325 research outputs found

    Concurrent Magnetic and Metal-Insulator Transitions in (Eu,Sm)B_6 Single Crystals

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    The effects of magnetic doping on a EuB_6 single crystal were investigated based on magnetic and transport measurements. A modest 5% Sm substitution for Eu changes the magnetic and transport properties dramatically and gives rise to concurrent antiferromagnetic and metal-insulator transitions (MIT) from ferromagnetic MIT for EuB6. Magnetic doping simultaneously changes the itinerant carrier density and the magnetic interactions. We discuss the origin of the concurrent magnetic MIT in (Eu,Sm)B_6.Comment: 13 pages, 3 figures, final version to appear in Appl. Phys. Lett

    Trends in Tissue Engineering for Blood Vessels

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    Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient’s conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering

    Bi-weekly Chemotherapy of Paclitaxel and Cisplatin in Patients with Metastatic or Recurrent Esophageal Cancer

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    Although various combinations of chemotherapy regimens have been tried for patients with esophageal cancer, their duration of survival is extremely poor. In this study, we investigated the safety and clinical efficacy of paclitaxel and cisplatin chemotherapy in metastatic or recurrent esophageal cancer. 32 patients enrolled in this study and the median age was 60 yr. Of all the 32, 28 patients (88%) had been treated previously, 22 of them with chemotherapy or radiation therapy. All patients in the study received biweekly paclitaxel (90 mg/m2) followed by cisplatin (50 mg/m2). One patient (3%) responded completely, and 12 patients (38%) showed a partial response; in 9 patients (28%) the disease remained stable, and in 10 patients (31%) it progressed. The objective response rate was 41%. The median duration of response was 4.8 months, and the median overall survival in all patients was 7 months. The 1-yr and 2-yr survival rates were 28.1% and 7.1%, respectively. Grade 3 or 4 of neutropenia and anemia were observed in 6 (19%) and 5 (16%) patients, respectively. The major non-hematologic toxicity was fatigue, but most of them could manageable. In conclusion, biweekly paclitaxel and cisplatin is effective in patients with metastatic or recurrent esophageal cancer

    Phase II Study of Paclitaxel, Cisplatin, and 5-Fluorouracil Combination Chemotherapy in Patients with Advanced Gastric Cancer

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    This phase II study evaluated the efficacy and safety of combination chemotherapy with paclitaxel, cisplatin, and 5-fluorouracil (5-FU) in advanced gastric cancer. Patients with histologically confirmed gastric adenocarcinoma were eligible for the study. Paclitaxel (175 mg/m2) and cisplatin (75 mg/m2) were given as a 1-hr intravenous infusion on day 1, followed by 5-FU (750 mg/m2) as a 24-hr continuous infusion for 5 days. This cycle was repeated every 3 weeks. Forty-five eligible patients (median age, 56 yr) were treated in this way. Of the 41 patients in whom efficacy was evaluable, an objective response rate (ORR) was seen in 51.2% (95% CI, 0.35-0.67), a complete response in two, and a partial response in 19 patients. The median progression free survival was 6.9 months (95% CI, 5.86-7.94 months), and the median overall survival was 12.7 months (95% CI, 9.9-15.5). The main hematological toxicity was neutropenia and greater than grade 3 neutropenia was observed in twelve patients (54%). Febrile neutropenia developed in three patients (6.8%). The major non-hematological toxicities were asthenia and peripheral neuropathy, but most of patients showed grade 1 or 2. In conclusion, combination chemotherapy with paclitaxel, cisplatin, and 5-FU is a promising regimen, and was well tolerated in patients with advanced gastric cancer

    Nonimmunity against hepatitis B virus infection in patients newly diagnosed with inflammatory bowel disease

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    Background/AimsThis study aimed to elucidate the prevalence of hepatitis B virus (HBV) serologic markers in Korean patients newly diagnosed with, but not yet treated for inflammatory bowel disease (IBD).MethodsWe prospectively enrolled 210 patients newly diagnosed with IBD (109 with ulcerative colitis and 101 with Crohn's disease). Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were measured and compared with those of 1,100 sex- and age-matched controls.ResultsThe prevalence of chronic HBV infection (positive HBsAg, positive anti-HBc, and negative anti-HBs results) and past infection (negative HBsAg, positive anti-HBc, and positive or negative anti-HBs results) were not significantly different between the patients and controls (chronic HBV infection: IBD, 3.8% vs. control, 4.9%, P=0.596; past infection: IBD, 26.2% vs. control, 28.8%, P=0.625). The patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) for HBV infection than the controls (IBD, 41.5% vs. control, 22.4%; P=0.018). In the multivariate analysis, an age of <20 years (P=0.024) and symptom duration of ≥12 months before diagnosis (P=0.027) were identified as independent risk factors for nonimmunity against HBV infection.ConclusionsThe patients newly diagnosed with IBD were susceptible to HBV infection. The frequency of nonimmunity was high, especially in the patients aged <20 years and those with a longer duration of symptoms before diagnosis. Therefore, it is necessary to screen for HBV serologic markers and generate a detailed vaccination plan for patients newly diagnosed with IBD

    Primary Human mDC1, mDC2, and pDC Dendritic Cells Are Differentially Infected and Activated by Respiratory Syncytial Virus

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    Respiratory syncytial virus (RSV) causes recurrent infections throughout life. Vaccine development may depend upon understanding the molecular basis for induction of ineffective immunity. Because dendritic cells (DCs) are critically involved in early responses to infection, their interaction with RSV may determine the immunological outcome of RSV infection. Therefore, we investigated the ability of RSV to infect and activate primary mDCs and pDCs using recombinant RSV expressing green fluorescent protein (GFP). At a multiplicity of infection of 5, initial studies demonstrated ∼6.8% of mDC1 and ∼0.9% pDCs were infected. We extended these studies to include CD1c−CD141+ mDC2, finding mDC2 infected at similar frequencies as mDC1. Both infected and uninfected cells upregulated phenotypic markers of maturation. Divalent cations were required for infection and maturation, but maturation did not require viral replication. There is evidence that attachment and entry/replication processes exert distinct effects on DC activation. Cell-specific patterns of RSV-induced maturation and cytokine production were detected in mDC1, mDC2, and pDC. We also demonstrate for the first time that RSV induces significant TIMP-2 production in all DC subsets. Defining the influence of RSV on the function of selected DC subsets may improve the likelihood of achieving protective vaccine-induced immunity

    Engineering the Melanocortin-4 Receptor to Control Constitutive and Ligand-Mediated Gs Signaling In Vivo

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    The molecular and functional diversity of G protein–coupled receptors is essential to many physiological processes. However, this diversity presents a significant challenge to understanding the G protein–mediated signaling events that underlie a specific physiological response. To increase our understanding of these processes, we sought to gain control of the timing and specificity of Gs signaling in vivo. We used naturally occurring human mutations to develop two Gs-coupled engineered receptors that respond solely to a synthetic ligand (RASSLs). Our Gs-coupled RASSLs are based on the melanocortin-4 receptor, a centrally expressed receptor that plays an important role in the regulation of body weight. These RASSLs are not activated by the endogenous hormone α-melanocyte-stimulating hormone but respond potently to a selective synthetic ligand, tetrahydroisoquinoline. The RASSL variants reported here differ in their intrinsic basal activities, allowing the separation of the effects of basal signaling from ligand-mediated activation of the Gs pathway in vivo. These RASSLs can be used to activate Gs signaling in any tissue, but would be particularly useful for analyzing downstream events that mediate body weight regulation in mice. Our study also demonstrates the use of human genetic variation for protein engineering
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