330 research outputs found

    High-Recycling Characteristics in the KSTAR Tokamak Divertor by Using Two-Dimensional Transport Simulations

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    The operation space in the conduction-limited divertor regime of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak is obtained in terms of the upstream density and the input power through numerical simulations using a two-dimensional two-fluid edge plasma transport code coupled with a two-dimensional Monte Carlo recycling neutral transport code in which the electron impact ionization and the charge exchange of recycling neutrals are taken into account. Two major high-recycling characteristics, the parallel temperature gradient and plasma pressure conservation, are identi ed in this operation space along the magnetic ux tubes between the upstream position and the divertor target plate in the KSTAR tokamak. Inclusion of ion pressures in the present simulations for total plasma pressures shows firm evidence of pressure conservation in the high-recycling regime. In addition, scalings of the plasma temperature and density at the divertor plate with the upstream plasma density are derived, and they are compared with those in a simple one-dimensional analytic transport model, the so-called two-point model. Finally, the simulation shows that the peaked feature of the upstream ion temperature pro le adjacent to the separatrix a ects the distribution of the divertor heat flux. This indicates that the ion parallel heat conduction near the separatrix plays an important role in determining the radial pro le of the heat flux onto the divertor target, as the electron parallel heat conduction does in the conduction-limited regime. It is, therefore, suggested that modification of the upstream plasma property profiles will make it possible to control the power dispersal on the divertor plate

    Evaluation of the transporter-mediated herb-drug interaction potential of DA-9801, a standardized dioscorea extract for diabetic neuropathy, in human in vitro and rat in vivo

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    BACKGROUND: Drug transporters play important roles in the absorption, distribution, and elimination of drugs and thereby, modulate drug efficacy and toxicity. With a growing use of poly pharmacy, concurrent administration of herbal extracts that modulate transporter activities with drugs can cause serious adverse reactions. Therefore, prediction and evaluation of drug-drug interaction potential is important in the clinic and in the drug development process. DA-9801, comprising a mixed extract of Dioscoreae rhizoma and Dioscorea nipponica Makino, is a new standardized extract currently being evaluated for diabetic peripheral neuropathy in a phase II clinical study. METHOD: The inhibitory effects of DA-9801 on the transport functions of organic cation transporter (OCT)1, OCT2, organic anion transporter (OAT)1, OAT3, organic anion transporting polypeptide (OATP)1B1, OATP1B3, P-glycoprotein (P-gp), and breast cancer resistance protein (BCRP) were investigated in HEK293 or LLC-PK1 cells. The effects of DA-9801 on the pharmacokinetics of relevant substrate drugs of these transporters were also examined in vivo in rats. RESULTS: DA-9801 inhibited the in vitro transport activities of OCT1, OCT2, OAT3, and OATP1B1, with IC(50) values of 106, 174, 48.1, and 273 μg/mL, respectively, while the other transporters were not inhibited by 300 μg/mL DA-9801. To investigate whether this inhibitory effect of DA-9801 on OCT1, OCT2, and OAT3 could change the pharmacokinetics of their substrates in vivo, we measured the pharmacokinetics of cimetidine, a substrate for OCT1, OCT2, and OAT3, and of furosemide, a substrate for OAT1 and OAT3, by co-administration of DA-9801 at a single oral dose of 1,000 mg/kg. Pre-dose of DA-9801 5 min or 2 h prior to cimetidine administration decreased the C(max) of cimetidine in rats. However, DA-9801 did not affect the elimination parameters such as half-life, clearance, or amount excreted in the urine, suggesting that it did not inhibit elimination process of cimetidine, which is governed by OCT1, OCT2, and OAT3. Moreover, DA-9801 did not affect the pharmacokinetic characteristics of furosemide, as evidenced by its unchanged pharmacokinetic parameters. CONCLUSION: Inhibitory effects of DA-9801 on OCT1, OCT2, and OAT3 observed in vitro may not necessarily translate into in vivo herb-drug interactions in rats even at its maximum effective dose

    The Clinical Significance of Intrarenal Reflux in Voiding Cystourethrography (VCUG)

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    PURPOSE: Intrarenal reflux (IRR) occurs in 3-10% of cases of total reflux and can lead to renal injury, which may eventually result in renal scarring. In this study, we evaluated the clinical importance of IRR detected by voiding cystourethrography and evaluated the relationship between IRR and renal scarring. MATERIALS AND METHODS: From January 2002 to May 2008, 50 patients who were diagnosed with vesicoureteral reflux (VUR) and showed IRR in voiding cystourethrography were enrolled. IRR was seen in 59 renal units in our enrolled patients. A 99mTc 2,3-dimercaptosuccinic acid (DMSA) renal scan was performed after VUR was detected in all cases. Nine patients were conservatively treated with prophylactic antibiotics, whereas 41 patients received an anti-reflux operation. A follow-up renal scan was performed after 3 to 6 months to check for any changes in renal scarring. RESULTS: The average patient age was 9.2 months (range, 1-42 months). Forty-nine patients were male; only one patient was female. The mean duration until surgery was 2.9 months. Generally, the IRR sites corresponded to the sites of photon defects on DMSA renal scans (76.3%). Furthermore, the photon defects on IRR sites tended to progress to renal scarring (65.2%). The rate of change in scarring was lower in the surgery group (47.1%) than in the prophylactic antibiotic group (75%). CONCLUSIONS: IRR sites and the sites of photon defects on DMSA renal scans showed a high correspondence, and these sites tended to progress to renal scarring. We suggest that VUR with IRR should be actively managed to decrease the chances of renal scarringope

    Phlegmonous Enteritis in a Patient with Congestive Heart Failure and Colon Cancer

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    Phlegmonous enteritis is a rare infective inflammatory disease of the intestine, predominantly involving the submucosal layer. It is difficult to diagnose and often fatal. Its association with alcoholism and various liver diseases, although rarely reported, is well documented. We report a case of phlegmonous enteritis in a male patient with congestive heart failure and colon cancer, and describe the ultrasonographic and CT findings

    Rupture of abdominal aortic aneurysm after spine surgery in the patient with Ehlers-Danlos syndrome -A case report-

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    Ehlers-Danlos syndrome (EDS) is a rare inherited disorder of the connective tissue that is characterized by hyperextensible skin, hypermobile joints and abnormalities of the cardiovascular system. A 15-year-old girl with Ehlers-Danlos syndrome underwent thoracolumbar surgery for deformity correction. After surgery, an abdominal aortic rupture occurred, and she complained of abdominal distension had an abdominal circumference of 80 cm. Abdominal computed tomography revealed a pseudoaneurysm and a large hematoma at the retroperitoneum. She died of a massive hemorrhage during subsequent abdominal aortic surgery

    Antiatherosclerotic Effect of Korean Red Ginseng Extract Involves Regulator of G-Protein Signaling 5

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    Regulator of G-protein signaling 5 (RGS5), an inhibitor of Gα(q) and Gα(i) activation, has been reported to have antiatherosclerosis. Previous studies showed antiatherosclerotic effect of Korean red ginseng water extract (KRGE) via multiple signaling pathways. However, potential protective effect of KRGE through RGS5 expression has not been elucidated. Here, we investigated the antiatherosclerotic effect of KRGE in vivo and in vitro and its role on RGS5 mRNA expression. Elevated levels of total cholesterol, lactate dehydrogenase (LDH), and triglyceride (TG) in western diet groups of low-density lipoprotein receptor deficient LDLr−/− mice were reversed by oral administration of KRGE. KRGE suppressed transcriptional activity of tumor necrotic factor alpha (TNF-α), interleukin-6 (IL-6), and leptin in adipose tissue. It also potently repressed western diet-induced atheroma formation in aortic sinus. While KRGE showed reduced mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-1β, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells, it enhanced mRNA expression of RGS5. Moreover, RGS5 siRNA transfection of microglia cells pretreated with KRGE reversed its inhibitory effect on the expression of iNOS, COX-2, and IL-1β mRNA. In conclusion, KRGE showed antiatherosclerotic and anti-inflammatory effects in western diet fed LDLr−/− mice and this effect could partly be mediated by RGS5 expression

    c-fos Expression in Bladder-Specific Spinal Neurons after Spinal Cord Injury Using Pseudorabies Virus

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    PURPOSE: c-fos expression in spinal neurons that are activated by lower urinary tract stimulation are not organ specific. In this experiment, we demonstrated changes of c-fos expression in bladder-specific preganglionic neurons (PGNs) and interneurons using pseudorabies virus (PRV). MATERIALS AND METHODS: Forty Sprague-Dawley rats were used. We identified the neuronal pathway associated with the bladder by injecting PRV into the detrusor. An immunohistochemical method was used to stain Fos-protein encoded by the c-fos gene. Immunofluorescent staining for PRV was performed to evaluate changes in bladder-specific spinal neurons. RESULTS: Immunofluorescent staining with choline acetyltransferase (ChAT) revealed that the sacral parasympathetic nucleus (SPN) regions contained 9.8 PGNs/ section. In rats with chronic spinal cord injury by intravesical saline instillation, 82.4+/-10.3% of PGNs in SPN exhibited Fos-immunoreactive (IR). Two and a half days after PRV infection, PRV-IR PGNs were observed at 5.4 PGNs/ section, and 2.7+/-1.6% of them exhibited Fos-IR. Unlike ChAT-IR PGNs, PRV-IR PGNs are bladder-specific neurons and PRV-IR and Fos-IR cells found in the back of PRV-IR PGNs are bladder- specific interneurons. Three days after PRV infection, we observed many PRV-IR and Fos-IR cells in the dorsal commissure. These neurons are interneurons distributed in the bladder. CONCLUSION: We confirmed that in chronic spinal cord injury, the patterns of c-fos expression in bladder-specific spinal neurons were similar to those in voiding-reflex related spinal neurons, which had already been demonstrated earlier. We believe that our methodology can be applied to study interactions between voiding and other organs as well, such as the urethra and prostate.ope

    Favorable response to doxorubicin combination chemotherapy does not yield good clinical outcome in patients with metastatic breast cancer with triple-negative phenotype

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    <p>Abstract</p> <p>Background</p> <p>We analyzed the responses to first line treatment and clinical outcomes of metastatic breast cancer patients treated with palliative doxorubicin/cyclophosphamide (AC) according to molecular cancer subtype.</p> <p>Methods</p> <p>A retrospective analysis was performed for 110 metastatic breast cancer patients selected on the basis of palliative AC treatment and the availability of immunohistochemical data for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2/neu) status.</p> <p>Results</p> <p>Of the 110 patients analyzed, 71 (64.5%) were hormone receptor positive (HR+), 14 (12.7%) were HER2+, and 25 (22.7%) were triple negative (TN). There were no differences in age, stage at diagnosis, total number of cycles of palliative chemotherapy, incidence of visceral metastasis, and metastatic sites with the exception of liver among breast cancer subtypes. The overall response rates to AC were 55.9% for the HR+ subgroup, 42.9% for the HER2+ subgroup, and 56.5% for the TN subgroup. The progression-free survival (PFS) in patients with HER2+ and TN were significantly shorter than in the HR+ (median PFS, 9.1 <it>vs </it>8.1 <it>vs </it>11.5 months, respectively; p = 0.0002). The overall survival (OS) was 25.4 months in the TN subgroup and 27.3 months in HER2+ subgroup. The median OS for these two groups was significantly shorter than for patients in the HR+ subgroup (median, 38.5 months; 95% CI, 30.1-46.9 months; p < 0.0001).</p> <p>Conclusions</p> <p>The response to palliative AC chemotherapy did not differ among breast cancer subtypes. Despite chemosensitivity for palliative AC, the TN subtype has a shorter overall survival than non-TN subtypes. Innovative treatment strategies should be developed to slow the course of disease.</p

    3D Graphics System with VLIW Processor for Geometry Acceleration

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    Abstract To process enormous 3D data, we have designed a VLIW (Very Long Instruction Word

    Epidemiologic survey of head and neck cancers in Korea.

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    Head and neck cancers have never been systematically studied for clinical purposes yet in Korea. This epidemiological survey on head and neck cancer patients was undertaken from January to December 2001 in 79 otorhinolaryngology resident-training hospitals nationwide. The number of head and neck cancer patients was 1,063 cases in the year. The largest proportion of cases arose in the larynx, as many as 488 cases, which accounted for 45.9%. It was followed by, in order of frequency, oral cavity (16.5%), oropharynx (10.0%), and hypopharynx (9.5%). The male:female ratio was 5:1, and the mean age was 60.3 yr. Surgery was the predominant treatment modality in head and neck cancers: 204 (21.5%) cases were treated with only surgery, 198 (20.8%) cases were treated with surgery and radiotherapy, 207 cases (21.8%) were treated with combined therapy of surgery, radiotherapy, and chemotherapy. Larynx and hypopharynx cancers had a stronger relationship with smoking and alcohol drinking than other primary site cancers. Of them, 21 cases were found to be metastasized at the time of diagnosis into the lung, gastrointestinal tract, bone, or brain. Coexisting second primary malignancies were found in 23 cases. At the time of diagnosis, a total of 354 cases had cervical lymph node metastasis accounting for 42.0%
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