Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Granular flow experiment using artificial gravity generator at International Space Station

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

Effect of Nd:YAG laser on bone formation in rat tibia defects: three-dimensional micro-computed tomography image analysis

Nd:YAG laser is in common clinical use for the treatment of tissue incision, transpiration, and haemostasis in soft tissues. However, few studies have reported the effects of low-level laser therapy (LLLT) from Nd:YAG laser on bone healing. The aim of this study was to perform three-dimensional (3D) morphological evaluation of the photobiomodulation of Nd:YAG laser in bone defects in rat tibiae using micro-computed tomography CT (micro-CT) imaging. A bone defect was created in each tibia of 30 rats. The right side was treated with LLLT from Nd:YAG laser (LT group) daily until sacrifice and the left tibiae served as controls (control group). All tibiae underwent micro-CT imaging at 7, 14, and 21 days after the operation. Three-dimensional image analysis of bone volume (BV) and bone surface area (BS) of new bone formation in the defects was performed and histologic analysis was conducted for all tibiae. Tibial BV and BS values were highest in both groups at 7 days after the operation and decreased at 14 days after operation. BV and BS values were both significantly higher in the LT group than in the control group at 7 and 14 days. There was no significant difference between the groups for either metric at 21 days. The present findings demonstrate that Nd:YAG laser simulates bone formation during the early healing period.

Methodological considerations of the acetaminophen Detection Kit®: Involvement of molecular oxygen (O2) in an indophenol reaction

The Acetaminophen Detection Kit® (Kanto Chemical Company Co. Inc., Tokyo, Japan) is a colorimetric test based on an indophenol reaction. The test involves three reactions: deproteination of the sample, hydrolysis of acetaminophen to yield p-aminophenol, and coupling p-aminophenol with a derivative of phenol in alkali conditions to form a blue-colored indophenol dye. The kit was devised to accomplish these three reactions with only two reagents, allowing the prompt diagnosis of acetaminophen overdose in emergency medicine. In the user instructions included with the kit and in reports introducing the kit, the chemical composition of the two reagents was not disclosed. Details about the composition can be found in the Safety Data Sheet from the manufacturer; however, there is little explanation about the principle (mechanism) of the coupling reaction. This lack of information appears to have hampered the use of this kit in forensic medicine. In this report, we conducted the coupling reaction by successively adding the two reagents to a p-aminophenol (intermediate molecule) solution with the reaction vessel open to the air and under an anaerobic condition. Development of the blue color was inhibited in the absence of air but gradually developed when the reaction vessel was opened to air. Thus, the coupling reaction is an oxidation-reduction (redox) reaction that requires molecular oxygen (O₂) dissolved from the air to act as an oxidant. This finding corroborates statements in previous reports and will hopefully facilitate the use of the kit for forensic purposes.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Diversity in Infection Specificity between the Bloom-forming Microalga Heterosigma akashiwo and Its dsDNA Virus, Heterosigma akashiwo Virus

Heterosigma akashiwo virus (HaV) is a dsDNA virus that infects the bloom-forming raphidoflagellate Heterosigma akashiwo. Both the host and its virus are phenotypically diverse in terms of infection specificity. Their relationships have been examined based on the occurrence or absence of algal lysis following virus inoculation; however, variations in the strain-level host-virus relationship regarding infectivity and lysis rates remain unclear. Therefore, we performed a series of cross-infectivity tests using 60 H. akashiwo and 22 HaV strains isolated from the coastal waters of western Japan. The host strains were divided into 5 different groups and viruses into 4 groups. Using a representative strain from each group, algal lysis was observed in 14 of the (5×4=) 20 host-virus combinations; the concentration of infectious units in each HaV suspension was then assessed using the most probable number (MPN) assay on the five host strains. Virus titers ranged between 1.1×10¹ and 2.1×10⁷ infectious units mL^-1; the titer of each viral lysate was differently estimated using distinct H. akashiwo strains as hosts. These results suggest that (1) a clonal viral lysate comprises virions with different intraspecific infection specificities and/or (2) the efficiency and error rates of each intracellular replication process vary in each host-virus combination.

Neutron crystallography and quantum chemical analysis of bilin reductase PcyA mutants reveal substrate and catalytic residue protonation states

PcyA, a ferredoxin-dependent bilin pigment reductase, catalyzes the site-specific reduction of the two vinyl groups of biliverdin (BV), producing phycocyanobilin. Previous neutron crystallography detected both the neutral BV and its protonated form (BVH⁺) in the wildtype (WT) PcyA-BV complex, and a nearby catalytic residue Asp105 was found to have two conformations (protonated and deprotonated). Semiempirical calculations have suggested that the protonation states of BV are reflected in the absorption spectrum of the WT PcyA-BV complex. In the previously determined absorption spectra of the PcyA D105N and I86D mutants, complexed with BV, a peak at 730 nm, observed in the WT, disappeared and increased, respectively. Here, we performed neutron crystallography and quantum chemical analysis of the D105N-BV and I86D-BV complexes to determine the protonation states of BV and the surrounding residues and study the correlation between the absorption spectra and protonation states around BV. Neutron structures elucidated that BV in the D105N mutant is in a neutral state, whereas that in the I86D mutant is dominantly in a protonated state. Glu76 and His88 showed different hydrogen bonding with surrounding residues compared with WT PcyA, further explaining why D105N and I86D have much lower activities for phycocyanobilin synthesis than the WT PcyA. Our quantum mechanics/molecular mechanics calculations of the absorption spectra showed that the spectral change in D105N arises from Glu76 deprotonation, consistent with the neutron structure. Collectively, our findings reveal more mechanistic details of bilin pigment biosynthesis.

Associations of soluble fms-like tyrosine kinase-1 with cardiovascular events and stroke in patients with atrial fibrillation and suspected or known coronary artery disease: the EXCEED-J study

Background

Atrial fibrillation (AF) increases the risk of stroke. Soluble fms-like tyrosine kinase-1 (sFlt-1), a vascular endothelial growth factor (VEGF) antagonist, has been suggested as a marker of endothelial dysfunction, which are associated with both AF and coronary artery disease (CAD). Recently, we demonstrated that sFlt-1 is independently associated with major adverse cardiovascular (CV) events (MACE) in patients with suspected or known CAD. However, the prognostic utility of sFlt-1 in patients with AF remains unknown.

Methods

Using data from a multicenter, prospective cohort of 3255 patients with suspected or known CAD, we investigated whether AF modifies the prognostic utility of sFlt-1. Heparin-free serum levels of sFlt-1, N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin-I, high-sensitivity C-reactive protein, cystatin C, neutrophil gelatinase-associated lipocalin, VEGF, and placental growth factor were measured in 324 patients with AF and 2931 patients without AF. The primary outcome was MACE defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke. The secondary outcomes were all-cause death, CV death, stroke, heart failure (HF) hospitalization, and coronary/peripheral artery revascularization. The biomarkers were natural log-transformed for use as continuous variables.

Results

After adjustment for potential clinical confounders including anticoagulant drug use, sFlt-1 was significantly associated with MACE (hazard ratio for 1 standard deviation increase [HR], 1.55; 95% confidence interval [CI], 1.14–2.08), CV death (HR, 1.68; 95% CI, 1.10–2.48), and stroke (HR, 1.89; 95% CI, 1.16–3.10), but not with all-cause death (HR, 1.32; 95% CI, 0.99–1.73), HF hospitalization (HR, 0.97; 95% CI, 0.73–1.25), or revascularization (HR, 0.99; 95% CI, 0.74–1.28) in patients with AF, whereas sFlt-1 was significantly associated with MACE (HR, 1.19; 95% CI, 1.02–1.37), all-cause death (HR, 1.19; 95% CI, 1.05–1.34), CV death (HR, 1.26; 95% CI, 1.03–1.48), and HF hospitalization (HR, 1.26; 95% CI, 1.11–1.42), but not with stroke (HR, 1.06; 95% CI, 0.81–1.33) or revascularization (HR, 1.01; 95% CI, 0.95–1.07) in patients without AF. Among other biomarkers, only VEGF was significantly associated with MACE (HR, 1.55; 95% CI, 1.02–2.44), and no biomarkers were significantly associated with CV death or stroke in patients with AF. sFlt-1 added incremental prognostic information for MACE (P=0.005 for net reclassification improvement [NRI], P=0.026 for integrated discrimination improvement [IDI]) and stroke (P=0.034 for NRI, P=0.018 for IDI), but not for CV death (P=0.021 for NRI, P=0.134 for IDI), to the model with potential clinical confounders in patients with AF.

Conclusions

sFlt-1 independently predicted MACE and stroke in patients with AF and suspected or known CAD. sFlt-1 may serve as a novel prognostic biomarker to stratify the risk of MACE and stroke in patients with AF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Labour Sciences Research Grant (2013-2014), AMED (2015-2017, Grant Number JP17ek0210008)

Effect of the duration of previous osteoporosis treatment on the effect of romosozumab treatment

The effect of romosozumab is affected by previous osteoporosis treatment. Here we showed that the duration of the previous treatment just before romosozumab affects the therapeutic effect of romosozumab. Using denosumab and oral bisphosphonates for more than 1 year attenuates the effect of romosozumab.

INTRODUCTION

As an anti-sclerostin antibody, romosozumab suppresses bone resorption and stimulates bone formation. We investigated whether the effectiveness of 12 months of romosozumab treatment depended on the duration of previous treatment with teriparatide, denosumab, or oral bisphosphonates.

METHODS

In total, 259 osteoporosis patients received subcutaneous injections of romosozumab (210 mg) every 4 weeks during 2019 and 2020. This study was designed as a pre-post comparison. The end points were the percent changes of bone mineral density (BMD) after 12 months of romosozumab treatment. The patients were divided into seven groups depending on the type and duration of previous treatment before starting romosozumab as follows: non-previous treatment group, change from teriparatide used for 1 year or less/more than 1 year, change from denosumab used for 1 year or less/more than 1 year, and change from oral bisphosphonates used for 1 year or less/more than 1 year.

RESULTS

The effects of previous treatment with teriparatide on the effectiveness of 12-month romosozumab did not clearly depend on the duration of treatment (p > 0.05). In contrast, the effects of previous treatments with denosumab or oral bisphosphonates on the effectiveness of 12-month romosozumab depended on the previous treatment duration, which was reflected by the differences in percent change of the spine BMD (both p < 0.05), however, there were no significant differences in the percent change of the total hip BMD (both p > 0.05).

CONCLUSION

The duration of the previous treatment affected the effectiveness of romosozumab. Using denosumab and oral bisphosphonate for more than 1 year attenuated the effect of romosozumab.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Effect of Low-intensity Pulsed Ultrasound on Healing of Bone Defects in Rat Tibia as Measured by Reconstructed Three-dimensional Analysis of Micro CT Images

BACKGROUND/AIM

The aim of this study was to evaluate the effect of low-intensity pulsed ultrasound (LIPUS) on bone metabolism during the healing period in rat tibiae bone defects using micro-computed tomography (micro CT) imaging for three-dimensional morphological evaluation.

MATERIALS AND METHODS

The right tibia received ultrasound exposure (US group) every day, whereas the opposite side served as a control (Control group). At 1, 2, and 3 weeks after the operation, micro CT was performed, and the volume and surface area of new bone formation in the bone defects was evaluated three-dimensionally.

RESULTS

Bone volume (BV) and bone surface (BS) in the tibiae of both the US and Control groups demonstrated the highest values 1 week after the operation, with no significant differences between the groups. At 2 weeks after the operation, the BV and BS values in both groups had decreased, but the decrease was smaller in the US group than the Control group. At 3 weeks after the operation, the BV and BS values in the Control group were significantly lower than those in the US group.

CONCLUSION

LIPUS stimulation can prevent bone loss during the healing of bone defects.

Degenerate PCR Targeting the Major Capsid Protein Gene of HcRNAV and Related Viruses

Heterocapsa circularisquama RNA virus (HcRNAV) is the only dinoflagellate-infecting RNA virus that has been isolated to date. We herein investigated the diversity of the major capsid protein gene of HcRNAV and related viruses using degenerate PCR and in silico ana-lyses. Diverse sequences related to HcRNAV were successfully amplified from marine sediments. Amplicons contained conserved and variable regions; the latter were predicted to be located on the outer surface of the capsid. Our approach provides insights into the diversity of viruses that are difficult to isolate in the environment and will enhance rapidly growing metagenome sequence repositories.

Early clinical effects, safety, and predictors of the effects of romosozumab treatment in osteoporosis patients: one-year study

Romosozumab is an effective treatment for spine osteoporosis because it reduces the incidence of new fractures and significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

INTRODUCTION

Romosozumab appeared as a new osteoporosis medication in Japan in 2019. It is an anti-sclerostin antibody, which increases bone formation and suppresses bone resorption. The aim of our study was to elucidate the clinical effects, safety, and predictors of the effects of one-year romosozumab treatment.

METHODS

This study was an observational study designed as a pre-post study in 262 patients. Romosozumab (210 mg) was administered subcutaneously once every 4 weeks during 12 months. We focused on incidence of new fractures, safety, bone mineral density (BMD) at the spine and total hip, and bone metabolism markers.

RESULTS

There were five cases of new fractures during one-year romosozumab treatment. There were no fatal adverse events. Percent changes from baseline in the spine and total hip BMD after 12 months of romosozumab treatment were 10.67% and 2.04%, respectively. Romosozumab had better effects in cases of severe osteoporosis with low spine BMD, high TRACP-5b, and high iP1NP at the start of romosozumab treatment. The percent change in the spine BMD at 12 months was significantly lower in the group transitioning from bisphosphonates than in the group not previously treated with other anti-osteoporosis medications.

CONCLUSION

Romosozumab is an effective treatment for spine osteoporosis because it significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

Chronological distribution of dinoflagellate-infecting RNA virus in marine sediment core

A bivalve-killing marine dinoflagellate, Heterocapsa circularisquama, is susceptible to the infectious single-stranded RNA virus, Heterocapsa circularisquama RNA virus (HcRNAV). The ecological relationship between H. circularisquama and HcRNAV was intensively studied from 2001 through 2005; however, only limited data are available for the ecological dynamics of HcRNAV before 2001. In this study, we applied radiometric dating and reverse transcription PCR (RT-PCR) to determine the chronological distribution of HcRNAV in a marine sediment core sampled from the Uranouchi Inlet, Kochi, Japan, where H. circularisquama was first discovered. Our results show that HcRNAV had existed in the inlet long before its first bloom in 1988. Furthermore, five HcRNAV variants, phylogenetically distinguishable based on the nucleotide sequence of the major capsid protein (MCP) gene, were identified. These variants were found to be distributed throughout the core over time, suggesting that the HcRNAV sequences registered in the NCBI database are only a portion of the variants that have emerged in the history of HcRNAV diversification. Herein, we have verified the applicability of the retrospective approach for speculating the distribution of algal RNA viruses over time in aquatic environments.

Early clinical effects, safety, and appropriate selection of bone markers in romosozumab treatment for osteoporosis patients: a 6-month study

Our 6-month study showed the usefulness of romosozumab for preventing fractures and its safety. It was effective in patients with low baseline spine BMD, high TRACP-5b, and high iP1NP. Percent change from baseline of TRACP-5b and iP1NP after 1 month correlated with that from baseline of BMD after four to 6-month treatment.

INTRODUCTION

Romosozumab appeared as a new osteoporosis medication in Japan in 2019. It is an anti-sclerostin antibody which increases bone formation and suppresses bone resorption. In this study, we analyzed the actual clinical effects, adverse effects, and the optimal way to evaluate the treatment.

METHODS

Romosozumab was administered as subcutaneous injection of 210 mg once every 4 weeks. We conducted pre-post study in 185 patients treated for 6 months. We focused on the incidence of new vertebral fractures, safety, bone mineral density (BMD) at the spine and total hip, and bone metabolism markers. We evaluated BMD before romosozumab treatment and after 4 to 6 months and performed the serum analysis before romosozumab treatment, after 1, 3, and 6 months.

RESULTS

There was no new fracture during treatment, and there was no fatal adverse event including cardiovascular disease. Since percent changes from baseline of the spine and total hip BMD were 6.34% and 1.53% after 4- to 6-month treatment, the treatment was effective for spine osteoporosis. Tartrate-resistant acid phosphatase 5b (TRACP-5b) and intact type I procollagen N-terminal propeptide (iP1NP) had significant changes during romosozumab treatment (p < 0.05). Percent change from baseline of TRACP-5b and iP1NP after 1 month correlated with percent change from baseline of BMD after 4 to 6 months of treatment.

CONCLUSION

Romosozumab is effective in preventing fractures and useful for increasing the spine BMD. Also, romosozumab is relatively safe to use. It is especially effective in patients with low baseline spine BMD, high TRACP-5b, and high iP1NP.

Crystal structures of hydroxymethylbilane synthase complexed with a substrate analog: a single substrate-binding site for four consecutive condensation steps

Hydroxymethylbilane synthase (HMBS), which is involved in the heme biosynthesis pathway, has a dipyrromethane cofactor and combines four porphobilinogen (PBG) molecules to form a linear tetrapyrrole, hydroxymethylbilane. Enzyme kinetic study of human HMBS using a PBG-derivative, 2-iodoporphobilinogen (2-I-PBG), exhibited noncompetitive inhibition with the inhibition constant being 5.4 ± 0.3 µM. To elucidate the reaction mechanism of HMBS in detail, crystal structure analysis of 2-I-PBG-bound holo-HMBS and its reaction intermediate possessing two PBG molecules (ES2), and inhibitor-free ES2 was performed at 2.40, 2.31, and 1.79 Å resolution, respectively. Their overall structures are similar to that of inhibitor-free holo-HMBS, and the differences are limited near the active site. In both 2-I-PBG-bound structures, 2-I-PBG is located near the terminus of the cofactor or the tetrapyrrole chain. The propionate group of 2-I-PBG interacts with the side chain of Arg173, and its acetate group is associated with the side chains of Arg26 and Ser28. Furthermore, the aminomethyl group and pyrrole nitrogen of 2-I-PBG form hydrogen bonds with the side chains of Gln34 and Asp99, respectively. These amino acid residues form a single substrate-binding site, where each of the four PBG molecules covalently binds to the cofactor (or oligopyrrole chain) consecutively, ultimately forming a hexapyrrole chain. Molecular dynamics simulation of the ES2 intermediate suggested that the thermal fluctuation of the lid and cofactor-binding loops causes substrate recruitment and oligopyrrole chain shift needed for consecutive condensation. Finally, the hexapyrrole chain is hydrolyzed self-catalytically to produce hydroxymethylbilane.

Quadriceps strength to body weight ratio is a significant indicator for initiating jogging after anterior cruciate ligament reconstruction

BACKGROUND

Quadriceps strength recovery after anterior cruciate ligament (ACL) reconstruction is an important criterion for progress in rehabilitation and return to sports. The purpose of this study was to determine whether quadriceps strength to body weight ratio (QS/BW) is a significant indicator for initiating jogging after ACL reconstruction.

METHODS

Isokinetic quadriceps strength at 60°/s was measured and a jogging trial was completed 3 months after ACL reconstruction with hamstring tendon autograft in 83 patients (36 male, 47 female; mean age, 26.6 ± 12.4 years). Based on the jogging trial results, patients were assigned to either a successful jogging group (mean velocity ≥ 9 km/h) or an unsuccessful jogging group (mean velocity < 9 km/h). The association between QS/BW and successful jogging after surgery was investigated by multivariate logistic regression analysis and the cut-off value was determined by receiver operating characteristic analysis.

RESULTS

Forty-four patients (53.0%) were assigned to the successful jogging group and 39 (47.0%) to the unsuccessful jogging group. QS/BW was independently associated with initiating jogging 3 months after surgery. The cut-off value of QS/BW for successful jogging was 1.45 Nm/kg (area under the curve = 0.94; sensitivity = 88.6%, specificity = 87.2%). All of the patients who initiated jogging with QS/BW of > 1.45 Nm/kg at 3 months returned to sports without recurrence or contralateral injury by 10 months after surgery.

CONCLUSIONS

QS/BW is a significant indicator for safely initiating jogging 3 months after ACL reconstruction. The cut-off value of QS/BW for initiating jogging was 1.45 Nm/kg.

Evidence for dynamic in vivo interconversion of the conformational states of IscU during iron-sulfur cluster biosynthesis

IscU is a central component of the ISC machinery and serves as a scaffold for de novo assembly of Fe-S clusters. The dedicated chaperone system composed of the Hsp70-chaperone HscA and the J-protein cochaperone HscB synergistically interacts with IscU and facilitates cluster transfer from IscU to recipient apo-proteins. Here, we report that the otherwise essential roles of HscA and HscB can be bypassed in vivo by a number of single amino acid substitutions in IscU. CD spectroscopic studies of the variant IscU proteins capable of this bypass activity revealed dynamic interconversion between two conformations: the denatured (D) and the structured (S) state in the absence and presence of Zn²⁺ , respectively, which was far more prominent than interconversion observed in wild-type IscU. Furthermore, we found that neither the S-shifted (more structured) variants of IscU nor the perpetually denatured variants could perform their in vivo role regardless of whether the chaperone system was present or not. The present study thus provides for the first time evidence that an in vivo D-state of IscU exists and implies that conformational interconversion between the S- and D-states of the scaffolding protein is a fundamental requirement for the assembly and transfer of the Fe-S cluster.

Caprylic acid enhances hydroxyhexylitaconic acid production in Aspergillus niger S17-5

AIM

Aspergillus niger S17-5 produces two alkylitaconic acids, 9-hydroxyhexylitaconic acid (9-HHIA) and 10-hydroxyhexylitaconic acid (10-HHIA), which have cytotoxic and polymer building block properties. In this study, we characterized the production of 9-HHIA and 10-HHIA by addition of their expected precursor, caprylic acid, to a culture of A. niger S17-5, and demonstrated batch fermentation of 9-HHIA and 10-HHIA in a jar fermenter with DO-stat.

METHODS AND RESULTS

Production titres of 9-HHIA and 10-HHIA from 3% glucose in a flask after 25 days cultivation were 0·35 and 1·01 g l^-1 respectively. Addition of 0·22 g l^-1 of caprylic acid to a suspension of resting cells of A. niger S17-5 led to 32% enhancement of total 9-HHIA and 10-HHIA production compared to no addition. No enhancement of the production of 9-HHIA or 10-HHIA by the addition of oxaloacetic acid was observed. Addition of caprylic acid to the culture at mid-growth phase was more suitable for 9-HHIA and 10-HHIA production due to less cell growth inhibition by caprylic acid. DO-stat batch fermentation with 3% glucose and 14·4 g l^-1 of caprylic acid in a 1·5 l jar fermenter resulted in the production titres of 9-HHIA and 10-HHIA being 0·48 and 1·54 g l^-1 respectively after 10 days of cultivation.

CONCLUSIONS

Addition of caprylic acid to the culture of A. niger S17-5 enhances 9-HHIA and 10-HHIA production.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results suggest that 9-HHIA and 10-HHIA are synthesized with octanoyl-CoA derived from caprylic acid, and that the supply of octanoyl-CoA is a rate-limiting step in 9-HHIA and 10-HHIA production. To the best of our knowledge, this is the first report regarding the fermentation of naturally occurring itaconic acid derivatives in a jar fermenter.

Impact of chronic kidney disease on the relationship between vascular endothelial growth factor C and mortality in patients with suspected coronary artery disease: a subanalysis of the ANOX study

Background

The lymphatic system has been suggested to play an important role in cholesterol metabolism and cardiovascular (CV) disease. Recently, we demonstrated that serum levels of vascular endothelial growth factor C (VEGF-C), a central player of lymphangiogenesis, are inversely and independently associated with the risk of all-cause mortality in patients with suspected or known coronary artery disease (CAD). However, the impact of chronic kidney disease (CKD) on the relationship between VEGF-C and mortality in patients with suspected CAD is unclear.

Methods

Serum VEGF-C levels were measured in 1,717 patients with suspected but no history of CAD undergoing elective coronary angiography, enrolled in the development of novel biomarkers related to angiogenesis or oxidative stress to predict CV events (ANOX) study, and followed up for 3 years. Patients were divided into 2 groups according to the presence (CKD, n=674) or absence (non-CKD, n=1,043) of CKD. The primary outcome was all-cause death. The secondary outcomes were CV death, and major adverse CV events (MACE) defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke.

Results

During the follow-up, 95 CKD and 66 non-CKD patients died from any cause, 37 CKD and 13 non-CKD died from CV disease, and 61 CKD and 43 non-CKD developed MACE. After adjustment for established risk factors, VEGF-C levels were significantly and inversely associated with all-cause death (hazard ratio [HR] for 1-SD increase, 0.72; 95% confidence interval [CI], 0.57–0.90) and CV death (HR, 0.69; 95% CI, 0.48–0.97), but not with MACE (HR, 0.78; 95% CI, 0.60–1.03) in CKD, while VEGF-C levels were significantly and inversely associated with all-cause death (HR, 0.69; 95% CI, 0.52–0.91), but not with CV death (HR, 0.91; 95% CI, 0.50–1.66) or MACE (HR, 1.09; 95% CI, 0.81–1.44) in non-CKD. Even after incorporation of N-terminal pro-brain natriuretic peptide, contemporary sensitive cardiac troponin I, and high-sensitivity C-reactive protein into a model with established risk factors, the addition of VEGF-C levels further improved the prediction of all-cause death (P=0.047 for continuous net reclassification improvement [NRI], P=0.048 for integrated discrimination improvement [IDI]), but not that of CV death (P=0.016 for NRI, P=0.245 for IDI) or MACE (P=0.166 for NRI, P=0.311 for IDI) in CKD, whereas the addition of VEGF-C levels did not improve the prediction of all-cause death (P=0.053 for NRI, P=0.012 for IDI), CV death (P=0.864 for NRI, P=0.602 for IDI) or MACE (P=0.999 for NRI, P=0.154 for IDI) in non-CKD.

Conclusions

The VEGF-C level inversely and independently predicted all-cause mortality in CKD, but not in non-CKD patients with suspected CAD. The inverse relationship between VEGF-C and all-cause mortality in patients with suspected CAD seems to be remarkable in the presence of CKD.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

Impact of smoking status on the relationships of growth differentiation factor 15 with mortality and cardiovascular events in patients with suspected or known coronary artery disease: the ANOX study

Background

Growth differentiation factor 15 (GDF-15) is a stress-responsive cytokine that plays an important role in the regulation of the inflammatory response, growth and cell differentiation. An elevated GDF-15 was found in various conditions including cigarette smoking and stable coronary artery disease (CAD), and it was reported to predict mortality and cardiovascular (CV) events in general population and in patients with established CAD. However, the impact of smoking status on the relationships of GDF-15 with mortality and CV events in patients with suspected or known CAD is unclear.

Methods

Serum GDF-15 levels were measured in 2,418 patients with suspected or known CAD undergoing elective coronary angiography, enrolled in the development of novel biomarkers related to angiogenesis or oxidative stress to predict CV events (ANOX) study, and followed up for 3 years. Patients were divided into 3 groups according to the smoking status: current (n=428), past (n=1,035), and never smokers (n=955). The outcomes were total death, CV death, and major adverse CV events (MACE) defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke.

Results

During the follow-up, 48 current, 120 past, and 86 never smokers died from any cause, 17 current, 47 past, and 24 never smokers died from CV disease, and 35 current, 80 past, and 50 never smokers developed MACE. After adjustment for established risk factors, GDF-15 levels were significantly associated with total death (hazard ratio [HR] for 1-SD increase, 1.30; 95% confidence interval [CI], 1.03–1.65), but not with CV death (HR, 1.09; 95% CI, 0.69–1.62) or MACE (HR, 0.95; 95% CI, 0.64–1.34) in current smokers; GDF-15 levels were significantly associated with total death (HR, 1.73; 95% CI, 1.46–2.05) and CV death (HR, 1.41; 95% CI, 1.09–1.85), but not with MACE (HR, 1.20; 95% CI, 0.96–1.48) in past smokers; GDF-15 levels were significantly associated with total death (HR, 1.62; 95% CI, 1.32–1.95), CV death (HR, 1.76; 95% CI, 1.22–2.46), and MACE (HR, 1.64; 95% CI, 1.27–2.07) in never smokers. Even after incorporation of N-terminal pro-brain natriuretic peptide, contemporary sensitive cardiac troponin I, and high-sensitivity C-reactive protein into a model with established risk factors, the addition of GDF-15 levels further improved the prediction of total death (P&lt;0.001 for continuous net reclassification improvement [NRI], P=0.001 for integrated discrimination improvement [IDI]) and MACE (P&lt;0.001 for NRI, P=0.045 for IDI), but not that of CV death, in never smokers, while it did not significantly improved the prediction of total death, CV death, or MACE either in current or in past smokers.

Conclusions

The GDF-15 level was independently associated with total death and MACE in never, but not in current or past smokers with suspected or known CAD. The relationships of GDF-15 with mortality and CV events seem to be attenuated by the presence of current and past smoking.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

Positronium formation at 4H SiC(0001) surfaces

Positronium formation at 4H SiC(0001) surfaces were investigated upon the removal of natural oxide layers by hydrofluoric acid etching and heat treatment at 1000 K in ultra-high vacuum. Two types of positronium were observed in the positronium time-of-flight (PsTOF) measurements irrespective of conduction type and surface polarity. One type formed the major part of the PsTOF spectrum with a maximum energy of 4.7 ± 0.3 eV. This energy exceeded the theoretical value calculated with valence electrons. The PsTOF spectrum shape was different from those of metal surfaces, suggesting that the surface state electrons or conduction electrons need to be considered as the positronium source. Another positronium appeared at 1000 K in the tail of the PsTOF spectrum with a maximum energy of 0.2-0.5 eV. This thermally-assisted athermal positronium may be formed via the surface state positrons and electrons.

Healed Edentulous Sites: Suitability for Dental Implant Placement, Need for Secondary Procedures, and Contemporary Implant Designs

PURPOSE

The purpose of this retrospective computed tomography study was to evaluate bone availability for dental implant placement, frequency of bone augmentation procedures, frequency of anatomical structures that compromise implant placement, and frequency of implant dimensions, and to determine which edentulous sites would benefit from the use of a sloped implant versus a traditional flat design.

MATERIALS AND METHODS

Recorded parameters included the width of the ridge, the buccal and lingual/palatal alveolar bone height in reference to different anatomical landmarks, determination of implant placement, selection of an implant with a flat or sloped top, and need for a secondary bone augmentation procedure.

RESULTS

One thousand three hundred seventy edentulous sites were evaluated in 216 patients. Implants could be placed in 60.6% of the total sites, where the coronal portion would be sloped in 59% of sites and conventionally flat in 41%; 39.4% of sites were not adequate for implant placement, where 56.5% needed additional guided bone regeneration procedures and 43.5% required sinus augmentation procedures. The inferior alveolar canal was the most frequent anatomical structure limiting size and/or placement.

CONCLUSION

The study indicates that implants can be placed in slightly over half of edentulous sites without a secondary grafting procedure. The possibility of dental implant placement varied according to the volume and morphology of alveolar bone and related anatomical structures. This decreased from anterior to posterior in both arches. The sloped implant design was beneficial. In addition, the sloped implant design resulted in the placement of a longer implant.

Pathological Features of Ruptured Coronary Plaque and Thrombus Interfaces: Fibrin and von Willebrand Factor as Platelet Scaffolds on Rupture Sites

Arterial thrombus formation is thought to be initiated by platelet adhesion to the subendothelial matrix, but ruptured atherosclerotic plaques are characterized by substantial reduction of matrix proteins compared with stable plaques. Intraplaque erythrocytes and/or fibrin have been reported in high-risk coronary plaques. The aims of the current study were to identify factors that provide scaffolds for platelets at the sites of ruptured coronary plaques and investigate depositions of iron and bilirubin as hemoglobin catabolites in the ruptured plaques. Histological characteristics of plaque components and the thrombus interface were examined in 73 acute coronary aspirated thrombi. Necrotic debris (95%), macrophages (95%), and cholesterin clefts (81%) were observed frequently at the ruptured plaque and thrombus interface. A fibrous matrix (47%), calcification (32%), and extracellular deoxyribonucleic acid (15%) were identified as small foci. Tissue factor was localized in the necrotic core and macrophages. Fibrin and von Willebrand factor were consistently deposited within the plaques and beneath platelet aggregations. The citrullinated histone H3-immunopositive area accounted for only 0.5% of the plaque area. Bilirubin and iron depositions were detected in approximately 20% of the plaques in addition to biliverdin reductase and ferritin expression in macrophages. Fibrin and von Willebrand factor rather than matrix proteins and neutrophil extracellular traps may be major adhesive molecules at the sites of ruptured plaques. Iron and bilirubin deposits may be markers for rupture-prone plaques.

Recent Advances in the Understanding of the Reaction Chemistries of the Heme Catabolizing Enzymes HO and BVR Based on High Resolution Protein Structures

In mammals, catabolism of the heme group is indispensable for life. Heme is first cleaved by the enzyme Heme Oxygenase (HO) to the linear tetrapyrrole Biliverdin IXα (BV), and BV is then converted into bilirubin by Biliverdin Reductase (BVR). HO utilizes three Oxygen molecules (O2) and seven electrons supplied by NADPH-cytochrome P450 oxidoreductase (CPR) to open the heme ring and BVR reduces BV through the use of NAD(P)H. Structural studies of HOs, including substrate-bound, reaction intermediate-bound, and several specific inhibitor-bound forms, reveal details explaining substrate binding to HO and mechanisms underlying-specific HO reaction progression. Cryo-trapped structures and a time-resolved spectroscopic study examining photolysis of the bond between the distal ligand and heme iron demonstrate how CO, produced during the HO reaction, dissociates from the reaction site with a corresponding conformational change in HO. The complex structure containing HO and CPR provides details of how electrons are transferred to the heme-HO complex. Although the tertiary structure of BVR and its complex with NAD+ was determined more than 10 years ago, the catalytic residues and the reaction mechanism of BVR remain unknown. A recent crystallographic study examining cyanobacterial BVR in complex with NADP+ and substrate BV provided some clarification regarding these issues. Two BV molecules are bound to BVR in a stacked manner, and one BV may assist in the reductive catalysis of the other BV. In this review, recent advances illustrated by biochemical, spectroscopic, and crystallographic studies detailing the chemistry underlying the molecular mechanism of HO and BVR reactions are presented.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

Super-activator variants of the cyanobacterial transcriptional regulator ChlR essential for tetrapyrrole biosynthesis under low oxygen conditions

ChlR is a MarR-type transcriptional regulator that activates the transcription of the chlAII-ho2-hemN operon in response to low oxygen conditions in the cyanobacterium Synechocystis sp. PCC 6803. Upon exposure to low oxygen conditions, ChlR activates transcription of the operon that encodes enzymes critical to tetrapyrrole biosynthesis under low oxygen conditions. We previously identified a super-activator variant, D35H, of ChlR that constitutively activates transcription of the operon. To gain insight into the low-oxygen induced activation of ChlR, we obtained eight additional super-activator variants of ChlR including D35H from pseudorevertants of a chlAI-disrupted mutant. Most substitutions were located in the N-terminal region of ChlR. Mapping of the substituted amino acid residues provided valuable structural insights that uncovered the activation mechanism of ChlR.

Crystal structure of phytochromobilin synthase in complex with biliverdin IXα, a key enzyme in the biosynthesis of phytochrome

Phytochromobilin (PΦB) is a red/far-red light sensory pigment in plant phytochrome. PΦB synthase is a ferredoxin-dependent bilin reductase (FDBR) that catalyzes the site-specific reduction of bilins, which are sensory and photosynthesis pigments, and produces PΦB from biliverdin, a heme-derived linear tetrapyrrole pigment. Here, we determined the crystal structure of tomato PΦB synthase in complex with biliverdin at 1.95 Å resolution. The overall structure of tomato PΦB synthase was similar to those of other FDBRs, except for the addition of a long C-terminal loop and short helices. The structure further revealed that the C-terminal loop is part of the biliverdin-binding pocket and that two basic residues in the C-terminal loop form salt bridges with the propionate groups of biliverdin. This suggested that the C-terminal loop is involved in the interaction with ferredoxin and biliverdin. The configuration of biliverdin bound to tomato PΦB synthase differed from that of biliverdin bound to other FDBRs, and its orientation in PΦB synthase was inverted relative to its orientation in the other FDBRs. Structural and enzymatic analyses disclosed that two aspartic acid residues, Asp-123 and Asp-263, form hydrogen bonds with water molecules and are essential for the site-specific A-ring reduction of biliverdin. On the basis of these observations and enzymatic assays with a V121A PΦB synthase variant, we propose the following mechanistic product release mechanism: PΦB synthase-catalyzed stereospecific reduction produces 2(R)-PΦB, which when bound to PΦB synthase collides with the side chain of Val-121, releasing 2(R)-PΦB from the synthase.

Combination gemcitabine plus S-1 versus gemcitabine plus cisplatin for advanced/recurrent biliary tract cancer: the FUGA-BT (JCOG1113) randomized phase III clinical trial

BACKGROUND

Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS).

PATIENTS AND METHODS

We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0 - 1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea.

RESULTS

Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC [median OS: 13.4 months with GC and 15.1 months with GS, HR, 0.945; 90% confidence interval (CI), 0.78-1.15; P = 0.046 for non-inferiority]. The median PFS was 5.8 months with GC and 6.8 months with GS (HR 0.86; 95% CI 0.70-1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.

CONCLUSIONS

GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.

CLINICAL TRIAL NUMBER

This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.

Identification of IscU residues critical for de novo iron-sulfur cluster assembly

IscU is a central component of the ISC machinery and serves as a scaffold for the de novo assembly of iron-sulfur (Fe-S) clusters prior to their delivery to target apo-Fe-S proteins. However, the molecular mechanism is not yet fully understood. In this study, we have conducted mutational analysis of E. coli IscU using the recently developed genetic complementation system of a mutant that can survive without Fe-S clusters. The Fe-S cluster ligands (C37, C63, H105, C106) and the proximal D39 and K103 residues are essential for in vivo function of IscU and could not be substituted with any other amino acids. Furthermore, we found that substitution of Y3, a strictly conserved residue among IscU homologs, abolished in vivo functions. Surprisingly, a second-site suppressor mutation in IscS (A349V) reverted the defect caused by IscU Y3 substitutions. Biochemical analysis revealed that IscU Y3 was crucial for functional interaction with IscS and sulfur transfer between the two proteins. Our findings suggest that the critical role of IscU Y3 is linked to the conformational dynamics of the flexible loop of IscS, which is required for the ingenious sulfur transfer to IscU.

P3639Vascular endothelial growth factor-C and mortality in patients with suspected but no history of coronary heart disease: a subanalysis of the ANOX study

Background

The lymphatic system has been suggested to play an important role in cholesterol metabolism and cardiovascular disease. Recently, we demonstrated that serum levels of vascular endothelial growth factor-C (VEGF-C), a central player of lymphangiogenesis, are inversely and independently associated with the risk of all-cause mortality in patients with suspected or known coronary heart disease (CHD). However, the prognostic value of VEGF-C in patients with suspected but no history of CHD is still unclear.

Methods

Serum VEGF-C levels were measured in 1,717 patients with suspected but no history of CHD undergoing elective coronary angiography, enrolled in the development of novel biomarkers related to angiogenesis or oxidative stress to predict cardiovascular events (ANOX) study, and followed up for 3 years. The primary outcome was all-cause death. The secondary outcomes were cardiovascular death, and major adverse cardiovascular events (MACE) defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke.

Results

During the follow-up, 161 patients died from any cause, 50 died from cardiovascular disease, and 104 developed MACE. After adjustment for established risk factors, VEGF-C levels were significantly and inversely associated with all-cause death (hazard ratio [HR] for 1-SD increase, 0.69; 95% confidence interval [CI], 0.58–0.83) and cardiovascular death (HR, 0.72; 95% CI, 0.52–0.998), but not with MACE (HR, 0.91; 95% CI, 0.74–1.13). Even after incorporation of N-terminal pro-brain natriuretic peptide, contemporary sensitive cardiac troponin-I, and high-sensitivity C-reactive protein into a model with established risk factors, the addition of VEGF-C levels further improved the prediction of all-cause death (continuous net reclassification improvement [NRI], 0.282; 95% CI, 0.121–0.443; P<0.001; integrated discrimination improvement [IDI], 0.009; 95% CI, 0.003–0.016; P=0.005), but not that of cardiovascular death (NRI, 0.178; 95% CI, r=−0.103–0.458; P=0.214; IDI, 0.004; 95% CI, r=−0.002–0.009; P=0.194) or MACE (NRI, 0.037; 95% CI, r=−0.162–0.235; P=0.717; IDI, 0.000; 95% CI, r=−0.0004–0.0005; P=0.872).

Conclusions

In patients with suspected but no history of CHD undergoing elective coronary angiography, a low VEGF-C value may predict all-cause mortality independent of established risk factors and cardiovascular biomarkers.

Acknowledgement/Funding

The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization

P3635Vascular endothelial growth factor-D and mortality in patients with suspected but no history of coronary heart disease: a subanalysis of the ANOX study

Background

Vascular endothelial growth factor-D (VEGF-D) is a secreted glycoprotein that can act as lymphangiogenic and angiogenic growth factors through binding to its specific receptors, VEGFR-3 (Flt-4) and VEGFR-2 (KDR/Flk-1). VEGF-D signaling via VEGFR-3 plays an important role in lipoprotein metabolisms which may contribute to coronary heart disease (CHD). VEGF-D signaling has been used as a therapeutic target of human diseases such as lymphangioleiomyomatosis and refractory angina. In clinical settings, the VEGF-D level is already established as a diagnostic biomarker for lymphangioleiomyomatosis. However, the prognostic value of VEGF-D in patients with suspected but no history of CHD is unknown.

Methods

Serum VEGF-D levels were measured in 1,717 patients with suspected but no history of CHD undergoing elective coronary angiography, enrolled in the development of novel biomarkers related to angiogenesis or oxidative stress to predict cardiovascular events (ANOX) study, and followed up for 3 years. The primary outcome was all-cause death. The secondary outcomes were cardiovascular death, and major adverse cardiovascular events (MACE) defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke.

Results

During the follow-up, 161 patients died from any cause, 50 died from cardiovascular disease, and 104 developed MACE. After adjustment for established risk factors, VEGF-D levels were significantly associated with all-cause death (hazard ratio [HR] for 1-SD increase, 1.29; 95% confidence interval [CI], 1.17–1.42), cardiovascular death (HR, 1.37; 95% CI, 1.20–1.56), and MACE (HR, 1.22; 95% CI, 1.08–1.37). Even after incorporation of N-terminal pro-brain natriuretic peptide, contemporary sensitive cardiac troponin-I, and high-sensitivity C-reactive protein into a model with established risk factors, the addition of VEGF-D levels further improved the prediction of all-cause death (continuous net reclassification improvement [NRI], 0.165; 95% CI, 0.004–0.325; P=0.044; integrated discrimination improvement [IDI], 0.012; 95% CI, 0.002–0.023; P=0.013), but not that of cardiovascular death (NRI, 0.078; 95% CI, r=−0.203–0.359; P=0.586; IDI, 0.014; 95% CI, r=−0.009–0.037; P=0.235) or MACE (NRI, r=−0.011; 95% CI, r=−0.207–0.184; P=0.337; IDI, 0.003; 95% CI, r=−0.003–0.009; P=0.354).

Conclusions

In patients with suspected but no history of CHD undergoing elective coronary angiography, elevated VEGF-D levels may predict all-cause mortality independent of established risk factors and cardiovascular biomarkers.

Acknowledgement/Funding

The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

Effect of a saline flush technique for head and neck imaging in dual-energy CT: improvement of image quality and perivenous artefact reduction using virtual monochromatic imaging

AIM

To evaluate the effect of the saline flush (SF) technique on the depiction of lesions and the reduction of perivenous artefacts in the head and neck region using dual-energy computed tomography (CT) with virtual monochromatic imaging (VMI).

MATERIALS AND METHODS

Fifty patients with head and neck cancer were divided into two groups: group A, without a SF and group B, with a 30-ml SF. All images were acquired using fast kilovolt-switching CT (Revolution HD, GE Healthcare, Milwaukee, WI, USA). Contrast-to-noise ratios (CNRs) of the lesions were calculated at VMI energy levels ranging from 40 to 80 keV. Subjective analysis of overall image quality, delineation of lesions, and perivenous artefacts was conducted by two reviewers at both VMI energy level 40 keV and the optimal energy level (which showed optimal CNR by objective analysis).

RESULTS

Optimal energy level was 63 keV for group A and 61 keV for group B. At VMI energy levels ranging from 40 to 80 keV, the CNR was higher for group B. The highest subjective overall image quality was shown for group B at the optimal energy level (subjective image quality mean value, 3.40). Subjective delineation of lesions was comparable. The perivenous artefact score was significantly higher for group B (2.44 versus 2.74 [p<0.05] at 40 keV, 3.20 versus 3.46 [p<0.05] at the optimal energy level).

CONCLUSION

The SF technique results in an improvement of lesion CNR and a reduction of perivenous artefacts in VMI using duel-energy CT, especially at 40 keV.

Bilin-metabolizing enzymes: site-specific reductions catalyzed by two different type of enzymes

In mammals, the green heme metabolite biliverdin is converted to a yellow anti-oxidant by NAD(P)H-dependent biliverdin reductase (BVR), whereas in O₂-dependent photosynthetic organisms it is converted to photosynthetic or light-sensing pigments by ferredoxin-dependent bilin reductases (FDBRs). In NADP⁺-bound and biliverdin-bound BVR-A, two biliverdins are stacked at the binding cleft; one is positioned to accept hydride from NADPH, and the other appears to donate a proton to the first biliverdin through a neighboring arginine residue. During the FDBR-catalyzed reaction, electrons and protons are supplied to bilins from ferredoxin and from FDBRs and waters bound within FDBRs, respectively. Thus, the protonation sites of bilin and catalytic residues are important for the analysis of site-specific reduction. The neutron structure of FDBR sheds light on this issue.

Crystal structure of a NADPH-cytochrome P450 oxidoreductase (CYPOR) and heme oxygenase 1 fusion protein implies a conformational change in CYPOR upon NADPH/NADP+ binding

Heme oxygenase-1 (HMOX1) catalyzes heme degradation utilizing reducing equivalents supplied from NADPH-cytochrome P450 reductase (CYPOR). Recently, we determined the complex structure of NADP⁺ -bound open-conformation stabilized CYPOR and heme-HMOX1, but the resolution was limited to 4.3 Å. Here, we determined the crystal structure of the fusion protein of open-conformation stabilized CYPOR and heme-HMOX1 at 3.25 Å resolution. Unexpectedly, no NADP⁺ was bound to this fusion protein in the crystal. Structural comparison of the NADP⁺ -bound complex and the NADP⁺ -free fusion protein suggests that NADP⁺ binding regulates the conformational change in the FAD-binding domain of CYPOR. As a result of this change, the FMN-binding domain of CYPOR approaches heme-bound HMOX1 upon NADP⁺ binding to enhance the electron-transfer efficiency from FMN to heme.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

Willingness to care for blood-borne virus-infected patients in Thailand

Background

Although stigma and discrimination by nurses against patients infected with human immunodeficiency virus (HIV) or hepatitis C virus (HCV) have been reported, potential determinants of nurses' willingness to care for these patients have not been well studied in Thailand.

Aims

To identify factors associated with Thai nurses' willingness to care for patients infected with HIV or HCV.

Methods

Multivariable logistic regression analysis of data from a questionnaire completed by nurses at a large hospital in Bangkok, Thailand.

Results

Of 626 nurses, 546 (87%) nurses participated. Eleven per cent (59) and 6% (34) had previously experienced HIV- or HCV-infected blood contamination incidents, respectively. Forty-four per cent (240) and 38% (208) reported unwillingness to care for HIV- or HCV-infected patients, respectively. Willingness to care was less common [adjusted odds ratios 0.51 (0.34-0.74) for HIV and 0.62 (0.42-0.89) for HCV] in nurses aged ≥ 40 years and in those who feared HCV [0.63 (0.37-0.99)], but not HIV [0.84 (0.5-1.26)] transmission. Nurses who had confidence in protecting themselves against infection with HIV [1.84 (1.52-2.04)] and HCV [1.87 (1.45-2.18)], and accepting attitudes towards HIV-infected co-workers [1.39 (1.08-1.66)] but not HCV-infected co-workers [1.16 (0.83-1.5)], were more willing to care for HIV- and HCV-infected patients.

Conclusions

Around 4 in 10 Thai nurses in our sample were unwilling to care for HIV- or HCV-infected patients. Minimizing the risk of nosocomial transmission and improving the public perception of infected individuals may help improve nurses' willingness to care for such patients, in Thailand or elsewhere.