Study of the K_{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment

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.

Search for K_{L}→π^{0}νν[over ¯] and K_{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment

A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135  MeV/c^{2}.

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K^{+}K^{-}p Reaction near Threshold

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1  GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

Effects of Air Pollution-Related Heavy Metals on the Viability and Inflammatory Responses of Human Airway Epithelial Cells

Various metals produced from human activity are ubiquitously detected in ambient air. The metals may lead to induction and/or exacerbation of respiratory diseases, but the significant metals and factors contributing to such diseases have not been identified. To compare the effects of each metal and different oxidation states of metals on human airway, we examined the viability and production of interleukin (IL)-6 and IL-8 using BEAS-2B cell line, derived from human airway epithelial cells. Airway epithelial cells were exposed to Mn2+, V4+, V5+, Cr3+, Cr6+, Zn2+, Ni2+, and Pb2+ at a concentration of 0.5, 5, 50, or 500 μmol/L for 24 hours. Mn and V decreased the cell viability in a concentration-dependent manner, and V5+ tended to have a greater effect than V4+. The Cr decreased the cell viability, and (Cr+6) at concentrations of 50 and 500 μmol/L was more toxic than (Cr+3). Zn at a concentration of 500 μmol/L greatly decreased the cell viability, whereas Ni at the same concentration increased it. Pb produced fewer changes. Mn and Ni at a concentration of 500 μmol/L induced the significant production of IL-6 and IL-8. However, most of the metals including (V+4, V+5), (Cr+3, Cr+6), Zn, and Pb inhibited the production of both IL-6 and IL-8. The present results indicate that various heavy metals have different effects on toxicity and the proinflammatory responses of airway epithelial cells, and those influences also depend on the oxidation states of the metals.

Effects of hydrogen peroxide on mucociliary transport in human airway epithelial cells

The effects of environmental pollutants on airway clearance have not been well elucidated. This study examined mucociliary transport using different sized-fluorescent particles on polarized human airway epithelial cells which were maintained in an air-liquid interface (ALI) culture system. The effects of hydrogen peroxide (H2O2) exposure on mucociliary transport were also investigated. The movement of fluorescent particles with diameters of 10-14 and 2.5-4.5 µm was observed by fluorescent microscopy as an index of the mucociliary transport. The mixture of the particles with two different sizes was propelled concentrically on the apical surface by the interaction of ciliary activity and mucus in the control condition, whereas H2O2 exposure for 24 h significantly inhibited the movement of the particles. The particle sizes did not affect their movement after the control or H2O2 exposure. These results suggest that particle tracking on polarized human airway epithelial cells is a useful experimental tool for the evaluation of the effect of environmental pollutants on mucociliary transport. In addition, reactive oxygen species may impair mucociliary transport, leading to the airway damage and exacerbation of respiratory diseases.

Streamer discharge reduces pollen-induced inflammatory responses and injury in human airway epithelial cells

Although epidemiological studies have demonstrated that cedar pollen influences respiratory health, effective method for inactivating cedar pollen has not been established. Streamer discharge is a type of plasma discharge in which high-speed electrons collide with oxygen and nitrogen molecules. It reportedly has the ability to eliminate bacteria, mould, chemical substances and allergens. The present study investigated the influence of pollen on BEAS-2B cell line, derived from human airway epithelial cells, as well as the efficiency of streamer discharge on pollen-induced health effects. Airway epithelial cells were exposed to non-treated pollen and streamer-discharged pollen at doses of 100 and 1000 μg/mL for 6 or 24 h. Non-treated pollen at a dose of 1000 μg/mL significantly decreased cell viability and induced both mRNA and protein expression of interleukin-6, whereas streamer-discharged pollen showed the attenuated changes as compared with non-treated pollen. Further, scanning electron micrographs showed that streamer discharge caused the fine structural changes of pollen. These results provide the first experimental evidence that pollen at a high dose affects cell viability and inflammatory responses, and streamer discharge technology attenuates their influences by decomposing pollen.

MAPKs, activator protein-1 and nuclear factor-κB mediate production of interleukin-1β-stimulated cytokines, prostaglandin E₂ and MMP-1 in human periodontal ligament cells

BACKGROUND AND OBJECTIVE

Determination of the interleukin-1 (IL-1) signaling cascades that lead to the production of various inflammatory mediators and catabolic factors may clarify attractive targets for therapeutic intervention for periodontitis. We comprehensively assessed the involvement of MAPKs, activator protein-1 (AP-1) and nuclear factor-κB (NF-κB) in IL-1β-induced production of interleukin-6 (IL-6), interleukin-8 (IL-8), prostaglandin E(2) (PGE(2) ) and MMP-1 in human periodontal ligament cells.

MATERIAL AND METHODS

Human periodontal ligament cells were pretreated with an inhibitor for each of the MAPKs or NF-κB and subsequently treated with IL-1β. Following treatment, phosphorylation of three types of MAPK (ERK, p38 MAPK and c-Jun N-terminal kinase), IκB kinase (IKK) α/β/γ and IκB-α, as well as the DNA binding activity of AP-1 and NF-κB and the production of IL-6, IL-8, PGE(2) and MMP-1, were determined by western blotting, a gel mobility shift assay and ELISA, respectively.

RESULTS

The three MAPKs, simultaneously activated by IL-1β, mediated the subsequent DNA binding of AP-1 at various magnitudes, while IKKα/β/γ, IκB-α and NF-κB were also involved in the IL-1 signaling cascade. Furthermore, IL-1β stimulated the production of IL-6, IL-8, PGE(2) and MMP-1 via activation of the three MAPKs and NF-κB, because inhibitors of these significantly suppressed the IL-1β-stimulated production of these factors.

CONCLUSION

Our results strongly suggest that MAPK, AP-1 and NF-κB mediate the IL-1β-stimulated synthesis of IL-6, IL-8, PGE(2) and MMP-1 in human periodontal ligament cells. Therefore, inhibition of activation of MAPK, AP-1 and/or NF-κB may lead to therapeutic effects on progression of periodontitis.

Measurements of exposure concentrations of benzene, toluene and xylene, and amounts of respiratory uptake

With respect to benzene, toluene, and o-, m- and p-xylene contained in indoor air, this study determined the amounts of their uptake through the human respiratory system using the difference between concentrations in inhalation and exhalation, and examined their relationship to concentrations in blood and urine measured before and after exposure. At relatively high concentrations, respiratory absorption of these compounds tended to increase rapidly in the early stage of exposure but decrease after several hours. It was also confirmed that concentrations of these compounds in both blood and urine increased during the first 3 hours of exposure. These results suggested that measurements of concentrations in inhalation and exhalation may provide a simple method for estimating the extent of respiratory exposure to these substances.

Salivary chromogranin A as a measure of stress response to noise

Effects of noise on the secretion of salivary chromogranin A (CgA), which is considered to be a substitute measure of catecholamines, were investigated in a laboratory experiment. This study included 20 male subjects with normal hearing; their ages ranged from 21 to 24 years. Prior to the experiment, the subjects were asked to answer a questionnaire containing the 28-item General Health Questionnaire (GHQ-28) and Weinstein's noise sensitivity scale. White noise at 90 dB was presented to the subjects for 15 min with 15-minute-rest periods before and after noise exposure. It was shown that salivary CgA levels increased significantly during noise exposure and decreased immediately after it (Friedman's test, p = 0.001, two tailed). This result suggests that salivary CgA can be used to measure the stress response to noise. Furthermore, individual differences in the change in salivary CgA levels were discussed in relation to the subjective responses of the participants to the questionnaire. Some subjects showed prolonged elevation in the salivary CgA levels and the others showed immediate recovery or no effects. These individual differences correlated with the score on the somatic symptoms in GHQ-28; this implies that the score on the somatic symptoms in GHQ-28 could be a measure of physiological sensitivity to noise.

Relationships between lifestyle factors and neutrophil functions in the elderly

We investigated the relationships between neutrophil functions and lifestyle factors in the elderly. The subjects (84 males, 73.9+/-5.8 years old; and 63 females, 70.0+/-4.6 years old) belonged to a recreational seniors club in Japan. Investigations of the subjects' stress, exercise habits, smoking habits, and alcohol-drinking habits were performed. The phagocytosis and superoxide productivity of the neutrophils were measured with a nitroblue tetrazolium (NBT) reduction test. In addition, leukocyte counts and serum total protein (TP) levels were determined. The results revealed that aging, high serum levels, and stress-coping factors (e.g., having hobbies, keeping pets, and close links with friends or family) significantly correlated with preferable neutrophil functions. In addition, significant effects of lifestyle factors on the balance between phagocytosis and subsequent superoxide production were observed. Thus, the results of the present study suggest that there are correlations between neutrophil functions and lifestyle factors in the elderly.

Increased serum concentrations of secretory leukoprotease inhibitor in patients with primary Sjögren's syndrome

BACKGROUND

Secretory leukoprotease inhibitor (SLPI), a 12 kDa serine antiprotease, is produced by serous cells including salivary and lacrimal glands.

OBJECTIVE

We sought to assess whether serum levels of SLPI in patients with primary Sjogren's syndrome (SS) are elevated and correlated with conventional and laboratory indices of disease activity.

PATIENTS AND METHODS

SLPI levels were determined by ELISA of serum from 21 primary SS, and 26 age-matched normal controls.

RESULTS

Increased SLPI concentrations were found in primary SS patients (p < 0.01). Serum SLPI levels were positively correlated with the duration of the disease (r = 0.517, p < 0.025), but not with age, erythrocyte sedimentation rate, CRP, immunoglobulins, number of extraglandular manifestations and saliva production. SLPI levels were also positively correlated with serum levels of beta 2-microglobulin (r = 0.607, p < 0.01).

CONCLUSION

Determination of serum SLPI may provide a new simple noninvasive technique for evaluation of primary SS.

Character of a wheat amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and hormones

BACKGROUND & AIMS

Amylase inhibition induces carbohydrate tolerance, satiety, and weight loss and prolongs gastric emptying, effects that may be useful in the treatment of obesity and non-insulin-dependent diabetes mellitus. The aim of this study was to determine (1) purity of a wheat amylase inhibitor preparation, (2) intraduodenal concentration of the wheat amylase inhibitor preparation that inhibits > 90% amylase activity (which causes carbohydrate malabsorption), and (3) if the inhibitor alters pancreaticobiliary secretions or intraluminal pH.

METHODS

High-performance liquid chromatography followed by electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used for characterization. Groups of 3 subjects received intraduodenal infusions of 3.0, 4.5, or 6.0 mg/mL of the inhibitor for 90 minutes during the middle of a 270-minute essential amino acid solution infusion (which stimulates 50% maximal pancreatic enzyme secretion). Pancreatic enzyme and bile acid delivery to the duodenum were measured for a 270-minute period.

RESULTS

The inhibitor is 96% protein, 59% containing 0.19, 0.28, 0.38, and 0.53 inhibitors. The 0.38 inhibitor has the most antipancreatic alpha-amylase activity. The inhibitor reduced amylase activity in the duodenum dose dependently (r = 0.7; P = 0.04); > 4 mg/mL inhibited > 90% amylase activity but did not affect delivery of other enzymes or bile acids to the duodenum or gastric or duodenal pH.

CONCLUSIONS

The preparation has a high protein purity and a high specific activity against alpha-amylase activity and effectively inhibits human pancreatic amylase activity secreted into the duodenum.

[Relation among lifestyle, social network, blood pressure and serum lipids in the elderly]

The relationships among seven lifestyle factors including stress, which is focused on as a risk factor for cardiovascular disease recently, social network, blood pressure and serum lipids in the elderly were examined in a cross sectional study of 85 males and 65 females aged 60 years or over in the city of Sayama, Saitama Prefecture. The seven lifestyle factors were as follows: (1) amount of alcohol consumption, (2) cigarette smoking, (3) Physical exercise, (4) sleeping time per night, (5) nutritional balance, (6) body weight, and (7) stress. As social network factors, marital status and coping factor for stress and/or anxiety were introduced. Stressful life events strongly associated with stress status were also discussed. In this study, it was clear that age, alcohol consumption, stress status and stressful life events caused higher blood pressure. On the other hand, the social network was associated with lifestyle status and a controlled blood pressure level. Obesity and physical exercise were significantly associated with serum lipids. There results suggest that it is very important for the maintenance and promotion of health and risk reduction of disease among the elderly to control socio-psychological factors such as stress and stressful life event, and that a social network helps maintain a healthy lifestyle.

[Effects of crowding on immune functions in mice]

The effects of several types of crowding on immune functions were studied in mice. This study consisted of two experiments. Experiment one: Male BALB/c mice were initially housed in groups of four mice per cage. After fourteen days of acclimation, the mice were randomly divided into three groups, Control (four mice per cage, control group), Crowd-I (four mice per small space) and Crowd-II (sixteen mice per cage). These conditions were maintained for seven days. The results of experiment one were as follows: (1) The percentage of lymphocytes in the blood of Crowd-II was significantly lower than that of Control (p < 0.05). (2) The percentage of neutrophils and the absolute number of neutrophils in blood of Crowd-II were significantly higher than in Control (p < 0.05). (3) Superoxide production activity (NBT reduction activity) of blood neutrophils in Crowd-II tended to be depressed, and phagocytic activity of neutrophils was significantly depressed in Crowd-II as compared with Control (p < 0.01). These results suggest that the complexity of interrelationships among mice caused by an increase in the number of animals per cage is a very important stress factor. Experiment two: Male BALB/c mice were initially housed in groups of five mice per cage. After fourteen days of acclimation, the mice were divided into three groups, Control (five mice per cage, control group), Crowd-(1) (five mice per cmall space) and Crowd-(2) (twenty mice per cage). In Control and Crowd-(1), the same mice were used as in the acclimation period. These conditions were maintained for seven days. In this period, on the second day, all the mice were injected intraperitoneally with sheep red blood cells (SRBC). The results of experiment two were as follows: (1) The specific humoral immune response to SRBC was investigated in terms of the number of PFC in the spleens and hemagglutination in sera, but significant differences were not found among the groups. (2) Plasma IgG levels in the Crowd-(1) were significantly higher than those in Control (p < 0.05). (3) Both superoxide production activity and phagocytic activity of neutrophils were significantly depressed in Crowd-(2) as compared with Control (p < 0.01, respectively), whereas each neutrophil function of Crowd-(1) tended to be enhanced as compared with Control.