138 research outputs found

    Countercurrent Air-Water Flow in a Scale-Down Model of a Pressurizer Surge Line

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    Steam generated in a reactor core and water condensed in a pressurizer form a countercurrent flow in a surge line between a hot leg and the pressurizer during reflux cooling. Characteristics of countercurrent flow limitation (CCFL) in a 1/10-scale model of the surge line were measured using air and water at atmospheric pressure and room temperature. The experimental results show that CCFL takes place at three different locations, that is, at the upper junction, in the surge line, and at the lower junction, and its characteristics are governed by the most dominating flow limitation among the three. Effects of inclination angle and elbows of the surge line on CCFL characteristics were also investigated experimentally. The effects of inclination angle on CCFL depend on the flow direction, that is, the effect is large for the nearly horizontal flow and small for the vertical flow at the upper junction. The presence of elbows increases the flow limitation in the surge line, whereas the flow limitations at the upper and lower junctions do not depend on the presence of elbows

    Phenotypes of pain behavior in phospholipase C-related but catalytically inactive protein type 1 knockout mice

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    Phospholipase C-related inactive protein (PRIP) plays important roles in trafficking to the plasma membrane of GABAA receptor, which is involved in the dominant inhibitory neurotransmission in the spinal cord and plays an important role in nociceptive transmission. However, the role of PRIP in pain sensation remains unknown. In this study, we investigated the phenotypes of pain behaviors in PRIP type 1 knockout (PRIP-1 -/- ) mice. The mutant mice showed hyperalgesic responses in the second phase of the formalin test and the von Frey test as compared with those in wild-type mice. In situ hybridization studies of GABAA receptors revealed significantly decreased expression of γ2 subunit mRNA in the dorsal and ventral horns of the spinal cord in PRIP-1 -/- mice, but no difference in α1 subunit mRNA expression. β2 subunit mRNA expression was significantly higher in PRIP-1 -/- mice than in wild-type mice in all areas of the spinal cord. On the other hand, the slow decay time constant for the spontaneous inhibitory current was significantly increased by treatment with diazepam in wild-type mice, but not in PRIP-1 -/- mice. These results suggest that PRIP-1 -/- mice exhibit the changes of the function and subunits expression of GABAA receptor in the spinal cord, which may be responsible for abnormal pain sensation in these mice

    Melt-Mixing by Novel Pitched-Tip Kneading Disks in a Co-Rotating Twin-Screw Extruder

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    Melt-mixing in twin-screw extruders is a key process in the development of polymer composites. Quantifying the mixing performance of kneading elements based on their internal physical processes is a challenging problem. We discuss melt-mixing by novel kneading elements called "pitched-tip kneading disk (ptKD)". The disk-stagger angle and tip angle are the main geometric parameters of the ptKDs. We investigated four typical arrangements of the ptKDs, which are forward and backward disk-staggers combined with forward and backward tips. Numerical simulations under a certain feed rate and screw revolution speed were performed, and the mixing process was investigated using Lagrangian statistics. It was found that the four types had different mixing characteristics, and their mixing processes were explained by the coupling effect of drag flow with the disk staggering and pitched-tip and pressure flows, which are controlled by operational conditions. The use of a pitched-tip effectively to controls the balance of the pressurization and mixing ability

    Incidentally Detected Amyloid Light-Chain Amyloidosis Caused by Monoclonal Gammopathy of Undetermined Significance: Possible Time-Dependent Change in Colonic Findings

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    Amyloid light-chain (AL) amyloidosis is associated with plasma cell disorder and monoclonal light chains. This type of amyloidosis is the prominent type involving the gastrointestinal tract. Monoclonal gammopathy of undetermined significance (MGUS) is the most common plasma cell disorder and a known precursor of more serious diseases. A 72-year-old male was treated for high blood pressure, diabetes, and gout at the clinic of a private physician. Due to a positive fecal occult blood test discovered during colon cancer screening, he underwent colonoscopy and was diagnosed with adenomatous polyps by biopsies. Two months later, he was referred to our hospital for endoscopic resection of the polyps. Although the polyps were successfully removed, a colonoscopy revealed two types of ulcerative lesions. Immunohistopathological evaluations obtained from these lesions and polyps confirmed amyloid deposition. Although esophagogastroduodenoscopy results were normal, a biopsy specimen from the patient’s stomach showed the same type of amyloid deposition. Immunoelectrophoresis showed M-proteins for anti-IgG-λ in the serum and λ type Bence-Jones protein in the urine. His blood, bone marrow, and urine test results led to a diagnosis of MGUS. A coronary angiography revealed multivessel stenosis, and the patient’s cardiac function improved after coronary artery stenting. Hereafter, a combination therapy with bortezomib, lenalidomide, and dexamethasone is planned. This is a case report of systemic AL amyloidosis caused by MGUS, which was incidentally detected by colonoscopy

    Axon terminal hypertrophy of striatal projection neurons with levodopa-induced dyskinesia priming

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    BackgroundA rat model of levodopa-induced dyskinesia (LID) showed enlarged axon terminals of striatal direct pathway neurons in the internal segment of the globus pallidus (GPi) with excessive gamma-aminobutyric acid (GABA) storage in them. Massive GABA release to GPi upon levodopa administration determines the emergence of LID.ObjectivesWe examined whether LID and axon terminal hypertrophy gradually develop with repeated levodopa treatment in Parkinsonian rats to examine if the hypertrophy reflects dyskinesia priming.Methods6-hydroxydopamine-lesioned hemiparkinsonian rats were randomly allocated to receive saline injections (placebo group, 14 days; n = 4), injections of 6 mg/kg levodopa methyl ester combined with 12.5 mg/kg benserazide (levodopa-treated groups, 3-day-treatment; n = 4, 7-day-treatment; n = 4, 14-day-treatment; n = 4), or injections of 6 mg/kg levodopa methyl ester with 12.5 mg/kg benserazide and 1 mg/kg 8-hydroxy-2-(di-n-propylamino)tetralin for 14 days (8-OH-DPAT-treated group; n = 4). We evaluated abnormal involuntary movement (AIM) scores and axon terminals in the GPi.ResultsThe AIM score increased with levodopa treatment, as did the hypertrophy of axon terminals in the GPi, showing an increased number of synaptic vesicles in hypertrophied terminals.ConclusionIncreased GABA storage in axon terminals of the direct pathway neurons represents the priming process of LID

    Impact of glycemic control with sitagliptin on the 2‑year progression of arterial stiffness : a sub‑analysis of the PROLOGUE study

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    Background: No conclusive evidence has been obtained yet on the significance of the effects of dipeptidyl peptidase-4 (DPP-4 inhibitor) treatment on the arterial stiffness in clinical settings. In addition, the effects of good glycemic control on the arterial stiffness have also not been clarified yet. As a sub-analysis of the PROLOGUE study, we examined the effect of a DPP-4 inhibitor (sitagliptin) on the 2-year progression of the arterial stiffness and also to determine the effect of good glycemic control on the rate of progression of the arterial stiffness. Methods: In the PROLOGUE study, the study participants were either allocated to add-on sitagliptin treatment or to continued treatment with conventional anti-diabetic agents. Among the 463 participants of the PROLOGUE study, we succeeded in measuring the brachial-ankle pulse wave velocity (baPWV) at least two times during the 2-year study period in 96 subjects. Results: The changes in the baPWV during the study period were similar between the both groups (i.e., with/without staglipitin), overall. On the other hand, when the study subjects were divided into two groups according to the glycemic control status during the study period {good glycemic control group (GC) = hemoglobin (Hb)A1c <7.0 at both 12 and 24 months after the treatment randomization; poor glycemic control group (PC) = HbA1c ≥7.0 at either 12 months, 24 months, or both}, the 2-year increase of the baPWV was marginally significantly larger in the PC group (144 ± 235 cm/s) as compared to that the GC group (−10 ± 282 cm/s) (p = 0.036). Conclusion: While the present study could not confirm the beneficial effect of sitagliptin per se on the arterial stiffness, the results suggested that good glycemic control appears to be beneficial for delaying the annual progression of the arterial stiffness

    Regeneration of Graft Livers and Limited Contribution of Extrahepatic Cells After Partial Liver Transplantation in Humans

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    Background Liver regeneration is still not fully understood. Partial liver transplantation (LT) can provide the opportunity to investigate the mechanisms of liver regeneration, including the contribution of extrahepatic cells to liver regeneration. Methods Of 61 patients transplanted with partial liver graft between August 1997 and October 2006, 56 patients were studied, including 49 adults and 7 children. Sequential computed tomography volumetric analysis was performed for volume measurement, while proliferating cell nuclear antigen (PCNA) labeling index was investigated for liver cell proliferation in nonprotocol liver biopsy specimens. In addition, 15 male recipients who had female liver grafts were investigated in order to detect Y chromosomes as extrahepatic cells in nonprotocol liver biopsy specimens. Results Graft volume per standard liver volume was markedly increased after adult-to-adult living-donor (LD) LT. In pediatric transplants, there was no volume increase over time. PCNA labeling index was vigorous in adult-to-adult LDLT in the early period after LDLT. No Y chromosome was evident in hepatocytes from female-donor male-recipient grafts during or after liver regeneration. However, in the cases of failing grafts of this type, many Y-chromosome-positive cells were observed in the graft liver. The character of those cells was CD34(−), CK9(−), hepatocyte-specific antigen(−), and CD68(+/−). Conclusion In adult-to-adult LDLT, vigorous liver regeneration occurs in the graft liver, demonstrated by not only volumetric but cell kinetic analysis. Involvement of extrahepatic cells in normal liver regeneration seems limited

    IL-12 and IL-18 Induction and Subsequent NKT Activation Effects of the Japanese Botanical Medicine Juzentaihoto

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    In this study, we first measured some cytokine concentrations in the serum of patients treated with Juzentaihoto (JTT). Of the cytokines measured interleukin (IL) -18 was the most prominently up-regulated cytokine in the serum of patients under long term JTT administration. We next evaluated the effects of JTT in mice, focusing especially on natural killer T (NKT) cell induction. Mice fed JTT were compared to control group ones. After sacrifice, the liver was fixed, embedded and stained. Transmission electron microscope (TEM) observations were performed. Although the mice receiving the herbal medicine had same appearance, their livers were infiltrated with massive mononuclear cells, some of which were aggregated to form clusters. Immunohistochemical staining revealed that there was abundant cytokine expression of IL-12 and IL-18 in the liver of JTT treated mice. To clarify what the key molecules that induce immunological restoration with JTT might be, we next examined in vitro lymphocyte cultures. Mononuclear cells isolated and prepared from healthy volunteers were cultured with and without JTT. Within 24 hours, JTT induced the IL-12 and IL-18 production and later (72 hours) induction of interferon (IFN)-gamma. Oral administration of JTT may induce the expression of IL-12 in the early stage, and IL-18 in the chronic stage, followed by NKT induction. Their activation, following immunological restoration could contribute to anti-tumor effects
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