460 research outputs found

    Physical and gas transport properties of asymmetric hyperbranched polyimide-silica hybrid membranes

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    Physical and gas transport properties of the asymmetric hyperbranched polyimide (HBPI) -silica hybrid membranes prepared with a dianhydride, 4,4’-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), and an asymmetric triamine, 2,4,4’-(triaminodiphenyl)ether (TADE), were investigated and compared with those of the symmetric HBPI-silica hybrid membranes prepared with a symmetric triamine, 1,3,5-tris(4-aminophenoxy)benzene (TAPOB). The HBPI-silica hybrid membranes were prepared via sol-gel reaction using hyperbranched polyamic acid of which end groups were modified with silane coupling agents, water and tetramethoxysilane. The thermal mechanical and dynamic mechanical analysis measurements confirmed that the rigidity of asymmetric HBPI was higher than that of symmetric HBPI because of the rigid and asymmetric structure of TADE monomer. In addition, the degree of branching of asymmetric HBPI is lower than that of symmetric HBPI because of the different reactivity of the three amino groups included in TADE. The rigidity and linearity of HBPIs had an effect on the progression of sol-gel reaction, consequently the gas transport properties. The increasing of the gas permeability coefficient of the asymmetric dianhydride(DA)-HBPI-silica hybrid membranes with increasing silica content was smaller than those of symmetric DA- and amine(AM)-HBPI-silica hybrid membranes. In addition, the gas permeability coefficient of the asymmetric AM-HBPI-silica hybrid membranes decreased with increasing silica content. This was due to the fact that the dispersibility of silica in the asymmetric HBPI-silica hybrids, of which polymer chain was more rigid and linear than those of symmetric HBPI-silica hybrid, was not as fine as in the symmetric HBPI-silica hybrids, and that the long and tortuous diffusion path was newly formed by hybridization with silica

    A right colonic volvulus requiring extensive colectomy in an infant with trisomy 13

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    AbstractColonic volvulus is a rare surgical emergency condition in children. Only approximately 40 children with cecal volvulus have been reported in English literature in the past 50 years. Among these, a right colonic volvulus involving the long segment from the ileal end to the transverse colon, as in our case, is limited to a few reports. Neurodevelopmental delay and a history of chronic constipation have been reported as common associated disorders. This is the first report about a case of right colonic volvulus in an infant with trisomy 13 who required extensive colectomy during an emergency laparotomy

    DFL2, a New Member of the Arabidopsis GH3 Gene Family, is Involved in Red Light-Specific Hypocotyl Elongation

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    A new GH3-related gene, designated DFL2, causes a short hypocotyl phenotype when overexpressed under red and blue light and a long hypocotyl when antisensed under red light conditions. Higher expression of this gene was observed in continuous white, blue and far-red light but the expression level was low in red light and darkness. DFL2 gene expression was induced transiently with red light pulse treatment. DFL2 transgenic plants exhibited a normal root phenotype including primary root elongation and lateral root formation, although primary root elongation was inhibited in antisense transgenic plants only under red light. The adult phenotypes of sense and antisense transgenic plants were not different from that of wild type. DFL2 promoter activity was observed in the hypocotyl. Our results suggest that DFL2 is located downstream of red light signal transduction and determines the degree of hypocotyl elongation.publishersversionPeer reviewe

    日本人血液透析患者におけるProtein-Energy Wasting(PEW)と高リン血症が予後に及ぼす影響 : 5年間の観察研究

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    Background & aims: In dialysis patients, malnutrition is a poor prognostic factor. In patients with chronic kidney disease (CKD), malnutrition is qualitatively different from general malnutrition, which is defined as “Protein-Energy Wasting (PEW).” Dietary therapy for the enhancement of PEW requires the aggressive intake of protein. Conversely, as protein intake and phosphorus intake correlate positively, increasing the protein intake increases the phosphorus intake, which is a poor prognostic factor in dialysis patients. One of the treatments for hyperphosphatemia in dialysis patients is the intake restriction of phosphorus by dietary counseling. However, protein uptake to maintain and augment the nutritional status and the protein intake restriction to correct hyperphosphatemia are contradictory treatments. Hence, this study aims to investigate the effects of PEW and hyperphosphatemia on the prognosis in hemodialysis patients. Methods: We enrolled 60 outpatients who underwent maintenance hemodialysis for 6 months (May–November 2012) at Iga City General Hospital (Mie, Japan). In November 2012, we assessed the presence or absence of PEW and hyperphosphatemia in patients and evaluated the survival rate over the next 5 years. Results: Overall, 10 patients (17%) were diagnosed as PEW. While 17 patients (28%) exhibited average phosphorus level >6.0 mg/dL (hyperphosphatemia). The 5-year survival rate was 30% in the PEW group, 66% in the non-PEW group, 57% in the hyperphosphatemia group, and 61% in the non-hyperphosphatemia group. A statistically significant difference existed between the PEW and non-PEW groups (P = 0.021). However, we observed no significant difference between the hyperphosphatemia and non-hyperphosphatemia groups. Conclusions: This study suggests that PEW affects the prognosis more than hyperphosphatemia in maintenance hemodialysis patients. The normalization of the serum phosphorus level by the protein intake restriction could prevent secondary hyperparathyroidism and vascular calcification. Conversely, restricting the protein intake poses a risk of malnutrition. In fact, early death occurred in patients with PEW in this study. Perhaps, patients with PEW should prioritize improving their nutritional status rather than controlling the serum phosphorus level

    Rectus sheath hematoma in an elderly woman under anti-coagulant therapy

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    Rectal sheath hematoma has been a well-known clinical entity from the ruin of the ancient Greece. It is relatively rare, however, to encounter this abdominal disorder in the clinical setting. Furthermore, the initial symptoms of rectus sheath hematoma are often similar to those of acute abdominal disorders. Therefore, the majority of the patients with rectus sheath hematoma have been treated with operative procedures because of the difficulty of a differential diagnosis from other abdominal disorders. We recently treated a 74-year female diagnosed with rectus sheath hematoma with the anticoagulants after an episode of cerebral infarction. From the findings of the physical examinations, ultrasound, and computed tomography, we could correctly diagnose, and could treat her with completely conservative methods without any invasive techniques. It is stressed that it is important to recognize this entity of rectus sheath hematoma when patients are examineed, after complaining of acute abdominal pain and with evidence abdominal masses in the clinical setting

    Discovery of a novel restriction endonuclease by genome comparison and application of a wheat-germ-based cell-free translation assay: PabI (5′-GTA/C) from the hyperthermophilic archaeon Pyrococcus abyssi

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    To search for restriction endonucleases, we used a novel plant-based cell-free translation procedure that bypasses the toxicity of these enzymes. To identify candidate genes, the related genomes of the hyperthermophilic archaea Pyrococcus abyssi and Pyrococcus horikoshii were compared. In line with the selfish mobile gene hypothesis for restriction–modification systems, apparent genome rearrangement around putative restriction genes served as a selecting criterion. Several candidate restriction genes were identified and then amplified in such a way that they were removed from their own translation signal. During their cloning into a plasmid, the genes became connected with a plant translation signal. After in vitro transcription by T7 RNA polymerase, the mRNAs were separated from the template DNA and translated in a wheat-germ-based cell-free protein synthesis system. The resulting solution could be directly assayed for restriction activity. We identified two deoxyribonucleases. The novel enzyme was denoted as PabI, purified and found to recognize 5′-GTAC and leave a 3′-TA overhang (5′-GTA/C), a novel restriction enzyme-generated terminus. PabI is active up to 90°C and optimally active at a pH of around 6 and in NaCl concentrations ranging from 100 to 200 mM. We predict that it has a novel 3D structure

    日本维持性血液透析患者蛋白质能量消耗的患病率和诊断标准评估

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    Background and Objectives: The International Society of Renal Nutrition and Metabolism (ISRNM) has recently recommended the use of the term “protein-energy wasting” (PEW). PEW is a state of malnutrition with decreased body stores of protein and energy fuel in hemodialysis patients and is known as a risk factor for morbidity and mortality. We examined the prevalence of PEW and the characteristics of PEW patients in a hemodialysis center in Japan. Methods and Study Design: Fifty-nine outpatients undergoing maintenance hemodialysis at Iga City General Hospital were evaluated. We observed their biochemical data, body composition, dietary intake, and the number of steps prospectively. PEW was defined according to ISRNM criteria. Results: Nine patients (15% of total) were diagnosed as having PEW. Among indicators of PEW criteria, the relevance ratios of “reduced muscle mass” and “unintentional low dietary energy intake” were significantly higher in PEW than in non-PEW. The number of steps was lower, and serum levels of glucose and C-reactive protein were higher in PEW. Conclusion: About 15% of Japanese hemodialysis patients are estimated to have PEW. Our results suggested that major contributing factors to PEW were reduced muscle mass, unintentional low dietary energy intake, lower amount of exercise, insulin resistance, and chronic inflammation.背景与目的:国际肾营养与代谢协会(ISRNM)最近推荐使用术语“蛋白质能量消耗(PEW)”。PEW 是血液透析患者体内蛋白质和能量储存减少的一种营养不良状态,并且被认为是患病率和死亡率的危险因素。我们在日本的一个血液透析中心研究了PEW 的患病率和PEW 患者的特征。方法与研究设计:我们评估了58 名在伊贺市综合医院做维持性血液透析的门诊患者,并观察了他们的生化数据、体成分、膳食摄入量和行走的步数。根据ISRNM 标准诊断PEW。结果:9 名(占总数的15%)患者被诊断为PEW。在PEW 诊断标准指标中,PEW 患者“肌肉量减少”和“无意识的低膳食能量摄入”的比例高于非PEW 患者。PEW 患者中行走的步数较低,而血清葡萄糖和C-反应蛋白水平较高。结论:约有15%的日本血液透析患者患有PEW。我们的研究结果表明:引起PEW 的主要因素是肌肉量减少、无意识的低膳食能量摄入、运动量低、胰岛素抵抗和慢性炎症

    Restriction-modification system with methyl-inhibited base excision and abasic-site cleavage activities

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    The restriction-modification systems use epigenetic modification to distinguish between self and nonself DNA. A modification enzyme transfers a methyl group to a base in a specific DNA sequence while its cognate restriction enzyme introduces breaks in DNA lacking this methyl group. So far, all the restriction enzymes hydrolyze phosphodiester bonds linking the monomer units of DNA. We recently reported that a restriction enzyme (R.PabI) of the PabI superfamily with half-pipe fold has DNA glycosylase activity that excises an adenine base in the recognition sequence (5′-GTAC). We now found a second activity in this enzyme: at the resulting apurinic/apyrimidinic (AP) (abasic) site (5′-GT#C, # = AP), its AP lyase activity generates an atypical strand break. Although the lyase activity is weak and lacks sequence specificity, its covalent DNA–R.PabI reaction intermediates can be trapped by NaBH[subscript 4] reduction. The base excision is not coupled with the strand breakage and yet causes restriction because the restriction enzyme action can impair transformation ability of unmethylated DNA even in the absence of strand breaks in vitro. The base excision of R.PabI is inhibited by methylation of the target adenine base. These findings expand our understanding of genetic and epigenetic processes linking those in prokaryotes and eukaryotes

    Specialized Pro-Resolving Mediators Do Not Inhibit the Synthesis of Inflammatory Mediators Induced by Tumor Necrosis Factor-α in Synovial Fibroblasts

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    Background : Tumor necrosis factor (TNF)-α, a proinflammatory cytokine, is involved in the pathogenesis of rheumatoid arthritis (RA). The omega-3 unsaturated fatty acid-derived metabolites resolvin (Rv) D1, RvE1, and maresin-1 (MaR1) have been reported as anti-inflammatory lipid mediators and are known as specialized pro-resolving mediators (SPMs). In this study, we aimed to investigate the anti-inflammatory effects of SPMs on TNF-α-induced responses in synovial fibroblasts. Methods: We investigated the effects of SPMs on gene expression and/or production of cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), interleukin (IL)-6, and matrix metalloproteinase (MMP)-3, which are involved in TNF-α-induced synovitis in RA or OA synovial fibroblasts, by quantitative real-time PCR. We also investigated the effects of SPMs on the mitogen-activated protein kinase (MAPK) signaling pathway by western blotting. Anti-inflammatory effects of SPMs were evaluated by applying SPMs to cultured synovial fibroblasts, followed by TNF-α stimulation. Results: The induction of COX-2, mPGES-1, IL-6, and MMP-3 by TNF-α in synovial fibroblasts was not suppressed by omega 3-derived SPMs regardless of their origin such as RA or OA. SPMs had no effect on lipid mediator receptor gene expression induce by TNF-α and did not inhibit the TNF-α-activated MAPK signaling pathway. The production of COX-2 and IL-6 protein was significantly decreased by p38 inhibitor. Conclusion: Despite reports on the anti-inflammatory effect of omega 3-derived SPMs, its anti-inflammatory effect on TNF-α-induced responses was not observed in synovial fibroblasts. The reason may be that SPMs have no suppressive effect on p38 activation, which plays an important role in the production of inflammatory cytokines in synovial fibroblasts
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