Development of a rapid detection method for the macrolide resistance gene in Mycobacterium avium using the amplification refractory mutation system-loop-mediated isothermal amplification method

Macrolide antibiotics such as clarithromycin (CLR) and azithromycin are the key drugs used in multidrug therapy for Mycobacterium avium complex (MAC) diseases. For these antibacterial drugs, drug susceptibility has been correlated with clinical response in MAC diseases. We have previously demonstrated the correlation between drug susceptibility and mutations in the 23S rRNA gene, which confers resistance to macrolides. Herein, we developed a rapid detection method using the amplification refractory mutation system (ARMS)-loop-mediated isothermal amplification (LAMP) technique to identify mutations in the 23S rRNA gene of M. avium. We examined the applicability of the ARMS-LAMP method to genomic DNA extracted from six genotypes of M. avium clinical isolates. The M. avium isolates were classified into 21 CLR-resistant and 9 CLR-susceptible strains based on the results of drug susceptibility tests; the 23S rRNA genes of these strains were sequenced and analyzed using the ARMS-LAMP method. Sequence analysis revealed that the 9 CLR-sensitive strains were wild-type strains, whereas the 21 CLR-resistant strains comprised 20 mutant-type strains and one wild-type strain. Using ARMS-LAMP, no amplification from genomic DNAs of the 10 wild-type strains was observed using the mutant-type mismatch primer sets (MTPSs); however, amplification from the 20 mutant-type strain DNAs was observed using the MTPSs. The rapid detection method developed by us integrates ARMS-LAMP with a real-time turbidimeter, which can help determine drug resistance in a few hours. In conclusion, ARMS-LAMP might be a new clinically beneficial technology for rapid detection of mutations.IMPORTANCEMultidrug therapy for pulmonary Mycobacterium avium complex disease is centered on the macrolide antibiotics clarithromycin and azithromycin, and resistance to macrolides is an important prognosticator for clinical aggravation. Therefore, it is important to develop a quick and easy method for detecting resistance to macrolides. Drug resistance is known to be correlated with mutations in macrolide resistance genes. We developed a rapid detection method using amplification refractory mutation system (ARMS)-loop-mediated isothermal amplification (LAMP) to identify a mutation in the 23S rRNA gene, which is a macrolide resistance gene. Furthermore, we examined the applicability of this method using M. avium clinical isolates. The rapid method developed by us for detection of the macrolide resistance gene by integrating ARMS-LAMP and a real-time turbidimeter can help in detection of drug resistance within a few hours. Since this method does not require expensive equipment or special techniques and shows high analytical speed, it would be very useful in clinical practice.

Amikacin liposome inhalation suspension for Mycobacterium avium complex pulmonary disease: A subgroup analysis of Japanese patients in the randomized, phase 3, CONVERT study

BACKGROUND

CONVERT, a randomized, active-controlled, global, Phase 3 trial demonstrated that patients with treatment-refractory Mycobacterium avium complex (MAC) pulmonary disease were more likely to achieve culture conversion with amikacin liposome inhalation suspension (ALIS) plus guideline-based therapy (GBT) versus those continuing on GBT alone. This subgroup analysis reports the efficacy and safety of ALIS in Japanese patients enrolled in CONVERT.

METHODS

Japanese patients aged ≥20 years with treatment-refractory MAC pulmonary disease from Japanese sites were included. Patients were randomized to receive once-daily 590 mg ALIS + GBT or GBT alone; patients converting by Month 6 remained in the study to complete 12-month treatment followed by a 12-month off-treatment period. Nonconverters exited the study at Month 8. The primary endpoint was the proportion of patients achieving culture conversion by Month 6.

RESULTS

Of the 59 Japanese patients screened, 48 were randomized to receive ALIS + GBT (n = 34) or GBT alone (n = 14), and 41/48 (85.4 %) were women. The mean (standard deviation) age of patients was 64.5 (8.6) years, and 83.3 % of patients had bronchiectasis at baseline. By Month 6, sputum culture conversion was cumulatively achieved in 9/34 (26.5 %) patients receiving ALIS + GBT versus none receiving GBT alone. Treatment-emergent adverse events were reported in 94.1 % and 100.0 % of patients receiving ALIS + GBT and GBT alone, respectively. No deaths were reported.

CONCLUSIONS

The efficacy observed in the Japanese subpopulation was largely consistent with that in the overall CONVERT study population, with more patients achieving culture conversion with ALIS + GBT versus GBT alone. Safety profiles were similar between the overall population and the Japanese subpopulation.

CLINICAL TRIAL REGISTRATION

NCT02344004.

Extended ICI treatment after first-line chemoimmunotherapy could predict the clinical benefit of ramucirumab plus docetaxel in advanced non-small lung cancer: Post hoc analysis from NEJ051 (REACTIVE study)

BACKGROUND

The factors that predict the clinical response to ramucirumab plus docetaxel (RD) after first-line chemoimmunotherapy are unresolved. We explored whether the therapeutic efficacy of prior chemoimmunotherapy could predict the outcome of RD as sequential therapy in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Our study comprised 288 patients with advanced NSCLC who received RD as the second-line treatment after first-line chemoimmunotherapy at 62 Japanese institutions. Chemoimmunotherapy consisted of a platinum-based regimen and immune checkpoint inhibitors (ICIs). The association between several variables and the therapeutic outcome of RD was determined via logistic regression analysis.

RESULTS

Of the 288 patients, 225 (78.1%) received maintenance therapy and 108 (37.5%) received both ICI treatment for >180 days and maintenance therapy. All of 108 patients having ICIs for >180 days received maintenance therapy. Univariate analysis identified performance status, histology (adenocarcinoma), maintenance therapy, and ICI treatment >180 days as significant predictors of better progression-free survival (PFS) and overall survival (OS) after RD administration. Multivariate analysis confirmed that these factors independently predicted favorable PFS and OS. The therapeutic response and PD-L1 expression were not closely associated with outcome after RD treatment. In particular, maintenance therapy >4 cycles was more predictive of the better prognosis for RD treatment.

CONCLUSION

Extended ICI treatment after chemoimmunotherapy and maintenance therapy enhanced the efficacy of second-line RD treatment in patients with advanced NSCLC.

A Prospective Cohort Study Assessing the Relationship between Plasma Levels of Osimertinib and Treatment Efficacy and Safety

Osimertinib is a standard treatment for patients with EGFR-mutated non-small cell lung carcinoma (NSCLC). We evaluated the relationship between plasma osimertinib concentrations and treatment outcome in patients with NSCLC for this cohort study. The plasma levels of osimertinib and its metabolite AZ5104 were measured a week after the start of treatment (P1). The primary endpoint was to evaluate the correlation between plasma concentration and adverse events (AEs). The correlation with treatment efficacy was one of the secondary endpoints. In patients with CNS metastases, the concentration in the cerebrospinal fluid was also measured. Forty-one patients were enrolled. The frequency of AEs was highest for rash, followed by anorexia and thrombocytopenia. Thirty-eight cases provided measurements for P1. The median plasma concentration of osimertinib was 227 ng/mL, and that of AZ5104 was 16.5 ng/mL. The mean CNS penetration rate of two cases was 3.8%. The P1 in the group with anorexia was significantly higher than that in the group without anorexia (385.0 ng/mL vs. 231.5 ng/mL, p = 0.009). Divided into quartiles by P1 trough level, Q2 + Q3 (164-338 ng/mL) had longer PFS, while Q1 and Q4 had shorter PFS. An appropriate plasma level of osimertinib may avoid some adverse events and induce long PFS. Further large-scale trials are warranted.

Development of continuous measurement system for hydrogen and impurity gases using detector tube

A relatively accurate, inexpensive, simple, and continuous quantification system for hydrogen and impurity gas(es) using a detector tube was developed in this study. Additionally, different detector tubes can be applied to measure different types of gases in a wide range from ppm order to % level. We optimized this system and evaluated its accuracy as well as the behavior of released H2 and impurity (NH3) gases from a hydrolysis of ammonia borane using a Pt/Al2O3 catalyst. The accuracy of hydrogen quantitation achieved by this system was comparable to that of commercial mass flow meters, and the accuracy of ammonia quantitation was 10% or 5% relative standard deviation, which depends on the detector tube. The concentration of released NH3 was evaluated by image analysis with a time-lapse video of the detector tube and succeeded in analyzing from ppm to % order. The H2 and NH3 release behaviors agreed with pH, and the percentage of reaction was estimated by NMR measurement of the reacted solution. These results confirmed the accuracy of this system.

Factors associated with adverse drug reactions or death in very elderly hospitalized patients with pulmonary tuberculosis

The aging of patients with tuberculosis and better therapeutic management for them are recent concerns. This study aimed to identify risk factors for adverse drug reactions (ADRs) or death in very elderly patients with pulmonary tuberculosis and to assess the association between the dosage of antituberculosis drugs and outcomes. We conducted a multicenter retrospective study at two hospitals. Hospitalized patients (≥ 80 years old) with pulmonary tuberculosis who were treated with antituberculosis drugs were enrolled. Multivariate analysis was performed to assess factors associated with ADRs or death within 60 days after treatment initiation. In total, 632 patients were included. The primary endpoint occurred in 268 patients (190 ADRs and 78 deaths). A serum albumin level < 2.5 g/dL, respiratory failure, and dependent activities of daily living were independent risk factors for ADRs or death. However, a low dosage (< 8 mg/kg/day) of rifampicin was associated with a lower risk of the primary outcomes. Delayed time to negative sputum culture conversion was not observed in the lower dosage of rifampicin group. Very elderly hospitalized tuberculosis patients with the aforementioned risk factors should be carefully monitored to receive safer treatment. Rifampicin dosage reduction may be considered for very elderly tuberculosis patients to prevent ADRs/death.

A Rapid Screening Assay for Clarithromycin-Resistant Mycobacterium avium Complex Using Melting Curve Analysis with Nonfluorescent Labeled Probes

Mycobacterium avium complex (MAC) thrives in various environments and mainly causes lung disease in humans. Because macrolide antibiotics such as clarithromycin or azithromycin are key drugs for MAC lung disease, the emergence of macrolide-resistant strains prevents the treatment of MAC. More than 95% of macrolide-resistant MAC strains are reported to have a point mutation in 23S rRNA domain V. This study successfully developed a melting curve assay using nonfluorescent labeled probes to detect the MAC mutation at positions 2058 to 2059 of the 23S rRNA gene (AA genotype, clarithromycin susceptible; TA, GA, AG, CA, AC, and AT genotypes, clarithromycin resistant). In the AA-specific probe assay, the melting peak of the DNA fragment of the AA genotype was higher than that of DNA fragments of other genotypes. Melting temperature (Tm) values of the AA genotype and the other genotypes were about 80°C and 77°C, respectively. DNA fragments of each genotype were identified correctly in six other genotype-specific probes (TA, GA, AG, CA, AC, and AT) assays. Using genomic DNA from six genotype strains of M. avium and four genotype strains of M. intracellulare, we confirmed that all genomic DNAs could be correctly identified as individual genotypes according to the highest Tm values among the same probe assays. These results indicate that this melting curve-based assay is able to determine MAC genotypes at positions 2058 to 2059 of the 23S rRNA gene. This simple method could contribute to the rapid detection of clarithromycin-resistant MAC strains and help to provide accurate drug therapy for MAC lung disease. IMPORTANCE Since macrolide antibiotics such as clarithromycin or azithromycin are key drugs in multidrug therapy for Mycobacterium avium complex (MAC) lung diseases, the rapid detection of macrolide-resistant MAC strains has important implications for the treatment of MAC. Previous studies have reported a correlation between drug susceptibility testing and the mutation of macrolide resistance genes. In this study, we developed a novel melting curve-based assay using nonfluorescent labeled probes to identify both clarithromycin-resistant M. avium and M. intracellulare with mutations in the 23S rRNA gene, which is the clarithromycin or azithromycin resistance gene. This assay contributed to not only the detection of MAC mutations but also the determination of all genotypes at positions 2058 to 2059 of the 23S rRNA gene. Furthermore, because nonfluorescent labeled probes are used, this assay is more easily and more immediately available than other methods.

A large-scale prospective concordance study of plasma- and tissue-based next-generation targeted sequencing for advanced non-small cell lung cancer (LC-SCRUM-Liquid)

PURPOSE

We evaluated plasma cell-free DNA (cfDNA) and tissue-based sequencing concordance for comprehensive oncogenic driver detection in non-small cell lung cancer (NSCLC) using a large-scale prospective screening cohort (LC-SCRUM-Liquid).

METHODS

Blood samples were prospectively collected within four weeks of corresponding tumor tissue sampling from advanced NSCLC patients to investigate plasma cfDNA sequencing concordance for alterations in eight oncogenes (EGFR, KRAS, BRAF, HER2, MET, ALK, RET, and ROS1) compared to tissue-based next-generation targeted sequencing.

RESULTS

Paired blood and tissue samples were obtained in 1062/1112 enrolled NSCLC patients. Oncogenic alteration was detected by plasma cfDNA sequencing and tissue assay in 455 (42·8%) and 537 (50·5%) patients, respectively. The positive percent agreement (PPA) of plasma cfDNA sequencing compared with tissue DNA and RNA assays were 77% (EGFR, 78%; KRAS, 75%; BRAF, 85%; HER2, 72%) and 47% (ALK, 46%; RET, 57%; ROS1, 18%; MET 66%), respectively. Oncogenic drivers were positive for plasma cfDNA and negative for tissue due to unsuccessful genomic analysis from poor-quality tissue samples (70%), and were negative for plasma cfDNA and positive for tissue due to low sensitivity of cfDNA analysis (61%). In patients with positive oncogenic drivers by plasma cfDNA sequencing but negative by tissue assay, response rate of genotype-matched therapy was 85% and median progression-free survival was 12·7 months.

CONCLUSIONS

Plasma cfDNA sequencing in advanced NSCLC patients showed relatively high sensitivity for detecting gene mutations but low sensitivity for gene fusions and MET exon 14 skipping. This may be an alternative only when tissue assay is unavailable due to insufficient DNA and RNA.

Pathophysiological Analysis of Uninephrectomized db/db Mice as a Model of Severe Diabetic Kidney Disease

Diabetic nephropathy, included in diabetic kidney disease (DKD), is the primary disease leading to end-stage renal disease (ESRD) or dialysis treatment, accounting for more than 40% of all patients with ESRD or receiving dialysis. Developing new therapeutics to prevent the transition to ESRD or dialysis treatment requires an understanding of the pathophysiology of DKD and an appropriate animal model for drug efficacy studies. In this study, we investigated the pathophysiology of diabetic kidney disease with type 2 diabetes in uninephrectomized db/db mice. In addition, the nephrectomized db/db mice from 10 weeks to 42 weeks were used to assess the efficacy of long-term administration of the angiotensin-II–receptor antagonist losartan. The blood and urinary biochemical parameters and the blood pressure which is a main pharmacological endpoint of the losartan therapy, were periodically measured. And at the end, histopathological analysis was performed. Uninephrectomized db/db mice clearly developed obesity and hyperglycemia from young age. Furthermore, they showed renal pathophysiological changes, such as increased urinary albumin-creatinine ratio (UACR) (the peak value 3104±986 in 40-week-old mice), glomerular hypertrophy and increased fibrotic areas in the tubulointerstitial tubules. The blood pressure in the losartan group was significantly low compared to the normotensive Vehicle group. However, as expected, Losartan suppressed the increase in UACR (829±500) indicating the medication was sufficient, but the histopathological abnormalities including tubular interstitial fibrosis did not improve. These results suggest that the uninephrectomized db/db mice are useful as an animal model of the severe DKD indicated by the comparison of the efficacy of losartan in this model with the efficacy of losartan in clinical practice.

Viscoplastic Material Modeling for the Stretch Blow Molding Simulation

In this paper, the viscoplastic material model of PET (polyethylene terephthalate), which is intended to be used in the FEM (finite element method) simulation of stretch blow molding process, has been studied. Material tests of PET were performed with the constant strain rates varying from 0.01 to 1 (1/s), at temperatures ranging from 90 to 150 °C, based on the obtained data a two-stage model was proposed. The proposed model could precisely take into account the effects of strain hardening, strain rate sensitivity, variation of the hardening index, and temperature dependency. This model has been implemented into the nonlinear finite element code PBLOW3D, which is developed in the Riken, and its performance in the stretch blow molding simulation has been studied. It has been demonstrated that the proposed material model provides significant improvements, compared with two existing material models, in the simulation of the blow molding process of PET bottles.

The use of SPECT/CT to assess resorptive activity in mandibular condyles

The aim of this study was to clarify the clinical significance of bone metabolism in the mandibular condyles in determining condylar resorptive changes. Twelve condyles of patients with idiopathic condylar resorption and degenerative joint disease were analysed using ^99mTc HMDP SPECT/CT at baseline and subsequent computed tomography during the follow-up period. Twenty-two healthy condyles were enrolled as controls. After generating three-dimensional SPECT/CT images, two independent observers scored the degree of condylar uptake and measured the morphological changes in the condylar height and condylar volume. In the group with positive condylar uptake, the follow-up computed tomography showed significant decreases in condylar height (-1.69 ± 0.93 mm) and condylar volume (-12.51 ± 10.30%) when compared to healthy controls (condylar height, 0.09 ± 0.54 mm; condylar volume, -0.29 ± 4.22%) (P < 0.001). Moreover, the degree of uptake correlated with the changes in condylar height (observer 1, P = 0.012; observer 2, P = 0.039) and condylar volume (observer 1, P = 0.005; observer 2, P = 0.037). These results suggest that condylar bone metabolism is closely related to the resorptive activity. Thus, SPECT/CT would be useful in the prognostic evaluation or determination of treatment strategies for idiopathic condylar resorption and degenerative joint disease.

Early tumor response assessment may avoid serious immune-related adverse events in nivolumab and ipilimumab combination therapy for stage IV melanoma

Nivolumab and ipilimumab combination therapy is one of the most promising treatments for patients with melanoma. However, this combination therapy is highly toxic and causes serious adverse events (SAEs) in more than half of the patients.

Phase I/II study of biweekly nab-paclitaxel in patients with platinum-pretreated non-small cell lung cancer: NJLCG1402

BACKGROUND

NJLCG1402 was a phase I/II trial investigating biweekly nanoparticle albumin-bound paclitaxel (nab-PTX) in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

The study included patients aged ≥20 years with previously treated NSCLC. Nab-PTX (100-150 mg/m² ) was administered biweekly in a 28-day cycle. The phase I portion was performed to determine the recommended phase II dose of nab-PTX. In the phase II portion, the primary endpoint was the objective response rate. Secondary endpoints were disease control rate, progression-free survival, overall survival, and safety.

RESULTS

A total of 15 patients received biweekly nab-PTX (100-150 mg/m² ) and 12 patients in phase II were treated with 150 mg/m² . In the phase I portion, 150 mg/m² was determined as the recommended dose. Among those treated with 150 mg/m² , the objective response rate was 22%, and the median progression-free and overall survival was 3.6 and 11.2 months, respectively. Adverse events grade ≥3 were observed in 39% of patients.

CONCLUSIONS

Biweekly nab-PTX monotherapy was well tolerated and exhibited favorable antitumor activity in patients with previously treated NSCLC.

Pre-operative endovascular coil embolisation for chronic pulmonary aspergillosis

OBJECTIVE: To retrospectively evaluate the clinical outcomes of pre-operative endovascular coil embolisation (ECE) for chronic pulmonary aspergillosis (CPA).METHODS: We evaluated surgical patients with CPA between November 2016 and April 2020. Pre-operative ECE for CPA with severe adhesions was selectively performed to reduce intra-operative blood loss. ECE procedures, operative procedures, intra-operative blood loss and complications were evaluated.RESULTS: Twenty-eight patients (21 males and 7 females; median age: 55 years) were included in the study. Of the 28 patients, 8 (28.6%) underwent pre-operative ECE. Technical success rate in pre-operative ECE was 100%. The median time required for ECE procedures was 123 min. The median number of vessels embolised per procedure was 2.5. The median period between embolisation and surgery was 5 days. Major complications were observed in three patients (10.7%). There were no significant differences between patients with and without pre-operative ECE in operative time (284 vs. 365 min, respectively, P = 0.7602) and intra-operative blood loss (294 vs. 228 mL, respectively, P = 0.8987).CONCLUSIONS: Pre-operative ECE for CPA appears to be feasible and safe; however, its role in reducing intra-operative blood loss needs further investigation.

Prospective Multicenter Study of Chemotherapy-Induced Clostridium (Clostridioides) difficile Infection in Patients With Lung Cancer: North Japan Lung Cancer Study Group Trial 1204

Background

Diarrhea post-antibiotic use is primarily attributed to mucosal lesions induced by Clostridium (Clostridioides) difficile (C. difficile) infection (CDI). Cancer patients undergoing chemotherapy might have a higher risk of CDI even when prior antibiotics are not used. Thus far, the relationship between lung cancer chemotherapy and the incidence of diarrhea remains unclear. This prospective multicenter study aimed to determine the incidence of CDI in lung cancer patients undergoing chemotherapy.

Methods

The presence of C. difficile and its toxins was investigated in lung cancer patients experiencing diarrhea during chemotherapy including paclitaxel (PTX), nanoparticle albumin-bound paclitaxel (nab-PTX), docetaxel (DOC), tegafur-gimeracil-oteracil (S-1), or irinotecan (CPT-11). If grade 2 or higher diarrhea occurred, then a stool culture was performed to detect anaerobic organisms and C. difficile toxins A and B. Additional data were collected through patient interviews and medical chart review.

Results

A total of 263 consecutive patients were enrolled in the study; grade 2 or higher diarrhea was observed in 22 patients (8.4%); CDI was confirmed in five of them (1.9%). The incidence of CDI was 22.7% of all diarrhea cases, and 50% of patients treated with PTX were CDI positive; the incidence of CDI was significantly higher in patients treated with PTX (P=0.039). Among the diarrhea cases, CDI patients had significantly worse ECOG performance status (PS) (P=0.043) and a significantly higher neutrophil count (P=0.028) than non-CDI patients. No CDI patients received antibiotics before cancer chemotherapy.

Conclusions

Although diarrhea does not always affect a large portion of lung cancer chemotherapy recipients, clinicians should consider the possibility of CDI occurrence in lung cancer patients receiving chemotherapy, particularly PTX, without prior antibiotic exposure.

Effects of H3 and H4 histones acetylation and bindings of CREB binding protein and p300 at the promoter on hepatic expression of gamma-glutamyltransferase gene in a streptozotocin-induced moderate hypoinsulinemic rat model

Gamma-glutamyltransferase (GGT), a marker of liver disease, has been shown to be associated with increased risk of diabetes and relative insulin secretion deficiency. However, the mechanism of hepatic Ggt regulation has not been explored fully. In this study, we made a concerted effort to understand the mechanism by investigating the effects of acetylation of histones H3 and H4, and bindings of histone acetyltransferases, CREB binding protein (CBP) and p300, at the Ggt promoter on the regulation of the expression of Ggt gene in the livers of streptozotocin (STZ)-induced moderate hypoinsulinemia rat model. The rats treated with STZ showed remarkably higher serum GGT level and hepatic Ggt/GGT expression than the untreated control rats. Furthermore, the acetylation of histones H3 and H4, and the binding of CBP not p300 at the Ggt promoter regions were significantly higher in the livers of STZ rats than those of the control rats. These results suggest that an enhanced hepatic expression of Ggt is associated with increased acetylation of histones H3 and H4 and CBP binding at the Ggt promoter in STZ-induced moderate hypoinsulinemic rats.

Left atrial strain and outcome in heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial (LA) function is impaired in heart failure with preserved ejection fraction (HFpEF). However, the association between LA longitudinal strain and heart failure (HF) events in patients with HFpEF is still unknown. We evaluated whether LA strain measurements would be useful to predict hospitalizations for worsening HF in this study.

Methods

This study included 121 patients (Male 73, Female 48) with HFpEF who had echocardiogram at our institute (Age = 76 ± 14y, Left ventricular ejection fraction; LVEF = 63 ± 8%). Patients with atrial fibrillation were excluded. LA longitudinal strain was measured by speckle-tracking echocardiography, using TOMTEC imaging system. The endpoints were hospitalizations for worsening HF.

Results

During follow-up period of 319 ± 269 days, 33 patients (27%) experienced hospitalizations for worsening HF. LA strain was markedly lower in patients with HF events at 11.3 ± 5.6, whereas LA strain was higher at 20.3 ± 10.1 in patients without HF events. Kaplan-Meier analysis demonstrated a significant separation of survival curves stratified by median value of LA strain (Figure).

Conclusions

LA dysfunction in HFpEF is associated with a higher risk of HF hospitalization, and LA strain measurements would be useful to predict HF events.

Abstract Figure

Randomized phase II trial of uracil/tegafur and cisplatin versus pemetrexed and cisplatin with concurrent thoracic radiotherapy for locally advanced unresectable stage III non-squamous non-small cell lung cancer: NJLCG1001

Background

The optimal regimen for concurrent chemoradiotherapy (CCRT) of locally advanced non-squamous non-small cell lung cancer (NSCLC) was not definitive. We conducted randomized phase II study, NJLCG0601, and chemoradiotherapy with uracil/tegafur (UFT) and cisplatin achieved promising efficacy without severe toxicities. Here, we evaluated between this regimen and pemetrexed plus cisplatin in chemoradiotherapy for stage III non-squamous NSCLC.

Methods

Patients with inoperable stage III non-squamous NSCLC were randomly assigned in a 1:1 ratio to UFT 400 mg/m² on days 1–14 and 29–42, and cisplatin 80 mg/m² on days 8 and 36 (UP), or cisplatin 75 mg/m² and pemetrexed 500 mg/m² on days 1, 22, and 43 (PP). Involved-field radiotherapy (IFRT) underwent from day 1 to a total dose of 66 Gy in 33 fractions. Consolidation chemotherapy after CCRT was prohibited for this study. The primary endpoint was defined as 2-year overall survival (OS). This trial was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000003948).

Results

From November 2010 to June 2017, 86 patients were entered from 11 institutions. Median follow-up was 54 months. Of the 85 eligible patients, the 2-year OS rate was 78.6% (95% CI, 62.8–88.3%) in UP and 85.5% (95% CI, 70.5–93.2%) in PP. Median PFS and OS was 12.3 and 64.2 months in UP, 26.2 months and not reached in PP, respectively. Grade 3/4 febrile neutropenia was more frequent in the UP group (14.0% vs. 2.0%).

Conclusions

Both UP and PP with IFRT achieved the expected 2-year OS. PP engendered more favorable OS and PFS compared to UP in terms.

1654. Evaluation of a rapid detection method of clarithromycin resistance genes in Mycobacterium avium using the Amplification Refractory Mutation System-Loop-Mediated Isothermal Amplification method

Background

Clarithromycin (CLR) is the key drug in multidrug therapy for Mycobacterium avium complex (MAC) diseases and the only drug for which drug susceptibility is correlated with a clinical response in these diseases. In the case of CLR-resistant MAC, a point mutation is present at either position 2058 or 2059 of the peptidyl transferase active center in the domain V region of 23S rRNA at the macrolide binding site. Using conventional investigation, we clarified the correlation between drug susceptibility testing and mutation of drug resistance genes. In this study, we adapted a rapid detection method using the amplification refractory mutation system (ARMS)-loop-mediated isothermal amplification (LAMP) to identify a mutation in the 23S rRNA gene in M. avium isolates (Figure 1). Furthermore, we evaluated the usefulness as point-of-care testing (POCT) technology using clinical isolates.

Figure 1. The designs of CLR resistance A2058G mutant-type mismatch primers used for the ARMS-LAMP assay. a) A strand-displacing DNA polymerase extends the DNA from FIP while separating from the DNA chain. The primer F3 binds to its complementary region on the DNA to displace the newly synthesized DNA. An analogous reaction is performed by BIP and B3. α (α = A, wild type; G, A2058G) and β (β = A, wild type; C, A2058G) are indicated by the point mutation at position 2058 of the 23S rRNA gene. The bold area indicates the mismatched base C (cytosine). b) The synthesized DNA self-anneals because of the complementary region at both ends and forms ‘dumbbell’ structures. c) After repeated rounds, a complementary region on the same chain is amplified.

Methods

Primers for ARMS-LAMP were designed using PrimerExplorerV5 software based on the nucleotide sequence data for 23S rRNA in M. avium strain 104 (Figure 2). Using the minimum inhibitory concentration of CLR, drug susceptibility was determined for 18 clinical M. avium isolates. Of these, eight CLR-susceptible and 10 CLR-resistant strains were analyzed by sequencing the 23S rRNA gene and ARMS-LAMP.

Figure 2. Alignment of the nucleotide sequences including the domain V region of 23S rRNA at the macrolide binding site. The constructed LAMP primer sets are shown in solid boxes (forward primers, F1-3) and dashed boxes (backward primers, B1-3). The bold area indicates the point mutation at position 2058 or 2059 of the 23S rRNA gene.

Results

Sequence analysis revealed that all eight CLR-sensitive strains tested were wild type, whereas all 10 CLR-resistant strains were mutants. Using ARMS-LAMP, no amplification with the mutant-type mismatch primer sets (MTPS) was observed in the eight wild-type strains, but amplification was observed with MTPS in the 10 mutant strains (Table 1).

Table 1. MICs of CLR and results of ARMS–LAMP using Mycobacterium avium isolates.

Conclusion

The developed rapid detection method for the CLR resistance gene using ARMS-LAMP can determine drug resistance in a few hours without the need for special equipment. ARMS-LAMP may be a new clinically beneficial POCT technology for examination that is novel and extremely practical.

Disclosures

All Authors: No reported disclosures

Evaluation of epithelial and mesenchymal cell markers in canine urinary bladder transitional cell carcinoma

Canine transitional cell carcinoma (cTCC) is the most common malignant tumour in the urinary bladder: it is highly invasive and exhibits metastatic characteristics. Inflammation is also strongly related to cTCC. Epithelial tumours often exhibit a mesenchymal cell phenotype during tumour invasion and metastasis owing to epithelial-mesenchymal transition (EMT), which is often induced in chronic inflammation. The aim of this retrospective study was to investigate the expression of epithelial and mesenchymal cell markers in tumour cells and to evaluate its relationship with prognosis of cTCC. In this study, 29 dogs with cTCC who underwent surgical treatment were enrolled. Clinical parameters were reviewed using medical records. Tissue expression of epithelial and mesenchymal markers was evaluated by immunohistochemical analysis. The association between the expression of mesenchymal cell markers and clinical parameters, including prognosis, was statistically examined. In five normal bladder tissues used as controls, no expression of mesenchymal markers was observed, except for one tissue that expressed fibronectin. Conversely, epithelial tumour cells expressed vimentin and fibronectin in 23/29 and 19/28 cTCC tissues, respectively. Regarding clinical parameters, vimentin score in Miniature Dachshunds was significantly higher than those in other dog breeds (P < 0.001). Multivariate survival analyses revealed that age>12 years was related to shorter progression-free survival (P = 0.02). Higher vimentin score, lower fibronectin score, and advanced clinical T stage were significantly correlated with shorter median survival time (P < 0.05). The results of this study indicate that vimentin expression was associated with cTCC progression. Further studies are needed to examine the incidence and relevance of EMT in cTCC.

Olfactory marker protein contributes to the evaluation of odour values by olfactory glomerular processing

Olfaction starts from olfactory receptor neurons (ORNs) that express olfactory marker protein (OMP). OMP deficit results in various behavioural phenotypes indicating olfactory dysfunction due to the impaired responses of ORNs. Recently, OMP was demonstrated to maintain strong olfaction by buffering olfactory cAMP signalling. However, the impact of OMP on olfaction behaviours, the assessment of which requires time to evaluate odour values, remains largely unexplained. Here, we examined the behaviour of heterozygous OMP^+/GFP (HET) mice vs. homologous GFP-knock-in OMP-deficient OMP ^{GFP/ GFP} (KI) mice during the olfactory investigation of odours with different values. When a swab containing an organic odour was presented, both HET and KI mice swiftly approached and investigated the swab with gradual habituation over test sessions. However, when another similar odour was presented, KI mice investigated the new swab much less intensively than HET mice. Next, mice were placed in a chamber with an aversive odour source in one corner of a test chamber. KI mice more frequently approached the compartment containing the aversive odour source than HET mice. Finally, we trained mice to associate two odours with solutions by utilizing reward-penalty values. HET mice stayed close to the reward-associated odour, while KI mice initially approached the reward-associated odour, occasionally turned towards the penalty-associated odour source and eventually stayed in the reward-odour compartment. Histologically, c-Fos-expressing juxtaglomerular cells were fewer and more broadly distributed around glomeruli in KI mice than HET mice. In conclusion, OMP contributes to the evaluation of odour values by glomerular processing during an olfactory investigation task.

Expression of the pacemaker channel HCN4 in excitatory interneurons in the dorsal horn of the murine spinal cord

In the central nervous system, hyperpolarization-activated, cyclic nucleotide-gated (HCN1–4) channels have been implicated in neuronal excitability and synaptic transmission. It has been reported that HCN channels are expressed in the spinal cord, but knowledge about their physiological roles, as well as their distribution profiles, appear to be limited. We generated a transgenic mouse in which the expression of HCN4 can be reversibly knocked down using a genetic tetracycline-dependent switch and conducted genetically validated immunohistochemistry for HCN4. We found that the somata of HCN4-immunoreactive (IR) cells were largely restricted to the ventral part of the inner lamina II and lamina III. Many of these cells were either parvalbumin- or protein kinase Cγ (PKCγ)-IR. By using two different mouse strains in which reporters are expressed only in inhibitory neurons, we determined that the vast majority of HCN4-IR cells were excitatory neurons. Mechanical and thermal noxious stimulation did not induce c-Fos expression in HCN4-IR cells. PKCγ-neurons in this area are known to play a pivotal role in the polysynaptic pathway between tactile afferents and nociceptive projection cells that contributes to tactile allodynia. Therefore, pharmacological and/or genetic manipulations of HCN4-expressing neurons may provide a novel therapeutic strategy for the pain relief of tactile allodynia.

Phase II Study of Low-Dose Afatinib Maintenance Treatment Among Patients with EGFR-Mutated Non-Small Cell Lung Cancer: North Japan Lung Cancer Study Group Trial 1601 (NJLCG1601)

LESSONS LEARNED

Low-dose afatinib maintenance treatment among patients with EGFR-mutated NSCLC achieved long-time to treatment failure with fewer treatment-related AEs without detracting from the therapeutic efficacy. This modified regimen represents a practical usage that balances effectiveness and safety.

BACKGROUND

Although afatinib is an effective therapy for patients with EGFR-mutated non-small cell lung cancer (NSCLC), drug-related adverse events (AEs) have often necessitated dose reductions. In a post hoc analysis of the LUX-Lung 3 and 6 trials, there was no difference in median progression-free survival (PFS) between patients who had the dose of afatinib reduced and those who did not. We thus evaluated the efficacy and tolerability of low-dose afatinib maintenance treatment among patients with NSCLC harboring EGFR mutations who had not been previously treated.

METHODS

Eligible patients received afatinib 40 mg orally once daily. When prescribed grade ≥ 2 AEs, rash of grade ≥ 3, or unacceptable toxicity occurred, the afatinib dose was reduced from 40 to 30 mg and if needed from 30 to 20 mg. The primary endpoint was the 1-year PFS rate. Secondary endpoints were PFS, overall response rate (ORR), and toxicity.

RESULTS

Among 30 patients, 93% had adenocarcinoma, 53% had exon 19 deletion, 37% had L858R, and 10% had minor mutations. The 1-year PFS rate was 50% (95% confidence interval [CI], 31.3-66.1) and the median PFS was 11.8 months (95% CI, 7.1-21.4). The incidence rate of grade ≥ 3 toxicities was 57%, including elevated aspartate aminotransferase/alanine aminotransferase level (13%), diarrhea (10%), and paronychia (10%).

CONCLUSION

Low-dose afatinib maintenance treatment reduced treatment-related AEs without detracting from the therapeutic efficacy.

Exploratory open-label clinical study to determine the S-588410 cancer peptide vaccine-induced tumor-infiltrating lymphocytes and changes in the tumor microenvironment in esophageal cancer patients

Cancer vaccines induce cancer-specific T-cells capable of eradicating cancer cells. The impact of cancer peptide vaccines (CPV) on the tumor microenvironment (TME) remains unclear. S-588410 is a CPV comprising five human leukocyte antigen (HLA)-A*24:02-restricted peptides derived from five cancer testis antigens, DEPDC1, MPHOSPH1, URLC10, CDCA1 and KOC1, which are overexpressed in esophageal cancer. This exploratory study investigated the immunologic mechanism of action of subcutaneous S-588410 emulsified with MONTANIDE ISA51VG adjuvant (median: 5 doses) by analyzing the expression of immune-related molecules, cytotoxic T-lymphocyte (CTL) response and T-lymphocytes bearing peptide-specific T-cell receptor (TCR) sequencing in tumor tissue or blood samples from 15 participants with HLA-A*24:02-positive esophageal cancer. Densities of CD8+, CD8+ Granzyme B+, CD8+ programmed death-1-positive (PD-1+) and programmed death-ligand 1-positive (PD-L1+) cells were higher in post- versus pre-vaccination tumor tissue. CTL response was induced in all patients for at least one of five peptides. The same sequences of peptide-specific TCRs were identified in post-vaccination T-lymphocytes derived from both tumor tissue and blood, suggesting that functional peptide-specific CTLs infiltrate tumor tissue after vaccination. Twelve (80%) participants had treatment-related adverse events (AEs). Injection site reaction was the most frequently reported AE (grade 1, n = 1; grade 2, n = 11). In conclusion, S-588410 induces a tumor immune response in esophageal cancer. Induction of CD8+ PD-1+ tumor-infiltrating lymphocytes and PD-L1 expression in the TME by vaccination suggests S-588410 in combination with anti-PD-(L)1 antibodies may offer a clinically useful therapy.Trial registration UMIN-CTR registration identifier: UMIN000023324.

Large scale clinico-genomic analyses among patients with BRAF-mutated non-small cell lung cancers (NSCLC) identified by nationwide genomic screening project (LC-SCRUM-Japan)

9590

Background: BRAF mutations are functionally classified into three groups, comprisingV600-mutant kinase-activating monomers (class I), kinase-activating dimers (class II), kinase-inactivating heterodimers (class III). The difference of clinical outcomes and concomitant genetic alterations among the three classes in non-small cell lung cancers (NSCLC) are unclear. Methods: We have prospectively analyzed NSCLC patients (pts) for cancer-related genes by a next-generation sequencing system, Oncomine™ Comprehensive Assay, in a large-scale genome screening project in Japan (LC-SCRUM-Japan). The clinical characteristics and outcomes of pts with BRAF-mutated non-squamous (non-sq) NSCLC were comparatively evaluated among the three classes of BRAF mutations. Results: A total of 5166 non-sq NSCLC pts were enrolled into the LC-SCRUM-Japan from 2015 to 2019. BRAF mutations were detected in 176 pts (3%). Among the 176 pts, 153 (87%) were classified into the three classes according to the mutation variants, including 65 (42%) into class I, 52 (34%) into class II and 36 (24%) into class III. The remaining 23 were not classified into any of the three classes. Compared with class I, class II or class III was significantly associated with smoking (P = 0.02 and < 0.01, respectively). Concomitant RAS mutations were significantly more frequent in class II and class III than in class I (P < 0.01 and = 0.04, respectively). The frequency of concomitant STK11 mutations was significantly higher in class III than in others (P < 0.01, respectively). There was no significant difference in the frequency of other oncogene and tumor suppressor gene mutations among the three classes. In the 1st-line platinum-containing chemotherapies for advanced or recurrent cases, median progression-free survival (mPFS) of class III pts was shorter than class I or class II pts (4.2, 11.5 and 4.8 months, I vs III; P < 0.01, II vs III; P = 0.06). In the treatment with 2nd-4th line PD-1/PD-L1 inhibitors, mPFS was not significantly different among the three classes. Overall survival of class III pts was significantly shorter than class I pts (11.9 vs 35.2 months, P = 0.03). Conclusions: Concomitant gene mutations and clinical features are largely different among the BRAF mutation classes. Especially in class III, concomitant RAS and STK11 mutations are more frequent and clinical outcomes were significantly less favorable. These results suggest the need of novel therapeutic strategy based on the mutation class for BRAF-mutated lung cancers.

Association between dexamethasone treatment and alterations in serum concentrations of trace metals

Previously, a significant elevation in the serum levels of iron (Fe) was observed within a few days after the initiation of cisplatin (CDDP)-based chemotherapy. To clarify the underlying mechanisms, the serum concentration of hepcidin, a negative regulator of Fe release, was determined in the clinical samples obtained from six patients with cancer. The result showed that the serum concentration of hepcidin in patients receiving CDDP-based chemotherapy was significantly increased after 4-6 days of treatment, in comparison to the baseline level, suggesting that aforementioned excessive systemic Fe was not explained by the change of serum hepcidin level. All these patients received antiemetic premedication. We next evaluated of the effects of Pt-containing drugs and prophylactic antiemetic dexamethasone medication on the serum concentration of trace metals in mice, and on the hepatic and renal concentration of trace metals. The serum concentrations of Fe, Cu, and Zn in the CDDP-treated and oxaliplatin-treated mice were not significantly altered in comparison to those of the vehicle-treated control group. The serum concentrations of Fe, Cu, and Zn were increased after 24 h of dexamethasone treatment, compared to those of the control group (P < 0.05). The hepatic concentration of Mn was significantly reduced, whereas those of Fe and Cu inclined to diminish. The present findings suggest that dexamethasone can partly contribute to the changes in the serum concentrations of trace metals during anticancer chemotherapy.

Caregiving centenarians: Cross-national comparison in Caregiver-Burden between the United States and Japan

Background and Objectives: The personal distress associated with caring for a family member has been well documented; however, questions about the burden of caregiving for centenarians and cross-national differences in the caregiving context, remain unanswered.Research Design and Methods: This study includes reports by caregivers of 538 near-centenarians and centenarians in the U.S. and Japan: 234 from the Georgia Centenarian Study and 304 from the Tokyo Centenarian Study. Basic descriptive and multivariate regression analyses were conducted. Mean levels of caregiver burden and near-centenarian and centenarians' characteristics (as predictors) for caregiver burden were compared between the U.S. and Japan. The near-centenarian and centenarians' functional capacity and personality were assessed as predictors.Results: Differential predictive patterns in caregiver burden were found in the two groups. In the U.S., near-centenarian and centenarians' agreeableness and conscientiousness were negatively associated with caregiver burden; whereas the near-centenarian and centenarians' neuroticism and number of diseases were positively associated with caregiver burden. In Japan, the near-centenarian and centenarians' activities of daily living, openness, and agreeableness were negatively associated with caregiving burden. Interaction effects between functional capacity and personality, on caregiver burden were observed only in the U.S. In the U.S., higher levels of agreeableness and openness significantly changed the level of caregiver burden associated with vision problems and a greater number of diseases.Discussion and Implications: Cross-national comparative predictors of caregiving burden between the two countries emphasized that caring for centenarians should be understood in the caregiving context, as well as the social context.

Fructose metabolism as a common evolutionary pathway of survival associated with climate change, food shortage and droughts

Mass extinctions occur frequently in natural history. While studies of animals that became extinct can be informative, it is the survivors that provide clues for mechanisms of adaptation when conditions are adverse. Here, we describe a survival pathway used by many species as a means for providing adequate fuel and water, while also providing protection from a decrease in oxygen availability. Fructose, whether supplied in the diet (primarily fruits and honey), or endogenously (via activation of the polyol pathway), preferentially shifts the organism towards the storing of fuel (fat, glycogen) that can be used to provide energy and water at a later date. Fructose causes sodium retention and raises blood pressure and likely helped survival in the setting of dehydration or salt deprivation. By shifting energy production from the mitochondria to glycolysis, fructose reduced oxygen demands to aid survival in situations where oxygen availability is low. The actions of fructose are driven in part by vasopressin and the generation of uric acid. Twice in history, mutations occurred during periods of mass extinction that enhanced the activity of fructose to generate fat, with the first being a mutation in vitamin C metabolism during the Cretaceous-Paleogene extinction (65 million years ago) and the second being a mutation in uricase that occurred during the Middle Miocene disruption (12-14 million years ago). Today, the excessive intake of fructose due to the availability of refined sugar and high-fructose corn syrup is driving 'burden of life style' diseases, including obesity, diabetes and high blood pressure.

Control system for the new RIKEN 28-GHz superconducting electron cyclotron resonance ion source for SRILAC

A new RIKEN 28-GHz superconducting electron cyclotron resonance ion source (SC-ECRIS) has been installed for the superconducting RIKEN linear accelerator (SRILAC). The new SC-ECRIS control system mainly consists of programmable logic controllers (PLCs) embedded with the Experimental Physics and Industrial Control System. To improve the reliability as compared with previous control systems, two types of PLC central processing units, sequential and Linux, have been installed in the same unit. Past experience has shown that new types of designs that can rapidly respond to system scalability are key. By connecting PLC stations using star-topology field buses, their rapid and cost-effective response to system changes is realized for the new devices. Furthermore, a unique data acquisition system employing a 920-MHz-band radio was developed to measure analog data such as the temperature at the high-voltage stage.

High intensity vanadium beam for synthesis of new superheavy elements with well-controlled emittance by using "slit triplet"

To provide a very powerful vanadium (V) beam with an intensity of at least 6 particle μA for synthesizing a new superheavy element (SHE) with atomic number Z = 119, we have developed a high-temperature oven (HTO) system to evaporate the metallic V powder inside the new superconducting (SC) electron cyclotron ion source. We successfully extracted a V¹³⁺ beam with a maximum beam intensity of 600 eμA with 2.8-kW microwave power and 900-W heating power of the HTO. Furthermore, from a systematic study of the dependence of the beam intensity on the microwave power and the HTO power, we successfully produced a V¹³⁺ beam of 300 eμA at a consumption rate of 3 mg/h, allowing a one-month duration continuous beam to carry out the SHE synthesis. In addition, to avoid serious damage to newly introduced SC acceleration cavities by beam losses, the beam should be transported with a well-controlled emittance. To efficiently limit the beam emittance, we employed a slit triplet consisting of three pairs of slits installed around the focus point of the low-energy beam transport. The first result of the emittance reduction was observed by a pepper-pot type emittance meter as a function of the acceptance of the slit triplet.

High-Fructose Diet-Induced Hypertriglyceridemia Is Associated With Enhanced Hepatic Expression of ACAT2 in Rats

High levels of fructose induce hypertriglyceridemia, characterized by excessive levels of triglyceride-rich lipoproteins such as very low-density lipoprotein (VLDL); however, the underlying mechanisms are poorly understood. The aim of this short communication was to examine hepatic changes in the expression of genes related to cholesterol metabolism in rats with hypertriglyceridemia induced by high-fructose or high-glucose diets. Rats were fed a 65 % (w/w) glucose diet or a 65 % (w/w) fructose diet for 12 days. Serum levels of triglycerides, total cholesterol, and VLDL+LDL-cholesterol, hepatic levels of triglycerides and cholesterol, and ACAT2 expression at the gene and protein levels were significantly higher in the fructose diet group compared to the glucose diet group. The hepatic levels of Abcg5/8 were lower in the fructose group than in the glucose group. Serum high-density lipoprotein (HDL)-cholesterol and hepatic expression levels of Hmgcr, Ldlr, Acat1, Mttp, Apob, and Cyp7a1 did not differ significantly between groups. These findings suggest that high-fructose diet-induced hypertriglyceridemia is associated with increased hepatic ACAT2 expression.

Clinical Outcomes of Second-Line Chemotherapy in Patients with Previously Treated Advanced Thymic Carcinoma: A Retrospective Analysis of 191 Patients from the NEJ023 Study

BACKGROUND

Owing to the rarity of this tumor, there is limited information about second-line chemotherapy for patients with previously treated advanced thymic carcinoma.

MATERIAL AND METHODS

We performed a multi-institutional, retrospective study named NEJ023 for patients with advanced thymic carcinoma. Patients without indications for curative treatment were treated with chemotherapy from 1995 to 2014 at 40 institutions in the North East Japan Study Group. Demographic and clinicopathologic characteristics, data on treatment methods, and outcomes of second-line chemotherapy were obtained from medical records.

RESULTS

In total, 191 patients were enrolled in this study. Second-line chemotherapy included platinum-based doublets in 57.6% of patients, other multidrug chemotherapy (e.g., cisplatin, doxorubicin, vincristine, and cyclophosphamide) in 13.6%, and monotherapy in 28.8%. The median follow-up time was 50.5 months, and the median overall survival (OS) from the start of second-line chemotherapy was 22.4 (95% confidence interval, 17.5-26.7) months. The average response rate (RR) was 20.0% overall; it was 21.6% for patients treated with platinum-based doublet chemotherapy, 13.6% for those treated with other multidrug chemotherapy, and 19.6% for those treated with single agent chemotherapy. There was no significant difference in OS between platinum-based doublet chemotherapy, other multidrug chemotherapy, and monotherapy (the median OS was 22.4, 25.7, and 21.4 months, respectively).

CONCLUSION

The median OS was 22.4 months in patients with advanced thymic carcinoma treated with second-line chemotherapy. There were no significant differences in RR and OS between monotherapy and multidrug chemotherapy in this study.

IMPLICATIONS FOR PRACTICE

Owing to the rarity of this tumor, there is limited information about second-line chemotherapy for patients with previously treated advanced thymic carcinoma. This is the largest data for those patients treated with second-line chemotherapy. This study suggests there is no significant difference in efficacy between monotherapy and multidrug chemotherapy for previously treated advanced thymic carcinoma. This result can support the adequacy to select monotherapy as treatment of those patients.

Combination of furosemide and fludrocortisone as a loading test for diagnosis of distal renal tubular acidosis in a pediatric case

Renal tubular acidosis (RTA) is a rare disease caused by a defect of urinary acidification. The ammonium chloride loading test is the gold standard method for determining the type of RTA. However, because this test has some side effects (e.g., nausea, vomiting, and stomach discomfort), applying this test for pediatric cases is difficult. Recently, a loading test with the combination of furosemide and fludrocortisone was reported to be an alternative to the ammonium chloride loading test, with 100% sensitivity and specificity in adult's cases. We report the first pediatric case of distal RTA in a patient who was successfully diagnosed by a drug loading test with the combination of furosemide and fludrocortisone without any side effects. We also performed genetic analysis and detected a known pathogenic variant in the SLC4A1 gene. The combination loading test of furosemide and fludrocortisone is a useful and safe diagnostic tool for pediatric cases of RTA.

P4500Cellular senescence of endothelial cells impairs angiogenesis by altering energy metabolism through p53-tigar axis

Background

Ischemic disease is prevalent in elderly population due to impaired angiogenesis. Endothelial cell (EC) generates energy largely via glycolysis, which is further activated when angiogenesis actively occurs. PFK-1 is one of the most important regulatory enzymes for glycolysis, which is activated by PFKFB3. On the other hand, TIGAR inhibits PFK-1 under the control of p53. Crucial roles of PFKFB3 in EC functions under physiological and pathological conditions have been reported; however, a role of TIGAR in EC angiogenic functions remains to be elucidated. Furthermore, it remains unknown whether and how cellular senescence affect the energy metabolism in EC.

Purpose

The purpose of this study is to investigate molecular mechanisms underlying EC dysfunction associated with ageing, especially by focusing on endothelial energy metabolism.

Method and result

Senescent EC showed reduced glucose consumption assessed by [U-13C]-glucose tracer assay in association with increased expression of p53 and TIGAR. Angiogenic capacity assessed by tube-formation assay was reduced in senescent EC. Of note, either silencing of TIGAR by siRNA or lentivirus-mediated overexpression of PFKFB3 improved angiogenic capacity in senescent EC. These results collectively suggest that senescence impairs glycolysis in EC by activating p53-TIGAR axis, which leads to senescence-associated endothelial dysfunction. To analyze an impact of EC senescence in angiogenesis in vivo, we generated EC-specific progeroid mice in which dominant negative form of telomere repeat-binding factor 2 (TRF2) was overexpressed in EC under the control of the TIE2 promoter. After confirming EC-specific senescence in these endothelial progeroid mice, we generated hind-limb ischemia model. Recovery of blood flow assessed by laser doppler velocimeter was significantly impaired in endothelial progeroid mice, indicating that EC senescence is directly and causally implicated in age-related angiogenic dysfunction. Of note, genetic inactivation of TIGAR completely rescued the impaired ischemia-induced neovessel formation in EC-specific progeroid mice.

Conclusion

Using unique endothelial progeroid mice, we revealed that EC senescence is a bona fide risk for ischemic disease, largely by reducing glycolysis in EC through p53-TIGAR axis. Our data suggest that endothelial energy metabolism is an attracting therapeutic target for the prevention and/or treatment of ischemic diseases, especially in elderly population.

P1535Clinical impact of carotid plaque score rather than carotid intima-media thickness on atherosclerotic cardiovascular disease

Background

Carotid intima-media thickness (cIMT) assessed by ultrasound has been widely accepted as a surrogate marker of atherosclerotic cardiovascular disease. On the other hand, carotid plaque score (cPS) reflecting throughout the carotid artery plaque burden may be better marker.

Methods

We retrospectively examined 2,035 patients who underwent carotid ultrasonography between January 2006 and December 2015 at our University Hospital. Median follow-up period was 4 years. We used Cox models that adjusted for established risk factors of ASCVD, including age, gender, hypertension, diabetes, smoking, and serum lipids to assess the association of cIMT as well as cPS with major adverse cardiac events (MACE). MACE was defined as all-cause mortality or rehospitalization for a cardiovascular-related illness

Results

During follow-up, 243 participants experienced MACE. After adjustment for established risk factors, cPS was associated with MACE (hazard ratio [HR] = 3.38 for top quintile vs. bottom quintile of cPS; 95% confidence interval [CI] 1.82 to 6.27; P-trend = 1.4×10–8), while cIMT was not (HR = 0.88, P=0.57). Addition of the cPS to established risk factors significantly improved risk discrimination (C-index 0.726 vs. 0.746; P=0.017)

Conclusion

As a marker, cPS, rather than cIMT can identify 20% of individuals who are at more than three-fold increased risk for MACE. Targeting diagnostic or therapeutic interventions to this subset may prove clinically useful.