Kerr-Enhanced Optical Spring.

We propose and experimentally demonstrate the generation of enhanced optical springs using the optical Kerr effect. A nonlinear optical crystal is inserted into a Fabry-Perot cavity with a movable mirror, and a chain of second-order nonlinear optical effects in the phase-mismatched condition induces the Kerr effect. The optical spring constant is enhanced by a factor of 1.6±0.1 over linear theory. To our knowledge, this is the first realization of optomechanical coupling enhancement using a nonlinear optical effect, which has been theoretically investigated to overcome the performance limitations of linear optomechanical systems. The tunable nonlinearity of demonstrated system has a wide range of potential applications, from observing gravitational waves emitted by binary neutron star postmerger remnants to cooling macroscopic oscillators to their quantum ground state.

RECAM-J 2023-Validation and development of the Japanese version of RECAM for the diagnosis of drug-induced liver injury.

AIM: The diagnosis of drug-induced liver injury (DILI) is challenging. We modified the revised electronic version of the Roussel Uclaf Causality Assessment Method (RUCAM) for the diagnosis of DILI (RECAM), the scoring system developed in US and Spanish cohorts in 2022, and developed RECAM-J 2023 to align with the clinical practice in Japan. In the current study, we introduce RECAM-J 2023 and verify its performance in the context of Japanese patients with DILI. METHODS: After translation of RECAM into Japanese, modifications were made to develop RECAM-J 2023 without any alteration to the scores. To examine the validity and performance of RECAM-J 2023, clinical information on DILI and non-DILI cases in Japan were retrospectively collected. The diagnosis of DILI was made by expert's decision. Then we scored each case using RECAM-J 2023, and calculated area under curve (AUC) values for identification for DILI. RESULTS: We collected data from 538 DILI and 128 non-DILI cases. The sum of highly probable (HP) and probable (PR) cases categorized by RECAM-J 2023 were only 206 (38%) in DILI cases. As the primary cause of low scores was the deduction with missing hepatitis virus markers, which is unlikely to be an issue in prospective applications, we rescored without these deductions. At this time, the sum of HP and PR was raised to 421 (78%). The AUCs of RECAM-J 2023 without deductions were 0.70 and 0.88 for identifying at least HP, and at least PR, respectively. CONCLUSION: RECAM-J 2023, when prospectively used without any missing hepatitis virus markers, provides acceptable performance for identifying at least PR DILI cases in Japanese daily clinical practice.

Multifunctional chemical inhibitors of the florigen activation complex discovered by structure-based high-throughput screening.

Structure-based high-throughput screening of chemical compounds that target protein-protein interactions (PPIs) is a promising technology for gaining insight into how plant development is regulated, leading to many potential agricultural applications. At present, there are no examples of using high-throughput screening to identify chemicals that target plant transcriptional complexes, some of which are responsible for regulating multiple physiological functions. Florigen, a protein encoded by FLOWERING LOCUS T (FT), was initially identified as a molecule that promotes flowering and has since been shown to regulate flowering and other developmental phenomena such as tuber formation in potato (Solanum tuberosum). FT functions as a component of the florigen activation complex (FAC) with a 14-3-3 scaffold protein and FD, a bZIP transcription factor that activates downstream gene expression. Although 14-3-3 is an important component of FAC, little is known about the function of the 14-3-3 protein itself. Here, we report the results of a high-throughput in vitro fluorescence resonance energy transfer (FRET) screening of chemical libraries that enabled us to identify small molecules capable of inhibiting FAC formation. These molecules abrogate the in vitro interaction between the 14-3-3 protein and the OsFD1 peptide, a rice (Oryza sativa) FD, by directly binding to the 14-3-3 protein. Treatment with S4, a specific hit molecule, strongly inhibited FAC activity and flowering in duckweed, tuber formation in potato, and branching in rice in a dose-dependent manner. Our results demonstrate that the high-throughput screening approach based on the three-dimensional structure of PPIs is suitable in plants. In this study, we have proposed good candidate compounds for future modification to obtain inhibitors of florigen-dependent processes through inhibition of FAC formation.

Efficacy and safety of pembrolizumab and axitinib as first-line treatment for patients with advanced renal cell carcinoma: Real-world experience in Japan.

OBJECTIVES: The objective of this study was to assess the clinical outcomes following combined treatment with pembrolizumab and axitinib as first-line therapy for patients with advanced RCC. METHODS: This study retrospectively included 47 consecutive Japanese patients who were diagnosed with advanced RCC and subsequently received pembrolizumab and axitinib between February 2020 and January 2022. Efficacy and safety of this combined therapy in these patients were comprehensively investigated. RESULTS: The 47 included patients were classified into the following 3 groups by the IMDC system: favorable, 7 (14.9%); intermediate, 24 (51.1%) and poor, 16 (34.0%). Responses to this combined therapy in the 47 patients were as follows: CR, 8 (17.0%); PR, 20 (42.6%); SD, 16 (34.0%) and PD, 3 (6.4%); thus, the ORR was 59.6%. During the observation period, disease progression and death occurred in 19 (40.4%) and 9 (19.1%) patients, respectively, and the median PFS and OS were 18 months and not reached, respectively. Univariate analyses identified the following significant predictors for poor prognostic outcomes: lack of nephrectomy, liver metastasis, bone metastasis, elevated CRP and IMDC poor risk for PFS; and lack of nephrectomy, non-CCC and elevated CRP for OS. AEs and those corresponding to grade ≥ 3 occurred in all (100%) and 30 (63.8%) patients, respectively. CONCLUSIONS: To our knowledge, this is the first study focusing on real-world outcomes following pembrolizumab and axitinib for treatment-naïve advanced Japanese RCC patients, which showed the efficacy and safety of this combined therapy being similar or even superior to those in clinical trial.

Differential impact of proton pump inhibitor on survival outcomes of patients with advanced urothelial carcinoma treated with chemotherapy versus pembrolizumab.

OBJECTIVES: We clarified the effect of concomitant proton pump inhibitor use on oncological outcomes in patients with advanced urothelial carcinoma treated either with chemotherapy or immune checkpoint inhibitor. METHODS: We retrospectively reviewed patients with advanced urothelial carcinoma who received paclitaxel-gemcitabine therapy or pembrolizumab after platinum-based chemotherapy. The patients were divided into four groups based on the treatment regimen and the concomitant use of proton pump inhibitor. We compared survival outcomes between the groups and determined which factors predicted overall survival. RESULTS: Among the 60 and 75 patients treated with paclitaxel-gemcitabine and pembrolizumab, 15 and 29 used a concomitant proton pump inhibitor. Progression-free and overall survival was significantly shorter in patients who were administered pembrolizumab with concomitant proton pump inhibitor compared to those without. The use of a concomitant proton pump inhibitor had no effect on survival outcomes in patients who received paclitaxel-gemcitabine therapy. Furthermore, progression-free and overall survival were significantly shorter in patients treated with paclitaxel-gemcitabine therapy compared to those treated with pembrolizumab among patients without concomitant proton pump inhibitor. In contrast, there was no difference in survival outcomes between the two regimens among patients with concomitant proton pump inhibitor. Concomitant proton pump inhibitor use was associated with poor overall survival only in patients treated with pembrolizumab. CONCLUSION: The use of a concomitant proton pump inhibitor use had no impact on oncological outcomes in patients with advanced urothelial carcinoma treated with paclitaxel-gemcitabine therapy, different from those treated with pembrolizumab.

Significance of second progression-free survival in patients with advanced urothelial cancer who received platinum-based combination chemotherapy followed by pembrolizumab.

OBJECTIVES: The present study comprehensively investigated the significance of several factors reflecting the therapeutic effects of anticancer treatment on overall survival (OS) in advanced urothelial cancer (UC) patients receiving sequential systemic therapy. METHODS: This study included 101 consecutive advanced UC patients who received first-line platinum-based combination chemotherapy followed by second-line pembrolizumab. The impacts of the following factors on OS in these patients were analyzed: responses to chemotherapy, responses to pembrolizumab, progression-free survival (PFS) with chemotherapy, PFS with pembrolizumab, and second PFS (PFS2). RESULTS: The median age of patients was 71 years, and 35 and 66 had UC in the upper urinary tract and bladder, respectively. objective response rate to first-line chemotherapy and second-line pembrolizumab were 37.6% and 19.8%, respectively. Median PFS with chemotherapy, pembrolizumab, and PFS2 were 5, 4, and 9 months, respectively. Uni- and multivariate analyses of the five factors examined identified PFS with pembrolizumab and PFS2 as independent surrogates for OS, with PFS2 (hazard ratio [HR] = 0.23) being more closely associated with OS than PFS with pembrolizumab (HR = 0.31). Furthermore, uni- and multivariate analyses of various prognostic parameters showed the independent impacts of baseline performance status (PS) and neutrophil-to-lymphocyte ratio (NLR) on PFS2. CONCLUSIONS: The present results suggest the potential of PFS2 as an optimal surrogate for OS in advanced UC patients receiving standard sequential systemic therapy and indicate that intensive treatment needs to be considered for those with poor PS and/or high NLR prior to the introduction of first-line chemotherapy.

Photothermal effect in macroscopic optomechanical systems with an intracavity nonlinear optical crystal.

Intracavity squeezing is a promising technique that may improve the sensitivity of gravitational wave detectors and cool optomechanical oscillators to the ground state. However, the photothermal effect may modify the occurrence of optomechanical coupling due to the presence of a nonlinear optical crystal in an optical cavity. We propose a novel method to predict the influence of the photothermal effect by measuring the susceptibility of the optomechanical oscillator and identifying the net optical spring constant and photothermal absorption rate. Using this method, we succeeded in precisely estimating parameters related to even minor photothermal effects, which could not be measured using a previously developed method.

Comprehensive assessments of immuno-oncology drug-based combination therapies as first-line treatment for advanced renal cell carcinoma.

Over the last decade, there have been substantial progress in the field of systemic therapy for advanced renal cell carcinoma. Through the transition from treatment with cytokines to molecular-targeted agents, and currently to immuno-oncology drugs, the prognostic outcomes of patients with advanced renal cell carcinoma have been markedly improved. In particular, based on the promising outcomes of recently conducted pivotal randomized clinical trials, immuno-oncology drug-based combination therapy by either dual immune checkpoint inhibition or combined inhibition of an immune checkpoint and tyrosine kinase, is currently regarded as a standard of care for treatment-naïve advanced renal cell carcinoma patients. However, insufficient data are available with respect to the selection of optimal systemic therapies for advanced renal cell carcinoma in the first-line setting due to the lack of a head-to-head comparison between approved immuno-oncology drug-based combination therapies. In this review, therefore, we summarize interesting findings associated with first-line combination therapies for advanced renal cell carcinoma obtained from both randomized clinical trials and real-world clinical practices, in order to present useful guidance to help make treatment decisions for patients with treatment-naïve advanced renal cell carcinoma.

Analytical Technique Optimization on the Detection of ß-cyclocitral in Microcystis Species.

ß-Cyclocitral, specifically produced by Microcystis, is one of the volatile organic compounds (VOCs) derived from cyanobacteria and has a lytic activity. It is postulated that ß-cyclocitral is a key compound for regulating the occurrence of cyanobacteria and related microorganisms in an aquatic environment. ß-Cyclocitral is sensitively detected when a high density of the cells is achieved from late summer to autumn. Moreover, it is expected to be involved in changes in the species composition of cyanobacteria in a lake. Although several analysis methods for ß-cyclocitral have already been reported, ß-cyclocitral could be detected using only solid phase micro-extraction (SPME), whereas it could not be found at all using the solvent extraction method in a previous study. In this study, we investigated why ß-cyclocitral was detected using only SPME GC/MS. Particularly, three operations in SPME, i.e., extraction temperature, sample stirring rate, and the effect of salt, were examined for the production of ß-cyclocitral. Among these, heating (60 °C) was critical for the ß-cyclocitral formation. Furthermore, acidification with a 1-h storage was more effective than heating when comparing the obtained amounts. The present results indicated that ß-cyclocitral did not exist as the intact form in cells, because it was formed by heating or acidification of the resulting intermediates during the analysis by SPME. The obtained results would be helpful to understand the formation and role of ß-cyclocitral in an aquatic environment.

Microbial Degradation of Amino Acid-Containing Compounds Using the Microcystin-Degrading Bacterial Strain B-9.

Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins produced by fungi. Among the tested mycotoxins, only ochratoxin A was completely hydrolyzed to provide the constituents ochratoxin α and l-phenylalanine, and levels of fumonisin B1 gradually decreased after 96 h. However, although drugs including antibiotics released into the aquatic environment were applied for microbial degradation using strain B-9, no degradation occurred. These results suggest that strain B-9 can only degrade amino acid-containing compounds. As expected, the tested compounds with amide and ester bonds, such as 3,4-dimethyl hippuric acid and 4-benzyl aspartate, were readily hydrolyzed by strain B-9, although the sulfonamides remained unchanged. The ester compounds were characteristically and rapidly hydrolyzed as soon as they came into contact with strain B-9. Furthermore, the degradation of amide and ester compounds with amino acids was not inhibited by the addition of ethylenediaminetetraacetic acid (EDTA), indicating that the responsible enzyme was not MlrC. These results suggest that strain B-9 possesses an additional hydrolytic enzyme that should be designated as MlrE, as well as an esterase.

Application of MALDI Biotyper to cyanobacterial profiling.

RATIONALE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been used for bacterial profiling. A few reports have shown MALDI-MS profiling of isolated/cultured cyanobacteria; however, these applications have been limited. In this study, we have investigated whether rapid profiling and differentiation of cyanobacteria including harmful genera Microcystis and Anabaena (Dolichospermum) can be performed by MALDI Biotyper analysis of intact cells. METHODS: Twenty-two cyanobacterial strains including 12 Microcystis, 7 Anabaena, 1 Pseudanabaena, 1 Planktothrix, and 1 Synechocystis were cultured. Also, natural pond water containing cyanobacteria was collected. Intact cyanobacterial cells were deposited on a target plate, and analyzed using an Autoflex Speed MALDI-TOF mass spectrometer with Biotyper software. Mass spectra obtained from m/z 2000 to 20000 were used for clustering and spectral library searching of cyanobacterial strains. RESULTS: MALDI-MS analysis of cultured cyanobacterial cells showed clear ion signals under optimized conditions. Hierarchical clustering of mass spectra using Biotyper resulted in a tight cluster of Microcystis strains which was clearly differentiated from a cluster of Anabaena strains. Spectral library searching was able to identify Microcystis aeruginosa NIES-298 and Synechocystis sp. PCC 6803 even when these two cells were mixed. Furthermore, cyanobacterial cells in the pond water were successfully classified as Anabaena. CONCLUSIONS: We have demonstrated that MALDI-MS in combination with Biotyper analysis is applicable to cyanobacterial profiling. Increasing the size of the spectral library may facilitate monitoring of cyanobacteria in crude cyanobacterial blooms. Copyright © 2016 John Wiley & Sons, Ltd.

FVIIa-sTF and Thrombin Inhibitory Activities of Compounds Isolated from Microcystis aeruginosa K-139.

The rise of bleeding and bleeding complications caused by oral anticoagulant use are serious problems nowadays. Strategies that block the initiation step in blood coagulation involving activated factor VII-tissue factor (fVIIa-TF) have been considered. This study explores toxic Microcystis aeruginosa K-139, from Lake Kasumigaura, Ibaraki, Japan, as a promising cyanobacterium for isolation of fVIIa-sTF inhibitors. M. aeruginosa K-139 underwent reversed-phase solid-phase extraction (ODS-SPE) from 20% MeOH to MeOH elution with 40%-MeOH increments, which afforded aeruginosin K-139 in the 60% MeOH fraction; micropeptin K-139 and microviridin B in the MeOH fraction. Aeruginosin K-139 displayed an fVIIa-sTF inhibitory activity of ~166 µM, within a 95% confidence interval. Micropeptin K-139 inhibited fVIIa-sTF with EC50 10.62 µM, which was more efficient than thrombin inhibition of EC50 26.94 µM. The thrombin/fVIIa-sTF ratio of 2.54 in micropeptin K-139 is higher than those in 4-amidinophenylmethane sulfonyl fluoride (APMSF) and leupeptin, when used as positive controls. This study proves that M. aeruginosa K-139 is a new source of fVIIa-sTF inhibitors. It also opens a new avenue for micropeptin K-139 and related depsipeptides as fVIIa-sTF inhibitors.

Cyanobacterial blue color formation during lysis under natural conditions.

Cyanobacteria produce numerous volatile organic compounds (VOCs), such as ß-cyclocitral, geosmin, and 2-methylisoborneol, which show lytic activity against cyanobacteria. Among these compounds, only ß-cyclocitral causes a characteristic color change from green to blue (blue color formation) in the culture broth during the lysis process. In August 2008 and September 2010, the lysis of cyanobacteria involving blue color formation was observed at Lake Tsukui in northern Kanagawa Prefecture, Japan. We collected lake water containing the cyanobacteria and investigated the VOCs, such as ß-cyclocitral, ß-ionone, 1-propanol, 3-methyl-1-butanol, and 2-phenylethanol, as well as the number of cyanobacterial cells and their damage and pH changes. As a result, the following results were confirmed: the detection of several VOCs, including ß-cyclocitral and its oxidation product, 2,2,6-trimethylcyclohexene-1-carboxylic acid; the identification of phycocyanin based on its visible spectrum; the lower pH (6.7 and 5.4) of the lysed samples; and characteristic morphological change in the damaged cyanobacterial cells. We also encountered the same phenomenon on 6 September 2013 in Lake Sagami in northern Kanagawa Prefecture and obtained almost the same results, such as blue color formation, decreasing pH, damaged cells, and detection of VOCs, including the oxidation products of ß-cyclocitral. ß-Cyclocitral derived from Microcystis has lytic activity against Microcystis itself but has stronger inhibitory activity against other cyanobacteria and algae, suggesting that the VOCs play an important role in the ecology of aquatic environments.

Non-significant impact of proteinuria on renal function in Japanese patients with metastatic renal cell carcinoma treated with axitinib.

BACKGROUND: To investigate the impact of proteinuria on the renal function of patients with metastatic renal cell carcinoma (mRCC) who received axitinib, a tyrosine kinase inhibitor specifically targeting vascular endothelial growth factor receptors. METHODS: This study included 65 consecutive Japanese patients who were diagnosed with mRCC and were subsequently treated with axitinib for at least 12 weeks. The association between the changes in the estimated glomerular filtration rate (eGFR) and proteinuria in these 65 patients was retrospectively assessed. RESULTS: Of the 65 patients, 41 (63.1 %) were judged to be positive for proteinuria. There were no significant differences between the eGFR value before the introduction of axitinib and that at the last clinic visit in either group with or without proteinuria. Furthermore, no significant correlation was noted between the changes in eGFR and the urine protein to creatinine ratio in the group positive for proteinuria, and there was no significant effect of the duration of treatment with axitinib on the changes in eGFR in the proteinuria group. Of several factors examined, univariate analysis identified age, eGFR prior to the introduction of axitinib, and timing of axitinib introduction, but not the presence of proteinuria, as predictors of a decrease in eGFR of >10 %; however, only age appeared to be independently associated with a decrease in eGFR of >10 %. CONCLUSIONS: These findings suggest that treatment with axitinib may not have a significant adverse impact on the renal function in patients with mRCC, irrespective of the presence of proteinuria.

Determination of FVIIa-sTF Inhibitors in Toxic Microcystis Cyanobacteria by LC-MS Technique.

The blood coagulation cascade involves the human coagulation factors thrombin and an activated factor VII (fVIIa). Thrombin and fVIIa are vitamin-K-dependent clotting factors associated with bleeding, bleeding complications and disorders. Thrombin and fVIIa cause excessive bleeding when treated with vitamin-K antagonists. In this research, we explored different strains of toxic Microcystis aeruginosa and cyanobacteria blooms for the probable fVIIa-soluble Tissue Factor (fVIIa-sTF) inhibitors. The algal cells were subjected to acidification, and reverse phase (ODS) chromatography-solid phase extraction eluted by water to 100% MeOH with 20%-MeOH increments except for M. aeruginosa NIES-89, from the National Institute for Environmental Studies (NIES), which was eluted with 5%-MeOH increments as an isolation procedure to separate aeruginosins 89A and B from co-eluting microcystins. The 40%-80% MeOH fractions of the cyanobacterial extract are active against fVIIa-sTF. The fVIIa-sTF active fractions from cultured cyanobacteria and cyanobacteria blooms were subjected to liquid chromatography-mass spectrometry (LC-MS). The 60% MeOH fraction of M. aeruginosa K139 exhibited an m/z 603 [M + H]⁺ attributed to aeruginosin K139, and the 40% MeOH fraction of M. aeruginosa NIES-89 displayed ions with m/z 617 [M - SO3 + H]⁺ and m/z [M + H]⁺ 717, which attributed to aeruginosin 89. Aeruginosins 102A/B and 298A/B were also observed from other toxic strains of M. aeruginosa with positive fVIIa-sTF inhibitory activity. The active fractions contained cyanobacterial peptides of the aeruginosin class as fVIIa-sTF inhibitors detected by LC-MS.

Assessment of efficacy, safety and quality of life of 55 patients with metastatic renal cell carcinoma treated with temsirolimus: a single-center experience in Japan.

BACKGROUND: To evaluate experience of the use of temsirolimus for metastatic renal cell carcinoma (mRCC) in a single center in Japan. METHODS: This study included 55 consecutive patients with mRCC who received temsirolimus in a routine clinical setting, and retrospectively reviewed the comprehensive outcomes of these patients. RESULTS: Of the 55 patients, 20 had a Karnofsky performance status of ≤80, and 5, 41 and 9 were classified into favorable, intermediate and poor risk groups, respectively, according to the Memorial Sloan-Kettering Cancer Center model. Initially, 25 mg of temsirolimus was applied weekly; however, dose modification was required in 19 patients, resulting in a relative dose intensity of 90.5 % throughout this series. As the best responses to temsirolimus, 4, 44 and 7 were judged to have a partial response, stable disease and progressive disease, respectively. The median progression-free survival (PFS) and overall survival (OS) of these patients following the introduction of temsirolimus was 7.0 and 25.0 months, respectively. Of several factors examined, only the pretreatment C-reactive protein level was shown to be independently associated with both PFS and OS. The common adverse events related to temsirolimus corresponding to ≥grade 3 were anemia in 4, thrombocytopenia in 3, stomatitis in 3 and hyperglycemia in 3. Quality of life analysis using 36-Item Short Form showed that there were no significant differences in any scale scores between surveys performed before and 3 months after the introduction of temsirolimus. CONCLUSIONS: Temsirolimus was well tolerated and facilitated comparatively favorable cancer control in Japanese patients with mRCC.

Assessment of postoperative quality of life: comparative study between laparoscopic and minimum incision endoscopic radical prostatectomies.

BACKGROUND: To investigate the changes in postoperative quality of life (QOL) in patients with prostate cancer who underwent laparoscopic radical prostatectomy (LRP) or minimum incision endoscopic radical prostatectomy (MIE-RP). METHODS: This study included a total of 115 Japanese patients with clinically localized prostate cancer who underwent either LRP or MIE-RP and were subsequently followed for more than 12 months. Before and 12 months after surgery, health-related QOL and disease-specific QOL were assessed using the Medical Outcomes Study 8-item Short-Form Health Survey (SF-8) and the Expanded Prostate Index Composite (EPIC), respectively. RESULTS: LRP and MIE-RP were performed in 57 and 58 patients, respectively, and there were no significant differences in major clinicopathological parameters between these two groups. There were no significant differences in perioperative outcomes between the two groups except for the estimated blood loss, which was lower in the LRP group. There were no significant differences between the two groups in the preoperative and postoperative all-scale scores of the SF-8 survey. Of the fourteen scores evaluated by the EPIC survey, postoperative scores for urinary summary, sexual summary, urinary function, urinary incontinence and sexual function were significantly worse than these preoperative scores in both LRP and MIE-RP groups, while there were no significant differences between the two groups in the preoperative and postoperative all-scale scores of the EPIC survey. CONCLUSIONS: The postoperative QOL status in patients undergoing MIE-RP appeared to be equivalent to that in those undergoing LRP.

Mobilize a Proton to Transform the Collision-Induced Dissociation Spectral Pattern of a Cyclic Peptide.

The collision-induced dissociation (CID) behaviors of protonated molecules of anabaenopeptins, a group of cyanobacterial cyclic peptides, were investigated in detail using liquid chromatography-tandem mass spectrometry. Although anabaenopeptin A and B share a macrocyclic peptide structure, they give strikingly different fragmentation patterns; the former gives a variety of product ions including cleavages in the cyclic peptide structure, which is useful for structural analysis; whereas the latter gives far fewer product ions and no fragmentation in the cyclic moiety. Energy-resolved CID experiments clarified the mechanism behind the striking difference attributable to the difference in exocyclic amino acid residues, Tyr or Arg. The guanidino group in Arg-containing analogue, anabaenopeptin B, should be by far the most preferred protonation site; the proton would be sequestered at the guanidino group in the protonated molecule, with the lack of proton mobility prohibiting opening of the charge-directed fragmentation channels in the cyclic moiety. Enzymatic hydrolysis of the guanidino group to give citrullinated-anabaenopeptin B restored proton mobility. The fragmentation pattern of the citrullinated peptide became almost identical to that of anabaenopeptin A. The observed fragmentation behaviors of these cyclic peptides were consistent with those of linear peptides, which have been well understood based on the mobile proton model.

Therapeutic outcome of combination therapy using immune-checkpoint inhibitors and tyrosine kinase inhibitors for metastatic non-clear-cell renal cell carcinoma.

INTRODUCTION: We aimed to clarify the therapeutic outcome of combination therapy using immune-checkpoint inhibitors (ICIs) and/or tyrosine kinase inhibitors (TKIs) for meta-static non-clear-cell renal cell carcinoma (nccRCC). METHODS: We have been retrospectively investigating the therapeutic efficacy and prognosis in 36 patients with metastatic nccRCC undergoing combination therapy using two ICIs, ipilimumab plus nivolumab (ICI-ICI), and ICI plus TKI (ICI-TKI), at Kobe University and affiliated institutions since 2018. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and adverse event (AE) were compared. RESULTS: The first-line regimen was ICI-ICI in 26 cases and ICI-TKI in 10 cases. The ORRs in the ICI-ICI and ICI-TKI groups were 34.6 and 30.0%, respectively (p=0.9433). The 50% PFS for the ICI-TKI group was 9.7 months, significantly longer than that for the ICI-ICI group (4.6 months, p=0.0499), and there was no significant difference in OS between groups (p=0.3984). There was no significant difference in the occurrence rate of AE for below grade 2 (p=0.8535), nor above grade 3 (p=0.3786) between the ICI-ICI and ICI-TKI groups. CONCLUSIONS: From our analysis of real-world data, a better outcome of PFS was expected in the ICI-TKI group compared with that in the ICI-ICI group, while there was no significant difference in OS or ORR.