Listening evaluation of cochlear implant users: comparison of subjective and objective evaluation by visual analogue scale

OBJECTIVE

This study aimed to use short-form visual analogue scale cochlear implantation questionnaires to evaluate subjective aspects at each out-patient visit. The correlation between subjective hearing tests using the short-form visual analogue scale and objective hearing outcomes was evaluated.

METHOD

This study was conducted in a single centre. Cochlear implant users (n = 199) evaluated their hearing on a scale of 0 to 100 for the right, left and both ears. The Japanese speech perception test (CI-2004) Japanese monosyllable speech perception test (67-S) and cochlear implantation threshold were used for the objective cochlear implantation evaluation.

RESULTS

A significant correlation was found between the short-form visual analogue scale questionnaire and objective hearing outcome, for words (r = 0.64) and sentences (r = 0.62) in CI-2004 and 67-S (r = 0.56) tests. No significant correlation was found between the short-form visual analogue scale score and cochlear implantation threshold (r = -0.18).

CONCLUSION

Short-form visual analogue scale cochlear implantation questionnaires mean cochlear implant users spend less time answering subjective visual analogue scale questionnaires, and clinicians estimate a patient's cochlear implantation hearing and abnormality by chronological evaluation.

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.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

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}.

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes: potential implication in Doxorubicin-induced cardiotoxicity

Background

The treatment with doxorubicin, a powerful chemotherapeutic agent, has been shown to be associated with an increased risk of lethal heart failure. Although various types of cell death pathway such as apoptosis and ferroptosis have been shown to be involved in the development of doxorubicin-induced cardiotoxicity, DIC, the involvement of necroptosis, a novel programmed necrosis induced by translocation of activated mixed lineage kinase domain-like protein, MLKL, to plasma membrane, remains unclear.

Purpose

The aim of this study was to determine whether necroptosis is involved in the development of DIC.

Methods and results

DIC was induced in C57BL/6J mice by intraperitoneal injection of doxorubicin at a dose of 10 mg/kg 3 times for a week. Eight days after the commencement of injection, echocardiographic analyses showed that left ventricular ejection fraction assessed by echocardiography was significantly lower in the doxorubicin-treated mice than in the vehicle-treated mice (44.0±13.7 vs. 70.5±3.7%), indicating the development of DIC. Immunoblot analysis showed that MLKL protein level was higher by 1.6 fold in the doxorubicin-treated mice than in the vehicle-treated mice. Interestingly, immunohistochemical analysis showed that signals of phospho-Ser345-MLKL, an activated form of MLKL, was found in the nuclei in addition to cytosol and intercalated discs of cardiomyocytes in the doxorubicin-treated mice. To get novel insight into significance of nuclear MLKL accumulation, a leucine-rich nuclear export signal (NES) spanning amino acids 280–284 of rat MLKL was identified by site-directed mutation analyses, and H9c2 cells, cultured rat cardiomyoblasts, were transfected with expression constructs for nucleus-directed MLKL (FLAG-mtNES-MLKL) or its wild type (FLAG-WT-MLKL). Percentage of FLAG-positive cells stained with Zombie Red, a fluorescent dye that is non-permeant to live cells, was higher in FLAG-mtNES-MLKL-transfected cells than in FLAG-WT-MLKL-transfected cells (80.0±3.5% vs. 6.3±1.3%, p<0.05), whereas percentage of cells immunostained with cleaved caspase-3 to FLAG-positive cells was similar in the two groups. The effect of the MLKL mutant on necroptosis was attenuated by treatment with GppNHp, an inhibitor of Ran-mediated nuclear protein import.

Conclusion

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes, which may contribute to progression of DIC.

Funding Acknowledgement

Type of funding sources: None.

Loss of social role awareness, a subdomain of social frailty, is an independent predictor of future adverse events in hospitalized older patients with heart failure

Background

Frailty is a complex syndrome characterized by a decline in functional reserve, and associated with aging and chronic diseases including heart failure (HF). The impact of physical frailty on prognosis and the effect of cardiac rehabilitation in HF patients have been well established. However, the data on the prognostic impact of social frailty (SF) in HF patients is limited.

Aims

We aimed to get new insight into mechanisms of the association of SF with clinical outcomes in older hospitalized HF patients.

Methods

A single-center, retrospective cohort study was conducted using data from 308 HF patients aged ≥65 years (mean age of 78±8 years; 49% females) who were admitted to our institute for the management of HF. SF was assessed using the validated Makizako's five questions. The following responses were considered positive for SF: (1) going out less frequently compared with last year; (2) not visiting friends; (3) not talking with someone every day; (4) not feeling helpful toward friends or family; and (5) living alone. SF was defined as two or more positive responses. The primary outcome was composite events defined by all-cause death and cardiovascular events. The missing data were imputed using multiple imputation by chained -equations algorithm.

Results

Of 308 older HF patients, 189 patients (61%) were SF. Patients with SF were significantly older, had lower body mass index, and a higher percentage of patients with physical frailty and cognitive frailty than those without SF. Seventy-five patients (24%) experienced composite events during a median follow-up period of 1.55-years (interquartile range, 0.88–2.20 years). Kaplan-Meier curves showed a significantly higher composite event rate in patients with SF than those without SF. In multivariate Cox regression analyses, SF was independently associated with a higher composite event rate after adjusting for pre-existing risk factors [adjusted hazard ratio (HR), 1.91; 95% confidence interval (CI), 1.09–3.35; p=0.03] (Figure 1A). In addition, further analyses showed that only the positive response on the question corresponding to the social role – not feeling helpful toward friends or family – among the questionnaire was an independent predictor for the incidence of the composite event (adjusted HR, 2.10; 95% CI, 1.29–3.41; p<0.01, Figure 1B). Inclusion of the response to the question regarding the social role into the baseline prognostic model improved the accuracy of prediction of the composite event (continuous net reclassification improvement, 0.46; 95% CI, 0.21–0.71; p<0.01; integrated discrimination improvement, 0.025; 95% CI 0.004–0.047; p=0.02; Figure 2).

Conclusion

Loss of social role awareness was associated with increased composite event risk and provided additive prognostic information in older HF patients, suggesting the importance of healthcare professionals' decision-making on the prevention and management of SF.

Funding Acknowledgement

Type of funding sources: None.

Coexistence of sarcopenia and osteoporosis in patients with heart failure: prevalence and association with functional status

Background

Sarcopenia, the loss of muscle mass and function, and osteoporosis, a condition of low bone mass and micro-architectural deterioration of bone, frequently coexist and are associated with low functional status in heart failure (HF) patients.

Aims

We aimed to investigate the impact of coexistence of sarcopenia and osteoporosis on functional status in HF patients.

Methods

This cross-sectional study was conducted using data from patients who admitted to our institute for the diagnosis and management of HF from 1 November 2015 to 30 April 2021. All patients received the dual-energy X-ray absorptiometry (DEXA) method before discharge. The diagnosis of sarcopenia was made according to the criteria of Asia Working Group for Sarcopenia 2019 recommendation as follows: reduced skeletal muscle mass [appendicular skeletal muscle mass index (ASMI) by DEXA, <7.00 kg/m2 in males and <5.40 kg/m2 in females] plus lower muscle strength (handgrip strength, <28 kg in males and <18 kg in females) and/or poor physical performance (gait speed, <1.0 m/s; chair stand test time. ≥12 s; short physical performance battery ≤9 points). In addition, bone mineral densities (BMDs) at the lumbar spine, femoral neck, and total femur were measured by DEXA, and osteoporosis was diagnosed when BMDs at any of the three sites were less than 70% of Young Adult Mean (YAM). Functional status was assessed by the Barthel Index (BI) within three days before discharge, and patients with a BI score of <85 points was defined as having functional dependence (FD). The missing data were imputed using multiple imputation by chained -equations algorithm.

Results

Four hundred-thirty eight patients [median age of 74 years (interquartile range, 65–82 years), 37% females] were included in the analyses. Of these, percentage of HF patients with sarcopenia, osteoporosis, and sarcopenia and osteoporosis was 45%, 34%, and 20%, respectively (Figure 1A). The analysis of covariance showed a lower %YAM at any sites in patients with sarcopenia than those without sarcopenia (Figure 1B). When patients were divided into subgroups according to the presence or absence of sarcopenia and osteoporosis, the prevalence of FD was 32%, 34%, and 48% in patients with osteoporosis alone, sarcopenia alone, and sarcopenia and osteoporosis, respectively. Multivariate logistic regression analysis indicated that an increase in adjusted odds ratio (OR) for predicting FD was observed across subgroups in the following order: patients with osteoporosis alone [OR, 1.64; 95% confidence interval (CI), 0.63–4.24; p=0.31], those with sarcopenia alone (OR, 2.44; 95% CI, 1.13–5.25; p=0.02) and those with both conditions (OR, 3.34; 95% CI, 1.52–7.38; p<0.01) (Figure 2).

Conclusion

There was considerable overlap between sarcopenia and osteoporosis in HF patients, which appeared to be a risk factor for FD.

Funding Acknowledgement

Type of funding sources: None.

CHEMORESISTANCE RELATED TO HYPOXIA ADAPTATION IN MESOTHELIOMA CELLS FROM TUMOR SPHEROIDS

BACKGROUND

Hypoxia has been noted as a key factor for induction and maintenance of cancer stemness thereby leading to therapy resistance. Three-dimensional (3D) spheroid models demonstrate a heterogeneity of hypoxic regions replicating the in vivo situation within tumors. Utilizing an established 3D spheroid model, we investigated whether extrinsic hypoxia reinforced chemoresistance in malignant pleural mesothelioma (MPM) spheroids.

MATERIALS AND METHODS

Tumor spheres were generated from Meso-1 (a typical human MPM cell line) cells having high spheroid-forming ability. To induce hypoxia condition, we utilized a hypoxia chamber with regulation of O2 and CO2 levels. Cell viability was estimated by a WST-8 assay. Real-time polymerase chain reaction and Western blot were performed to evaluate the expression at mRNA and protein levels.

RESULTS

Compared with cells cultured in the two-dimensional monolayer model, tumor sphere cells showed elevated mRNA levels of cancer stemness markers (CD26, CD44 and ABCG2) and protein levels of the stemness and hypoxia adaptation markers (ABCG2, ALDH1A1 and HIFs). Correlating with this, 3D spheroid cells were more resistant to permetrexed and topotecan than the two-dimensional cells, indicative of their potential for hypoxic adaptation. Furthermore, significantly stronger resistance to both chemotherapeutic agents was observed in spheroid cells upon hypoxic challenge compared to spheroid cells under normoxia.

CONCLUSION

From the present data, it is concluded that hypoxia adaptation of MPM cells from tumor spheres could enhance their chemoresistance.

Does serum 25-hydroxyvitamin D levels have impacts on sarcopenia in patients with chronic heart failure?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Sarcopenia is associated with poor functional status and clinical outcomes in heart failure (HF) patients. Although recent observational studies showed the relationship between lower serum vitamin D levels and the development of poor physical function in community-dwelling older adults, involvement of vitamin D status in the development of sarcopenia in HF patients remain unclear. This study aimed to investigate the impact of serum vitamin D concentrations on sarcopenia in patients with HF.

Methods

We retrospectively enrolled 269 consecutive patients [median age of 73 years (interquartile range 63-82 years); 35% female] admitted to our institute for diagnosis and management of HF, and received the dual-energy X-ray absorptiometry (DEXA) method during the period from 1 September 2018 to 30 September 2021. The 25-hydroxyvitamin D [25(OH)D] was detected by a chemiluminescence immunoassay (CLIA) technology. The diagnosis of sarcopenia was made according to the criteria of Asia Working Group for Sarcopenia incorporating reduced skeletal muscle mass (appendicular skeletal muscle index [ASMI], <7.00 kg/m2 in males and <5.40 kg/m2 in females), and lower muscle strength (handgrip strength, <28 kg in males and <18 kg in females) and/or poor physical performance (gait speed, <1.0 m/s; chair stand test time, ≥12 s; short physical performance battery, ≤9 points).

Results

Of 269 patients, 116 (43%) patients had sarcopenia. An adjusted logistic regression model with a restricted cubic spline function showed that the odds ratio (OR) for sarcopenia increased as the serum 25(OH)D levels decreased. When the value that corresponded to an upper limit of 95% confidence interval (CI) for an OR of 1.0 was defined as the cut-off value of 25(OH)D levels for predicting sarcopenia, it was 18 ng/mL (Figure 1A). A multivariate logistic regression model was fit to calculate the propensity score (PS) for the 25(OH)D levels being <18 ng/mL based on covariates such as age, sex, and N-terminal pro B-type natriuretic peptide. (C-statistics 0.761). The inverse probability of treatment weighting (IPTW) was computed using PS to minimize differences in potential confounding factors between patients with a low serum 25(OH)D levels (<18 ng/mL) and those with a high serum 25(OH)D levels (≥18 ng/mL, Figure 1B). Results of the multivariate logistic regression analysis in the IPTW-weighted patients showed that a low serum 25(OH)D was independently associated with presence of sarcopenia (adjusted OR 2.03, 95% CI 1.31-3.16, p<0.01). In addition, patients with a low serum 25(OH)D had a significantly lower muscle strength and poor physical performance, but not ASMI, than those with a high serum 25(OH)D (Figure 2).

Conclusion

Decreased serum 25(OH)D levels are associated with decline in muscle strength and physical performance in HF patients. Serum 25(OH)D levels of <18 ng/mL may be a novel risk factor of sarcopenia in HF patients.

Novel equation for skeletal muscle mass estimation is useful for predicting mortality in patients with heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

Skeletal muscle mass in heart failure (HF) patients is closely related to exercise tolerance and prognosis. Although the dual-energy X-ray absorptiometry (DEXA) method is a standard method for measuring skeletal muscle mass, it is not suitable in a daily clinical setting since it is a costly and hospital-based modality. We recently reported that an equation for appendicular skeletal muscle mass index (ASMI) estimation using anthropometric parameters predicted DEXA-measured ASMI in HF patients with reasonable accuracy. Here, we examined the prognostic impacts of ASMI predicted by the equation (predicted ASMI) in HF patients.

Methods

Data for 539 patients with HF ( 73 ± 14 years old, 43% female) who received the DEXA method and measurements of calf circumference (CC) and mid-arm circumference (MAC) between August 1, 2015, to August 31, 2020, were used for analyses. DEXA measured-appendicular skeletal muscle (ASM) was calculated as the sum of bone-free lean masses in the arms and legs, and ASMI was defined as ASM/height². Predicted ASMI was calculated as we previously reported: predicted ASMI (kg/m²) = [0.214 × weight (kg) + 0.217 × CC (cm) - 0.189 × MAC (cm) + 1.098 (male = 1, female = -1) + 0.576]/height² (m²). Low ASMI was defined as <7.0 kg/m² in males and <5.4 kg/m² in females, respectively. The primary endpoint was all-cause death. Multiple imputation using chained equations was used for the substitution of missing values.

Results

The median follow-up period was 1.75 years (interquartile range, 0.96 to 2.37 years), and 73 patients (15%) has died. Kaplan-Meier survival curves showed that patients with low DEXA measured-ASMI and patients with low predicted ASMI had significantly lower survival rates than those with high ASMI (Figure 1). In a multivariate Cox proportional hazard analyses adjusted for age, sex, logarithmic B-type natriuretic peptide, cystatin C based-estimated glomerular filtration rate, and gait speed, DEXA-measured ASMI [hazard ratio (HR), 0.982; 95% confidence interval (CI), 0.967 to 0.988; p<0.001] and predicted ASMI (HR, 0.979; 95% CI, 0.962 to 0.996; p=0.018) were independent predictors of all-cause mortality, respectively. Inclusion of predicted ASMI into the adjustment model improved the accuracy of prediction of the mortality after discharge [continuous net reclassification improvement, 0.338, p<0.01; integrated discrimination improvement, 0.020, p < 0.05] (Figure 2).

Conclusions

ASMI estimated by an equation using CC and MAC predicted the prognosis of HF patients at a similar level of accuracy to DEXA-measured ASMI, and it can be applied to the assessment of skeletal muscle mass in a daily clinical setting and in large population-based studies.

Barthel Index score predicts mortality in elderly heart failure: a goal of comprehensive cardiac rehabilitation

Background

Accurate prediction of mortality in heart failure (HF) patients is crucial for decision-making regarding HF therapies, but a strategy for the prediction of mortality in elderly HF patients has not been established. In addition, although favorable effects of comprehensive cardiac rehabilitation (CR) on clinical outcomes and functional status in HF patients have been demonstrated, a goal of comprehensive CR during hospitalization for reducing mortality remains unclear.

Aims

We examined whether assessment of basic activities of daily living (ADL) by the Barthel Index (BI), the most widely used tool for assessment of basic ADL, is useful for predicting all-cause mortality in elderly HF patients who received comprehensive CR.

Methods

This study was a single-center, retrospective and observational study. We retrospectively examined 413 HF patients aged ≥65 years (mean age, 78±7 years; 50% female) who were admitted to our institute for management of HF and received comprehensive CR during hospitalization. Functional status for performing basic ADL ability was assessed by the BI within 3 days before discharge. The clinical endpoint was all-cause death during the follow-up period.

Results

Of 413 HF patients, 116 patients (28%) died during a follow-up period of median 1.90-years (interquartile range, 1.20–3.23 years). Results of an adjusted dose-dependent association analysis showed that the hazard ratio (HR) of mortality increases in an almost linear fashion as the BI score decreases and that the BI score corresponding the hazard ratio of 1.0 is 85 (Figure A). To minimize the differences in potential confounding factors between patient with low BI (<85) and patients with high BI (≥85), inverse probability treatment weighting (IPTW) was calculated using propensity score. Kaplan-Meier survival curves, in which selection bias was minimized by use of IPTW for confounders, showed that patients with low BI (<85) had a higher mortality rate than did patients with high BI (≥85) (Figure B). In multivariate Cox regression analyses, low BI was independently associated with higher mortality after adjustment for predictors including brain natriuretic peptide and prior HF hospitalization (IPTW-adjusted HR, 1.75 [95% confidence interval, 1.03–2.98], p<0.001). Inclusion of the BI into the adjustment model improved the accuracy of prediction of mortality (continuous net reclassification improvement, 0.292, p=0.008; integrated discrimination improvement, 0.017, p=0.022).

Conclusion

A BI score of <85 at the time of discharge is associated with increased mortality independently of known prognostic markers, and achievement of functional status of a BI score ≥85 by comprehensive CR during hospitalization may contribute to a favorable outcome in elderly HF patients.

Funding Acknowledgement

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

Intracellular localization of AMP deaminase and its novel role in BCAA and lipid metabolism in diabetic cardiomyopathy

Background

A metabolomic study in the human heart suggested a pivotal role of amino acid (AA) metabolism in fatty acid oxidation, which is dysregulated in type 2 diabetes mellitus (T2DM) and heart failure. We previously reported that aberrant up-regulation of AMP deaminase 3 (AMPD3) impairs cardiac energetics in T2DM hearts, and AMPD3 was recently shown to be activated by fasting and to promote AA metabolism and fatty acid oxidation in skeletal muscle. A sodium glucose cotransporter 2 inhibitor (SGLT2i) has been shown to augment systemic AA metabolism, but its effect on cardiac AA metabolism remains unknown.

Purpose

We hypothesized that AMPD3 has a role in AA and lipid metabolism in cardiomyocytes and that the protective effect of an SGLT2i in diabetic hearts is mediated by modification of AA and lipid metabolism.

Methods and results

Proteomic analyses of AMPD3 immunoprecipitates in rat hearts revealed that AMPD3 interacted with the E1α and E2 components of the BCKDH complex, a rate-limiting enzyme of branched-chain AA (BCAA) catabolism. Immunoblotting using subcellular fractions revealed that BCKDH localized not only in the mitochondria matrix but also in the cytosol and endoplasmic reticulum (ER) and that AMPD3 interacted with BCKDH in the cytosol and ER. Despite comparable expression of BCKDH components and phosphorylation of E1α at Ser293, significant accumulation of BCAA was observed in T2DM rats (OLETF; 317±30 nmol/g) compared to that in control rats (LETO; 213±16 nmol/g), and the accumulation of BCAA was accompanied by up-regulation of AMPD3 in the cytosol and ER by 98% and 231%, respectively. In cardiomyocytes, disruption of BCAA catabolism by knockdown of BCKDH-E1α resulted in a 5.8-fold increase in AMPD3 at the transcriptional level and blunted lipid droplet biogenesis in response to a long-chain fatty acid challenge. Next, myocardial infarction (MI) was induced in LETO and OLETF pretreated with empagliflozin (10 mg/kg/day, 14 days) or a vehicle. Pathway analysis of cardiac metabolites revealed arginine biosynthesis and BCAA metabolism as the most significantly changed pathways with empagliflozin, with BCAA (791±187 nmol/g), glutamate, glutamine and urea being significantly increased. Empagliflozin restored myocardial ATP and survival after MI in OLETF to levels comparable to those in LETO. Electron microscopy showed a significantly higher prevalence of myocardium lipid droplets in OLETF, which was further increased by empagliflozin.

Conclusions

The results support the hypotheses that imbalance of extra-mitochondrial AMPD3-BCKDH interaction underlies dysregulated BCAA metabolism in T2DM hearts and that activation of cardiac AA metabolism by an SGLT2i normalizes fatty acid overload through sequestration into intracellular lipid droplets.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Boehringer Ingelheim

Population-based incidence and outcomes of acute aortic dissection in Japan

Background

The population-based incidence and outcomes of acute aortic dissection (AAD) are still unknown because some patients are already dead on arrival at the hospital, and the accurate diagnosis of AAD is difficult due to the low autopsy rate for patients with cardiopulmonary arrest outside of the hospital. We performed a population-based review of all patients with AAD in a well-defined geographical area in the southern part of Japan between 2016 and 2018.

Methods

Data of all patients with AAD at our Hospital, which performs medical care for 120,000 residents, were collected retrospectively. The emergency medical service is dedicated to the transfer of all patients in this area to the MPNH. For all patients who were dead on arrival, the diagnosis of AAD was made by autopsy imaging (AI) using computed tomography. The age-adjusted incidence and mortality per 100,000 population were calculated using the Japanese population distribution model in 2015.

Results

The total incidence of AAD was 79 (type A: 64.5%, n=51). Of those, 60.8% (31/51) of patients with type A and 21.4% (6/28) with type B were dead on arrival and diagnosed by AI. The 30-day mortality rates after the onset of AAD were 74.5% (38/51) in type A and 25.0% (7/28) in type B. Excluding the dead-on-arrival patients, the 30-day mortality rates were 35.0% (7/20) in type A and 4.5% (1/22) in type B. The age-adjusted incidence and mortality of AAD per 100,000 inhabitants were 17.3 (type A: 11.3, type B: 6.0) and 9.6 (type A: 8.4, type B: 1.2), respectively. Both values were significantly higher in men than in women.

Conclusions

The population-based survey of emergency medical care for AAD showed that the age-adjusted incidence of AAD was two-fold higher than in previous reports, and the actual mortality rates after AAD onset were markedly higher due to the high incidence of dead-on-arrival.

Funding Acknowledgement

Type of funding sources: None. Representative CT images of type A AAD

Bladder perforation by orthopedic implants 26 years after limb-sparing surgery for left proximal femoral chondrosarcoma: A case report

•

A patient underwent limb-sparing surgery for left proximal femoral chondrosarcoma.

•

Bladder perforation by staples occurred 26 years after limb-sparing surgery.

•

No reports describe staple migration into the bladder after limb-sparing surgery.

•

Bladder injury is possible in patients with urinary symptoms after pelvic surgery.

•

Implant complications may occur even after a long postoperative period.

Introduction

The need for implant use during orthopedic surgeries has been increasing. Accordingly, increased implant failures have been reported. However, bladder perforation remains a rare complication after orthopedic surgery. Although a few reports have described bladder perforation after total hip arthroplasty, no previous studies have reported the migration of staples into the bladder after limb-sparing surgery.

Presentation of case

A 65-year-old patient underwent limb-sparing surgery to remove a chondrosarcoma in the left proximal thigh. Twenty-six years after surgery, a staple that had been used to fix artificial ligaments to the pubis migrated to perforate the bladder, resulting in painful urination. The staple was removed, and her symptoms improved.

Discussion

In this case, bladder perforation by the staple resulted in painful urination. The bladder perforation was not detected until 26 years after the initial surgery.

Conclusion

Our observations emphasize that implant complications may occur even after a long postoperative period, and the possibility of delayed bladder perforation from previous pelvic surgeries should be considered in patients presenting with urinary tract symptoms.

Joint hemorrhage accelerates cartilage degeneration in a rat immobilized knee model

Background

Joint hemorrhage is caused by trauma, ligament reconstruction surgery, and bleeding disorders such as hemophilia. Recurrence of hemorrhage in the joint space induces hemosiderotic synovitis and oxidative stress, resulting in both articular cartilage degeneration and arthropathy. Joint immobilization is a common treatment option for articular fractures accompanied by joint hemorrhage. Although joint hemorrhage has negative effects on the articular cartilage, there is no consensus on whether a reduction in joint hemorrhage would effectively prevent articular cartilage degeneration. The purpose of this study was to investigate the effect of joint hemorrhage combined with joint immobilization on articular cartilage degeneration in a rat immobilized knee model.

Methods

The knee joints of adult male rats were immobilized at the flexion using an internal fixator from 3 days to 8 weeks. The rats were randomly divided into the following groups: immobilized blood injection (Im-B) and immobilized-normal saline injection (Im-NS) groups. The cartilage was evaluated in two areas (contact and non-contact areas). The cartilage was used to assess chondrocyte count, Modified Mankin score, and cartilage thickness. The total RNA was extracted from the cartilage in both areas, and the expression of metalloproteinase (MMP)-8, MMP-13, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α was measured by quantitative real-time polymerase chain reaction.

Results

The number of chondrocytes in the Im-B group significantly decreased in both areas, compared with that in the Im-NS group. Modified Mankin score from 4 to 8 weeks of the Im-B group was significantly higher than that of the Im-NS group only in the contact area. The expression of MMP-8 and MMP-13 from 2 to 4 weeks and TNF-α from 2 to 8 weeks significantly increased in the Im-B group compared with those in the Im-NS group, but there was no significant difference in IL-1β expression.

Conclusions

The results showed that joint hemorrhage exacerbated immobilization-induced articular cartilage degeneration. Drainage of a joint hemorrhage or avoidance of loading may help prevent cartilage degeneration during joint immobilization with a hemorrhage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03795-0.

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<0.01), BMI (OR, 0.83; 95% CI, 0.75–0.91; p<0.01), gait speed (OR, 0.80; 95% CI, 0.70–0.92; p<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

Inhibition of xanthine oxidase ameliorates functional and metabolic impairment in type 2 diabetic hearts under pressure overload

Background

We recently reported that upregulated AMP deaminase (AMPD), via reduction in the tissue adenine nucleotide pool, contributes to exacerbation of diastolic dysfunction under pressure overload in OLETF, a rat model of obese type 2 diabetes (T2DM). Upregulated AMPD also possibly promotes xanthine oxidase (XO)-mediated ROS production, since AMPD deaminases AMP to IMP, which is further converted to inosine, providing substrates of XO, hypoxanthine and xanthine. Here, we examined the hypothesis that inhibition of XO ameliorates the pressure overload-induced diastolic dysfunction by suppression of ROS-mediated mitochondrial dysfunction and/or vascular dysfunction in T2DM rats.

Methods and results

Metabolomic analyses revealed that levels of xanthine and uric acid in the LV myocardium were significantly higher by 37% and 51%, respectively, in OLETF than in LETO, non-diabetic control rats, under the condition of phenylephrine-induced pressure overloading (200–230 mmHg). Myocardial XO activity in OLETF was 57.9% higher than that in LETO, which may be attributed to 31% higher level of inosine, a positive regulator of XO, in OLETF than in LETO. The activity of XO was significantly attenuated by administration of topiroxostat, an XO inhibitor at 0.5 mg/kg/day for 14 days. Pressure volume loop analyses showed that the pressure overloading resulted in significantly higher LVEDP in OLETF than in LETO (18.3±1.5 vs. 12.2±1.3 mmHg, p<0.05, n=7), though LVEDPs at baseline were comparable in OLETF and LETO (5.6±0.4 vs. 4.7±0.7 mmHg). Treatment with topiroxostat significantly suppressed the pressure overload-induced elevation of LVEDP in OLETF (18.3±1.5 vs. 11.3±1.1 mmHg, p<0.05) but not in LETO. Under the condition of pressure overloading, Ea/Ees, an index for ventricular-arterial coupling, was higher in OLETF than in LETO (2.3±0.3 vs. 1.6±0.3, p<0.05), and it was also improved by topiroxostat in OLETF (1.2±0.2, p<0.05). Myocardial ATP content was lower in OLETF than in LETO (2966±400 vs. 1818±171 nmol/g wet tissue, p<0.05), and treatment with topiroxostat significantly restored the ATP level (2629±307 nmol/g wet tissue). The LV myocardium of OLETF under pressure overload showed significantly higher level of malondialdehyde and 4-hydroxynonenal, an indicator of lipid peroxidation, than that of LETO. Measurement of oxygen consumption rate by Seahorse XFe96 Analyzer in mitochondria isolated from LV tissues revealed that state 3 respiration was significantly suppressed in OLETF by 43% compared to LETO, and it was restored by treatment with topiroxostat.

Conclusion

Both activity and substrates of XO are increased in T2DM hearts, in which upregulation of AMPD may play a role. Inhibition of XO ameliorates pressure overload-induced diastolic dysfunction and improves ventricular-arterial coupling in diabetic hearts, most likely through protection of mitochondrial function from ROS-mediated injury.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-aid for Scientific Research (#26461132, #17K09584) from the Japanese Society for the Promotion of Science

Upper Extremity Pain Is Associated with Lower Back Pain among Young Basketball Players: A Cross-Sectional Study

Basketball is a major sport worldwide among different age groups that leads to a high frequency of injuries at multiple body sites. Upper and lower extremities and lower back are common pain sites in basketball players; however, there is little information about the relationship between upper or lower extremity pain and lower back pain. This study elucidated the associations between upper extremity (shoulder and elbow) pain and lower back pain (LBP) among young basketball players. We conducted a cross-sectional study using self-reported questionnaires mailed to 25,669 young athletes; the final study population comprised 590 basketball players, and their median age was 13 years (range: 6-15 years). The point prevalence rates of lower back, shoulder, elbow, and upper extremity pain among young basketball players were 12.9% (76/590), 4.6% (27/590), 2.7% (16/590), and 7.1% (42/590), respectively. Multivariate logistic regression analyses revealed that upper extremity pain was significantly associated with LBP (adjusted odds ratio [OR]: 7.86; 95% confidential interval [CI], 3.93-15.72). Shoulder pain was significantly associated with training per week (> 4 days) (adjusted OR: 4.15; 95% CI: 1.29-13.40) and LBP (adjusted OR: 13.77; 95% CI: 5.70-33.24). This study indicates that upper extremity and shoulder pain is associated with LBP among young basketball players. Assessing for lower back pain, as well as elbow and/or shoulder pain, may help prevent severe injuries in young basketball players. In conclusion, parents and coaches should be properly re-educated to help improve lower back, upper extremity, and shoulder pain among young basketball players.

RAGE-dependent NF-kB inflammation processes in the capsule of frozen shoulders

BACKGROUND

The etiology of frozen shoulder (FS) remains uncertain. Advanced glycation end-products (AGEs) cause the cross-linking and stabilization of collagen and are increased in FS. The purpose of this study was to elucidate the pathogenesis of FS by evaluating the receptor of AGE (RAGE)-dependent pathways.

METHODS

Tissue samples of the coracohumeral ligament (CHL) and anterior inferior glenohumeral ligament (IGHL) were collected from 33 patients with FS, with severe stiffness, and 25 with rotator cuff tears (RCTs) as controls. Gene expression levels of RAGE, high-mobility group box 1 (HMGB1), Toll-like receptor 2 (TLR2), TLR4, nuclear factor-kappa B (NF-kB), and cytokines were evaluated using a quantitative real-time polymerase chain reaction. The immunoreactivities of carboxymethyllysine (CML), pentosidine, and RAGE were also evaluated. CML and pentosidine were further evaluated using high-performance liquid chromatography.

RESULTS

Gene expression levels of RAGE, HMGB1, TLR2, TLR4, and NF-kB were significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group. Immunoreactivities of RAGE and CML were stronger in the CHLs and IGHLs from the FS group than in those from the RCT group. Pentosidine was weakly immunostained in the CHLs and IGHLs from the FS group. CML using high-performance liquid chromatography was significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group.

CONCLUSIONS

AGEs and HMGB1 might play important roles in the pathogenesis of FS by binding to RAGE and activating NF-kB signaling pathways. Suppression of these pathways could be a treatment option for FS.

Low Back Pain in School-Aged Martial Arts Athletes in Japan: A Comparison among Judo, Kendo, and Karate

Martial arts, such as judo, kendo, and karate, are popular worldwide, not only among adults but also among children and adolescents. Although low back pain (LBP) is considered to be a common problem in these sports, it has been scarcely studied, especially in young athletes. The purpose of this study was to elucidate the point prevalence of and factors related to LBP among school-aged athletes in judo, kendo, and karate. A cross-sectional study was conducted in school-aged athletes (age, 6-15 years; n = 896) using a self-reported questionnaire. Multiple logistic regression models were used to assess the factors related to LBP along with the odds ratio (OR) and 95% confidence interval (95% CI). Variables included in the analysis were sex, age, body mass index, team level, number of days and hours of training, frequency of participation in games, practice intensity, and lower extremity pain. The prevalence of LBP was 6.9% in judo, 4.7% in kendo, and 2.9% in karate. Older age was significantly associated with LBP in judo (adjusted OR, 2.12 [95% CI, 1.24-3.61]), kendo (1.77 [1.27-2.47]), and karate (2.22 [1.14-4.33]). Lower extremity pain was significantly associated with LBP in judo (6.56 [1.57-27.34]) and kendo (21.66 [6.96-67.41]). Coaches should understand the characteristics of LBP in each martial art to develop strategies to prevent LBP among school-aged martial arts athletes.

High prevalence of low back pain among young basketball players with lower extremity pain: a cross-sectional study

Background

Low back pain (LBP) is a common problem among young basketball players in addition to lower extremity injuries. However, studies that focus on LBP with lower extremity pain are limited. From the perspective of the kinematic chain, disrupted lower extremity function can lead to LBP. The association between these two symptoms in basketball players, however, has not been reported. Therefore, this study aimed to clarify the association between lower extremity pain and LBP among young basketball players.

Methods

This cross-sectional study was conducted on school-aged basketball players (n = 592). Information regarding their sporting activities was collected using a self-reported questionnaire. Musculoskeletal pain such as low back, knee, and ankle pain was assessed. The sports players with knee and/or ankle pain were defined as having lower extremity pain. Multivariate logistic regression analysis was used to assess the association between lower extremity pain and LBP. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. The associations of knee or ankle pain with LBP were similarly assessed.

Results

School-aged basketball players had a point prevalence of 12.8% for LBP. Compared with the players without lower extremity pain, the players with lower extremity pain had higher rates of LBP, with an adjusted OR (95% CI) of 6.21 (3.57-10.80). There was also a significant association of knee and ankle pain with LBP. Compared with the players without knee or ankle pain, the adjusted ORs (95% CI) for LBP were 4.25 (2.55-7.07) in the players with knee pain and 3.79 (2.26-6.36) in the players with ankle pain.

Conclusions

Lower extremity pain was associated with LBP among school-aged basketball players. Further research is needed to clarify the mechanism of this association, which will provide useful information for prevention and treatment of LBP among young basketball players.

Involvement of inflammasome activation via elevation of uric acid level in nociception in a mouse model of muscle pain

Muscle pain is a common condition in many diseases and is induced by muscle overuse. Muscle overuse induces an increase in uric acid, which stimulates the nucleotide-binding oligomerization domain-like receptor (NLR). This receptor contains the pyrin domain NLRP-3 inflammasome which when activated, results in the secretion of potent pro-inflammatory cytokines such as interleukin-1β (IL-1β). The aim of this study was to investigate the involvement of inflammasome activation via the elevation of uric acid level in nociception in a mouse model of muscle pain. The right hind leg muscles of BALB/c mice were stimulated electrically to induce excessive muscle contraction. The left hind leg muscles were not stimulated as a control. Mechanical withdrawal thresholds, levels of uric acid, IL-1β, and NLRP3, caspase-1 activity, and the number of macrophages were investigated. Furthermore, the effects of xanthine oxidase inhibitors, such as Brilliant Blue G, caspase-1 inhibitor, and clodronate liposome, on pain were investigated. In the stimulated muscles, mechanical withdrawal thresholds decreased, and the levels of uric acid, NLRP3, and IL-1β, caspase-1 activity, and the number of macrophages increased compared to that in the non-stimulated muscles. Administration of the inhibitors attenuated hyperalgesia caused by excessive muscle contraction. These results suggested that IL-1β secretion and NLRP3 inflammasome activation in macrophages produced mechanical hyperalgesia by elevating uric acid level, and xanthine oxidase inhibitors may potentially reduce over-exercised muscle pain.

Parents' Own Experience of Verbal Abuse Is Associated with their Acceptance of Abuse towards Children from Youth Sports Coaches

Verbal or physical abuse from coaches has negative effects on young athletes, and the parents of athletes also have an influence on the sports environment. It is therefore important to understand parents' attitudes towards abuse against their children from the coaches. This study aimed to elucidate the characteristics of parents who accept the infliction of verbal or physical abuse on their children from coaches of youth sports teams. A cross-sectional study using self-report questionnaires was conducted with parents of young athletes (n = 6,493). Multivariate logistic regression models were used to assess the factors associated with parents' acceptability of verbal or physical abuse against their children. The proportion of parents who were accepting of verbal or physical abuse was 21.5%. Acceptability of verbal or physical abuse was significantly associated with male (odds ratio: 1.67, 95% confidence interval: 1.43-1.95), younger age (1.24, 1.09-1.41), lower educational attainment (1.32, 1.17-1.50), smoking habits (1.42, 1.23-1.63), experience of playing on a team with high levels of competition during their junior or high school days (1.31, 1.15-1.50), and experience of verbal and physical abuse by their own former coaches (3.59, 3.03-4.26 and 1.17, 1.02-1.35). About 58% and 28% of parents had experienced verbal and physical abuse from their own former coaches, and parents who had experienced verbal abuse themselves were most likely to be accepting of verbal or physical abuse towards their children. Educating parents is considered to be important for preventing and eradicating abuse against young athletes.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Musculoskeletal pain in other body sites is associated with new-onset low back pain: a longitudinal study among survivors of the great East Japan earthquake

Background

Low back pain (LBP) is a common health problem experienced after natural disasters. LBP is often concurrent with other musculoskeletal pain; however, the effects of preexisting musculoskeletal pain on the development of LBP are not clear. The purpose of this study was to elucidate the association of musculoskeletal pain in other body sites with new-onset LBP among survivors of the Great East Japan Earthquake (GEJE).

Methods

A longitudinal study was conducted with survivors of the GEJE. The survivors who did not have LBP at the 3 year time period after the GEJE were followed up 1 year later (n = 1782). Musculoskeletal pain, such as low back, hand and/or foot, knee, shoulder, and neck pain, were assessed with self-reported questionnaires. The outcome of interest was new-onset LBP, which was defined as LBP absent at 3 years but present at 4 years after the disaster. The main predictor was musculoskeletal pain in other body sites 3 years after the GEJE, which was categorized according to the number of pain sites (0, 1, ≥ 2). Multiple regression analyses were performed to calculate the odds ratio (OR) and 95% confidence interval (CI) for new-onset LBP due to musculoskeletal pain in other body sites.

Results

The incidence of new-onset LBP was 14.1% (251/1782). Musculoskeletal pain in other body sites was significantly associated with new-onset LBP. Including people without other musculoskeletal pain as a reference, the adjusted OR and 95% CI for new-onset LBP were 1.73 (1.16–2.57) for people with one musculoskeletal pain site and 3.20 (2.01–5.09) for people with ≥ 2 sites (p <  0.001).

Conclusions

Preexisting musculoskeletal pain in other body sites was associated with new-onset LBP among survivors in the recovery period after the GEJE.

Association between lower back pain and lower extremity pain among young volleyball players: A cross-sectional study

BACKGROUND

Lower back pain (LBP), as well as lower extremity injuries, are major problems among young volleyball players. Nevertheless, only few studies have focused on the relationship between lower extremity injuries and LBP.

OBJECTIVE

This study investigated the association between LBP and lower extremity pain, including knee and ankle pain, among young volleyball players.

DESIGN

Cross-sectional study.

SETTING

Amateur sports association.

PARTICIPANTS

Elementary and middle school-aged athletes (6-15 years of age).

MAIN OUTCOME MEASURES

LBP and lower extremity pain.

RESULTS

A total of 566 young volleyball players participated in this study. The point prevalence of LBP among young volleyball players was 9.5%. Using absence of lower extremity pain as a reference, the adjusted odds ratio (95% confidence interval) for LBP was 11.07 (5.64-21.71) in the presence of lower extremity pain.

CONCLUSIONS

LBP is associated with Lower extremity pain among young volleyball players. Careful attention should be paid to lower extremity complaints to prevent and treat LBP among young volleyball players.

P207 Synergetic effect of amino acid and ketone metabolism underlies empagliflozin-mediated cardioprotection in the type 2 diabetic heart

Funding Acknowledgements

Boehringer Ingelheim

Background

 Although emerging evidence has indicated that sodium glucose cotransporter 2 (SGLT2) inhibitors restore impaired cardiac energetics in type 2 diabetes mellitus (T2DM), the underlying molecular mechanisms have yet to be established.  Augmented utilization of ketone is one proposed hypothesis, but depletion of succinyl-CoA triggered by the conversion of ketone back to acetyl-CoA by SCOT (succinyl-CoA:3-oxoacid CoA transferase) may hamper oxidative capacity of the tricarboxylic acid (TCA) cycle, which also requires succinyl-CoA.  The recent finding that empagliflozin augments systemic amino acid metabolism in patients with T2DM led us to hypothesize that the anaplerotic effect of amino acid on the TCA cycle complements ketone oxidation.

Methods and Results

 Myocardial infarction (MI) was induced in T2DM rats (OLETF) and control rats (LETO).  Survival rate at 48 hours after MI was significantly lower in OLETF than in LETO (40% vs 84%), and empagliflozin treatment (10 mg/kg/day, 14 days) before MI improved the survival rate in OLETF to 70%.  Metabolome analysis was performed using heart tissues from the non-infarct region 12 hours after MI.  Using principal component analysis, data from 92 metabolites that were detected were compressed into 2 dimensions, and the first component (PC1) clearly separated empagliflozin-treated OLETF from non-treated LETO and OLETF.  Analysis of factor loading of each metabolite for PC1 revealed that branched chain amino acids leucine, isoleucine and valine, the latter two of which can be oxidized to succynyl-CoA, and β-hydroxybutyrate were the top four metabolites that characterized empagliflozin treatment.  Furthermore, in comparison to LETO, OLETF treated with empagliflozin showed 50% higher levels of glutamine and glutamate, both of which can replenish the TCA cycle at the level of α-ketoglutarate.  In OLETF, empagliflozin significantly increased the TCA cycle intermediates citrate, cis-aconitate and malate by 74%, 119% and 59%, respectively.  OLETF showed 86% higher lactate and 38% lower ATP than those in LETO, but levels of the metabolites were normalized by empagliflozin, suggesting improved glucose oxidation.

Conclusions

  The present analyses showed that amino acid and ketone metabolism are metabolic pathways that are most affected by empagliflozin.  Coordination of these "starvation-induced pathways" may underlie the favorable metabolic effect of empagliflozin in T2DM hearts.

Association of Dietary Variety and Appetite with Sleep Quality in Urban-Dwelling Older Japanese Adults

OBJECTIVES

Although it has been shown that specific foods and nutrients are associated with sleep quality, few studies have examined the association of dietary variety and appetite with sleep quality in older adults.

DESIGN AND SETTING

A cross-sectional study was conducted that examined the association of dietary variety and appetite with sleep quality in Japanese adults aged ≥70 years who resided in the metropolitan area of Tokyo, Japan.

PARTICIPANTS

Data were collected in two steps: a mailed interview survey and an on-site survey. Those who responded to the surveys and met the inclusion criteria were included.

MEASUREMENTS

Dietary variety, appetite, and sleep quality were assessed using a Dietary Variety Score (DVS), Council on Nutrition Appetite Questionnaire (CNAQ) score, and sleep efficiency, respectively. The sleep efficiency is the ratio of sleep duration to total time in bed (retiring time-awakening time). We defined the individuals with a sleep efficiency less than 75% as having poor sleep quality.

RESULTS

Mean DVS and CNAQ score were 3.8 and 29.6 points, respectively. The rate of individuals with poor sleep quality was 11.7%. In the fully adjusted model, the odds ratios (OR) for low sleep efficiency in the middle and highest group categories of the DVS were 0.83 (95% confidence interval [CI], 0.54-1.29) and 0.50 (95% CI, 0.28-0.90), respectively, in reference to the lowest group category (p for trend = 0.023). The OR for low sleep efficiency in the middle and highest group categories of the CNAQ score were 0.73 (95% CI, 0.47-1.14) and 0.54 (95% CI, 0.30-0.96), respectively, in reference to the lowest group category (p for trend = 0.031).

CONCLUSIONS

The higher DVS and CNAQ scores were significantly associated with higher sleep efficiency. Thus, dietary variety and good appetite might help maintain good sleep quality in urban-dwelling older Japanese adults.

P121 Pressure overload-induced functional and metabolic impairments in type 2 diabetic hearts are ameliorated by inhibition of xanthine oxidase

Funding Acknowledgements

SANWA KAGAKU KENKYUSHO Co., Ltd.

Background

  We have recently demonstrated that AMP deaminase (AMPD) is upregulated in OLETF, obese type 2 diabetic (T2DM) rats, and that the upregulated AMPD contributes to depletion of myocardial ATP at the time of pressure overload, leading to diastolic dysfunction.  On the other hand, AMPD promotes the formation of IMP from AMP, and IMP is in turn further converted to hypoxanthine and xanthine, substrates of xanthine oxidase (XO), which produces uric acid with ROS as a byproduct.  Based on these findings, we tested the hypothesis that inhibition of XO ameliorates the pressure overload-induced diastolic dysfunction in T2DM rats. 

Methods and results

Metabolomic analyses of the left ventricular myocardium revealed that levels of myocardial hypoxanthine and xanthine were significantly higher by 30% and 28%, respectively, in OLETF than in LETO, non-diabetic control rats, under the condition of pressure overloading (200-230 mmHg) induced by phenylephrine infusion. Myocardial XO activity in OLETF was 57.9% higher than that in LETO, and the activity was significantly attenuated by oral administration of topiroxostat, an XO inhibitor, at 0.1-0.5 mg/kg/day for 14 days in a dose-dependent manner.  Pressure volume loop analyses showed that the pressure overloading induced by phenylephrine infusion resulted in significantly higher LVEDP in OLETF than in LETO (18.3 ± 1.5 vs. 12.2 ± 1.3 mmHg, p &lt; 0.05, n = 7), though LVEDPs at baseline were comparable in OLETF and LETO (5.6 ± 0.4 vs. 4.7 ± 0.7 mmHg).  Treatment with topiroxostat significantly suppressed the pressure overload-induced elevation of LVEDP in OLETF (18.3 ± 1.5 vs. 11.3 ± 1.1 mmHg, p &lt; 0.05) but not in LETO.  Tau, the time constant of LV pressure decay, was significantly prolonged to 14.7 ± 0.7 ms (p &lt; 0.05) by pressure overloading in OLETF but not in LETO, though baseline Tau values were similar in LETO and OLETF (6.1 ± 0.2 vs. 8.0 ± 0.4 ms).  The prolongation of Tau by pressure overloading in OLETF was significantly attenuated by treatment with topiroxostat.  Ea/Ees, an index for ventricular-arterial coupling, was higher in OLETF than in LETO (2.3 ± 0.3 vs. 1.6 ± 0.3, p &lt; 0.05) under the condition of pressure overloading, and it was also improved by topiroxostat in OLETF (1.2 ± 0.2, p &lt; 0.05).  Myocardial ATP content was lower in OLETF than in LETO under the condition of pressure overloading (2966 ± 400 vs. 1818 ± 171 nmol/g wet tissue, p &lt; 0.05), but treatment with topiroxostat significantly restored the ATP level (2629 ± 307 nmo/g wet tissue). Conclusion:  In T2DM hearts, not only XO activity but also XO substrates are upregulated and upregulated AMPD may be involved in the upregulation.  Inhibition of XO ameliorates pressure overload-induced diastolic dysfunction and improves ventricular-arterial coupling most likely through augmented ATP preservation.

Restriction in the hip internal rotation of the stride leg is associated with elbow and shoulder pain in elite young baseball players

BACKGROUND

Evidence is scarce concerning the relationship of physical dysfunction of the trunk and lower extremities with elbow and shoulder pain in young baseball players. This study aimed to examine the association of joint flexibility of the trunk and lower extremities and dynamic postural control with elbow and shoulder pain among elite young baseball players.

METHODS

We analyzed baseball players (aged 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival. Range of motion in external rotation and internal rotation (IR) of the hip, as well as the finger-to-floor distance and heel-to-buttock distance, was measured. The straight-leg-raise test was also conducted. Dynamic postural control was evaluated using the Star Excursion Balance Test. Multivariable logistic regression analyses were conducted to examine the association of physical function with the elbow or shoulder pain incidence.

RESULTS

Of 210 players surveyed, 177 without elbow or shoulder pain were included in the analysis. Of the participants, 16 (9.0%) reported having elbow or shoulder pain during the tournament. Participants with the incidence of elbow or shoulder pain had a significant restriction in hip IR of the stride leg compared with those without pain (35.8° vs. 43.7°, P = .022). There were no significant associations of other joint flexibilities and the Star Excursion Balance Test with elbow or shoulder pain.

CONCLUSION

Decreased hip IR range of motion of the stride leg was significantly associated with the elbow or shoulder pain incidence. Players, coaches, and clinicians should consider the physical function of the trunk and lower extremities for the prevention of elbow and shoulder pain.

Verbal Abuse from Coaches Is Associated with Loss of Motivation for the Present Sport in Young Athletes: A Cross-Sectional Study in Miyagi Prefecture

Verbal and physical abuse from coaches has negative effects on young athletes. Although the abuse can lead to the athletes' dropping out, no studies have reported on this topic. The purpose of this study was to elucidate the association between experience of verbal or physical abuse from coaches and loss of motivation for the present sport in young athletes. School-aged athletes (age range, 6-15 years, n = 6,791) were assessed using a self-reported questionnaire. Multivariate logistic regression models were used to assess the association between experience of verbal or physical abuse and loss of motivation for the present sport. Variables considered in the models were sex, age, body mass index, presence of bodily pain, team levels, number of training days per week, number of training hours per day on weekdays and weekends, and frequency of participation in games. The prevalence of loss of motivation for the present sport was 8.1%. Experience of verbal or physical abuse was significantly associated with loss of motivation for the present sport and the adjusted odds ratios (95% confidence intervals) were 1.93 (1.54-2.42, p < 0.001) for verbal abuse and 1.76 (1.27-2.42, p = 0.001) for physical abuse. Findings of this study suggest that experience of verbal or physical abuse from coaches is associated with loss of motivation for the present sport. Eradication of verbal and physical abuse from coaches is important for young athletes to continue sport participation.

Determination of Walnut Protein in Processed Foods by Enzyme-Linked Immunosorbent Assay: Interlaboratory Study

Because food allergens from tree nuts, including walnuts, are a frequent cause of adverse food reactions for allergic patients, the labeling of foods containing ingredients derived from tree nuts is required in numerous countries. According to Japanese regulations, the labeling of food products containing walnuts is recommended. To ensure proper labeling, a novel sandwich ELISA kit for the determination of walnut protein in processed foods (Walnut Protein [2S-Albumin] Kit; Morinaga Institute of Biological Science, Inc.; walnut kit) has been developed. We prepared seven types of incurred samples (model processed foods: biscuits, bread, sponge cake, orange juice, jelly, chicken meatballs, and rice gruel) containing 10 g walnut soluble protein/g of food for use in interlaboratory evaluations of the walnut kit. The walnut kit displayed sufficient reproducibility relative standard deviations (interlaboratory precision: 5.89.9 RSDR) and a high level of recovery (81119) for all the incurred samples. All the repeatability relative standard deviation (RSDr) values for the incurred samples that were examined were less than 6.0. The results of this interlaboratory evaluation suggested that the walnut kit could be used as a precise and reliable tool for determination of walnut protein in processed foods.

Enzyme-Linked Immunosorbent Assay Kit for the Determination of Soybean Protein in Processed Foods: Interlaboratory Evaluation

The labeling of foods containing ingredients derived from soybean is recommended in Japan because of an increasing number of patients who are allergic to soybeans. To ensure proper labeling, a novel sandwich ELISA kit for the determination of soybean protein in processed foods (FASTKIT Ver. II, Soybean, Nippon Meat Packers, Inc.; soy kit) has been developed. Five types of incurred samples (model processed foods: rice gruel, sausage, sweet adzuki bean soup, sweet potato cake, and tomato sauce) containing 10 g soybean soluble protein/g food were prepared for use in interlaboratory evaluations of the soy kit. The soy kit displayed a sufficient RSDR value (interlaboratory precision: 9.313.4 RSDR) and a high level of recovery (97114) for all the incurred samples. The RSDr value for the incurred samples was mostly &lt;4.8. The results of this interlaboratory evaluation suggest that the soy kit can be used as a precise and reliable tool for the determination of soybean proteins in processed foods.

Automatic detection of early gastric cancer in endoscopic images using a transferring convolutional neural network

Endoscopic image diagnosis assisted by machine learning is useful for reducing misdetection and interobserver variability. Although many results have been reported, few effective methods are available to automatically detect early gastric cancer. Early gastric cancer have poor morphological features, which implies that automatic detection methods can be extremely difficult to construct. In this study, we proposed a convolutional neural network-based automatic detection scheme to assist the diagnosis of early gastric cancer in endoscopic images. We performed transfer learning using two classes (cancer and normal) of image datasets that have detailed texture information on lesions derived from a small number of annotated images. The accuracy of our trained network was 87.6%, and the sensitivity and specificity were well balanced, which is important for future practical use. We also succeeded in presenting a candidate region of early gastric cancer as a heat map of unknown images. The detection accuracy was 82.8%. This means that our proposed scheme may offer substantial assistance to endoscopists in decision making.

Musculoskeletal pain and new-onset poor physical function in elderly survivors of a natural disaster: a longitudinal study after the great East Japan earthquake

Background

Functional disability is a significant problem after natural disasters. Musculoskeletal pain is reported to increase after disasters, which can cause functional disability among survivors. However, the effects of musculoskeletal pain on functional decline after natural disasters are unclear. The present study aimed to examine the association between musculoskeletal pain and new-onset poor physical function among elderly survivors after the Great East Japan Earthquake.

Methods

A longitudinal study was conducted on survivors aged ≥65 years at three and 4 years after the Great East Japan Earthquake. A total of 747 persons were included in this study. Physical function was assessed using the Kihon Checklist. New-onset poor physical function was defined as low physical function not present at 3 years but present at 4 years after the disaster. Knee, hand or foot, low back, shoulder, and neck pain was assessed using a self-reported questionnaire and was defined as musculoskeletal pain. Musculoskeletal pain at 3 years after the disaster was categorized according to the number of pain regions (0, 1, ≥ 2). Multiple logistic regression analyses were performed to calculate the odds ratio (OR) and 95% confidence interval (95% CI) for new-onset poor physical function due to musculoskeletal pain.

Results

The incidence of new-onset poor physical function was 14.9%. New-onset poor physical function was significantly associated with musculoskeletal pain. Compared with “0” musculoskeletal pain region, the adjusted ORs (95% CI) were 1.39 (0.75–2.58) and 2.69 (1.52–4.77) in “1” and “≥ 2” musculoskeletal pain regions, respectively (p for trend = 0.003).

Conclusions

Musculoskeletal pain is associated with new-onset poor physical function among elderly survivors after the Great East Japan Earthquake. Monitoring musculoskeletal pain is important to prevent physical function decline after natural disasters.

Association between continued residence in temporary prefabricated housing and musculoskeletal pain in survivors of the Great East Japan Earthquake: a longitudinal study

OBJECTIVE

Prolonged periods of living in prefabricated houses (PHs) may increase the risk of musculoskeletal (MSK) symptoms; however, the association is not clear. This study aimed to investigate the association between continued residence in PHs and MSK pain in a population affected by a natural disaster, the Great East Japan Earthquake (GEJE) survivors.

DESIGN, SETTING AND PARTICIPANTS

A panel study was conducted including 1059 and 792 survivors at 2 and 4 years, respectively, after the GEJE, using a self-reported questionnaire. Those with no response on living status and those who did not live in a PH were excluded. Participants were classified into two groups by living status: continued residence in a PH (lived in a PH during both periods) or moving out of a PH (lived in a PH in the first period and did not live in a PH in the second).

PRIMARY OUTCOME MEASURE

MSK pain included lower back, shoulder, knee, hand or foot, and neck pain. Changes in the occurrence of MSK pain during the two periods were assessed and defined as 'new-onset' and 'continuing' MSK pain. Multiple logistic regression analysis was used to examine the influence of continued residence in a PH on new-onset and continuing MSK pain.

RESULTS

Continued residence in a PH was significantly associated with new-onset MSK pain, even after adjustment for covariates (adjusted OR 2.18, 95% CI 1.25 to 3.79, p=0.006). Participants who continued living in a PH had higher rates of continuing MSK pain than those who moved out; however, the difference was not significant (adjusted OR 1.69, 95% CI 0.94 to 3.05, p=0.079).

CONCLUSION

Continued residence in a PH was associated with new-onset MSK pain among survivors. Public support should be provided to such people to ensure a more comfortable life.

P4537Impact of body composition analysis on prediction of short-term readmission events in heart failure: muscle wasting vs. obesity

Background

Obesity, defined as higher body mass index (BMI), is associated with better prognosis in patients with chronic heart failure (CHF), though the presence of obesity is a risk factor of development of CHF (Obesity paradox). On the other hand, muscle wasting, i.e. reduction in skeletal muscle mass, is frequently observed in CHF, leading to lower exercise capacity and poor cardiovascular outcome.

Purpose

The aim of this study was to examine whether analysis of body composition improves prediction of short-term readmission rates in patients with CHF.

Methods

We retrospectively analyzed data for 167 consecutive HF patients who were admitted to our institute for management of HF and received a Dual-energy X-ray absorptiometry (DEXA) scan. Muscle wasting was defined as DEXA-measured appendicular skeletal muscle mass index <7.0 kg/m2 in male and <5.4 kg/m2 in female according to the Asian Working Group for Sarcopenia criteria. Obesity was defined according to the criteria by the use of DEXA-measured percent body fat mass: >25% in male, >30% in female. The primary endpoint was readmission due to cardiac events including worsening heart failure, arrhythmia, and cardiopulmonary arrest during a 180-days follow-up period after discharge.

Results

The mean age of the patients was 74±13 years and 46% of them were male. The mean BMI was 21.8±3.8 kg/m2. Forty-seven percent of the patients were classified as NYHA functional class III. The most frequent etiology of HF was cardiomyopathy (30%), followed by ischemic heart disease (27%) and valvular heart disease (27%). The prevalence of muscle wasting and that of obesity were 69% and 59%, respectively. Patients with muscle wasting had lower BMI level, higher prevalence of NYHA functional class III and diabetes mellitus compared with those without muscle wasting. On the other hand, patients with obesity had higher prevalence of hypertension and dyslipidemia, higher level of BMI, fasting plasma insulin and triglyceride, and lower level of HDL-cholesterol compared with those without obesity. During the follow-up period, 34 patients (19%) were re-hospitalized due to cardiac events. Kaplan-Meier survival curves showed that patients with obesity had a significantly lower readmission rate during a 180-days follow-up period than did the patients without obesity (14.3% vs. 29.0%, Log-Rank test, p<0.01). There was no difference in readmission rates between patients with and without muscle wasting (20.0% vs. 21.2%, p=0.88). In multivariate Cox regression analyses adjusted for age, sex, diabetes, and renal function, obesity was independently associated with lower readmission rates (hazard ratio 0.45, 95% confidence interval 0.22–0.93). However, the association between obesity and readmission rate was lost after the adjustment for NT-proBNP levels.

Conclusion

Body composition analysis by DEXA enables to find CHF patients with increased fat mass who have lower risk of short-term readmission.

P1538Low energy intake predicts readmission of elderly heart failure patients independently of nutritional status

Background

Malnutrition is frequently present and closely associated with poor clinical outcomes in elderly heart failure (HF) patients. Our previous study showed that low energy intake (EI) is associated with worse functional status in elderly HF inpatients after cardiac rehabilitation, but significance of EI in prediction of hospital readmission has not been elucidated fully.

Purpose

We examined whether low EI is a predictor of readmission for cardiac events in elderly HF patients.

Methods

We retrospectively retrieved data for 298 HF patients aged ≥65 years (median age of 77 years, interquartile range [IQR]: 71 - 82, female: 53%) who admitted to our institute for diagnosis and treatment of HF. Medical records were reviewed with regard to demography, medical history, comorbidities, medications, laboratory data, echocardiograms, functional status, nutritional status and total energy intake. Nutritional status was assessed using the Mini Nutritional Assessment Short Form (MNA-SF) and total EI per day were calculated at discharge by a registered dietitian and a trained physical therapist. The primary endpoint was readmission due to cardiovascular events including worsening HF, arrhythmia, angina pectoris and myocardial infarction during a 1-year follow-up period.

Results

The median period of follow-up was 235 days (IQR: 78–365 days). The 1-year readmission rate for cardiovascular events was 54.4%. The cutoff values of MNA-SF score and EI, calculated by ROC curve analysis to predict the primary endpoint, were 7 points (area under the curve [AUC]: 0.59, sensitivity: 0.65, specificity: 0.50) and 31.8 kcal/kg/day (AUC: 0.59, sensitivity: 0.83, specificity: 0.35), respectively. Patients with low MNF-SF score (≤7) or low EI (≤31.8 kcal/kg/day) had significantly higher readmission rate during a 1-year follow-up period than did the patients with high MNF-SF score or EI (MNA-SF: 60.7% vs. 45.6%, p<0.01, EI: 60.4% vs. 36.8%, p<0.01), respectively. When patients were classified into four groups using cutoff values of MNA-SF score and EI, 1-year readmission rate was significantly higher in patients with low EI than in those with high EI regardless of MNF-SF scores. In multivariate Cox proportional hazard analyses adjusted for known prognostic factors in addition to age and gender, hazard ratios (HR) were significantly higher in patients with high MNA-SF score and low EI (adjusted HR: 2.81, 95% confidential interval [CI]: 1.15 - 9.32, p=0.02) and low MNA-SF score (≤7) and low EI (adjusted HR: 4.16, 95% CI: 1.72 - 13.72, p<0.01) than those with high MNA-SF score and high EI.

Kaplan-Meier curves of readmission rates

Conclusions

Low energy intake is a nutritional status-independent predictor of 1-year readmission rate in elderly HF patients.

P6453Activation of necroptotic pathway by downregulated caspase-8 expression is associated with progression of left ventricular remodeling in nonischemic dilated cardiomyopathy

Background

Necroptosis, a form of programmed necrosis, has been suggested to be involved in the pathogenesis of various pathological conditions including heart failure. Protein expression of caspase-8, an endogenous inhibitor of necroptosis, is reported to be downregulated in human failing hearts, but its clinical significance remains unclear.

Methods

Endomyocardial biopsy specimens were obtained from patients with nonischemic dilated cardiomyopathy (n=57, 56.2±14.5 years old, 70% male). The area stained with antibodies against caspase-8 and phospho-MLKL-Ser358 was calculated using an image analyzer, and fibrotic and cardiomyocyte areas were determined by Masson's Trichrome staining. Using a level of median caspase-8 expression (6.04% of the area of the myocardium with caspase-8 signal), patients were classified into a high caspase-8 expression group (H-cas8) and a low caspase-8 expression group (L-cas8).

Results

Caspase-8 signals were detected in cytoplasm and intercalated disks of cardiomyocytes. Patients in the L-cas8 group was younger (51.3±13.1 vs. 61.2±14.3 years old) and had larger left ventricular end-diastolic volume (LVEDV: 174±49 vs. 131±41 ml), larger left ventricular end-systolic volume (LVESV: 123±51 vs. 87±39 ml), and higher ratio of mitral peak velocity of early filling to late diastolic filling (E/A: 1.94±1.48 vs. 1.12±0.66) compared with the H-cas8 group. Caspase-8 expression level was positively correlated with age (r=0.34, p=0.01) and negatively correlated with LVEDV (r=−0.47, p<0.01), LVESV (r=−0.40, p<0.01), and E/A (r=−0.39, p<0.01) in simple linear regression analysis. The extent of myocardial fibrosis was not correlated with caspase-8 expression level. Multiple regression analysis indicated that LVEDV, LVESV, and E/A were independent explanatory factors of caspase-8 expression level after adjusting age and sex. Phospho-MLKL signals, an index of activation of necroptotic pathway, were frequently observed in cytoplasm, intercalated disks, and nuclei in the L-cas8 group but not in the H-cas8 group.

Conclusion

Lower caspase-8 expression in cardiomyocytes was associated with increased phosphorylation of MLKL and larger left ventricular volume, suggesting that downregulated caspase-8 may contribute to progression of myocardial remodeling via activation of MLKL in human dilated cardiomyopathy.

P6273Inhibitory phosphorylation of RIP1 at Ser320 induces nuclear translocation of TFEB, leading to suppression of necroptosis in cardiomyocytes

Background

Necroptosis, a form of programmed necrosis, has been shown to contribute to the pathogenesis of various diseases including ischemia/reperfusion injury and heart failure. We recently reported that necroptotic signals suppresses autophagy in cardiomyocytes and that rapamycin, an mTORC1 inhibitor, not only promotes autophagy but also protect the cells from necroptosis.

Purpose

We examined the mechanism by which rapamycin suppresses necroptosis of cardiomyocytes, focusing on regulation of RIP1 activity and autophagic flux.

Methods and results

In H9c2 cardiomyoblasts, necroptosis was induced by treatment with TNF and z-VAD-fmk (zVAD) for 24 h, and cell death was determined by LDH release (as % of total). The treatment with TNF/zVAD increased LDH release from 3.4±1.3% to 46.1±2.3%, and LDH release was suppressed by necrostatin-1 (5.9±0.9%), a RIP1 inhibitor, and by rapamycin (23.5±1.4%). The protective effect of rapamycin was mimicked by Ku-0063794, an mTORC1/2 inhibitor. TNF/zVAD induced RIP1-RIP3 complex formation, together with suppression of TNF-induced RIP1 cleavage, which was mitigated by rapamycin. In addition, rapamycin not only suppressed TNF/zVAD-induced phosphorylation of RIP1-Ser166, an index of RIP1 activation, but also increased phosphorylation of RIP1-Ser320, an inhibitory phosphorylation site. In cells transfected with RIP1-S320A, which lack Ser320 for inhibitory phosphorylation, rapamycin failed to suppress TNF/zVAD-induced RIP1-RIP3 binding and cell death. Immunoblot analyses showed that TNF/zVAD significantly increased level of LC3-II. The accumulation of LC3-II protein was not further increased by bafilomycin A1 (100 nM), an inhibitor of lysosomal protein degradation, indicating that accumulation of LC3-II by TNF/zVAD reflected suppression of autophagic flux. Inhibition of RIP1 by necrostatin-1 attenuated TNF/zVAD-induced accumulation of LC3 II. The restoration of autophagic flux in TNF/zVAD-treated cells by necrostatin-1 was confirmed by monitoring tandem RFP-GFP-LC3 transfected cells; necrostatin-1 increased a ratio of RFP-LC3-puncta (autolysosomes) to RFP-GFP-LC3-puncta (autophagosomes) in TNF/zVAD-treated cells. In addition, necrostatin-1 and rapamycin induced nuclear translocation of TFEB, a regulator of lysosome biogenesis, which was associated with upregulation of MCOLN1 mRNA, a downstream target of TFEB. Restoration of autophagic flux in TNF/zVAD-treated cells by necrostatin-1 was inhibited by siRNA-mediated knockdown of TFEB.

Conclusion

Activation of TFEB by inhibitiory phosphorylation of RIP1-Ser320 is a primary mechanism of cytoprotection afforded by mTORC1 inhibition against necroptosis.

Coherence between oscillations in the cardiorespiratory system and tissue oxygen index in muscle recovering from intensive exercise in humans

It has been shown that the tissue oxygen index (TOI) measured by near-infrared spectroscopy oscillates at very low frequencies during recovery after exercise and that this oscillation is derived from interactions among biochemical substances involved in oxidative metabolism in skeletal muscle. As a further step, we examined whether TOI in muscle interacts through oscillation with factors related to oxygen in the cardiorespiratory system. For this examination, coherence and phase difference between the TOI in the vastus lateralis and heart rate (HR) and between TOI and arterial oxygen saturation (SpO₂) were sequentially determined during recovery (2-60 min) after severe cycle exercise with a workload of 7.5% of body weight for 20 s. Significant coherence between TOI and HR was obtained in the very low-frequency band (approximate range: 0.002-0.03 Hz) and in the low-frequency band (approximate range: 0.06-0.12 Hz). The phase difference was negative in the low-frequency band and positive in the very low-frequency band. The coherence between TOI and SpO₂ was significant in the very low-frequency band. The phase difference was negative. There were no sequential changes in these coherences and phase differences. The results suggest that TOI in skeletal muscle interrelates with factors related to the heart and lungs.