Accurate gamma-ray dose measurement up to 10 MeV by glass dosimeter with a sensitivity control filter for BNCT

Glass dosimeters are very useful and convenient detection elements in radiation dosimetry. In this study, this glass dosimeter was applied to a BNCT treatment field. Boron Neutron Capture Therapy (BNCT) is a next-generation radiation therapy that can selectively kill only cancer cells. In the BNCT treatment field, both neutrons and secondary gamma-rays are generated. In other words, it is a mixed radiation field of neutrons and gamma-rays. We thus proposed a novel method to measure only gamma-ray dose in the mixed field using two RPLGD (Radiophoto-luminescence Glass Dosimeter) and two sensitivity control filters in order to control the dose response of the filtered RPLGD to be proportional to the air kerma coefficients, even if the gamma-ray energy spectrum is unknown. As the filter material iron was selected, and it was finally confirmed that reproduction of the air kerma coefficients was excellent within an error of 5.3% in the entire energy range up to 10 MeV. In order to validate this method, irradiation experiments were carried out using standard gamma-ray sources. As the result, the measured doses were in acceptably good agreement with the theoretical calculation results by PHITS. In the irradiation experiment with a volume source in a nuclear fuel storage room, the measured dose rates showed larger compared with survey meter values. In conclusion, the results of the standard sources showed the feasibility of this method, however for the volume source the dependence of the gamma-ray incident angle on the dosimeter was found to be not neglected. In the next step, it will be necessary to design a thinner filter in order to suppress the effect of the incident angle.

Diazotrophic nitrogen fixation through aerial roots occurs in Avicennia marina: implications for adaptation of mangrove plant growth to low-nitrogen tidal flats

Nitrogen limitation of primary production is common in coastal ecosystems. Mangrove trees maintain high levels of nitrogen fixation around their roots. The interior aerial space of mangrove roots, in which atmospheric gas is supplied through lenticels, could be efficient sites for nitrogen fixation. We measured tidal variations of partial pressure of N2 in root aerenchyma and conducted field experiments using 15 N2 as a tracer to track N2 movement through aerial roots of Avicennia marina. We used the acetylene reduction assay to identify the root parts harboring diazotrophs. The nitrogenase activity and estimated nitrogen fixation through aerenchyma were higher in pneumatophores and absorbing roots than in cable roots. Positive correlations between root nitrogen contents and turnover rates of root nitrogen derived from N2 through aerenchyma suggested that the internal supply of N2 to diazotrophs could be the main source for nitrogen assimilation by A. marina roots. Our results confirmed that N2 is supplied to diazotrophs through aerial roots and that nitrogen fixation occurs in A. marina roots. The aerial root structures, which occur across families of mangrove plants, could be an adaptation to survival in not only low-oxygen environments but also tidal flats with little plant-available nitrogen.

Temporal and interspecific dietary variation in wintering ducks in agricultural landscapes

Farmlands are becoming more important as waterfowl foraging habitats, while natural wetlands are being lost globally. However, it is unclear how waterfowl coexist in agricultural landscapes by resource partitioning. We evaluated the diets of seven sympatric dabbling ducks foraging in rice paddy and lotus fields around Lake Kasumigaura, the second largest lake in Japan, during two wintering seasons (from November to February) by faecal DNA metabarcoding using chloroplast trnL and mitochondrial CO1 region sequences. We examined 420 faecal samples and found different patterns of dietary diversity and composition among the duck species. The pattern also differed between plant and invertebrate food. Dietary niche partitioning was clear in plant food. Large-bodied ducks intensively use crop plants, and other ducks might mediate competition by using terrestrial and aquatic plants that are suitable for their foraging behaviours or microhabitats. Dietary segregation among species was the most apparent in February, when the abundance of foraging ducks was the largest. This study illustrated the complex pattern of dietary niche partitioning of dabbling ducks in agricultural landscapes, which might be difficult to evaluate by conventional approaches. The availability of crop plants, as well as other plant food resources in flooted areas and farmland dikes, may enable ducks to coexist by spatial or behavioural resource partitioning.

Response control of RPLGD for gamma-ray dose measurement using lead filters for BNCT

Boron Neutron Capture Therapy (BNCT) is a cell-selective radiotherapy using a neutron capture reaction of ¹⁰B. In recent years, Accelerator Based Neutron Sources (ABNS) are under development instead of nuclear reactors for the next-generation neutron irradiation system for BNCT. However, ABNS as well as nuclear reactor usually generates unavoidable secondary gamma-rays by neutron-nuclear reactions such as capture reaction. In this research, we aimed to develop a separate measurement method of only gamma-rays in a mixed field of neutrons and gamma-rays using a fluorescent glass dosimeter (RPLGD), because most dosimeters have sensitivity to both radiation types. For this purpose, we proposed a lead filter method using two RPLGDs and lead filters. However, this method has a problem that the sensitivity to low energy gamma-rays (∼100 keV) is very small. In order to improve the sensitivity to low energy gamma-rays, we devised a method using a specially shaped lead filter. From theoretical calculations, we have shown that it was possible to estimate the air dose rate of the field where the gamma-ray energy spectrum shape was known for energies up to 10 MeV. In addition, we produced the specially shaped lead filter and experimentally confirmed the validity of the lead filter method using several gamma-ray standard sources and by measurements in a nuclear fuel storage room.

Applicability of on-site disinfection of personal protective equipment by ozone gas

On-site disinfection techniques are beneficial during a pandemic when there is a marked shortage of personal protective equipment (PPE), as experienced during the coronavirus disease 2019 outbreak. Ozone gas has been considered an alternative on-site disinfectant during a pandemic because it has antimicrobial activities, can be produced from air by electricity without the need for storage, and can be easily deactivated after use. However, ozone gas might become distributed at the lower layer because it has a larger molecular weight than air. This study aimed to reveal the applicability of ozone gas for the on-site disinfection of PPE. The lockers meant for changing dresses were used as ozone gas exposure boxes, and the distribution of ozone was assayed. Considering that the determined ozone levels were not consistent in the types of ozone analysers, we studied the chemical and biological activities of ozone, which were evenly detected in the locker. The gown in the locker was also uniformly exposed to ozone. Results showed that ozone gas could be used for the on-site disinfection of PPE in a closed box, such as a locker. This finding is valuable during a pandemic when PPE is in short supply.

Temperature dependence of O2 respiration in mangrove leaves and roots: implications for seedling dispersal phenology

Seasonal differences in diaspore dispersal of three mangrove species, Kandelia obovata, Bruguiera gymnorrhiza and Rhizophora stylosa, suggest that respiratory energy production and demand may differ as a result of interspecific differences in temperature dependence of growth and maintenance processes during seedling establishment. We analyzed growth, temperature dependencies of respiratory O₂ consumption and amounts of respiratory chain enzymes in seedlings of these species grown at various temperatures. Respiration rates measured at the low reference temperature, R_REF , were highest in leaves of 15°C-grown K. obovata, whose dispersal occurs in the cold season, while root R_REF of 15°C-grown R. stylosa was 60% those of the other species, possibly because of warm conditions during its establishment phase. In leaves and roots of K. obovata and leaves of R. stylosa, the overall activation energy, E_o , changed with growth temperature associated with changes in the ratios of the amount of protein in the two respiratory pathways. However, E_o of seedlings of B. gymnorrhiza, which has a long dispersal phase, were constant and independent of growth temperature. The different temperature responses of seedling respiration and growth among these three species may reflect the seasonal temperature range of seedling dispersal and establishment in each species.

[The relationship between physical activity and sleep status among older adults requiring nursing care in the community]

AIM

We investigated the relationship between physical activity and sleep status among older adults requiring nursing care in the community.

METHOD

We included 45 participants ≥65 years old (33 females; mean age, 83.2±4.4 years old) requiring nursing care. Physical activity was evaluated using the Life Space Assessment (LSA), and sleep status was measured by the Pittsburg Sleep Quality Index (PSQI) to determine the total sleep time, sleep efficiency, and PSQI total score. The physical function was measured by the timed up and go test (TUG) and grip strength. We performed a multiple regression analysis with the LSA as the dependent variable and sleep indicators (total sleep time, sleep efficiency, PSQI total score) and TUG as independent variables (demonstrating significant correlations with the LSA), and gender and age as adjusted variables. The analysis was divided into sleep time (Model 1), sleep efficiency (Model 2), and PSQI total score (Model 3). We used R commander, and < 0.05 was considered statistically significant.

RESULTS

TUG (β=-0.375) and sleep time (β=0.383) in Model 1, TUG (β=-0.368) and sleep efficiency (β=0.570) in Model 2, and TUG (β=-0.392) and PSQI total score (β=-0.590) in Model 3 were independently selected as significant variables.

CONCLUSION

In addition to TUG, sleep status, such as the sleep duration and sleep quality, was shown to be related to physical activity in older adults who require nursing care. To improve physical activity, it is necessary to consider not only the physical function but also quantitative and qualitative assessments of sleep.

P-185 The migration speed of nucleolar precursor bodies in pronuclei affects in vitro fertilization-derived human embryo ploidy status

Study question

Does the migration speed of nucleolar precursor bodies (NPBs) in male and female pronuclei (mPN and fPN) affect in vitro fertilization (IVF)-derived embryo ploidy status?

Summary answer

The NPB migration speed in mPN impacts the IVF-derived human embryo ploidy status and this indicator could be an attractive marker for noninvasive embryo selection.

What is known already

NPBs are not considered as simple nucleolar components transmitted from an oocyte to an embryo, and they could participate in genome remodeling during embryo development. NPBs are essential only shortly after fertilization, suggesting that they may actively participate in centromeric chromatin establishment. A previous study demonstrated that NPBs migrated faster in intracytoplasmic sperm injection-derived zygotes having the potential to develop into a blastocyst and eventually into a baby (Inoue et al., 2021). However, the relationship between NPB migration speed and IVF-derived embryo ploidy status is unclear.

Study design, size, duration

The relationship between the NPB migration speed and embryo ploidy status was retrospectively analyzed in patients with recurrent assisted reproductive technology failure (euploid n =18; aneuploid n =19; and total = 219 NPBs). Archived time-lapse videos (images were recorded every 5 min; Geri+) from incubation after IVF were retrieved after the patients were identified for the study, and the NPB migration speed was analyzed. The retrospective analyses were performed with the patient’s identities masked.

Participants/materials, setting, methods

mPN and fPN were identified by appearance location in a zygote (fPN appearance is just below the polar bodies). The mPN, fPN, and 2–3 NPBs/PN central coordinates were measured by Kinovea (motion capture software). Their central coordinates were confirmed/revised every image and were decided. The migration distance of NPBs between two sequential images was calculated as the standard of the central PN coordinates. Thereafter, the migration speed of NPBs was calculated.

Main results and the role of chance

Both NPB speeds were significantly faster in the euploid than in the aneuploid groups (mPN: 4.08±0.61 vs. 3.54±0.54 µm/h, P =0.003, power [1-β]: 0.999, fPN: 4.03±0.89 vs. 3.26±0.45 µm/h, P &lt;0.003, 1-β: 0.987). The NPB speed in mPN was correlated with that in fPN (rs =0.523, P =0.001). The ploidy status was related to the NPB speeds in mPN and fPN (P &lt;0.05) in univariate logistic analysis including male/female ages, ICM/TE grades, and 29 morphokinetic parameters. The factors associated with ploidy status were the NPB speed in mPN (odds ratio [OR], 10.2; 95% confidence interval [CI], 1.90–54.90; P =0.007) and female age (OR, 0.8; 95%CI, 0.64–0.98; P =0.03) in multivariate logistic analysis. The cutoff value for the NPB speeds in mPN and fPN were 3.65 μm/h (specificity, 73.7%; sensitivity, 77.8%; AUC, 0.78; 95%CI, 0.62–0.93) and 3.77 μm/h (specificity, 89.5%; sensitivity, 66.7%; AUC, 0.78; 95%CI, 0.62–0.94). When the zygotes were categorized by their cutoff values, the euploid rate in zygotes with NPB speeds greater than the cutoff value was significantly higher than that in zygotes with the speeds less than the cutoff value (mPN = 73.7% vs. 22.2% [P =0.003]; fPN = 85.7% vs. 26.1% [P &lt;0.001]).

Limitations, reasons for caution

The NPB migration in the z-axis direction could not be analyzed. NPB tracking could not be performed when NPBs were large in number or drastically moved. Our findings should help in elucidating the relationship, although they did not completely explain the relationship between NPB migration and embryo development.

Wider implications of the findings

The migration speed of NPBs impacts human embryo ploidy status. NPB migration speed may add clinical value for embryo selection, which may be associated with live birth, and consequently, the time of the live birth could be shorter. The indicator could be an attractive marker for noninvasive embryo selection.

Trial registration number

Not applicable

The prognostic value of 18F-FDG PET/CT taken immediately after completion of radiotherapy for lung cancer treated with concurrent chemoradiotherapy: A pilot study

PURPOSE

The prognostic value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) taken immediately after completion of radiotherapy in lung cancer patients is not well known. The purpose of this study is to assess the prognostic value of PET/CT taken immediately after completion of radiotherapy in lung cancer patients.

MATERIALS AND METHODS

Patients with primary lung cancer planned to undergo concurrent chemoradiotherapy were enrolled. Patients underwent PET/CT scans at 3 time points: before radiotherapy, within 24hours of completing radiotherapy (im-PET/CT), and 2-9 months after radiotherapy (post-PET/CT). Maximum standardized uptake value (SUV_max) was obtained. A post-PET/CT-SUV_max cut-off of 2.5 was determined as radiotherapy success.

RESULTS

Nineteen patients were enrolled. im-PET/CT-SUV_max for patients in the high post-PET/CT-SUV_max group was significantly higher than that of the low group (P=0.004). Receiver operator curve analysis indicated that im-PET/CT-SUV_max of 4.35 was an optimal cut-off value to discriminate between the two groups. Multivariable analysis showed that a high im-PET/CT-SUV_max was significantly associated with a high post-PET/CT-SUV_max (P=0.003).

CONCLUSION

PET/CT-SUV_max taken immediately following radiotherapy was associated with that evaluated 2-9 months after radiotherapy.

POS0875 LATENT TRAJECTORY MODELING OF PULMONARY ARTERY PRESSURE IN SYSTEMIC SCLEROSIS: A RETROSPECTIVE COHORT STUDY

Background

Systemic sclerosis (SSc) is an autoimmune disease that is characterized by systemic vasculopathy and fibrosis. Pulmonary hypertension (PH), defined as elevated pulmonary arterial pressure (PAP), is one of the leading causes of death of SSc1. In recent years, various therapies have been developed to target each of the pathogenesis of SSc – autoimmunity, vasculopathy, and fibrosis. Accordingly, treatment strategies based on risk stratification for PH progression are aspired; however, prediction of changes in PAP in diverse patients with SSc has not been established2.

Objectives

To visualize the patterns of PAP elevation in SSc and to identify the clinical characteristics of each trajectory, by applying latent trajectory modeling for PAP measured repeatedly by echocardiography.

Methods

This was a multicenter, retrospective cohort study conducted at four referral hospitals in Kyoto, Japan. Patients with SSc who visited the study site between April 2008 and March 2021 and had at least three echocardiographic measurements of systolic pulmonary arterial pressure (sPAP) were included in this study. Follow-up concluded in March 2021. A group-based trajectory model3 was applied to the change in sPAP over time, and individual patients were classified into distinct subgroups that followed similar trajectories. The number and shape of the trajectories were estimated based on adequacy, goodness of fit, parsimony, and interpretability of the model. Clinical plausibility was assessed by comparing PH-free survival, i.e., time to either PH or death, for each trajectory. Multinomial logistic regression analysis was performed for baseline clinical characteristics associated with trajectory assignment.

Results

A total of 236 patients with a total of 1097 sPAP measurements were included. We identified five trajectories following the quadratic function as “rapid progression (n=9, 3.8%)”, “early elevation (n=30, 12.7%)”, “mid elevation (n=54, 22.9%)”, “late elevation (n=24, 10.2%)”, and “low stable (n=119, 50.4%)”. Each trajectory, in this order, showed earlier elevation of sPAP and shorter PH-free survival (Figure 1). In the multinomial logistic regression (with the “low stable” as reference), cardiac involvement was associated with the “rapid progression” (adjusted odds ratio [OR] 28.9, 95% confidence interval [CI] 3.21–259.5), diffuse cutaneous SSc was associated with the “early elevation” (OR 4.08, 95% CI 1.27–13.1), anti-centromere antibody positive was associated with the “mid elevation” (OR 4.50, 95% CI 1.11–18.2), and older age of onset was associated with the above three trajectories.

Conclusion

The pattern of changes in pulmonary artery pressure over time in SSc can be classified into five distinct trajectories. Each trajectory differed in baseline clinical characteristics and outcomes.

References

[1]Pokeerbux MR, et al. Survival and prognosis factors in systemic sclerosis: data of a French multicenter cohort, systematic review, and meta-analysis of the literature. Arthritis Res Ther. 2019;21(1):86.

[2]Denton CP, et al. Systemic sclerosis. Lancet. 2017;390(10103):1685-1699.

[3]Nagin DS, et al. Group-based trajectory modeling in clinical research. Annu Rev Clin Psychol. 2010;6:109-38.

Disclosure of Interests

None declared

Biometric palm vein authentication of psychiatric patients for reducing in-hospital medication errors: a pre-post observational study

OBJECTIVES

This study aimed to evaluate a biometric palm vein authentication system to prevent medication administration errors in psychiatric hospitals.

DESIGN

This is a pre-post observational study.

SETTING

Conventionally, the medication was distributed after a double check. We developed and introduced a new medication administration cart in two psychiatric hospitals in Japan, in which each patient-specific drug box had to be electronically opened only by palm vein authentication.

PARTICIPANTS

A total of 3444 and 3523 patients were present 18 months before and after introducing the cart, respectively. Of the 212 nurses recruited, 28 were excluded due to a lack of experience with the conventional medication administration system and incomplete questionnaires.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the efficacy of this system by comparing the incidence of medication administration errors before and after introducing the cart. The secondary outcome was a survey regarding nurses' attitudes toward this system.

RESULTS

After introduction of the new system, the number of medication errors due to misidentification of persons relative to the total number of admitted patients was significantly reduced from 6/3444 to 2/3523 (p<0.0001). Among 184 nurses, 182 responded that anxiety regarding administration errors was either reduced or unchanged using this system. Male nurses reported a greater increase in work burden than female nurses (OR=3.11, 95% CI=1.44 to 6.72). Nurses working in chronic care wards reported greater time pressure than nurses working in emergency wards (OR=3.33, 95% CI=1.16 to 9.57). Nurses working in dementia care wards reported a greater patient care burden than nurses working in emergency wards (OR=5.67, 95% CI=1.22 to 26.27).

CONCLUSIONS

This new system might have potential for reducing the patient misidentification risk during medication without increasing the anxiety experienced by nurses concerning administration errors. However, system usability and efficiency must be improved to reduce additional work burden, time pressure and patient care burden.

Non‐invasive transcriptomic analysis using mRNAs in skin surface lipids obtained from children with mild‐to‐moderate atopic dermatitis

Background

Specimens for analysing the molecular pathology of skin disease are generally obtained through invasive methods, such as biopsy. However, less burdensome methods are desirable for paediatric patients. We recently established a method that comprehensively analyses RNA present in sebum (skin surface lipid–RNAs: SSL‐RNAs) using a next‐generation sequencer. Using this method, biological information can be obtained from the skin in a completely non‐invasive manner.

Objectives

To verify the applicability of the SSL‐RNA method for analysis of paediatric skin and analyse the molecular pathology of mild‐to‐moderate atopic dermatitis (AD) in children.

Methods

We collected sebum specimens from the whole faces of 23 healthy children and 16 children with mild‐to‐moderate AD (eczema area and severity index (EASI) score: 5.9 ± 2.6) ranging in age from 6 months to 5 years, using an oil‐blotting film. We then extracted SSL‐RNAs from the samples and performed an AmpliSeq transcriptomic analysis.

Results

The expressions of genes related to keratinization (LCE, PSORS1C2, IVL and KRT17), triglyceride synthesis and storage (PLIN2, DGAT2 and CIDEA), wax synthesis (FAR2), ceramide synthesis (GBA2, SMPD3 and SPTLC3), antimicrobial peptides (DEFB1) and intercellular adhesion (CDSN), all of which are related to the skin barrier, are lower in children with AD than in healthy children. The children with AD also have higher expression of CCL17, a Th2‐cytokine and an increased Th2‐immune response as demonstrated by a gene set variation analysis. Moreover, KRT17 and CCL17 expression levels are significantly correlated with the EASI score.

Conclusions

Molecular changes associated with abnormal immune responses and the epidermal barrier in children with mild‐to‐moderate AD can be determined using the SSL‐RNA method. This non‐invasive method could therefore be a useful means for understanding the molecular pathology of paediatric AD.

Social Detachment Influenced Muscle Mass and Strength during the COVID-19 Pandemic in Japanese Community-Dwelling Older Women

Social detachment due to coronavirus disease (COVID-19) has caused a decline in physical activity, leading to sarcopenia and frailty in older adults. This study aimed to compare muscle mass, strength, and function values in older women before and after the first wave of the COVID-19 pandemic (April-May 2020). Furthermore, changes in muscle measures across women who experienced different levels of impact on their social participation due to the COVID-19 pandemic were examined. Muscle mass (total, trunk, and appendicular muscle), grip strength, oral motor skills, social interactions (social network and participation), and social support were assessed in 46 Japanese community-dwelling older women (mean, 77.5 y; range 66-93 y) before and after the first wave of the COVID-19 pandemic. Trunk muscle mass significantly decreased after the first wave of the pandemic. When comparing changed values between the enhanced/maintained and reduced group during the pandemic, significant group difference was observed in trunk muscular mass, grip strength, and oral motor skills. Intriguingly, those who enhanced social participation had a positive change of grip strength values, showing that social participation might influence muscle function during the COVID-19 pandemic.

Distinct responses of growth and respiration to growth temperatures in two mangrove species

BACKGROUND AND AIMS

Mangrove plants are mostly found in tropical and sub-tropical tidal flats, and their limited distribution may be related to their responses to growth temperatures. However, the mechanisms underlying these responses have not been clarified. Here, we measured the dependencies of the growth parameters and respiration rates of leaves and roots on growth temperatures in typical mangrove species.

METHODS

We grew two typical species of Indo-Pacific mangroves, Bruguiera gymnorrhiza and Rhizophora stylosa, at four different temperatures (15, 20, 25 and 30 °C) by irrigating with fresh water containing nutrients, and we measured growth parameters, chemical composition, and leaf and root O2 respiration rates. We then estimated the construction costs of leaves and roots and the respiration rates required for maintenance and growth.

KEY RESULTS

The relative growth rates of both species increased with growth temperature due to changes in physiological parameters such as net assimilation rate and respiration rate rather than to changes in structural parameters such as leaf area ratio. Both species required a threshold temperature for growth (12.2 °C in B. gymnorrhiza and 18.1 °C in R. stylosa). At the low growth temperature, root nitrogen uptake rate was lower in R. stylosa than in B. gymnorrhiza, leading to a slower growth rate in R. stylosa. This indicates that R. stylosa is more sensitive than B. gymnorrhiza to low temperature.

CONCLUSIONS

Our results suggest that the mangrove species require a certain warm temperature to ensure respiration rates sufficient for maintenance and growth, particularly in roots. The underground temperature probably limits their growth under the low-temperature condition. The lower sensitivity of B. gymnorrhiza to low temperature shows its potential to adapt to a wider habitat temperature range than R. stylosa. These growth and respiratory features may explain the distribution patterns of the two mangrove species.

Growth temperature affects O2 consumption rates and plasticity of respiratory flux to support shoot growth at various growth temperatures

The temperature dependence of respiration rates and their acclimation to growth temperature vary among species/ecotypes, but the details remain unclear. Here, we compared the temperature dependence of shoot O₂ consumption rates among Arabidopsis thaliana ecotypes to clarify how the temperature dependence and their acclimation to temperature differ among ecotypes, and how these differences relate to shoot growth. We examined growth analysis, temperature dependence of O₂ consumption rates, and protein amounts of the respiratory chain components in shoots of twelve ecotypes of A. thaliana grown at three different temperatures. The temperature dependence of the O₂ consumption rates were fitted to the modified Arrhenius model. The dynamic response of activation energy to measurement temperature was different among growth temperatures, suggesting that the plasticity of respiratory flux to temperatures differs among growth temperatures. The similar values of activation energy at growth temperature among ecotypes suggest that a similar process may determine the O₂ consumption rates at the growth temperature in any ecotype. These results suggest that the growth temperature affects not only the absolute rate of O₂ consumption but also the plasticity of respiratory flux in response to temperature, supporting the acclimation of shoot growth to various temperatures.

Relationship of early intensive- or coronary care unit admission and post-discharge performance of activities of daily living in patients with acute decompensated heart failure

Background

The management of acute decompensated heart failure (ADHF) often requires intensive care. However, the effects of early intensive care unit (ICU)/coronary care unit (CCU) admission on activities of daily living (ADL) in ADHF patients have not been precisely evaluated. Thus, we assessed whether early ICU entry can improve post-discharge ADL performance in these patients.

Methods and results

ADHF patients (New York Heart Association I–III) admitted on emergency between April 1, 2014, and December 31, 2018, were selected from the Diagnosis Procedure Combination database and divided into ICU/CCU (ICU) and general ward (GW) groups according to the hospitalization type on admission day 1. The propensity score was calculated to create matched cohorts where treatment assignment (ICU/CCU admission) is independent of measured baseline confounding factors including ADL at admission. The primary outcome was post-ADL defined according to the Barthel index (BI) at discharge. Secondary outcomes included length of stay (LOS) and total hospitalization cost (expense). Overall, 12,231 patients were eligible, and propensity score matching created 2,985 pairs. After matching, post-ADL was significantly higher in the ICU group (GW 71.5±35.3 vs. ICU 78.2±31.2, P&lt;0.001, difference in mean 6.7 (95% CI 5.1–8.4) points). After matching, LOS was significantly shorter and expenses were significantly higher in the ICU group. Subanalyses showed that patients with low ADL at admission (BI&lt;60) mainly benefited from early ICU/CCU entry.

Conclusions

Early ICU/CCU entry was beneficially associated with post-ADL in patients with emergency ADHF admission. ADL at admission might serve as a useful criterion for ICU admission.

Funding Acknowledgement

Type of funding sources: None.

Heat-killed Lactobacillus brevis KB290 attenuates visceral fat accumulation induced by high-fat diet in mice

AIMS

This study aimed to evaluate the anti-adiposity effect of heat-killed Lactobacillus brevis KB290 originating from traditional Japanese fermented pickles in mice fed a high-fat diet (HFD).

METHODS AND RESULTS

C57BL/6J mice were fed a normal-fat diet, HFD or HFD supplemented with heat-killed KB290 for 8 weeks. Epididymal and renal adipose tissue weights, as well as areas of epididymal adipocytes, were significantly lower in the mice fed a HFD supplemented with KB290 than in those fed an unsupplemented HFD. Mice whose diets were supplemented with KB290 had elevated adiponectin and β3-adrenergic receptor expression in epididymal adipose tissue and an accompanying higher serum free fatty acid level. Furthermore, the HFD-induced elevations in serum glucose, insulin and HOMA-IR were significantly suppressed by dietary supplementation with KB290. Amplicon sequencing of 16S rRNA genes revealed that KB290 ingestion altered the composition of the intestinal microbiota.

CONCLUSIONS

Heat-killed L. brevis KB290 suppressed diet-induced visceral fat accumulation and ameliorated diet-induced metabolic symptoms and intestinal gut microbiota modifications, suggesting possibility of novel paraprobiotic.

SIGNIFICANCE AND IMPACT OF THE STUDY

Heat-killed L. brevis KB290 is useable as a material to develop functional foods that attenuate visceral fat accumulation.

Theoretical analysis of a temperature-dependent model of respiratory O2 consumption using the kinetics of the cytochrome and alternative pathways

Temperature dependence of plant respiratory O2 -consumption has been empirically described by the Arrhenius equation. The slope of the Arrhenius plot (which is proportional to activation energy) sometimes deviates from a constant value. We conducted kinetic model simulations of mitochondrial electron flow dynamics to clarify factors affecting the shape of the Arrhenius plot. We constructed a kinetic model of respiration in which competitive O2 -consumption by the cytochrome pathway (CP) and the alternative pathway (AP) were considered, and we used this model to describe the temperature dependence of respiratory O2 -consumption of Arabidopsis. The model indicated that the electron partitioning and activation energy differences between CP and AP were reflected in the slope and magnitude of the dependent variables of the Arrhenius plot. When the electron partitioning and activation energies of CP and AP were constant with temperature change, our model suggested that the Arrhenius plot would be almost linear. When the electron partitioning or activation energy of CP, or both, rapidly changed with temperature, the Arrhenius plot deviated from linearity, as reported in previous experimental studies. Our simulation analysis quantitatively linked the kinetic model parameters with physiological mechanisms underlying the instantaneous temperature dependence of plant respiration rate.

SARC-F Predicts Mortality Risk of Older Adults during Hospitalization

OBJECTIVES

To determine the association between SARC-F scores and the in-hospital mortality risk among older patients admitted to acute care hospitals.

DESIGN

Single-center retrospective study.

SETTING

A university hospital.

PARTICIPANTS

All consecutive patients aged older than 65 were admitted and discharged from the study hospital between July 2019 and September 2019.

MEASUREMENTS

Relevant patient data included age, sex, body mass index, nutritional status, fat-free mass, disease, activities of daily living (ADL), duration of hospital stay, SARC-F, and occurrence of death within 30 days of hospitalization. The diseases that caused hospitalization and comorbidities (Charlson Comorbidity Index; CCI) were obtained from medical records. The Eastern Cooperative Oncology Group-performance status (PS) was used to determine ADL, and the in-hospital mortality rate within 30 days of hospitalization as the outcome.

RESULTS

We analyzed 2,424 patients. The mean age was 75.9±6.9 and 55.5% were male. Fifty-three in-hospital mortalities occurred among the participants within the first 30 days of hospitalization. Patients who died in-hospital were older, had poorer nutritional status and severer PS scores, and more comorbidities than those who did not. A SARC-F score of ≥4 predicted a higher mortality risk within those 30 days with the following precision: sensitivity 0.792 and specificity 0.805. There were significantly more deaths in Kaplan-Meier curves regarding a score of SARC-F≥4 than a score of SARC-F<4 (p<0.001). Cox proportional hazard analysis was used to identify the clinical indicators most associated with in-hospital mortality. SARC-F≥4 (Hazard Ratio: HR 5.65, p<0.001), CCI scores (HR1.11, p=0.004), and infectious and parasitic diseases (HR3.13, p=0.031) were associated with in-hospital mortality. The SARC-F items with significant in-hospital mortality effects were assistance with walking (HR 2.55, p<0.001) and climbing stairs (HR 2.46, p=0.002).

CONCLUSION

The SARC-F questionnaire is a useful prognostic indicator for older adults because a SARC-F ≥4 score during admission to an acute care hospital predicts in-hospital mortality within 30 days of hospitalization.

Validation of the Japanese version of the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities

BACKGROUND

Dementia in people with intellectual disabilities (IDs) is difficult to detect because of preexisting cognitive deficits. An effective screening method is required. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was developed as an observer rating tool to screen dementia in people with ID. The aim of this study was to verify the screening accuracy of the DSQIID for Japanese people with ID.

METHODS

Four-hundred ninety-three subjects with ID participated in this study. Caregivers who had observed the participants for more than 2 years scored the Japanese version of the DSQIID (DSQIID-J) of the participants. Three doctors examined participants directly and diagnosed dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. To identify the key screening items that predict dementia, the specificities of a single and pairs of items with 100% sensitivity were evaluated relative to the dementia diagnosis.

RESULTS

Of 493 participants, 34 were people with Down syndrome (DS), and 459 were people without DS. Seventeen participants were diagnosed with dementia. The suitable cut-off score of the DSQIID-J was 10/11 (sensitivity 100% and specificity 96.8%) for screening dementia. The inter-rater reliability, test-retest reliability and internal consistency of the DSQIID-J were excellent. Regarding key items, there was no single item with 100% sensitivity, and the best two-item combination was the pair of 'Cannot dress without help' and 'Walks slower' (sensitivity 100% and specificity 93.5%).

CONCLUSIONS

We identified several important question items of the DSQIID-J related to the diagnosis of dementia in people with ID. The DSQIID-J is a useful screening tool for dementia in adults with ID.

Effects of cyclic stretching exercise on long-lasting hyperalgesia, joint contracture, and muscle injury following cast immobilization in rats

The effects of exercise on mechanical hyperalgesia, joint contracture, and muscle injury resulting from immobilization are not completely understood. This study aimed to investigate the effects of cyclic stretching on these parameters in a rat model of chronic post-cast pain (CPCP). Seventeen 8-week-old Wistar rats were randomly assigned to (1) control group, (2) immobilization (CPCP) group, or (3) immobilization and stretching exercise (CPCP+STR) group. In the CPCP and CPCP+STR groups, both hindlimbs of each rat were immobilized in full plantar flexion with a plaster cast for a 4-week period. In the CPCP+STR group, cyclic stretching exercise was performed 6 days/week for 2 weeks, beginning immediately after cast removal prior to reloading. Although mechanical hyperalgesia in the plantar skin and calf muscle, ankle joint contracture, and gastrocnemius muscle injury were observed in both immobilized groups, these changes were significantly less severe in the CPCP+STR group than in the CPCP group. These results clearly demonstrate the beneficial effect of cyclic stretching exercises on widespread mechanical hyperalgesia, joint contracture, and muscle injury in a rat model of CPCP.

Clinical determinants and prognostic impact of osteoporosis in patients with chronic heart failure

Background

Despite accumulating evidence of a close association between orthopedic fractures and chronic heart failure (CHF), the clinical risk factors of osteoporosis, defined as reduction in bone mineral densities (BMDs), in CHF patients have not been systematically analyzed. In addition, the impact of osteoporosis on prognosis of CHF remains unclear.

Aims

We aimed to clarify the prevalence, clinical risk factors, and prognostic impact of osteoporosis in CHF patients.

Methods

We retrospectively examined 303 CHF patients (75 years, [interquartile range (IQR), 66–82 years]; 41% female). BMDs at the lumber spine, femoral neck, and total femur were measured by dual-energy X-ray absorptiometry (DEXA), and osteoporosis was diagnosed when BMD at any of the three sites was less than 70% of Young Adult Mean.

Results

The prevalence of osteoporosis in the CHF patients was 40%. Patients with osteoporosis were older (79 [IQR, 74–86] vs. 72 [IQR, 62–80] years), included a large percentage of females, had slower gait speed and had lower body mass index (BMI). Loop diuretics and warfarin were used more frequently and direct oral anticoagulants (DOACs) were used less frequently in patients with osteoporosis than in patients without osteoporosis. Multivariate logistic regression analysis indicated that sex (odds ratio [OR] 5.07, 95% Confidence Interval [CI] 2.68–9.61, p&lt;0.01), BMI (OR, 0.83; 95% CI, 0.75–0.91; p&lt;0.01), gait speed (OR, 0.80; 95% CI, 0.70–0.92; p&lt;0.01), loop diuretics use (OR, 2.52; 95% CI, 1.20–5.27; p=0.01) and no DOACs use (OR, 0.43; 95% CI, 0.19–0.96; p=0.04) were independently associated with osteoporosis. During the mean follow-up period of 290±254 days, 92 patients (30.4%) had adverse events. When patients with osteoporosis were divided into subgroups according to the number of sites with BMD of an osteoporosis level, Kaplan-Meier survival curves showed that the rate of adverse events (death and cardiovascular events) was higher in patients with osteoporotic BMD at two or more sites than in patients without osteoporosis (51% vs. 23%, p=0.03) (Figure). In multivariate Cox regression analyses, osteoporotic BMD at two or more sites was an independent predictor of adverse events after adjustment for age, sex, and NT-proBNP level (Hazard ratio, 1.74; 95% CI, 1.01–2.99; p=0.04).

Conclusion

The risk of osteoporosis may be increased in users of loop diuretics and may be decreased in users of DOACs in CHF patients. Extent of osteoporosis is a novel predictor of adverse events in CHF patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Japan Society for the Promotion of Science KAKENHI

Practice patterns, feasibility and efficacy of coronary artery angiography using distal radial approach

Background

Most patients undergo coronary angiography by transradial approach. However, recently distal radial approach has been introduced as a novel approach for coronary angiography and intervention. There is uncertainty on the feasibility and safety of distal radial approach for coronary angiography.

Methods

All consecutive 1450 coronary angiography cases (distal radial approach 237 cases, conventional transradial approach 1213 cases) between October 2018 and December 2019 were included in this study. Emergency coronary angiography cases and ad hoc coronary intervention cases were excluded. Patients were stratified into distal radial approach and conventional radial approach subgroups. Baseline characteristics, contrast amount, procedure time, radiation amount, fluoroscopy time, and complications in catheterization laboratory were statistically analyzed.

Results

There were no significant differences in age and gender between distal radial vs transradial groups: mean age, 70.8±10.5 vs 70.8±11.0 years; % of males, 77.2% vs 66.9%. Procedure time was significantly shorter in distal radial approach group (28.7±13.3 min vs 32.3±14.2 min, p&lt;0.05) and total radiation amount during procedure was significantly less in distal radial approach group (366.4±189.5 ml vs 412.9±220.3 mGy, p&lt;0.05).

Conclusions

Coronary angiography with distal radial approach decreases the procedure time and total radiation amount. It is feasible and safe in most stable patients.

Funding Acknowledgement

Type of funding source: None

Design of photonic-crystal surface-emitting lasers with enhanced in-plane optical feedback for high-speed operation

Photonic-crystal surface-emitting lasers (PCSELs) use the two-dimensional (2D) resonance at the band-edge of a photonic crystal for lasing, and they feature various outstanding functionalities such as high-brightness lasing, arbitrary shaping of beam patterns and on-chip 2D beam steering. In this paper, to investigate the applicability of PCSELs for high-speed operation, we design PCSELs with enhanced in-plane optical feedback, which enable single-mode lasing inside a circular region the diameter of which is less than 10 µm. To realize a strong in-plane confinement of the lasing mode, we increase the one-dimensional coupling coefficients between counter-propagating waves through the careful design of the lattice points. We also introduce an in-plane heterostructure composed of two photonic crystals with different photonic bandgaps and utilize reflection at the boundary of the two photonic crystals in addition to the optical feedback at the band-edge of each photonic crystal. By using three-dimensional finite-difference time-domain method (3D-FDTD), we confirm that the proposed hetero-PCSELs can achieve single-mode lasing operation inside a 9-µm-diameter and possibly realize a 3-dB modulation bandwidth larger than 40 GHz.

Mangrove-diazotroph relationships at the root, tree and forest scales: diazotrophic communities create high soil nitrogenase activities in Rhizophora stylosa rhizospheres

BACKGROUND AND AIMS

The tidal flats on which mangrove plants grow tend to have low soil nitrogen contents because nitrogen-containing litter is repeatedly washed offshore by ebb tides. Under such circumstances, it is unclear how mangrove plants acquire the nitrogen required to support their vigorous growth. In the present work, chemical and biological characteristics of diazotrophy around mangrove plant roots were surveyed under natural conditions to elucidate mangrove-diazotroph relationships.

METHODS

Soil nitrogenase activity of a representative mangrove plant, Rhizophora stylosa, which has a broad geographical distribution, was measured using the acetylene reduction assay at forest, tree and prop root scales. In addition, diazotrophic community composition was compared between rhizosphere and bulk soil based on sequencing of nifH genes.

KEY RESULTS

Soil nitrogenase activity was high near prop roots, and this pattern was enhanced as soil live root content increased. At the forest scale, we observed high soil nitrogenase activity (acetylene-reducing activity) inside the forest (the highest value was 90.9 µmol C2H2 min-1 cm-3, average 46.8 ± 18.2 µmol C2H2 min-1 cm-3). Rates decreased sharply from the forest to the tidal flat (range 1.2-22.2 µmol C2H2 min-1 cm-3, average 7.9 ± 4.5 µmol C2H2 min-1 cm-3). The nifH operational taxonomic unit composition differed significantly among forest and tree rhizospheres and the bulk soil (P < 0.0001).

CONCLUSIONS

Our results suggest that the accumulation of diazotrophs around R. stylosa mangrove trees enhances the supply of biologically fixed nitrogen to the mangrove roots. This supply is especially important when the soil naturally contains little nitrogen. This nitrogen acquisition system may be a key process that explains the high productivity of mangrove ecosystems.

Tracking the route of atmospheric nitrogen to diazotrophs colonizing buried mangrove roots

Nitrogen-fixing activity has been observed in the rhizosphere of mangrove ecosystems, suggesting a close mangrove-diazotroph relationship. In regularly flooded soil, however, the pathway by which atmospheric nitrogen reaches the diazotrophs in the rhizosphere is unknown. This study provides evidence that mangrove aerial roots serve as pathways that supply nitrogen gas to the diazotrophs colonizing buried roots. A plastic chamber was attached on the exposed part of a Rhizophora stylosa Griff prop root, and 15N2 tracer gas was injected into it. The entire root, including the below-ground part, was collected for analysis of 15N labelling and nitrogenase activity. We detected 15N labelling in buried root materials 2 h after gas injection. Compared with the δ15N contents in root material from an untreated tree, the increment was >10‰ in lateral roots. The nitrogenase activity measured on the other R. stylosa roots was highest in lateral roots, matching well with the results of 15N labelling. Our results indicate that atmospheric nitrogen is taken into aerial mangrove roots through lenticels, diffuses into the buried root system and is fixed by diazotrophs. The unusual appearance of mangrove aerial roots, which has intrigued researchers for many years, could be a key to the high productivity of mangrove ecosystems.