Search for the Pair Production of Dark Particles X with K_{L}

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110 MeV/c^{2} and 210-240 MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

Implementation of Bronchoscopic Lung Volume Reduction Using One-Way Endobronchial Valves: A Retrospective Single-Centre Cohort Study.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) using 1-way endobronchial valves (EBV) has become a guideline treatment in patients with advanced emphysema. Evidence from this minimally invasive treatment derives mainly from well-designed controlled trials conducted in high-volume specialized intervention centres. Little is known about real-life outcome data in hospitals setting up this novel treatment and which favourable conditions are required for a continuous successful program. OBJECTIVES: In this study, we aim to evaluate the eligibility rate for BLVR and whether the implementation of BLVR in our academic hospital is feasible and yields clinically significant outcomes. METHOD: A retrospective evaluation of patients treated with EBV between January 2016 and August 2019 was conducted. COPD assessment test (CAT), forced expiratory volume in 1 s (FEV1), residual volume (RV), and 6-min walking test (6MWT) were measured at baseline and 3 months after intervention. Paired sample t tests were performed to compare means before and after intervention. RESULTS: Of 350 subjects screened, 283 (81%) were not suitable for intervention mostly due to lack of a target lobe. The remaining 67 subjects (19%) underwent bronchoscopic assessment, and if suitable, valves were placed in the same session. In total, 55 subjects (16%) were treated with EBV of which 10 did not have complete follow-up: 6 subjects had their valves removed because of severe pneumothorax (n = 2) or lack of benefit (n = 4) and the remaining 4 had missing follow-up data. Finally, 45 patients had complete follow-up at 3 months and showed an average change ± SD in CAT -4 ± 6 points, FEV1 +190 ± 140 mL, RV -770 ± 790 mL, and +37 ± 65 m on the 6MWT (all p < 0.001). After 1-year follow-up, 34 (76%) subjects had their EBV in situ. CONCLUSION: Implementing BLVR with EBV is feasible and effective. Only 16% of screened patients were eligible, indicating that this intervention is only applicable in a small subset of highly selected subjects with advanced emphysema, and therefore a high volume of COPD patients is essential for a sustainable BLVR program.

Study of the K_{L}→π

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

Dual-Energy Computed Tomography Compared to Lung Perfusion Scintigraphy to Assess Pulmonary Perfusion in Patients Screened for Endoscopic Lung Volume Reduction.

BACKGROUND: Endoscopic lung volume reduction (ELVR) using one-way endobronchial valves is a technique to reduce hyperinflation in patients with severe emphysema by inducing collapse of a severely destroyed pulmonary lobe. Patient selection is mainly based on evaluation of emphysema severity on high-resolution computed tomography and evaluation of lung perfusion with perfusion scintigraphy. Dual-energy contrast-enhanced CT scans may be useful for perfusion assessment in emphysema but has not been compared against perfusion scintigraphy. AIMS: The aim of the study was to compare perfusion distribution assessed with dual-energy contrast-enhanced computed tomography and perfusion scintigraphy. MATERIAL AND METHODS: Forty consecutive patients with severe emphysema, who were screened for ELVR, were included. Perfusion was assessed with 99mTc perfusion scintigraphy and using the iodine map calculated from the dual-energy contrast-enhanced CT scans. Perfusion distribution was calculated as usually for the upper, middle, and lower thirds of both lungs with the planar technique and the iodine overlay. RESULTS: Perfusion distribution between the right and left lung showed good correlation (r = 0.8). The limits of agreement of the mean absolute difference in percentage perfusion per region of interest were 0.75-5.6%. The upper lobes showed more severe perfusion reduction than the lower lobes. Mean difference in measured pulmonary perfusion ranged from -2.8% to 2.3%. Lower limit of agreement ranged from -8.9% to 4.6% and upper limit was 3.3-10.0%. CONCLUSION: Quantification of perfusion distribution using planar 99mTc perfusion scintigraphy and iodine overlays calculated from dual-energy contrast-enhanced CTs correlates well with acceptable variability.

Energy transfer from adipocytes to cancer cells in breast cancer.

Limitations of the current therapeutic approach have raised the need for a novel therapeutic agent in breast cancer. Recently, interest in drugs targeting the tumor microenvironment (TME) had drawn attention in the treatment of breast cancer. Furthermore, recent studies have suggested the role of adipocytes, which are part of the TME, in tumor initiation, growth, and metastasis. In this study, we investigated the metabolic interaction between adipocytes and breast cancer cells and its potential as a new therapeutic target in breast cancer. Breast cancer cell lines and human breast cancer tissue samples were evaluated. Compared to cancer cells cultured alone, or the control group, those co-cultured with adipocytes showed lipid transfer from adipocytes to cancer cells and it was different according to the molecular subtype of breast cancer. Breast cancer cells affected the lipolysis of adipocytes and adipocytes affected the ß-oxidation of breast cancer cells. The key molecule of the process was fatty acid binding protein 4 (FABP4), which is combined with free fatty acid (FFA) and supports its migration to cancer cells. When FABP4 was suppressed, lipid transfer between adipocytes and cancer cells, lipolysis of adipocytes, and ß-oxidation of breast cancer cells were reduced. Furthermore, the expression of lipid metabolism-related proteins and lipolysis-related proteins in breast cancer with adipose stroma showed significantly different expression according to the region of breast cancer tissue. Taken together, we demonstrated the metabolic interaction between adipocytes and breast cancer cells. Breast cancer cells increase the lipolysis in adipocytes and produce a fatty acid, and fatty acid enters into cancer cells. Also, adipocytes contribute to the survival and growth of cancer cells through increased mitochondrial ß-oxidation by using fatty acid from adipocytes. The key molecule of the process is FABP4 and when FABP4 is suppressed, the metabolic interaction is reduced, suggesting its role as a potential therapeutic target.

iNKT cells prevent obesity-induced hepatic steatosis in mice in a C-C chemokine receptor 7-dependent manner.

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are characterized by an increase in hepatic triglyceride content with infiltration of immune cells, which can cause steatohepatitis and hepatic insulin resistance. C-C chemokine receptor 7 (CCR7) is primarily expressed in immune cells, and CCR7 deficiency leads to the development of multi-organ autoimmunity, chronic renal disease and autoimmune diabetes. Here, we investigated the effect of CCR7 on hepatic steatosis in a mouse model and its underlying mechanism. Our results demonstrated that body and liver weights were higher in the CCR7-/- mice than in the wild-type (WT) mice when they were fed a high-fat diet. Further, glucose tolerance and insulin sensitivity were markedly diminished in CCR7-/- mice. The number of invariant natural killer T (iNKT) cells was reduced in the livers of the CCR7-/- mice. Moreover, liver inflammation was detected in obese CCR7-/- mice, which was ameliorated by the adoptive transfer of hepatic mononuclear cells from WT mice, but not through the transfer of hepatic mononuclear cells from CD1d-/- or interleukin-10-deficient (IL-10-/-) mice. Overall, these results suggest that CCR7+ mononuclear cells in the liver could regulate obesity-induced hepatic steatosis via induction of IL-10-expressing iNKT cells.

Src-type tyrosine kinase p56lck is critical for thymic stromal lymphopoietin-induced allergic rhinitis.

BACKGROUND: Thymic stromal lymphopoietin (TSLP) is a regulator of mast cell-mediated allergic inflammatory reactions, but the manner in which TSLP contributes to allergic rhinitis (AR) remains unclear. OBJECTIVE: Here, we sought to determine that TSLP plays a crucial role in AR by interacting with Src-type tyrosine kinase p56lck and STAT6 and promoting mast cells degranulation. METHODS: The effects of TSLP on mast cell degranulation and AR were analysed in human mast cell line (HMC-1 cells), ovalbumin (OVA)-induced AR animal model, and human subjects. Small interfering RNA experiments were performed in HMC-1 cells and OVA-induced AR model. Immune responses were analysed by enzyme-linked immunosorbent assay, Western blotting, immunoprecipitation, and histological studies. RESULTS: Thymic stromal lymphopoietin levels and mast cell-derived p56lck activation were elevated in human subjects with AR, and in AR mice, exogenous TSLP accelerated TH2-allergic inflammatory reactions by up-regulating p56lck and STAT6. On the other hand, depletion of TSLP, p56lck, and STAT6 ameliorated clinical symptoms in AR mice. The selective inhibitor of p56lck, damnacanthal, inhibits AR reactions. CONCLUSION: Collectively, these observations suggest a role for TSLP/p56lck/STAT6 in AR and offer insight into potential therapeutic strategies.

Reliability and validity of the Atopic Dermatitis Symptom Score (ADSS).

BACKGROUND: We have developed the Atopic Dermatitis Symptom Score (ADSS) by which patients or parents can easily assess and record AD symptoms on a daily basis in a smartphone application. The aim of this study was to evaluate the reliability and validity of the ADSS. METHODS: We enrolled 307 children and adolescents with AD. Parents or caregivers were asked to record daily symptoms of the patients (itching, sleep disturbance, erythema, dryness, oozing, and edema) using a scale of 0-4. Statistical analyses consisted of the test-retest reliability, concurrent validity, minimal clinically important difference (MCID), responsiveness, floor or ceiling effects, and screening accuracy. Receiver-operating characteristic analyses were conducted to evaluate the ADSS cutoff point for predicting severe AD (SCORing AD [SCORAD] ≥40). RESULTS: Test-retest reliability between daytime and night-time ADSS was good (intraclass correlation coefficient, 0.82 [95% CI: 0.70-0.90]). An increase in ADSS was significantly associated with an increase in SCORAD (r = 0.64, P < .0001) (concurrent validity). The MCID was 4.1 points for the ADSS. There was a significant association between changes in ADSS and SCORAD (r = 0.56, P < .0001), indicating good responsiveness. At the optimal ADSS cutoff value of 7.0, sensitivity, specificity, and positive and negative predictive values were 88.4%, 78.6%, 21.1%, and 99.1%, respectively (screening accuracy). CONCLUSIONS: The ADSS can be a useful tool for self-assessment of skin symptoms in children with AD.

Therapeutic effects of Artemisia scoparia Waldst. et Kitaib in a murine model of atopic dermatitis.

BACKGROUND: Artemisia scoparia Waldst. et Kitaib (AS) (Oriental wormwood, known as Bissuk in Korea) is a plant used in cosmetic and pharmaceutical treatments. However, the effect of AS on atopic dermatitis (AD) has not been described. AIM: To examine the inhibitory effect of AS on AD using a murine model. METHODS: We applied either AS, the butanol-extracted fraction of AS (Bu-OH) or 3,5-dicaffeoyl-epi-quinic acid (DEQA, a major component of Bu-OH) topically for 3 weeks to 2,4-dinitrofluorobenzene (DNFB)-induced skin lesions in BALB/c mice. RESULTS: AS, Bu-OH and DEQA suppressed the clinical symptoms of DNFB-induced skin lesions and he associated scratching behaviour. Numbers of inflammatory cells infiltrating skin lesions were significantly reduced by AS or Bu-OH application but not by DEQA. In addition, AS significantly suppressed serum levels of histamine and IgE, while Bu-OH significantly suppressed serum levels of histamine, IgE, thymic stromal lymphopoietin (TSLP), interleukin (IL)-4 and IL-6, and DEQA significantly suppressed serum levels of histamine, IgE, TSLP and IL-4 in DNFB-induced AD mice. In skin lesions, AS and Bu-OH significantly reduced inflammatory cytokines, whereas DEQA did not. AS, Bu-OH and DEQA all significantly suppressed caspase-1 activities. CONCLUSIONS: These results demonstrate the anti-AD effects of AS, Bu-OH and DEQA, and suggest that all three have therapeutic potential.

Exogenous administration of DLK1 ameliorates hepatic steatosis and regulates gluconeogenesis via activation of AMPK.

BACKGROUND/OBJECTIVES: Activation of Notch signaling pathologically enhances lipogenesis and gluconeogenesis in the liver causing non-alcoholic fatty liver disease (NAFLD) and diabetes. Delta-like 1 homolog (DLK1), an imprinted gene that can modulate adipogenesis and muscle development in mice, was found as an inhibitory regulator of Notch signaling. Therefore, we investigated the metabolic effect of exogenous DLK1 in vitro and in vivo. SUBJECTS/METHODS: A soluble DLK1 peptide was generated with fusion between a human Fc fragment and extracellular domain of DLK1. Male db/db mice were randomly assigned to two groups: vehicle treated and DLK1-treated group (25 mg kg(-1), intraperitoneal injection, twice a week for 4 weeks). Primary mice hepatocytes and HepG2 cells were used for in vitro experiments. RESULTS: After 4 weeks of DLK1 administration, hepatic triglyceride content and lipid droplets in liver tissues, as well as serum levels of liver enzymes, were markedly decreased in db/db mice. DLK1 treatment induced phosphorylation of AMPK and ACC and suppressed nuclear expression of SREBP-1c in the mouse liver or hepatocytes, indicating regulation of fatty acid oxidation and synthesis pathways. Furthermore, DLK1-treated mice showed significantly lower levels of fasting and random glucose, with improved glucose and insulin tolerance compared with the vehicle-treated group. Macrophage infiltration and proinflammatory cytokine levels in the epididymal fat were decreased in DLK1-treated db/db mice. Moreover, DLK1 suppressed glucose production from hepatocytes, which was blocked after co-administration of an AMPK inhibitor, compound C. DLK1-treated hepatocytes and mouse liver tissues showed lower PEPCK and G6Pase expression. DLK1 triggered AKT phosphorylation followed by cytosolic translocation of FOXO1 from the nucleus in hepatocytes. CONCLUSIONS: The present study demonstrated that exogenous administration of DLK1 reduced hepatic steatosis and hyperglycemia via AMPK activation in the liver. This result suggests that DLK1 may be a novel therapeutic approach for treating NAFLD and diabetes.