131 research outputs found
Theoretical Analysis of Susceptibility of Ferritic Stainless Steel to Intergranular Corrosion Caused by Welding(Materials, Metallurgy & Weldability)
OCEANOGRAPHICAL CONDITIONS OBSERVED AT DEFINITE STATION OFF ASAMUSHI DURING OCTOBER, 1985-NOVEMBER, 1987
Concentration-dependent Dual Effects of Hydrogen Peroxide on Insulin Signal Transduction in H4IIEC Hepatocytes
BACKGROUND: Oxidative stress induced by the accumulation of reactive oxygen species (ROS) has a causal role in the development of insulin resistance, whereas ROS themselves function as intracellular second messengers that promote insulin signal transduction. ROS can act both positively and negatively on insulin signaling, but the molecular mechanisms controlling these dual actions of ROS are not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we directly treated H4IIEC hepatocytes with hydrogen peroxide (H2O2), a representative membrane-permeable oxidant and the most abundant ROS in cells, to identify the key factors determining whether ROS impair or enhance intracellular insulin signaling. Treatment with high concentrations of H2O2 (25-50 µM) for 3 h reduced insulin-stimulated Akt phosphorylation, and increased the phosphorylation of both JNK and its substrate c-Jun. In contrast, lower concentrations of H2O2 (5-10 µM) enhanced insulin-stimulated phosphorylation of Akt. Moreover, lower concentrations suppressed PTP1B activity, suggesting that JNK and phosphatases such as PTP1B may play roles in determining the thresholds for the diametrical effects of H2O2 on cellular insulin signaling. Pretreatment with antioxidant N-acetyl-L-cysteine (10 mM) canceled the signal-promoting action of low H2O2 (5 µM), and it canceled out further impairment of insulin of insulin signaling induced by high H₂O₂ (25 µM). CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that depending on its concentration, H2O2 can have the positive or negative effect on insulin signal transduction in H4IIEC hepatocytes, suggesting that the concentration of intracellular ROS may be a major factor in determining whether ROS impair or enhance insulin signaling
OCEANOGRAPHICAL CONDITIONS OBSERVED AT DEFINITE STATION OFF ASAMUSHI DURING MAY, 1984-AUGUST, 1985
OCEANOGRAPHICAL CONDITIONS OBSERVED AT DEFINITE STATION OFF ASAMUSHI DURING DECEMBER, 1987-DECEMBER, 1988
Children with unilateral aural atresia
The effects of FM system fitted into the normal hearing ear (NHE) or a cartilage conduction hearing aid (CCHA) fitted into the affected ear (AE) on the speech recognition ability in noise were examined in children with unilateral congenital aural atresia (UCAA). In children with bilateral normal hearing (BNH), speech recognition score (SRS) was significantly decreased in the noisy environment of -5 dB signal-to-noise ratio (SNR), compared with those in quiet. In children with UCAA, SRS was significantly decreased in noisy environments of 0 and -5 dB SNR, compared with those in quiet. In noisy environments of 0 and -5 dB SNR, SRS in children with UCAA was significantly decreased, compared those in children with BNH. In the noisy environment of -5 dB SNR, SRS in UCAA children aided by FM system fitted into NHE was significantly better than those in unaided children in the same group. In the noisy environment of 0 dB SNR, SRS in UCAA children aided by CCHA into AE tended to be higher than those in unaided children in the same group. FM system and CCHA can be recommended as an audiological management for the improvement of speech recognition in children with UCHL in classrooms
Flow Characteristics of Gas and Liquid through a Cell Porous Disk
This paper describes applications of cell porous materials. The authors investigated the flow characteristics of a gas-liquid mixture in a rotating porous disk. For theoretical analyses, the gas is assumed to permeate the entire disk surface. A simple one-dimensional model illustrates that the residence time of the liquid is much greater than that of the gas. Violent interaction in small cells is likely to enhance the chemical reaction between gas and liquid. Cell porous materials might also be exploited for chemical reaction purposes
cytokine profile of PFAPA
Objective : An attempt was made to identify characteristic cytokine profiles to distinguish periodic fever with aphthous stomatitis, pharyngitis and cervical adenitis syndrome (PFAPAS) from recurrent tonsillitis, of which clinical manifestations are similar to those of PFAPAS in children. Methods : Serum concentrations of IL-6, IL-4 and IFN-γ were measured during febrile episodes in pediatric patients. Results : The levels of IL-6 during febrile episodes were markedly increased above the upper limit of normal ranges in patients with both PFAPAS and recurrent tonsillitis, but there were no significant differences between groups. The levels of IL-4 during febrile episodes in PFAPAS patients were significantly lower than those in recurrent tonsillitis patients. The levels of IFN-γ during febrile episodes in PFAPAS patients were significantly higher than those in recurrent tonsillitis patients. Conclusion : In pediatric patients with PFAPAS, despite an increase of IL-6, IL-4 was suppressed with a marked increase of IFN-γ during febrile episodes. On the contrary, in febrile pediatric patients with recurrent tonsillitis, both IL-6 and IL-4, but not IFN-γ were increased. The characteristic cytokine profiles of IL-6, IL-4 and IFN-γ can be used for differential diagnosis of PFAPAS from recurrent tonsillitis in children in clinical ear, nose and throat (ENT) settings
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