4,719 research outputs found

    Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy

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    AIM: To study the contribution of tonicity response element binding protein (TonEBP) in retinal ganglion cell (RGC) death of diabetic retinopathy (DR). METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin (STZ). Control mice received vehicle (phosphate -buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of TonEBP and aldose reductase (AR) were examined. RESULTS: The TonEBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase (TdT) -mediated dUTP nick end labeling (TUNEL) -positive signals co -localized with TonEBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls. CONCLUSION: The present data show that AR and TonEBP are upregulated in the DR and TonEBP may contribute to apoptosis of RGC in the DR.close2

    The dark side of mobile work during non-work hours: moderated mediation model of presenteeism through conservation of resources lens

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    Owing to the development of Information and Communication Technology (ICT) and the inevitability of telecommuting in the COVID-19 environment, the boundary between working and non-working hours has become blurred. mWork, that is, ICT-based off-hour work, which has increased through the pandemic, affects employees’ work attitudes, such as presenteeism. Hence, we designed a study to investigate the antecedents and mechanisms of employee presenteeism from the perspective of the conservation of resources theory. We supported our hypothesis using a sample of 325 Korean office workers obtained through three rounds of time-delay surveys. The results show that presenteeism is higher among employees with high mWork. In addition, employees’ mWork increases sleep deprivation and presenteeism, and the exchange ideology of employees reinforces the positive effect of sleep deprivation on presenteeism. Additionally, the higher the level of exchange ideology, the stronger the mediating effect of mWork on presenteeism through sleep deprivation. This study verified the conservation of resources theory by identifying the mechanism by which mWork affects an employee’s life, which in turn affects their work, and provides practical implications for managing productivity loss due to presenteeism

    Histidine 454 plays an important role in polymerization of human glutamate dehydrogenase

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    AbstractAlthough previous chemical modification studies have suggested several residues to be involved in the maintenance of the quaternary structure of glutamate dehydrogenase (GDH), there are conflicting views for the polymerization process and no clear evidence has been reported yet. In the present study, cassette mutagenesis at seven putative positions (Lys333, Lys337, Lys344, Lys346, Ser445, Gly446, and His454) was performed using a synthetic human GDH gene to examine the polymerization process. Of the mutations at the seven different sites, only the mutagenesis at His454 results in depolymerization of the hexameric GDH into active trimers as determined by HPLC gel filtration analysis and native gradient polyacrylamide gel electrophoresis. The mutagenesis at His454 has no effects on expression or stability of the protein. The KM values for NADH and 2-oxoglutarate were 1.5-fold and 2.5-fold greater, respectively, for the mutant GDH than for wild-type GDH, indicating that substitution at position 454 had appreciable effects on the affinity of the enzyme for both NADH and 2-oxoglutarate. The Vmax values were similar for wild-type and mutant GDH. The kcat/KM value of the mutant GDH was reduced up to 2.8-fold. The decreased efficiency of the mutant, therefore, results from the increase in KM values for NADH and 2-oxoglutarate. The results with cassette mutagenesis and HPLC gel filtration analysis suggest that His454 is involved in the polymerization process of human GDH

    Remission of diffuse ulcerative duodenitis in a patient with ulcerative colitis after infliximab therapy: a case study and review of the literature

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    Although ulcerative colitis (UC) is confined to colonic and rectal mucosa in a continuous fashion, recent studies have also demonstrated the involvement of upper gastrointestinal tract as diagnostic endoscopy becomes more available and technically advanced. The pathogenesis of UC is not well established yet. It might be associated with an inappropriate response of host mucosal immune system to gut microflora. Although continuous and symmetric distribution of mucosal inflammation from rectum to colon is a typical pattern of UC, clinical feature and course of atypically distributed lesions in UC might also help us understand the pathogenesis of UC. Herein, we report a case of duodenal involvement of UC which successfully remitted after infliximab therapy. Endoscopic and pathologic findings before and after administration of anti-tumor necrosis factor suggest that the pathogenesis of upper gastrointestinal involvement of UC may be similar to that of colon involvement

    Optical biochemical sensor based on half-circled microdisk laser diode

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    In this study, a half-circled cavity based microdisk laser diode is proposed and demonstrated experimentally for an integrated photonic biochemical sensor. Conventional microdisk sensors have limitations in optical coupling and reproducibility. In order to overcome these drawbacks, we design a novel half-circled micro disk laser (HC-MDL) which is easy to manufacture and has optical output directionality. The Q-factor of the fabricated HC-MDL was measured as 7.72 × 106 using the self-heterodyne method and the side mode suppression ratio was measured as 23 dB. Moreover, gas sensing experiments were performed using the HC-MDL sensor. A wavelength shift response of 14.21 pm was obtained for 100 ppb dimethyl methylphosphonate (DMMP) gas and that of 14.70 pm was obtained for 1 ppm ethanol gas. These results indicate the possibility of highly sensitive gas detection at ppb levels using HC-MDL. This attractive feature of the HC-MDL sensor is believed to be very useful for a wide variety of optical biochemical sensor applications. © 2017 Optical Society of America.1

    Assessing brain function in self-identified individuals suspected of being on the autism spectrum using fMRI: a case study.

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    Autism Spectrum Disorder(ASD)is a widely recognized neurodevelopmental disorder that has gained recognition among both the general public and professional groups such as physicians and researchers. However, with this increasing awareness, some individuals have begun to suspect that they may be autistic based on their own knowledge and understanding. This suspicion can lead to unnecessary anxiety and other difficulties in one’s life. A simple objective method of assessment prior to formal diagnosis would be beneficial for those who suspect they may have autism. Thus, we posited that measuring brain function would be a viable candidate for this. As a preliminary study, we evaluated the brain function of an individual who suspected he may be autistic using our developed estimator of human characteristics. Additionally, we also compared this individual to a cohort of typical subjects based on functional networks consisting of previously identified ASD-related brain regions. The individual was determined to be typical by our estimator, however, the comparison with the normal group indicated deviation in brain regions such as the precuneus and ventral prefrontal cortex from the normal group. These results suggest that the individual is considered normal, but some brain functions may deviate from the normal group. Brain function measuring may be a good assessment method for those who suspect they may have autism.journal articl

    Kaempferol inhibits IL‑1β‑induced proliferation of rheumatoid arthritis synovial fibroblasts and the production of COX‑2, PGE2 and MMPs

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    Inflammatory cytokines, matrix metalloproteinases (MMPs) and cyclooxygenase (COX)‑2 released from rheumatoid arthritis synovial fibroblasts (RASFs) are involved in the destruction of both articular bone and cartilage. Kaempferol has been reported to act as an antioxidant and anti‑inflammatory agent by inhibiting nitric oxide synthase and COX enzymes. The aim of the present study was to determine the effects of kaempferol on the interleukin‑1β (IL‑1β)‑induced proliferation of RASFs and the production of MMPs, COX and prostaglandin E2 (PGE2) by RASFs. The proliferation of the RASFs stimulated with IL‑1β and treated with/without kaempferol was evaluated by CCK‑8 assay. The expression of MMPs, TIMP metallopeptidase inhibitor‑1 (TIMP‑1), COXs, PGE2 and that of intracellular MAPK signaling molecules, including p‑ERK, p‑p38, p‑JNK and nuclear factor‑κB (NF‑κB) was examined by immunoblotting or semi‑quantitative reverse transcription‑polymerase chain reaction (RT‑PCR) and ELISA under the conditions described above. Kaempferol inhibited the proliferation of both unstimulated and IL‑1β‑stimulated RASFs, as well as the mRNA and protein expression of MMP‑1, MMP-3, COX‑2 and PGE2 induced by IL‑1β. Kaempferol also inhibited the phosphorylation of ERK‑1/2, p38 and JNK, as well as the activation of NF‑κB induced by IL‑1β. These results indicate that kaempferol inhibits synovial fibroblast proliferation, as well as the production of and MMPs, COX‑2 and PGE2, which is involved in articular inflammation and destruction in rheumatoid arthritis (RA). Our data suggest that kaempferol may be a novel therapeutic agent for the treatment of RA

    Expression of Heat Shock Proteins and Cytokines in Response to Ethanol Induced Damage in the Small Intestine of ICR Mice

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    Background/AimsEthanol administration causes intestinal epithelial cell damage by increasing intestinal permeability and the translocation of endotoxins from intestinal bacterial flora. Heat shock proteins (HSPs) are associated with recovery and protection from cell damage. The aim of the current study was to investigate differences in the expression of HSPs in the small intestine and the biochemical changes attributable to ethanol-induced intestinal damage.MethodsEthanol (20%) was injected intraperitoneally (2.75 g/kg, 5.5 g/kg, 8.25 g/kg) in ICR mice and the same volume of saline was administered to controls. After 1 hour, the proximal, middle, and distal segments were taken from the small intestine and the degree of damage was analyzed. In each segment, the expression of HSPs was analyzed by western blotting. The expression of inflammatory mediators including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), and antioxidant enzyme such as glutathione-S-transferase were compared using real-time polymerase chain reaction assays.ResultsIn the control group, HSP70 increased in all segments of small intestine. Additionally, increases in the expression of HSP40 and HSP90 in the distal regions and an increase in HSP32 in the middle regions were observed. After ethanol treatment, greater histological damage was observed in the distal small intestine and significant decreases in HSPs were observed generally. Increased expression of IL-1β, TNF-α, and COX-2 was observed in small intestinal tissues exposed to ethanol-induced damage. However, there was no significant difference in the expression of an antioxidant enzyme.ConclusionsSignificant differences in the expression of HSPs in different intestinal regions were observed. These differences may have been attributable to the distribution of intestinal bacteria
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