Chemokines Up-Regulated in Epithelial Cells Control Senescence-Associated T Cell Accumulation in Salivary Glands of Aged and Sjögren’s Syndrome Model Mice

Immunosenescence is characterized by age-associated changes in immunological functions. Although age- and autoimmune-related sialadenitis cause dry mouth (xerostomia), the roles of immunosenescence and cellular senescence in the pathogenesis of sialadenitis remain unknown. We demonstrated that acquired immune cells rather than innate immune cells infiltrated the salivary glands (SG) of aged mice. An analysis of isolated epithelial cells from SG revealed that the expression levels of the chemokine CXCL13 were elevated in aged mice. Senescence-associated T cells (SA-Ts), which secrete large amounts of atypical pro-inflammatory cytokines, are involved in the pathogenesis of metabolic disorders and autoimmune diseases. The present results showed that SA-Ts and B cells, which express the CXCL13 receptor CXCR5, accumulated in the SG of aged mice, particularly females. CD4⁺ T cells derived from aged mice exhibited stronger in vitro migratory activity toward CXCL13 than those from young mice. In a mouse model of Sjögren’s syndrome (SS), SA-Ts also accumulated in SG, presumably via CXCL12-CXCR4 signaling. Collectively, the present results indicate that SA-Ts accumulate in SG, contribute to the pathogenesis of age- and SS-related sialadenitis by up-regulating chemokines in epithelial cells, and have potential as therapeutic targets for the treatment of xerostomia caused by these types of sialadenitis.     

Combustion of Aluminum Particles near the Burning Surface in AP/AN Composite Propellants

Aluminum (Al) particles are commonly used in ammonium perchlorate (AP) composite propellants of solid rockets for increasing performance. When propellants including Al particles burn, Al particles easily agglomerate on the burning surface of the propellant. The diameters of agglomerated Al particles are greater than those of mixed particles. The combustion efficiency of the propellant decreases with increasing burning time of the agglomerated Al particles. Therefore, it is important to observe how the agglomerated Al particles burn on the burning surface of AP composite propellant. A lot of researchers have studied Al agglomerate characteristics. Previous studies clarified the relation between the agglomerated Al particle diameter and luminous flame diameter around Al particles near the burning surface. The shapes of luminous flames around agglomerated Al particles are spherical or elliptical. This study evaluates the shapes of the luminous flame around agglomerated Al particles at a constant diameter or a different diameter. When the proportion of the luminous flame diameter (D_f) to the diameter of agglomerated Al particles (D₀) is 1.54–1.71 at a constant D₀, the luminous flames are almost perfectly spherical. Otherwise, the luminous flames are elliptical at a constant D₀. Furthermore, when D_f/D₀ is close to the mean value, the luminous flame is more spherical than elliptical at different D₀. The evaporation rate and the burning rate of Al vapor are inversely proportional to D₀. The oxidation gas temperatures were changed and the activation energy of Al vapor was obtained as 39.2 kJ mol⁻¹.     

Host-dependent activation of IS1203v excision in Shiga toxin-producing Escherichia coli

IS1203v is an insertion sequence (IS) which is identical to the most abundant IS elements in the genome of Escherichia coli O157:H7. However, there is no sequence homologous to IS1203v in the genome of E. coli K-12. We constructed a system to analyze the excision frequency of IS1203v, and demonstrated that the frequency in E. coli O157:H7 was approximately 10(5) times higher than that in E. coli K-12. We also investigated the excision frequencies of IS1203v in various E. coli isolates, and showed that the excision frequencies of IS1203v-possessing strains were approximately 10(3) times higher than those of IS1203v-nonpossessing strains. The results suggest that the IS1203v-possessing strains use a common system to enhance IS1203v excision.     

From "Dial-a-Porn" to "Cyberporn": Approaches to and Limitations of Regulation in the United States and Japan

This article is a general overview of the present state of the law with respect to new online communication services, comparing the views of pioneer users that there is something new and distinctly different about communication via computer and modem from other forms of communication with those of lawyers and law enforcement officials who are attempting to apply existing statutes and case law to abusive behavior and controversies that arise online.
The differences between the two approaches will be compared with the successes and failures concluding with some suggestions of what approaches might be taken in the future.     

Synthesis, characterization and aggregation behavior of block copolymers containing a polyisocyanopeptide segment

Following up on previous preliminary communications the synthesis of a series of block copolymers by applying amine end-capped polymers as initiators for the nickel(II) catalyzed polymerization of isocyanides is reported. Using a polystyrene derivative as the initiator, superamphiphiles containing a hydrophobic polystyrene tail and a charged helical polyisocyanide headgroup were prepared. Under proper conditions these superamphiphiles self-assembled in water to give a variety of aggregate morphologies, among which are superhelical architectures. Initiators derived from carbosilane dendritic wedges gave block copolymers with a unique combination of structural elements, i.e. a flexible dendritic block and a rigid polyisocyanide block. Block copolymers derived from the 3rd generation dendrimers form well-defined micellar aggregates in the presence of Ag⁺ ions. These aggregates have been used to construct nanoarrays of metallic silver.     

Evaluation of a nitric acid-based partial-digestion method for selective determination of inorganic arsenic in rice

Arsenic (As) uptake in human occurs via the food chain mainly. The Joint FAO/WHO Expert Committee on Food Additives has established the provisional tolerable weekly intake level for As as an inorganic As (iAs) value, because iAs in food is much more toxic than organic As. In this study, we studied an acid based partial-digestion method for the complete extraction of arsenicals from rice. HPLC/ICP-MS was used to determine the concentration of iAs selectively. The conditions adopted to extract arsenicals from a 0.5 g of finely ground rice sample were addition of 2 mL of 0.15 mol/L nitric acid and heating at 80 degrees C for 2 hr. The LOD and LOQ for iAs were 0.0024 and 0.0079 mg/kg dry weight, respectively. Recovery studies showed good accuracy. When the method was applied to ten short-grain brown rice samples, the iAs concentrations were 0.108-0.227 mg/kg dry weight and the total As concentrations were 0.118-0.260 mg/kg dry weight. Although dimethylarsinic acid was also detected in most samples, the percentage of iAs content in total As content was 62.2-96.3%. Thus, iAs was the principal As species in the short-grain brown rice samples tested.     

Dietary intake of dioxins in Japan in 2016 with time trends since 1998

Total diet samples collected from seven regions throughout Japan in 2016 were analysed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls (DL-PCBs), known collectively as dioxins. This led to estimates of the latest dietary intake of these contaminants for the general Japanese population (≥1 year old). The average daily intake of dioxins for a person weighing 50 kg, calculated at non-detected congener concentrations assumed to be equal to zero, was estimated to be 0.54 pg TEQ (toxic equivalents) kg^?1 body weight (bw) day^?1. This value is well below the tolerable daily intake of 4 pg TEQ kg^?1 bw day^?1 for dioxins in Japan. The average intake was highest from fish and shellfish, followed by meat and eggs. The TEQ contribution of the fish and shellfish group to the total dietary TEQs was significant (89%). The DL-PCBs accounted for about 67% of the dioxin intake. The latest dioxin intake level was compared with previous estimates from total diet study results obtained annually since 1998 to determine the time trends in the dietary intake of dioxins in Japan. Overall, the average dioxin intake appeared to be decreasing gradually during the period of study. The previous average intakes of dioxins ranged from 0.58 to 1.9 pg TEQ kg^?1 bw day^?1. The latest average intake was the lowest since 1998 and was about one-third of the average intake in 1998. This decreasing trend in the dietary intake of dioxins was mainly influenced by the decreased dioxin intakes from two food groups, fish and shellfish, and meat and eggs.     

Accumulation of paralytic shellfish poison (PSP) and biotransformation of its components in oysters, Crassostrea gigas, fed with the toxic dinoflagellate Alexandrium tamarense

As a part of our studies on the mechanism of uptake of paralytic shellfish poison (PSP) and the kinetics of its accumulation in bivalves, oysters Crassostrea gigas were experimentally contaminated with PSP by being fed with the toxic dinoflagellate Alexandrium tamarense for 2, 4, 6, 8 and 10 days. Temporal variations in the PSP contents and their profiles in oysters during the feeding experiment were monitored by high-performance liquid chromatography (HPLC) and the toxin profile of the oysters was compared with that of A. tamarense. Toxins excreted from the infested oysters into the seawater for 2 and 10 days were recovered and analyzed by HPLC. PSP toxicity rapidly appeared in the tissues of oysters and their toxicity levels reached 0.6 (0.3), 2.2 (1.1), 1.0 (0.5), 3.4 (1.6) and 1.1 (0.5) MU/g (nmol/g) shucked meat at 2, 4, 6, 8 and 10 days, respectively. The accumulation rates of toxin, calculated from the total amount (nmol) of toxins expressed by the total cell number fed during the exposure period and the toxicity of the oysters, were 14.1, 18.7, 5.1, 14.9 and 3.2% for 2, 4, 6, 8 and 10 days. During feeding experiments, the toxin profile of oysters changed substantially, showing marked differences from the proportions found in the toxigenic dinoflagellate used as food. The toxin components in this strain existed almost exclusively as beta-epimers, which accounted for 66.3 mol% of the total. This contrasts with the case of the oysters, where the beta-epimers represented 24.8, 29.8, 25.1, 27.3 and 25.2 mol% of the total at 2, 4, 6, 8 and 10 days, respectively. The amount of gonyautoxin-1 (GTX1) accumulated in oysters increased linearly and slowly for 8 days and the maximum content of GTX1 reached 51.3 mol%. The composition of GTX group compounds recovered from the seawater in which the oysters had been reared was a little different from that within the oyster tissues.