybridization detected EHV-5 in the alveolar macrophages in the lesions. In one case, electron microscopy revealed herpesvirus-like particles and EHV-5 was isolated from pulmonary lesions.

[Using Super Resolution to Denoise on PET Images]

A high-resolution display panel comes to practical use, but the resolution of the indicated contents does not change. The up-sampling processing is applied to indication of the low-resolution contents. In the up-sampling process, the super resolution enables an up-sampling process which estimates information of high frequency components lost by sampling while analyzing input images is noticed. In this paper, we aimed at reconstructing an image of normal resolution in which the influence of statistical noise is reduced by applying super resolution after down-sampling processing is applied to positron emission tomography (PET) image with many statistical noises. To evaluate the noise reduction effect, we compared it with the Gaussian filter which is frequently used to reduce the influence of the statistical noise of the PET image. A 3D Hoffman brain phantom was used to evaluate objectively by peak signal-to-noise ratio and power spectral density. The objective index of the PET image applying super resolution is positive results, suggesting the possibility of being useful as compared with the conventional method.

Deep Learning for MR Angiography: Automated Detection of Cerebral Aneurysms

Purpose To develop and evaluate a supportive algorithm using deep learning for detecting cerebral aneurysms at time-of-flight MR angiography to provide a second assessment of images already interpreted by radiologists. Materials and Methods MR images reported by radiologists to contain aneurysms were extracted from four institutions for the period from November 2006 through October 2017. The images were divided into three data sets: training data set, internal test data set, and external test data set. The algorithm was constructed by deep learning with the training data set, and its sensitivity to detect aneurysms in the test data sets was evaluated. To find aneurysms that had been overlooked in the initial reports, two radiologists independently performed a blinded interpretation of aneurysm candidates detected by the algorithm. When there was disagreement, the final diagnosis was made in consensus. The number of newly detected aneurysms was also evaluated. Results The training data set, which provided training and validation data, included 748 aneurysms (mean size, 3.1 mm ± 2.0 [standard deviation]) from 683 examinations; 318 of these examinations were on male patients (mean age, 63 years ± 13) and 365 were on female patients (mean age, 64 years ± 13). Test data were provided by the internal test data set (649 aneurysms [mean size, 4.1 mm ± 3.2] in 521 examinations, including 177 male patients and 344 female patients with mean age of 66 years ± 12 and 67 years ± 13, respectively) and the external test data set (80 aneurysms [mean size, 4.1 mm ± 2.1] in 67 examinations, including 19 male patients and 48 female patients with mean age of 63 years ± 12 and 68 years ± 12, respectively). The sensitivity was 91% (592 of 649) and 93% (74 of 80) for the internal and external test data sets, respectively. The algorithm improved aneurysm detection in the internal and external test data sets by 4.8% (31 of 649) and 13% (10 of 80), respectively, compared with the initial reports. Conclusion A deep learning algorithm detected cerebral aneurysms in radiologic reports with high sensitivity and improved aneurysm detection compared with the initial reports. © RSNA, 2018 See also the editorial by Flanders in this issue.

Differentiation of Brain Metastases and Gliomas Based on Color Map of Phase Difference Enhanced Imaging

Background and objective: Phase difference enhanced imaging (PADRE), a new phase-related MRI technique, can enhance both paramagnetic and diamagnetic substances, and select which phases to be enhanced. Utilizing these characteristics, we developed color map of PADRE (Color PADRE), which enables simultaneous visualization of myelin-rich structures and veins. Our aim was to determine whether Color PADRE is sufficient to delineate the characteristics of non-gadolinium-enhancing T2-hyperintense regions related with metastatic tumors (MTs), diffuse astrocytomas (DAs) and glioblastomas (GBs), and whether it can contribute to the differentiation of MTs from GBs.

Methods: Color PADRE images of 11 patients with MTs, nine with DAs and 17 with GBs were created by combining tissue-enhanced, vessel-enhanced and magnitude images of PADRE, and then retrospectively reviewed. First, predominant visibility of superficial white matter and deep medullary veins within non-gadolinium-enhancing T2-hyperintense regions were compared among the three groups. Then, the discriminatory power to differentiate MTs from GBs was assessed using receiver operating characteristic analysis.

Results: The degree of visibility of superficial white matter was significantly better in MTs than in GBs (p = 0.017), better in GBs than in DAs (p = 0.014), and better in MTs than in DAs (p = 0.0021). On the contrary, the difference in the visibility of deep medullary veins was not significant (p = 0.065). The area under the receiver operating characteristic curve to discriminate MTs from GBs was 0.76 with a sensitivity of 80% and specificity of 64%.

Conclusion: Visibility of superficial white matter on Color PADRE reflects inferred differences in the proportion of vasogenic edema and tumoral infiltration within non-gadolinium-enhancing T2-hyperintense regions of MTs, DAs and GBs. Evaluation of peritumoral areas on Color PADRE can help to distinguish MTs from GBs.

Scatter Correction of Septal Penetration for 123I-IMP Cerebral Blood Flow SPECT Adding Radioactivity from the Outside of Field of View-Comparison between Simulation-based and Multi-window Scatter Corrections

PURPOSE

The N-Isopropyl-p-[123I] Iodoamphetamine (¹²³I-IMP) SPECT imaging reduces the image quality and quantitative accuracy due to scatter and septal penetration occurred by radioactive uptake from outside of the field of view such as the lungs. We evaluated the influence of scatter and septal penetration using phantom-simulated radioactivity from outside of the field of view, and subsequently compared the effect of scatter and septal penetration corrections between the simulation-based effective scatter source estimation (ESSE) method and the multi-window method (ellipse approximation method).

METHODS

We used the phantom filled with 10 and 25 kBq/mL for the brain and lung parts corresponding to radioactive concentration in the clinical study. The SPECT images were acquired with and without lung phantom using low-energy high-resolution (LEHR) and cardiac high-resolution (CHR) collimators. We quantitatively evaluated a brain phantom by count analysis and coefficient of variation as reference data without lung phantom simulated the radioactivity from outside of the field of view, and compared between two scatter corrections by each collimator.

RESULTS

The brain count in cerebral base with the ESSE method using LEHR collimator was higher than that of the ellipse approximation method. The whole brain count with the ellipse approximation method using CHR collimator shows 28.8% lower than the ESSE method, so that it suggests that the ellipse approximation method for LEHR collimator and the ESSE method for CHR collimator was close to reference counts. The coefficient of variation of the ESSE method was lower than that of the ellipse approximation method for both two collimators.

CONCLUSIONS

It was possible to correct the scatter and penetration from outside the field of view with high accuracy, by using the ellipse approximation method with LEHR collimator and the ESSE method with CHR collimator.

Intraoperative 5-aminolevulinic acid-induced photodynamic diagnosis of metastatic brain tumors with histopathological analysis

BACKGROUND

Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) is a promising real-time navigation method in the surgical resection of malignant gliomas. In order to determine whether this method is applicable to metastatic brain tumors, we evaluated the usefulness of intraoperative fluorescence patterns and histopathological features in patients with metastatic brain tumors.

METHODS

We retrospectively reviewed the cases of 16 patients with metastatic brain tumors who underwent intraoperative 5-ALA fluorescence-guided resection. Patients were given 20 mg/kg of 5-ALA orally 2 h prior to the surgery. High-powered excitation illumination and a low-pass filter (420, 450, or 500 nm) were used to visualize the fluorescence of protoporphyrin IX (PpIX), the 5-ALA metabolite. We evaluated the relationships between the fluorescence and histopathological findings in both tumoral and peritumoral brain tissue.

RESULTS

Tumoral PpIX fluorescence was seen in only 5 patients (31%); in the remaining 11 patients (69%), there was no fluorescence in the tumor bulk itself. In 14 patients (86%), vague fluorescence was seen in peritumoral brain tissue, at a thickness of 2-6 mm. The histopathological examination found cancer cell invasion of adjacent brain tissue in 75% of patients (12/16), at a mean ± SD depth of 1.4 ± 1.0 mm (range 0.2-3.4 mm) from the microscopic border of the tumor. There was a moderate correlation between vague fluorescence in adjacent brain tissue and the depth of cancer cell invasion (P = 0.004).

CONCLUSION

Peritumoral fluorescence may be a good intraoperative indicator of tumor extent, preceding more complete microscopic gross total resection.

TRIAL REGISTRATION

Institutional Review Board of Osaka Medical College No. 42, registered February 17, 1998, and No. 300, registered April 1, 2008. They were retrospectively registered.

Influence of carbonization temperature and press processing on the electrochemical characteristics of self-standing iron oxide/carbon composite electrospun nanofibers

Schematic illustration of self-standing active material composite carbon nanofibrous electrodes for lithium ion battery applications.

Understanding the Scatter Radiation Distribution during C-arm CT Examination: A Body Phantom Study

The purpose of this study was to understand the scatter radiation distribution during C-arm CT examination in the interventional radiography (IVR) room to show the escaped area and the radiation protective method. The C-arm rotates 200° in 5 s. The tube voltage was 90 kV, and the entrance dose to the detector was 0.36 μGy/frame during C-arm CT examination. The scattered doses were measured each 50 cm from the isocenter like a grid pattern. The heights of the measurement were 50, 100, and 150 cm from the floor. The maximum scattered doses were 38.23±0.60 μGy at 50 cm, 43.86±0.20 μGy at 100 cm, and 25.78±0.37 μGy at 150 cm. The scatter radiation distribution at 100 cm was the highest scattered dose. The operator should protect their reproductive gland, thyroid, and lens. The scattered dose was low behind the C-arm body and the bed, so they will be able to become the escaped area for staff.

A Predictive Model of Plasma Lamotrigine Levels

Introduction: Lamotrigine is one of several mood stabilizers and its effects for the treatment and prevention of depressive episodes, particularly in bipolar disorder, are generally accepted. Although the findings about a therapeutic window of lamotrigine are yet to be determined, it seems important to obtain information on individual pharmacokinetic peculiarities. This study was conducted to formulate the predictive model of plasma lamotrigine levels. Methods: Using the data of 47 patients whose lamotrigine levels, liver function, and renal function were measured, predictive models of lamotrigine levels were formulated by stepwise multiple regression analyses. The predictive power of the models was compared using another dataset of 25 patients. Results: Two models were created using stepwise multiple regression. The first model was: plasma lamotrigine level (μg/mL)=2.308+0.019×lamotrigine dose (mg/day). The second model was: plasma lamotrigine level (μg/mL)=0.08+0.024×lamotrigine dose (mg/day)+4.088×valproate combination (no=0, yes=1). The predictive power of the second model was better than that of the first model. Discussion: The present study proposes a prompt and relatively accurate equation to predict lamotrigine levels.

Usefulness of standardized uptake value normalized by individual CT-based lean body mass in application of PET response criteria in solid tumors (PERCIST)

Our aim in this study was to verify the usefulness of the standardized uptake value (SUV) normalized by individual CT-based lean body mass (LBMCT) in application of PET response criteria in solid tumors (PERCIST).We retrospectively investigated 14 patients (4 male and 10 female) with malignant lymphoma who were undergoing chemotherapy. (18)F-FDG PET/CT examinations were performed before and after chemotherapy. The LBMCT was calculated by estimation of fat weight from CT data (from skull base to pelvis). The mean ± standard deviation (SD) and the Bland-Altman plot were used for comparison among body weight, LBMCT, and LBM derived from a predictive equation (LBMPE). Indices for FDG uptake in the liver were: SUV, SUV based on LBMPE (SULPE), and SUV based on LBMCT (SULCT). Overall differences between the uptake values were analyzed by one-way ANOVA. If the ANOVA showed significance, differences between uptake values were investigated further by use of the Tukey-Kramer test. The mean values of body weight, LBMPE, and LBMCT were: 55.4 ± 14.9 (39.0-112.0), 43.0 ± 10.5 (31.3-75.2), and 35.3 ± 9.8 (23.4-75.8) kg, respectively. There was a wide dispersion between LBMPE and LBMCT (differences, 7.6 ± 3.6 kg; 95 % CI, 6.42-8.85). LBMPE was higher than LBMCT in all the cases except in Case 11. The mean uptake values significantly differed among SUV, SULPE, and SULCT (F = 68.3, p < 0.05). Whereas SULPE deviated from PERCIST criteria in seven patients, SULCT satisfied the criteria except in one case. These results suggest that liver SULCT is useful for application of PERCIST.

[Clinical Experience of Dual-phase Cone Beam Computed Tomography during Hepatic Arteriography to Apply 3D-DSA]

We report on the methods and experiences of the dual-phase cone beam computed tomography during hepatic arteriography (CBCTHA) to apply the 3D-DSA. A total of 32 ml contrast medium (150 mgI/ml) was injected at the rate of 2.0 ml/s for 16 s. The early phase scan was initiated 10 s after the start of contrast media injection. The delayed phase scan was started 40 s after that (24 s after the end of CM injection). When using the dual phase CBCTHA, it was able to obtain the classical hepatocellular carcinoma (HCC) images same as computed tomography during hepatic arteriography (CTHA). In the early phase, the tumor can be highly enhanced against the liver parenchyma. In delayed phase, corona enhancement was clearly appeared at the liver parenchyma. Of 58 cases of acquisitions, we experienced six cases with miss breath holding and 14 cases with over the field of view (FOV) due to hepatomegaly. We evaluated the tumor contrast in 18 cases because the other 40 cases were not applied to our criteria. The pixel values of ROIs on the tumor, coronal enhancement, and liver parenchyma were measured, respectively. Then, we calculated tumor-parenchyma contrast (T-P contrast), corona-tumor contrast (C-T contrast), and corona-parenchyma contrast (C-P contrast). The T-P contrast was 358±112, the C-T contrast was 132±51, and the C-P contrast was 168±66. The contrast was clearly visualized among them. The dual-phase CBCTHA that applies the 3D-DSA is a simple and useful technique for hepatocellular carcinoma treatment.

Reply to the letter from Grunze and Walden

Professors Grunze and Walden sent a letter associated with our article. In this letter, we reply to their comments.

Multi-drug-resistant Staphylococcus aureus and future chemotherapy

Staphylococcus (S.) aureus silently stays as our natural flora, and yet sometimes threatens our life as a tenacious pathogen. In addition to its ability to outwit our immune system, its multi-drug resistance phenotype makes it one of the most intractable pathogenic bacteria in the history of antibiotic chemotherapy. It conquered practically all the antibiotics that have been developed since 1940s. In 1961, the first MRSA was found among S. aureus clinical isolates. Then MRSA prevailed throughout the world as a multi-resistant hospital pathogen. In 1997, MRSA strain Mu50 with reduced susceptibility to vancomycin was isolated. Vancomycin-intermediate S. aureus (VISA), so named according to the CLSI criteria, was the product of adaptive mutation of S. aureus against vancomycin that had long been the last resort to MRSA infection. Here, we describe the genetic basis for the remarkable ability of S. aureus to acquire multi-antibiotic resistance, and propose a novel paradigm for future chemotherapy against the multi-resistant pathogens.

Long-term complete remission of multiple extranodal natural killer/T-cell-type posttransplant lymphoproliferative disorder after surgical resection: a case report

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of organ transplantation that results from immunosuppression therapy. Most cases of PTLD derive from the B-cell lineage. T-cell PTLD, particularly natural killer (NK)/T-cell PTLD, is quite rare; only a few cases have been described.

CASE REPORT

A 42-year-old woman received a living-related renal allograft from her father. Sixteen years after transplantation, the patient presented with a 1-week history of low-grade fever and epigastralgia. Computed tomography revealed intestinal masses and a right upper lung lobe mass. Gallium scintigraphy showed uptake in the abdominal mass. Epstein-Barr virus-related antibody was not detected in the patient's serum sample. We performed extirpation of the jejunum and ileum tumors. The pathologic findings showed that these 2 tumors were NK/T-cell lymphoma. After the operation, the lung mass rapidly enlarged, and right upper lobectomy was performed. The right upper lung lobe tumor showed the same histopathologic findings as the small bowel tumor. The final histologic diagnosis was established as multiple extranodal NK/T cell type PTLD of the small bowel and right upper lung lobe.

CONCLUSIONS

After reduction of the immunosuppressive agent, no recurrence of PTLD has been observed for the past 9 years.

In vivo evaluation of lateral lipid chain packing in human stratum corneum

BACKGROUND/AIMS

The matrix of intercellular lipids (ICL) of stratum corneum (SC) plays an important role in the barrier function of SC. It is important to understand the structure of the ICL matrix for dermatology and cosmetic science. Several methods exist for the analysis of the structure; however, it is difficult to conduct these analyses noninvasively.

METHODS

We have developed a method for the analysis of the lateral packing of ICL using Raman spectroscopy. As a proof-of-principle experiment, we prepared a human SC sheet sample and analyzed its structure by the proposed method and by a conventional method involving X-ray diffraction. We compared the results of both methods. In addition, we applied the proposed method to living human skin, and we analyzed the lateral packing of ICL of SC taken from three separate body sites.

RESULTS

The results of our method corresponded to those of the conventional method. We detected regional differences of ICL lateral packing using our method in vivo. The results indicated that the packing of ICL in SC taken from the forearm and upper arm are more ordered than that taken from the cheek.

CONCLUSION

The results verify that our developed method allows the evaluation of the lateral packing of ICL inside the SC layer of the skin in vivo. Using this method, we can detect regional differences of SC samples taken from various body sites.

Valproic acid enhances the effect of bone marrow-derived mononuclear cells in a rat ischemic stroke model

Bone marrow derived mononuclear cell (MNC) transplantation is a potential therapy for ischemic stroke. Here, we hypothesized that valproic acid (VPA) would modulate transplantation effects of MNCs in a rat ischemic stroke model. Male Sprague-Dawley rats were subjected to transient 90min middle cerebral artery occlusion. Infarct volume, neurological outcome, and immunohistological assessments were performed 7 days after ischemia. MNCs injected 6 or 24h but not 48 or 72h after ischemia significantly reduced infarct volume and improved neurological deficits. We then tested whether the therapeutic window of MNC transplantation could be expanded through combination therapy with VPA. MNC transplantation at 48h combined with VPA injection three times at 47, 53, and 72h after ischemia significantly ameliorated infarct volume and neurological deficits compared to a vehicle group. Combination therapy reduced the number of myeloperoxidase-positive cells, ionized calcium binding adapter molecule 1-positive cells, tumor necrosis factor-α-positive cells, and von Willebrand factor-positive cells in the ischemic boundary zone. The number of engrafted MNCs that were fluorescently labeled with PKH 26, on day 7, was significantly higher after combination therapy than after that MNC transplantation alone. Our results demonstrated that combination therapy with VPA enhanced the anti-inflammatory and vasculo-protective effects against endothelial damage following ischemia, and increased the survival of transplanted cells, leading to expansion of the therapeutic time window for MNC transplantation. Together, these findings suggest that VPA may be an appropriate partner for cell-based treatment of ischemic stroke.

Postoperative Clostridium difficile infection with PCR ribotype 078 strain identified at necropsy in five Thoroughbred racehorses

Clostridium difficile is an important cause of acute enterocolitis in horses. We describe five cases of C difficile infection occurring postoperatively in Thoroughbred racehorses. Following diarrhoea or colic accompanied by a marked increase in packed cell volume (to ≥60 per cent) and leucopenia (≤4000 cells/μl) within two to four days after surgery in all five horses, four of them died or were euthanased because of colitis or severe diarrhoea. In these four horses, necrotising entero-typhlo-colitis was revealed by postmortem examination, and C difficile was recovered from the contents of the small and/or large intestine. The remaining horse was euthanased because of marked decline in general condition and the presence of a lung abscess, from which C difficile was isolated. The horse had had severe postoperative diarrhoea before the onset of respiratory disorder; laboratory tests for C difficile were not performed on the faeces. All C difficile isolates were toxin-A-positive, toxin-B-positive and actin-specific ADP-ribosyltransferase (CDT)-positive. The isolates were indistinguishable by pulsed field gel electrophoresis analysis, PCR ribotyping, and slpA sequence typing, and the slpA sequences and PCR ribotype patterns were identical to those of known PCR type 078. This case sequence might have been healthcare-associated infection, although there was about a four-month interval between each disease onset.