Low-dose CT angiography of the lower extremities: a comparison study of image quality and radiation dose

AIM

To investigate the image quality and radiation dose of ultralow-dose (ULD) and low-dose (LD) lower-extremity computed tomography (CT) angiography (LE-CTA) using the advanced modelled iterative reconstruction (ADMIRE) algorithm to detect peripheral arterial disease (PAD) in comparison with standard-dose (SD) CT.

MATERIALS AND METHODS

One hundred and seven consecutive patients were examined using LE-CTA at 70 kVp and a dual-source scanner to achieve three image sets using 30% (ULD), 70% (LD), and 100% (SD) tube loads. Qualitative analysis was conducted by examining the three image sets for overall quality. The image quality of arterial segments was analysed by two independent readers. In addition, the CT dose index (CTDI_vol) was measured in the three image sets.

RESULTS

The mean overall quality scores were 3.4±0.6 for ULD CT, 3.9±0.3 for LD CT, and 3.9±0.2 for SD CT. Both readers scored the arterial segments as 2-4 (adequate-excellent) in the three image sets. In addition, 89.4% (93/104) and 54.8% (57/104) segments of PAD with calcified plaques were scored 4 between SD and LD CT and between SD and ULD CT, respectively, and 45.2% (47/104) segments had a lower score by one point in ULD CT compared with SD CT. The mean CTDI_vol was 4.1±1.1 mGy for SD CT, 2.9±0.8 mGy for LD CT, and 1.2±0.3 mGy for ULD CT.

CONCLUSIONS

LD/ULD CT at 70 kVp using ADMIRE reconstruction enables a reduction in the radiation dose while enabling adequate evaluation or follow-up of PAD based on LE-CTA.

Maternal Oral Health Influences Infant Salivary Microbiome

Oral microbiomes vary in cariogenic potential; these differences may be established early in life. A major concern is whether mothers transmit cariogenic bacteria to their children. Here we characterize early salivary microbiome development and the potential associations of that development with route of delivery, breastfeeding, and mother's oral health, and we evaluate transmission of microbes between mother and child. We analyzed saliva and metadata from the Center for Oral Health Research in Appalachia. For this cohort study, we sequenced the V6 region of the 16S rRNA gene and used quantitative polymerase chain reaction to detect Streptococcus mitis, Streptococcus sobrinus, Streptococcus mutans, Streptococcus oralis, and Candida albicans in the saliva from mothers and their infants, collected at 2, 9, and 12 mo (Pennsylvania site) and 2, 12, and 24 mo (West Virginia site). Breastfed children had lower relative abundances of Prevotella and Veillonella. If mothers had decayed, missing, or filled teeth, children had greater abundances of Veillonella and Actinomyces. There was little evidence of maternal transmission of selected microbes. At 12 mo, children's microbiomes were more similar to other children's than to their mothers'. Infants' salivary microbiomes became more adult-like with age but still differed with mothers' microbiomes at 12 mo. There was little evidence supporting transmission of selected microbes from mothers to children, but risk of colonization was associated with tooth emergence. Children are likely to acquire cariogenic bacteria from a variety of sources, including foods and contact with other children and adults.

P279 Standard dose of rivaroxaban in Asian patients with atrial fibrillation: 20ms vs.15mg? Off label dose reduction of rivaroxaban should be avoided

Background

Rivaroxaban emerged as potential alternatives to warfarin for the prevention of thromboembolisim in patients with atrial fibrillation (AF). Because of the concern for the risk of major bleeding with rivaroxaban in Asian patients, off label rivaroxaban dose reduction to15mg is common in Asian real-world practice. We aimed to set standard rivaroxaban dose in Asian patients with AF by comparison between on-label rivaroxaban 20mg and off-label reduced rivaroxaban dose 15mg.

Methods

A total of 2,208 consecutive non-valvular AF patients were enrolled between 2011 and 2017. After propensity score matching, both warfarin (n = 804) and rivaroxaban group (n = 804) had comparable baseline characteristics. Rivaroxaban group was further divided into on-label rivaroxaban 20mg group (n = 390) and off-label reduced rivaroxaban 15mg group (n = 333). Efficacy outcome was stroke/systemic embolism. Safety outcome was major bleeding. Primary net clinical benefit (NCB) was defined as the composite of stroke, systemic embolism, major bleeding and all-cause mortality. Secondary NCB was defined as the composite of stroke, systemic embolism and major bleeding. Patients were followed upto one-year or until the first occurrence of any study outcomes.

Results

Both Rivaroxaban groups had comparable efficacy compared to warfarin. However, both on-label rivaroxaban 20mg (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.18-0.90, p = 0.026) and off-label reduced rivaroxaban 15mg (HR 0.37, 95% CI 0.16-0.88, p = 0.025) significantly reduced major bleeding. There were no differences in efficacy and safety outcomes between on-label rivaroxaban 20mg and off-label reduced rivaroxaban 15mg group. On-label rivaroxaban 20mg significantly reduced primary (HR 0.44, 95% CI 0.25-0.79, p = 0.006) and secondary (HR 0.51, 95% CI 0.27-0.96, p = 0.038) NCBs compared to warfarin. However, off-label reduced rivaroxaban 15mg did not reduce both primary and secondary NCBs.

Conclusion

Off-label rivaroxaban dose reduction to 15mg had no benefit compared to on-label rivaroxaban 20mg. Compared to warfarin, on-label rivaroxaban 20mg significantly improved primary and secondary NCBs, whereas off-label reduced rivaroxaban 15mg did not. Therefore, rivaroxaban 20mg is favorable as standard dose in Asian patients.

P99 Rapid ventricular stimulation induces augmented conduction delay in Brugada syndrome patients

Background

The exact mechanism for Brugada Syndrome (BrS) is still not clear. There are two main physiologic hypotheses that have been suggested: the repolarization and the depolarization disorder models. Right ventricular (RV) activation delay was verified by echocardiography, conduction time in an explanted heart or in computer simulation. Verification of prolonged longitudinal activation time in human RV of only 5 patients of type-1 BrS and 5 controls was reported in 2008.

Methods

Bidirectional longitudinal activation times were assessed between RV outflow tract (RVot) and RV-apex (RVa) by stimulating and mapping RV endocardium in BrS patients. Conduction velocity was calculated considering ventricle size and distance between catheters.

Results

The studies were performed in controls (n = 18) and BrS patients (n = 6). There was no statistical difference in RP interval and QRS duration (PR 146 ± 21.7 vs 167 ± 45.2 ms, p = 0.325; QRS 102 ± 28.2 vs 122 ± 32.2 ms, p = 0.163). There was no difference of longitudinal activation time on stimulation at 500 ms (RVa to RVot: 63 ± 14.3 versus 80 ± 34.2 ms, p = 0.290; RVot to RVa: 50 ± 12.2 versus 76 ± 35.1 ms, p = 0.122). The BrS patients had longer longitudinal activation time on stimulation at 400 ms (RVa to RVot: 61 ± 15.2 versus 87 ± 28.7 ms, p = 0.009; RVot to RVa: 52 ± 11.1 versus 76 ± 35.3 ms, p = 0.029). The difference was not significant when isoproterenol was infused.

Conclusions

BrS patients display bidirectional longitudinal conduction delay when rapid stimulation. These findings support that BrS might be partly attributable to depolarization abnormality.

Abstract P3-11-07: Exploratory biomarker analysis from a phase II, multicenter, randomized trial of eribulin plus gemcitabine(EG) versus paclitaxel plus gemcitabine(PG) as first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)- negative metastatic breast cancer(MBC): Korean cancer study group trial (KCSG BR13-11)

Introduction : A phase II, multicenter, randomized clinical trial of the comparison between eribulin plus gemcitabine (EG) and paclitaxel plus gemcitabine (PG) as first-line chemotherapy for patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) found EG was less neurotoxic, but had similar efficacy of PG. In this study, we performed exploratory biomarker analysis of the impact of genetic alterations on the efficacy according to EG and PG chemotherapy.

Methods : This biomarker study was conducted using tumor samples from 40patients. When tissue collection was possible after disease progression, we performed paired sample analysis. Tumor DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissues. To perform targeted deep sequencing, we used CancerScanTM, a 375 cancer gene panel. And we performed an nCounter expression assay for gene expression analysis using 730 PanCancer panel and 730 Immune panel.

Results: In total, we obtained 44 tissue samples from 40 patients. Twenty two patients were assigned in EG arm and 18 patients were in PG arm. Thirty-eight were at baseline and six after disease progression. Gene expression assay were performed in 44 tissue samples but only 31 samples were possible to be targeted deep sequencing.

We performed differently expressed gene(DEG) analysis for detecting the association between level of gene expression and disease progression. In this analysis, high expression of CCNE1, TGFB4 and BAMBI and low expression of DDB2, CD14 and SHC3 were associated with disease progression among 730 PanCancer panel genes (p<0.05, respectively). In terms of immune panel genes, most of immune related genes were highly expressed in a group without disease progression compared with that with disease progression. Only 2 genes, C8G and CD24 were highly expressed in a group with disease progression. Paired sample analysis showed that expression levels of THBS4 and CD27 decreased after disease progression while those of CCNE2 and FGFR4 increased.

In targeted deep sequencing, FAT3 (42.3%) was most frequently mutated gene followed by PKHD1, PIK3CA and TP53. Among mutated genes, EWSR1 mutation and upstream mutation of ETV1 were associated with disease progression, respectively (p<0.05, respectively). In mutation signature analysis, signature 1 (S, age related), S3(homologous recombination deficiency, HRD), S6 (mismatch repair, MMR), S20(MMR) and S21(microsatellite instability, MSI) were enriched in this population. Mutation signature 3 related to short disease free survival (p=0.0026).

Conclusion: In gene expression analysis, high expression of TGF-B signaling pathway related genes was associated with disease progression while high expression of immune related genes were related to prolonged disease free survival. In mutation analysis, EWSR1 and ETV1 mutations indicated short disease free interval and HRD mutation signature was also related to poor prognosis.

Citation Format: Kim J-Y, Lee EJ, Park KH, Im S-A, Kim S-B, Sohn SH, Lee KS, Chae YS, Lee KH, Kim JH, Im Y-H, Kim T-Y, Lee K-H, Ahn J-H, Kim GM, Park IH, Lee SJ, Han HS, Kim SH, Jung KH, Park YH. Exploratory biomarker analysis from a phase II, multicenter, randomized trial of eribulin plus gemcitabine(EG) versus paclitaxel plus gemcitabine(PG) as first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)- negative metastatic breast cancer(MBC): Korean cancer study group trial (KCSG BR13-11) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-07.

Acquisition of Carbapenemase-Producing Enterobacteriaceae in Solid Organ Transplantation Recipients

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) can lead to life-threatening outcomes with rapid spread of the carbapenemase gene in solid organ transplantation (SOT) recipients because of limitations of available antibiotics. We examined the characteristics and importance of CPE acquisition in SOT recipients with large numbers of CPE isolates.

METHODS

Between November 2015 and October 2016, 584 CPE isolates were found in 37 recipients and verified by carbapenemase gene multiplex polymerase chain reaction (PCR). One hundred recipients with at least 2 negative results in carbapenemase PCR for stool surveillance and no CPE isolates in clinical samples were retrospectively included.

RESULTS

Most CPE isolates were Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (546, 93.5%). The most frequent transplantation organ was lung (43.3%), and the most common sample with CPE isolates other than stool was respiratory tract (22.6%). The median time between SOT and first CPE acquisition was 7 days. All-cause mortality was significantly higher in recipients with CPE than in those without CPE (24.3% vs 10.0%; P = .03). In multivariate regression analysis, stool colonization of vancomycin-resistant Enterococci and/or Clostridium difficile during 30 days before SOT (odds ratio [OR], 3.28; 95% CI, 1.24-8.68; P = .02), lung transplantation (OR, 4.50; 95% CI, 1.19-17.03; P = .03), and intensive care unit stay ≥2 weeks (OR, 6.21; 95% CI, 1.72-22.45; P = .005) were associated with acquisition of CPE.

CONCLUSIONS

Early posttransplantation CPE acquisition may affect the clinical outcome of SOT recipients. Careful screening for CPE during the early posttransplantation period would be meaningful in recipients with risk factors.

Isolation of internal and external sphincter progenitor cells from the human anal sphincter with or without radiotherapy

AIM

We aimed to isolate and propagate internal and external anal sphincter progenitor cells from the human anal sphincter, with or without radiotherapy, for tailored cell therapy of faecal incontinence.

METHODS

Sphincter progenitor cells were isolated from normal internal and external anal sphincters collected from 10 patients with rectal cancer who had undergone abdominoperineal resection with (n = 6) or without (n = 4) preoperative chemoradiotherapy. The isolated cells and differentiated muscle fibres were identified using immunofluorescence assay, western blotting and reverse transcription polymerase chain reaction (RT-PCR). The proliferation of progenitor cells with and without radiotherapy was compared by quantitative 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

The immunofluorescence assay before differentiation confirmed that the internal anal sphincter progenitor cells expressed CD34 and neural-glial antigen 2 (NG2), whereas the external anal sphincter progenitor cells expressed CD34 and PAX7. After differentiation, the internal anal sphincter progenitor cells expressed desmin, calponin and α-smooth muscle actin, whereas the external anal sphincter progenitor cells expressed desmin, myogenic factor 4 and myosin heavy chain. The differential expression profiles of both cell types were confirmed by western blotting and RT-PCR. MTT assays showed that the viability of internal and external anal sphincter progenitor cells was significantly lower in the radiotherapy group than that in the nonradiotherapy group.

CONCLUSIONS

This study describes the differential harvest internal and external sphincter muscle progenitor cells from human anal sphincters. We confirm that radiotherapy decreases the viability of internal and external anal sphincter progenitor cells.

Percutaneous Transhepatic Biliary Drainage in a Two-Month-Old Infant with Inspissated Bile Syndrome

Inspissated bile syndrome (IBS) is a relatively rare condition. Many treatment options are available, including medication, surgery, and surgical interventions, such as insertion of cholecystostomy drain, endoscopic retrograde cholangiopancreatography, internal biliary drainage, and percutaneous transhepatic biliary drainage (PTBD). We herein report the first case of IBS that was successfully treated with PTBD in a two-month-old infant in Korea. PTBD was initiated on postnatal day 72. On postnatal day 105, we confirmed complete improvement and successfully removed the catheters. This report suggests that PTBD is a viable and safe treatment option for obstructive jaundice in very young infants.

Sensitization to various minor house dust mite allergens is greater in patients with atopic dermatitis than in those with respiratory allergic disease

BACKGROUND

Various allergenic proteins are produced by house dust mites (HDM). However, the allergenicity and clinical implications of these allergens are unknown.

OBJECTIVE

The purpose of this study was to identify allergens in Dermatophagoides farinae and elucidate the sensitization profiles to these in Korean patients suffering from respiratory (allergic rhinitis and/or asthma) and atopic dermatitis symptoms.

METHODS

IgE reactivities in sera from 160 HDM allergy patients were analysed by one- and two-dimensional gel electrophoresis and immunoblotting. IgE-reactive components were identified by liquid chromatography-coupled electrospray ionization-tandem mass spectrometry. Nine recombinant mite allergens (Der f 1, Der f 2, Der f 10, Der f 11, Der f 13, Der f 14, Der f 30, Der f 32 and Der f Alt a 10) were produced, and the IgE reactivity in sera to each was determined by ELISAs.

RESULTS

Der f 1 and Der f 2 were recognized by IgE in serum samples from 88.1% and 78.1% of all patients, respectively. Patients with respiratory allergies were mainly sensitized to these major allergens, whereas patients with atopic dermatitis symptoms showed polysensitization to major and minor allergen components (including Der f 11, Der f 13, Der f 14, Der f 32 and Der f Alt a 10).

CONCLUSIONS

Patients with respiratory allergic disease sensitize to major allergen components of HDM. Those with atopic dermatitis were sensitized to a broader range of minor allergen components of HDM (Der f 11, Der f 13, Der f 14, Der f 32 and Der f Alt a 10).

Quantification of NETs-associated markers by flow cytometry and serum assays in patients with thrombosis and sepsis

INTRODUCTION

Neutrophil extracellular traps (NETs) are networks of extracellular fibres produced from neutrophil DNA with a pathogenic role in infection, thrombosis and other conditions. Reliable assays for measuring NETs are desirable as novel treatments targeting NETs are being explored for the treatment of these conditions. We compare a whole blood flow cytometry method with serum assays to measure NETs-associated markers in patients with sepsis and thrombosis.

METHODS

Patients with deep venous thrombosis (n = 25), sepsis (n = 21) and healthy controls (n = 23) were included in the study. Neutrophil surface NETs markers were determined by flow cytometry on whole blood samples by gating of neutrophils stained for surface citrullinated histone (H3cit) and myeloperoxidase (MPO). Serum double-stranded (ds) DNA, MPO, myeloid-related protein, nucleosomes, DNAse, elastase, human high-mobility group box 1 and MPO-DNA complexes were quantified as circulating markers of NETs.

RESULTS

Neutrophil NETs markers by flow cytometry and serum NETs markers were significantly higher in patients with thrombosis and sepsis compared with healthy controls. Neutrophil NETs markers significantly correlated with the serum marker dsDNA.

CONCLUSION

Flow cytometry detection of neutrophil NETs markers is feasible in whole blood and correlates with serum markers of NETs. We propose the flow cytometry detection of MPO/H3cit positive neutrophils and serum dsDNA as simple methods to quantify cellular and extracellular NET markers in patients with thrombosis and sepsis.