446 research outputs found

    Rapamycin attenuates PLA2R activation-mediated podocyte apoptosis via the PI3K/AKT/mTOR pathway

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    Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in adults without diabetes. Primary MN has been associated with circulating antibodies against native podocyte antigens, including phospholipase A2 receptor (PLA2R); however, precision therapy targeting the signaling cascade of PLA2R activation is lacking. Both PLA2R and the mammalian target of rapamycin (mTOR) exist in podocytes, but the interplay between these two proteins and their roles in MN warrants further exploration. This study aimed to investigate the crosstalk between PLA2R activation and mTOR signaling in a human podocyte cell line. We demonstrated that podocyte apoptosis was induced by Group IB secretory phospholipase A2 (sPLA2IB) in a concentration- and time-dependent manner via upregulation of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and mTOR, and inhibited by rapamycin or LY294002. Furthermore, aberrant activation of the PI3K/AKT/mTOR pathway triggers both extrinsic (caspase-8 and caspase-3) and intrinsic (Bcl-2-associated X protein [BAX], B-cell lymphoma 2 [BCL-2], cytochrome c, caspase-9, and caspase-3) apoptotic cascades in podocytes. The therapeutic implications of our findings are that strategies to reduce PLA2R activation and PI3K/AKT/mTOR pathway inhibition in PLA2R-activated podocytes help protect podocytes from apoptosis. The therapeutic potential of rapamycin shown in this study provides cellular evidence supporting the repurposing of rapamycin for MN treatment

    Metal-free sp(3) C-H functionalization: a novel approach for the syntheses of selenide ethers and thioesters from methyl arenes

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    A DTBP-promoted metal-free and solvent-free formation of C-Se and C-S bonds through sp(3) C-H functionalization of methyl arenes with diselenides and disulfides is described

    Viral load and clinical features in children infected with seasonal influenza B in 2006/2007

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    Background/PurposeIn influenza B infection, viral load is believed to be related to the severity of clinical illness. The correlation between viral load and symptoms is not known. We conducted a study to assess the relationship between virus load and clinical features in children infected with influenza B, in the hope that clinical features could be used as surrogate markers of viral load to guide treatment.MethodsBetween December 2006 and February 2007, 228 patients with fever and respiratory symptoms were prospectively enrolled in our tertiary hospital-based study. Real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to determine viral load.ResultsReal-time RT-PCR was positive for influenza B in 76 patients. Using virus culture as the gold standard, the sensitivity and specificity were 95% and 87%, respectively. Influenza culture positive rate significantly correlated with viral load (p = 0.03). The median copy number of influenza B virus in the 76 RT-PCR positive patients was 9735 copies/ml (range 4.8×101–2.0×106 copies/ml). Samples obtained later in the clinical course tended to have lower viral load (p = 0.7), while patient age (p = 0.72) and fever duration (p = 0.96) positively related to viral load. In patients >3 years of age, myalgia was related to statistically lower viral loads (14300 vs. 1180; p = 0.025). Patients with chills tended to have higher viral loads (72450 vs. 7640; p = 0.1). Patients with abdominal pain tended to have lower viral loads (1998 vs. 12550; p = 0.06).ConclusionCulture rate positively correlated with viral load. Patients with myalgia had a lower viral load

    Overcome Cancer Cell Drug Resistance Using Natural Products

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    Chemotherapy is one of the major treatment methods for cancer. However, failure in chemotherapy is not uncommon, mainly due to dose-limiting toxicity associated with drug resistance. Management of drug resistance is important towards successful chemotherapy. There are many reports in the Chinese literature that natural products can overcome cancer cell drug resistance, which deserve sharing with scientific and industrial communities. We summarized the reports into four categories: (1) in vitro studies using cell line models; (2) serum pharmacology; (3) in vivo studies using animal models; and (4) clinical studies. Fourteen single compounds were reported to have antidrug resistance activity for the first time. In vitro, compounds were able to overcome drug resistance at nontoxic or subtoxic concentrations, in a dose-dependent manner, by inhibiting drug transporters, cell detoxification capacity, or cell apoptosis sensitivity. Studies in vivo showed that single compounds, herbal extract, and formulas had potent antidrug resistance activities. Importantly, many single compounds, herbal extracts, and formulas have been used clinically to treat various diseases including cancer. The review provides comprehensive data on use of natural compounds to overcome cancer cell drug resistance in China, which may facilitate the therapeutic development of natural products for clinical management of cancer drug resistance

    Overcome Cancer Cell Drug Resistance Using Natural Products

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    Chemotherapy is one of the major treatment methods for cancer. However, failure in chemotherapy is not uncommon, mainly due to dose-limiting toxicity associated with drug resistance. Management of drug resistance is important towards successful chemotherapy. There are many reports in the Chinese literature that natural products can overcome cancer cell drug resistance, which deserve sharing with scientific and industrial communities. We summarized the reports into four categories: (1) in vitro studies using cell line models; (2) serum pharmacology; (3) in vivo studies using animal models; and (4) clinical studies. Fourteen single compounds were reported to have antidrug resistance activity for the first time. In vitro, compounds were able to overcome drug resistance at nontoxic or subtoxic concentrations, in a dose-dependent manner, by inhibiting drug transporters, cell detoxification capacity, or cell apoptosis sensitivity. Studies in vivo showed that single compounds, herbal extract, and formulas had potent antidrug resistance activities. Importantly, many single compounds, herbal extracts, and formulas have been used clinically to treat various diseases including cancer. The review provides comprehensive data on use of natural compounds to overcome cancer cell drug resistance in China, which may facilitate the therapeutic development of natural products for clinical management of cancer drug resistance

    Serologic Status for Pandemic (H1N1) 2009 Virus, Taiwan

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    We studied preexisting immunity to pandemic (H1N1) 2009 virus in persons in Taiwan. A total of 18 (36%) of 50 elderly adults in Taiwan born before 1935 had protective antibodies against currently circulating pandemic (H1N1) 2009 virus. Seasonal influenza vaccines induced antibodies that did not protect against pandemic (H1N1) 2009 virus

    Serotype Competence and Penicillin Resistance in Streptococcus pneumoniae

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    Enhanced molecular surveillance of virulent clones with higher competence can detect serotype switching

    Cetuximab plus platinum-based chemotherapy in head and neck squamous cell carcinoma: A randomized, double-blind safety study comparing cetuximab produced from two manufacturing processes using the EXTREME study regimen

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    BACKGROUND: Cetuximab, in combination with platinum chemotherapy plus 5-fluoruracil (5-FU), is approved for the first-line treatment of recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN). Cetuximab manufactured by ImClone (US commercial cetuximab) potentially results in higher systemic exposures than cetuximab manufactured by Boehringer Ingelheim (BI-manufactured cetuximab). This prospective, randomized, double-blind study compared the safety profiles of the two cetuximab formulations. METHODS: Patients with previously untreated locoregionally recurrent and/or metastatic SCCHN were randomly assigned to receive the same dose of US commercial cetuximab (Arm A) or BI-manufactured cetuximab (Arm B), each in combination with cisplatin or carboplatin plus 5-FU. The primary outcome was all-grade, all-cause treatment-emergent adverse events (TEAEs). RESULTS: The majority of patients experienced ≥1 TEAE, regardless of causality (Arm A: 75/77 patients, 97.4 %; Arm B: 68/71 patients, 95.8 %). TEAEs with the highest incidence included nausea, fatigue, and hypomagnesemia in both arms. The absolute risk difference between the two arms for patients experiencing at least one adverse event (AE) was 0.029 (p = 0.281, 95 % confidence interval [CI]: -0.024, 0.082) for AEs regardless of causality and 0.005 (p = 0.915, 95 % CI: -0.092, 0.103) for AEs possibly related to study drug. There were no significant differences between the two arms in the incidence of acneiform rash, cardiac events, infusion reactions, or hypomagnesemia. Overall survival, progression-free survival, and overall response rates were similar in the two arms. CONCLUSIONS: There were no clinically meaningful differences in safety between US commercial cetuximab and BI-manufactured cetuximab in combination with platinum-based therapy with 5-FU in patients with locoregionally recurrent and/or metastatic SCCHN. The use of US commercial cetuximab in this combination chemotherapy regimen did not result in any unexpected safety signals. The efficacy results of this study are consistent with the efficacy results of the cetuximab arm of the EXTREME study. TRIAL REGISTRATION: ClinicalTrials.gov NCT01081041; date of registration: March 3, 2010)
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