Validation of Inter-Rater and Intra-Rater Reliability of Remote Dielectric Sensing Measurement.

Remote dielectric sensing (ReDS) is a recently introduced non-invasive electromagnetic-based device used to quantify lung fluid levels. Nevertheless, its inter-rater and intra-rater reliability remain uncertain. In 10 healthy volunteers, ReDS values were measured three times successively by the officially trained expert examiner to validate intra-rater reliability. Similar measures were performed by a total of three examiners to validate inter-rater reliability. Intra-class correlation (ICC) was applied to validate each reliability. Ten healthy volunteers [median 34 (32, 40) years old, 10 men, body mass index 23.0 (21.2, 23.9) ] were included. Median ReDS value was 28% (25%, 31%). For the intra-rater reliability, ICC (1, 1) and ICC (1, 3) were 0.966 and 0.988, respectively (P < 0.001). For the inter-rater reliability, ICC (2, 1) and ICC (2, 3) were 0.683 and 0.866, respectively (P < 0.001). Given almost perfect intra-rater reliability, an examiner does not need to repeat ReDS measurement. Given substantial inter-rater reliability, ReDS measurements had better be measured by multiple examiners if possible.

Trans-Apical Transcatheter Aortic Valve Replacement in a Dialysis Patient with Systolic Heart Failure.

Mortality and morbidity remain high following transcatheter aortic valve replacement (TAVR) in dialysis patients or those with low left ventricular ejection fraction. Therapeutic strategy for those with these comorbidities remains unestablished. We had a dialysis patient with peripheral artery disease and low left ventricular ejection fraction, who received successfully scheduled trans-apical TAVR following sufficient reverse remodeling by 3-month optimal medical therapy. Our strategy should be validated in a larger robust cohort.

Impact of optimal heart rate on left ventricular reverse remodeling and functional improvement in patients with systolic heart failure.

Heart rate modulation therapy using ivabradine reduces mortality and morbidity in patients with systolic heart failure, whereas too reduced heart rate seems to worsen the clinical outcome. The optimal heart rate during heart rate modulation therapy remains unknown. Consecutive patients with left ventricular ejection fraction < 50% who received echocardiographic assessments and simultaneous heart rate measurements were retrospectively investigated. Theoretically ideal heart rate was calculated using a previously proposed formula: 93 - 0.13 × (deceleration time [msec]). Impacts of heart rate on the 1-year echocardiographic left ventricular reverse remodeling were compared among the three groups stratified by the heart rate status: optimal heart rate group (within 10 bpm of ideal heart rate), below-optimal heart rate group (< 10 bpm of ideal heart rate), and above-optimal heart rate group (> 10 bpm of ideal heart rate). A total of 75 patients (70 years old, 60 men) were included. There were no significant differences in the baseline characteristics among the three groups, except for the higher prevalence of tolvaptan use and higher plasma B-type natriuretic peptide level in the below-optimal heart rate group. Left ventricular end-diastolic diameter (from 55 to 54) and left ventricular ejection fraction (from 39 to 46) improved significantly only in the optimal heart rate group at 1-year follow-up (p < 0.05 for both). Optimal heart rate, which was calculated using a formula consisting of deceleration time, was associated with cardiac reverse remodeling in patients with systolic heart failure. Prospective study to investigate the implication of deceleration time-guided aggressive heart rate optimization is the next concern.

How to Estimate the Optimal Heart Rate in Patients with Heart Failure with Preserved Ejection Fraction.

Ideal heart rate (HR), particularly for those with heart failure with preserved ejection fraction (HFpEF), remains unknown. We hypothesized that cardiac output would be maximum when the overlap between E-wave and A-wave at the trans-mitral flow is "zero" in the Doppler echocardiography. We retrospectively investigated the association among the overlap length between two waves, actual HR, and other echocardiographic parameters to construct a formula for estimating theoretically ideal HR among those with HFpEF. In total, 48 HFpEF patients were included (70-year-olds, 18 males). Given the results of multivariate linear regression analyses, the overlap length was estimated as follows: -1,050 + 8.4 × (HR [bpm]) + 0.6 × (deceleration time [millisecond]) + 1.7 × (A-width [millisecond]), which had a strong agreement with the actually measured overlap length (r = 0.86, P < 0.001). Theoretically ideal HR was calculated by substituting zero into the estimated overlap length as follows: 125 - 0.07 × (deceleration time [millisecond]) - 0.20 × (A-width [millisecond]). In the validation cohort including another 143 HFpEF patients, the estimated overlap using the formula again had a strong agreement with the actually measured overlap (r = 0.72, P < 0.001). In this study, we proposed a novel formula for calculating theoretically ideal HR, consisting of deceleration time and A-width, in the HFpEF cohort. Clinical implication to optimize the HR targeting the theoretically ideal HR should be investigated in prospective studies.

Acute Heart Failure in a Patient with Occult Barlow's Disease Receiving Bevacizumab.

Bevacizumab is a recombinant humanized monoclonal antibody and a key drug for treatment of various types of cancer. Bevacizumab is associated with the occurrence of heart failure, but its risk factors remain unknown. A 55-year-old woman was diagnosed with cervical cancer, which was completely treated by bevacizumab-incorporated chemotherapy. During the 9-month bevacizumab therapy, she suffered from hypertension requiring multiple antihypertensive agents. She was admitted to our hospital due to acute heart failure with afterload mismatch and severe mitral regurgitation. A transesophageal echocardiography showed Barlow's disease with a degenerated and widely prolapsed mitral valve. She received a scheduled surgical mitral valve repair. Post-operative cause was uneventful, but metastatic dissemination developed later. The existence of mitral valve regurgitation, even when sub-clinical, might be a risk of worsening heart failure during bevacizumab therapy. Careful follow-up at an onco-cardiology clinic is highly encouraged particularly for such a cohort during bevacizumab therapy.

Impact of the angle between aortic and mitral annulus on the occurrence of hemolysis during Impella support.

Despite optimal management, we sometimes experience refractory hemolysis requiring extensive device speed reduction or continuous hemodiafiltration following Impella implantation. However, pre-procedural predictors of such a refractory hemolysis remain unknown. In this study, we investigated the pre-procedural factors, including the echocardiographic narrow angle between aortic and mitral annulus, associating with the occurrence of refractory hemolysis following Impella insertion. We enrolled 26 patients (71 years, 65% male) who received Impella insertion between March 2018 and November 2019. Among baseline characteristics, the angle between aortic and mitral annulus, < 126.5°, was an independent risk factor of refractory hemolysis with an adjusted hazard ratio of 7.840 (95% confidence interval 0.925-66.44) and was associated with lower 30-day survival (64% vs. 100%, p = 0.0116). The narrow angle between aortic and mitral annulus might be a useful tool to risk-stratify the occurrence of refractory hemolysis following Impella insertion.

Highly efficient production of VHH antibody fragments in Brevibacillus choshinensis expression system.

Anti-IZUMO1PFF VHH (variable domain of camelid heavy chain antibody) clones, N6 and N15, from immunized alpaca (Lama pacos) phage library were efficiently expressed and their VHH products were secreted into the culture medium of Brevibacillus choshinensis HPD31-SP3, e.g., at a level of 26-95mg in 100ml conventional flask culture. With a 3-L scale fed-batch culture for 65h, the N15 VHH protein with C-terminal His-tag was produced at ∼3g/l culture medium. The N6 and N15 proteins were easily purified to apparent homogeneity by cation exchange and Ni-affinity chromatographies. Both proteins showed specific antigen-binding activity by ELISA and high antigen binding affinity, KD=6.0-8.6nM, by surface plasmon resonance analysis. Size exclusion chromatography-multi-angle laser light scattering analysis revealed that N6 and N15 proteins purified were exclusively monomeric form in phosphate buffered saline. CD spectrum showed beta-sheet rich structure, consistent with a typical antibody structure and also suggested aromatic-aromatic interactions, as indicated by a positive peak at 232nm. Thermal melting analysis of the N15 protein with C-terminal His-tag demonstrated a clear thermal transition with a Tm at 67°C. The heat-denatured sample recovered antigen binding activity upon cooling, indicating a reversible denaturation.

Molecular evolution of the substrate specificity of ent-kaurene synthases to adapt to gibberellin biosynthesis in land plants.

ent-Kaurene is a key intermediate in the biosynthesis of the plant hormone gibberellin. In ent-kaurene biosynthesis in flowering plants, two diterpene cyclases (DTCs), ent-copalyl diphosphate (ent-CDP) synthase (ent-CPS) and ent-kaurene synthase (KS), catalyse the cyclization of geranylgeranyl diphosphate to ent-CDP and ent-CDP to ent-kaurene, respectively. In contrast, the moss Physcomitrella patens has a bifunctional ent-CPS/KS (PpCPS/KS) that catalyses both cyclization reactions. To gain more insight into the functional diversity of ent-kaurene biosynthetic enzymes in land plants, we focused on DTCs in the lycophyte Selaginella moellendorffii. The present paper describes the characterization of two S. moellendorffii DTCs (SmKS and SmDTC3) in vitro. SmDTC3 converted ent-CDP into ent-16α-hydroxykaurane and also used other CDP stereoisomers as substrate. Remarkably, SmKS, which produces ent-kaurene from ent-CDP, showed similar substrate selectivity: both SmKS and SmDTC3 synthesized sandaracopimaradiene from normal CDP. Therefore, the diversity of substrate recognition among KSs from other plants was investigated. PpCPS/KS could use normal CDP and syn-CDP as well as ent-CDP as substrate. In contrast, lettuce KS showed high specificity for ent-CDP, and rice KS recognized only ent-CDP. Our studies imply that ancient KS having low substrate specificity has evolved to be specific for ent-CDP to the biosynthesis of gibberellin.

Prognostic impact of elevated erythropoietin levels in patients with severe aortic stenosis receiving trans-catheter aortic valve implantation.

BACKGROUND: Elevated endogenous erythropoietin (EPO) levels are associated with worse clinical outcomes in patients with heart failure (HF). The clinical implication of endogenous EPO levels in patients undergoing trans-catheter aortic valve implantation (TAVI) beyond other conventional risk factors remains unknown. METHODS: Consecutive patients with EPO measurements who underwent TAVI for the treatment of their severe aortic stenosis at our institute between May 2015 and December 2020 were included. The association between the endogenous EPO levels and the primary outcome consisting of all-cause mortality and HF hospitalization was evaluated. RESULTS: A total of 263 patients (85.1 ±â€¯5.1 years old, 74 men) were included and tertiled according to the baseline EPO levels. The high EPO group had more advanced anemia, renal impairment, and hypoalbuminemia than the other two tertiled groups (p < 0.05 for both). Patients with high EPO had a significantly higher cumulative incidence of the primary outcomes compared to the other two groups (p = 0.002) with an adjusted hazard ratio of 6.0 (95 % confidence interval 1.9-18.1) in its logarithmic value (p < 0.001). CONCLUSIONS: Elevated baseline EPO levels were independently associated with mortality and morbidity following TAVI. The clinical implication of aggressive intervention on the elevated EPO levels in this cohort remains the next concern.

The no-flow phenomenon following drug-coated balloon angioplasty in a patient with chronic limb-threatening ischemia and a history of below-knee amputation.

The endovascular treatment using a drug-coated balloon (DCB) reduces restenosis and target vessel re-vascularization rate in patients with peripheral artery disease such as claudication and chronic limb-threatening ischemia (CLTI). However, its safety and efficacy in patients with post-below-knee amputation remain unknown. We had a patient with CLTI and a history of below-knee amputation, who suffered a no-flow phenomenon following DCB angioplasty that required above-knee amputation. DCB angioplasty might not be appropriate for those with severe CLTI and histories of amputation. Learning objective: The present report describes the risk of endovascular treatment using a drug-coated balloon for chronic limb-threatening ischemia patients with a below-knee amputated limb.

Enzymatic (13)C labeling and multidimensional NMR analysis of miltiradiene synthesized by bifunctional diterpene cyclase in Selaginella moellendorffii.

Diterpenes show diverse chemical structures and various physiological roles. The diversity of diterpene is primarily established by diterpene cyclases that catalyze a cyclization reaction to form the carbon skeleton of cyclic diterpene. Diterpene cyclases are divided into two types, monofunctional and bifunctional cyclases. Bifunctional diterpene cyclases (BDTCs) are involved in hormone and defense compound biosyntheses in bryophytes and gymnosperms, respectively. The BDTCs catalyze the successive two-step type-B (protonation-initiated cyclization) and type-A (ionization-initiated cyclization) reactions of geranylgeranyl diphosphate (GGDP). We found that the genome of a lycophyte, Selaginella moellendorffii, contains six BDTC genes with the majority being uncharacterized. The cDNA from S. moellendorffii encoding a BDTC-like enzyme, miltiradiene synthase (SmMDS), was cloned. The recombinant SmMDS converted GGDP to a diterpene hydrocarbon product with a molecular mass of 272 Da. Mutation in the type-B active motif of SmMDS abolished the cyclase activity, whereas (+)-copalyl diphosphate, the reaction intermediate from the conversion of GGDP to the hydrocarbon product, rescued the cyclase activity of the mutant to form a diterpene hydrocarbon. Another mutant lacking type-A activity accumulated copalyl diphosphate as the reaction intermediate. When the diterpene hydrocarbon was enzymatically synthesized from [U-(13)C(6)]mevalonate, all carbons were labeled with (13)C stable isotope (>99%). The fully (13)C-labeled product was subjected to (13)C-(13)C COSY NMR spectroscopic analyses. The direct carbon-carbon connectivities observed in the multidimensional NMR spectra demonstrated that the hydrocarbon product by SmMDS is miltiradiene, a putative biosynthetic precursor of tanshinone identified from the Chinese medicinal herb Salvia miltiorrhiza. Hence, SmMDS functions as a bifunctional miltiradiene synthase in S. moellendorffii. In this study, we demonstrate that one-dimensional and multidimensional (13)C NMR analyses of completely (13)C-labeled compound are powerful methods for biosynthetic studies.

Chronotype of Lung Fluid Levels in Patients with Chronic Heart Failure.

BACKGROUND: The variation in lung fluid levels dependent on chronotype in patients with chronic heart failure is unclear. Remote dielectric sensing (ReDSTM) is a novel non-invasive system to quantify the lung fluids, which may correlate to intracardiac filling pressures. We aimed to understand the variation in ReDS measurements by chronotype in patients with chronic heart failure. METHODS: The patients who were hospitalized for heart failure exacerbations between November 2021 and March 2022 were prospectively included. ReDS values were measured at clinically stable conditions at the following three time points during the day: 5:00 (morning), 12:00 (noon), and 21:00 (night) (manufacture-recommended reference of ReDS value: between 25% and 35%). RESULTS: Twelve patients were included. The median age was 84 (75, 90) years and four patients (33%) were men. The median plasma B-type natriuretic peptide was 235 (178, 450) pg/mL. The median ReDS value was 38% (23%, 41%) in the morning. The ReDS value decreased significantly at the noon measurement, down to 28% (23%, 29%) (p = 0.005) and again increased significantly at the night measurement, up to 31% (27%, 42%) (p = 0.002). The patients were clinically stabilized during the observational period. CONCLUSIONS: the lung fluid level varied considerably in patients with chronic heart failure following clinical stabilization.

Clinical Implications of Changes in Respiratory Instability Following Transcatheter Aortic Valve Replacement.

BACKGROUND: Respiratory instability, which can be quantified using respiratory stability time (RST), is associated with the severity and prognostic impact of the disease in patients with chronic heart failure. However, its clinical implications in patients with severe aortic stenosis receiving transcatheter aortic valve replacement (TAVR) remain unknown. METHODS: Patients who received TAVR and had paired measurements of RST at a baseline and one week following TAVR were prospectively included. Changes in RST following TAVR and its impact on post-TAVR heart failure readmissions were investigated. RESULTS: Seventy-one patients (median age, 86 years old; 35% men) were included. The baseline RST was correlated with the severity of heart failure including elevated levels of plasma B-type natriuretic peptide (p < 0.05 for all). RST improved significantly following TAVR from 34 (26, 37) s to 36 (33, 38) s (p < 0.001). Post-TAVR lower RST (<33 s, n = 18) was associated with a higher 2-year cumulative incidence of heart failure readmission (21% vs. 8%, p = 0.039) with a hazard ratio of 5.47 (95% confidence interval 0.90-33.2). CONCLUSION: Overall, respiratory instability improved following TAVR. Persistent respiratory instability following TAVR was associated with heart failure recurrence.

Cardio-Ankle Vascular Index and Heart Failure Hospitalization in Patients With Aortic Stenosis Following Transcatheter Aortic Valve Implantation.

Background: The cardio-ankle vascular index (CAVI) is associated with the severity of vascular stiffness and heart failure (HF). However, little is known about CAVI in aortic stenosis (AS) patients, probably because of the difficulty of accurately measuring CAVI in these patients owing to their slow-rising pulse. In this study, we investigated the prevalence and prognostic impact of abnormally elevated CAVI measured after transcatheter aortic valve implantation (TAVI). Methods and Results: Among patients with AS who underwent TAVI, those with bilateral peripheral artery disease, atrial fibrillation, and systolic HF were excluded. The effect of post-TAVI elevated CAVI (defined as ≥9.0) on HF readmission after the index discharge was investigated. In all, 149 patients (mean [±SD] age 84.8±5.6 years, 24.2% men, mean [±SD] post-TAVI CAVI 9.6±1.4) were included in the study. There was no significant difference in baseline characteristics between groups with and without elevated CAVI, except for lower high-density lipoprotein cholesterol (HDL-C) and a higher prevalence of HF history in the group with elevated CAVI (P<0.05 for both). Post-TAVI elevated CAVI (n=102) was associated with lower freedom from HF recurrence during the observational period (89.1% vs. 100%; median 726 days [interquartile range 329-1,104 days]; P<0.05). Moreover, CAVI was an independent predictor of HF occurrence (hazard ratio 1.62; 95% confidence interval 1.07-2.46; P=0.022). Conclusions: Elevated CAVI was associated with HF occurrence before and after TAVI.

Association between Lung Fluid Levels Estimated by Remote Dielectric Sensing Values and Invasive Hemodynamic Measurements.

Background: Remote dielectric sensing (ReDS™) is an electromagnetic-based technology used to noninvasively measure lung fluid levels. The association between ReDS values and invasively measured hemodynamics, particularly among those with small physics, remains unknown. Methods: Consecutive patients with chronic heart failure who were admitted to our institute and underwent invasive right heart catheterization as well as simultaneous ReDS measurement at clinically stable conditions between September and November 2021 were prospectively included. The colinearity between ReDS values and pulmonary capillary wedge pressure was studied. Results: In total, 30 patients (median 79 (73, 84) years old, 13 men) were included. Median ReDS value was 26% (22%, 28%). ReDS values had a moderate collinearity with pulmonary capillary wedge pressure (r = 0.698, p < 0.001), even among those with a body height < 155 cm. ReDS values with a cutoff of 28% predicted a pulmonary capillary wedge pressure > 15 mmHg with sensitivity 0.70 and specificity 0.75. Conclusions: An electromagnetic-based engineering ReDS might be a potential tool to estimate cardiac pressure in patients with heart failure, including those with small physics.

Relationship Between Body Posture and Lung Fluid Volume Assessed Using a Novel Noninvasive Remote Dielectric Sensing System.

Background: The relationship between body posture and lung fluid level has not been quantified thus far. Remote dielectric sensing (ReDSTM) is a recently introduced non-invasive electromagnetic-based technology to quantify lung fluid percentage. Methods and Results: ReDS values were measured at different body postures (i.e., sitting, supine, and supine with legs elevated) in a healthy volunteer cohort (n=16; median age 39 years, 69% men, median [interquartile range {IQR}] body mass index 23.3 kg/m2 [21.0-26.2 kg/m2]). In the sitting position, the median ReDS value was 27% (IQR 25-29%). The ReDS value increased significantly in the supine position (median 28%; IQR 27-30%; P=0.009), and increased further upon leg elevation (median 29%; IQR 28-32%; P=0.001). Conclusions: In this proof-of-concept study, the relationship between body posture and lung fluid level was quantitatively validated in a healthy cohort.

Spatially resolved measurement of helium atom emission line spectrum in scrape-off layer of Heliotron J by near-infrared Stokes spectropolarimetry.

For plasma spectroscopy, Stokes spectropolarimetry is used as a method to spatially invert the viewing-chord-integrated spectrum on the basis of the correspondence between the given magnetic field profile along the viewing chord and the Zeeman effect appearing on the spectrum. Its application to fusion-related toroidal plasmas is, however, limited owing to the low spatial resolution as a result of the difficulty in distinguishing between the Zeeman and Doppler effects. To resolve this issue, we increased the relative magnitude of the Zeeman effect by observing a near-infrared emission line on the basis of the greater wavelength dependence of the Zeeman effect than of the Doppler effect. By utilizing the increased Zeeman effect, we are able to invert the measured spectrum with a high spatial resolution by Monte Carlo particle transport simulation and by reproducing the measured spectra with the semiempirical adjustment of the recycling condition at the first walls. The inversion result revealed that when the momentum exchange collisions of atoms are negligible, the velocity distribution of core-fueling atoms is mainly determined by the initial distribution at the time of recycling. The inversion result was compared with that obtained using a two-point emission model used in previous studies. The latter approximately reflects the parameters of atoms near the emissivity peak.

Evaluation of the bitterness of green tea catechins by a cell-based assay with the human bitter taste receptor hTAS2R39.

Catechins have a broad range of physiological functions and act as the main taste ingredient of green tea. Although catechins show a strong bitterness, the bitter taste receptor for catechins has not been fully understood. The objective of this study was to identify the receptor for the major green tea catechins such as (-)-epicatechin (EC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin (EGC), and (-)-epigallocatechin gallate (EGCg). By the cell-based assay using cultured cells expressing human bitter taste receptor, a clear response of hTAS2R39-expressing cells was observed to 300µM of either ECg or EGCg, which elicit a strong bitterness in humans. The response of hTAS2R39-expressing cells to ECg was the strongest among the tested catechins, followed by EGCg. Because the cellular response to EC and EGC is much weaker than those of ECg and EGCg, galloyl groups was strongly supposed to be involved in the bitter intensity. This finding is similar to the observations of taste intensity obtained from a human sensory study. Our results suggest the participation of hTAS2R39 in the detection of catechins in humans, indicating the possibility that bitterness of tea catechins can be evaluated by using cells expressing hTAS2R39.

Human bitter taste receptors hTAS2R8 and hTAS2R39 with differential functions to recognize bitter peptides.

The strong bitter peptide, Phe-Phe-Pro-Arg, activated cultured cells expressing either of the known human bitter taste receptors, hTAS2R8 and hTAS2R39. The partial structure of Pro-Arg activated hTAS2R39, but did not activate hTAS2R8. These receptors may not indiscriminately recognize bitter peptides, but have a differential function in their recognition.

Impact of Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor on Renal Function in Patient with Heart Failure.

Hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor is a recently introduced oral agent to treat renal anemia, but its clinical implications on renal functioning in patients with heart failure remains unknown. We studied an 81-year-old man with heart failure with mildly reduced ejection fraction, chronic kidney disease, and renal anemia. The seven-month HIF-PH inhibitor daprodustat treatment improved the hemoglobin level from 7.4 g/dL to 11.8 g/dL and estimated glomerular filtration ratio from 24 mL/min/1.73 m2 to 35 mL/min/1.73 m2 without any complications, including thromboembolic events. HIF-PH inhibitor might be a promising therapeutic tool to improve renal anemia and renal function in patients with heart failure, although large-scale studies are warranted to validate our findings.