194 research outputs found

    Melody, an ENU mutation in Caspase 3, alters the catalytic cysteine residue and causes sensorineural hearing loss in mice

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    Progeny from the Harwell N-ethyl-N-nitrosourea (ENU) recessive mutagenesis screen were assessed for auditory defects. A pedigree was identified with multiple progeny lacking response to a clickbox test. Auditory brainstem response (ABR) analysis showed that homozygous mutant mice were profoundly deaf and the line was named melody. We subsequently mapped this mutation to a 6-Mb region on chromosome 8 and identified a point mutation in melody that results in a C163S substitution in the catalytic site of Caspase 3, a cysteine protease involved in apoptosis. Melody fails to complement a null Caspase-3 mutant. Scanning electron microscopy (SEM) has revealed disorganised sensory hair cells and hair cell loss. Histological analysis of melody has shown degeneration of spiral ganglion cells in homozygote mice, with a gradient of severity from apical to basal turns. Melody heterozygotes also show evidence of loss of spiral ganglion neurons, suggesting that the C163S mutation may show dominant negative effects by binding and sequestering proteins at the active site. The melody line provides a new model for studying the role of Caspase 3 in deafness and a number of other pathways and systems

    Predictive factors for skeletal complications in hormone-refractory prostate cancer patients with metastatic bone disease

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    Factors predictive of skeletal-related events (SREs) in bone metastatic prostate cancer patients with hormone-refractory disease were investigated. We evaluated the frequency of SREs in 200 hormone-refractory patients consecutively observed at our Institution and followed until death or the last follow-up. Baseline parameters were evaluated in univariate and multivariate analysis as potential predictive factors of SREs. Skeletal-related events were observed in 86 patients (43.0%), 10 of which (5.0%) occurred before the onset of hormone-refractory disease. In univariate analysis, patient performance status (P=0.002), disease extent (DE) in bone (P=0.0001), bone pain (P=0.0001), serum alkaline phosphatase (P=0.0001) and urinary N-telopeptide of type one collagen (P=0.0001) directly correlated with a greater risk to develop SREs, whereas Gleason score at diagnosis, serum PSA, Hb, serum albumin, serum calcium, types of bone lesions and duration of androgen deprivation therapy did not. Both DE in bone (hazard ratio (HR): 1.16, 95% confidence interval (CI): 1.07–1.25, P=0.000) and pain score (HR: 1.13, 95% CI: 1.06–1.20, P=0.000) were independent variables predicting for the onset of SREs in multivariate analysis. In patients with heavy tumour load in bone and great bone pain, the percentage of SREs was almost twice as high as (26 vs 52%, P<0.02) and occurred significantly earlier (P=0.000) than SREs in patients with limited DE in bone and low pain. Bone pain and DE in bone independently predict the occurrence of SREs in bone metastatic prostate cancer patients with hormone-refractory disease. These findings could help physicians in tailoring the skeletal follow-up most appropriate to individual patients and may prove useful for stratifying patients enrolled in bisphosphonate clinical trials

    Brain tumor location influences the onset of acute psychiatric adverse events of levetiracetam therapy: an observational study.

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    To explore possible correlations among brain lesion location, development of psychiatric symptoms and the use of antiepileptic drugs (AEDs) in a population of patients with brain tumor and epilepsy. The medical records of 283 patients with various types of brain tumor (161 M/122 F, mean age 64.9 years) were analysed retrospectively. Patients with grade III and IV glioma, previous history of epileptic seizures and/or psychiatric disorders were excluded. Psychiatric symptoms occurring after initiation of AED therapy were considered as treatment emergent psychiatric adverse events (TE-PAEs) if they fulfilled the following conditions: (1) onset within 4 weeks after the beginning of AED therapy; (2) disappearance on drug discontinuation; (3) absence of any other identified possible concurrent cause. The possible influence of the following variables were analysed: (a) AED drug and dose; (b) location and neuroradiologic features of the tumor, (c) location and type of EEG epileptic abnormalities, (d) tumor excision already or not yet performed; (e) initiation or not of radiotherapy. TE-PAEs occurred in 27 of the 175 AED-treated patients (15.4%). Multivariate analysis showed a significant association of TE-PAEs occurrence with location of the tumor in the frontal lobe (Odds ratio: 5.56; 95% confidence interval 1.95-15.82; p value: 0.005) and treatment with levetiracetam (Odds ratio: 3.61; 95% confidence interval 1.48-8.2; p value: 0.001). Drug-unrelated acute psychiatric symptoms were observed in 4 of the 108 AED-untreated patients (3.7%) and in 7 of the 175 AED-treated patients (4%). The results of the present study suggest that an AED alternative to levetiracetam should be chosen to treat epileptic seizures in patients with a brain tumor located in the frontal lobe to minimize the possible onset of TE-PAEs

    NMR studies of p7 protein from hepatitis C virus

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    The p7 protein of hepatitis C virus (HCV) plays an important role in the viral lifecycle. Like other members of the viroporin family of small membrane proteins, the amino acid sequence of p7 is largely conserved over the entire range of genotypes, and it forms ion channels that can be blocked by a number of established channel-blocking compounds. Its characteristics as a membrane protein make it difficult to study by most structural techniques, since it requires the presence of lipids to fold and function properly. Purified p7 can be incorporated into phospholipid bilayers and micelles. Initial solid-state nuclear magnetic resonance (NMR) studies of p7 in 14-O-PC/6-O-PC bicelles indicate that the protein contains helical segments that are tilted approximately 10° and 25° relative to the bilayer normal. A truncated construct corresponding to the second transmembrane domain of p7 is shown to have properties similar to those of the full-length protein, and was used to determine that the helix segment tilted at 10° is in the C-terminal portion of the protein. The addition of the channel blocker amantadine to the full-length protein resulted in selective chemical shift changes, demonstrating that NMR has a potential role in the development of drugs targeted to p7

    Compared Efficacy of Adjuvant Intravesical BCG-TICE vs. BCG-RIVM for High-Risk Non-Muscle Invasive Bladder Cancer (NMIBC): A Propensity Score Matched Analysis

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    Background: Intravesical immunotherapy with bacillus Calmette-Guerin (BCG) is the standard therapy for high-risk non-muscle invasive bladder cancer (NMIBC). The superiority of any BCG strain over another could not be demonstrated yet. Methods: Patients with NMIBCs underwent adjuvant induction ± maintenance schedule of intravesical immunotherapy with either BCG TICE or RIVM at two high-volume tertiary institutions. Only BCG-naïve patients and those treated with the same strain over the course of follow-up were included. One-to-one (1:1) propensity score matching (PSM) between the two cohorts was utilized to adjust for baseline demographic and tumor characteristics imbalances. Kaplan-Meier estimates and multivariable Cox regression models according to high-risk NMIBC prognostic factors were implemented to address survival differences between the strains. Sub-group analysis modeling of the influence of routine secondary resection (re-TUR) in the setting of the sole maintenance adjuvant schedule for the two strains was further performed. Results: 852 Ta-T1 NMIBCs (n = 719, 84.4% on TICE; n = 133, 15.6% on RIVM) with a median of 53 (24-77) months of follow-up were reviewed. After PSM, no differences at 5-years RFS, PFS, and CSS at both Kaplan-Meier and Cox regression analyses were detected for the whole cohort. In the sub-group setting of full adherence to European/American Urology Guidelines (EAU/NCCN), BCG TICE demonstrated longer 5-years RFS compared to RIVM (68% vs. 43%, p = 0.008; HR: 0.45 95% CI 0.25-0.81). Conclusion: When routinely performing re-TUR followed by a maintenance BCG schedule, TICE was superior to RIVM for RFS outcomes. However, no significant differences were detected for PFS and CSS, respectively

    Understanding Performance Limiting Interfacial Recombination in pin Perovskite Solar Cells

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    Funder: Alexander von Humboldt Foundation; Id: http://dx.doi.org/10.13039/100005156Abstract: Perovskite semiconductors are an attractive option to overcome the limitations of established silicon based photovoltaic (PV) technologies due to their exceptional opto‐electronic properties and their successful integration into multijunction cells. However, the performance of single‐ and multijunction cells is largely limited by significant nonradiative recombination at the perovskite/organic electron transport layer junctions. In this work, the cause of interfacial recombination at the perovskite/C60 interface is revealed via a combination of photoluminescence, photoelectron spectroscopy, and first‐principle numerical simulations. It is found that the most significant contribution to the total C60‐induced recombination loss occurs within the first monolayer of C60, rather than in the bulk of C60 or at the perovskite surface. The experiments show that the C60 molecules act as deep trap states when in direct contact with the perovskite. It is further demonstrated that by reducing the surface coverage of C60, the radiative efficiency of the bare perovskite layer can be retained. The findings of this work pave the way toward overcoming one of the most critical remaining performance losses in perovskite solar cells

    The rise and fall of methanotrophy following a deepwater oil-well blowout

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    The blowout of the Macondo oil well in the Gulf of Mexico in April 2010 injected up to 500,000 tonnes of natural gas, mainly methane, into the deep sea1. Most of the methane released was thought to have been consumed by marine microbes between July and August 20102, 3. Here, we report spatially extensive measurements of methane concentrations and oxidation rates in the nine months following the spill. We show that although gas-rich deepwater plumes were a short-lived feature, water column concentrations of methane remained above background levels throughout the rest of the year. Rates of microbial methane oxidation peaked in the deepwater plumes in May and early June, coincident with a rapid rise in the abundance of known and new methane-oxidizing microbes. At this time, rates of methane oxidation reached up to 5,900 nmol l−1 d−1—the highest rates documented in the global pelagic ocean before the blowout4. Rates of methane oxidation fell to less than 50 nmol l−1 d−1 in late June, and continued to decline throughout the remainder of the year. We suggest the precipitous drop in methane consumption in late June, despite the persistence of methane in the water column, underscores the important role that physiological and environmental factors play in constraining the activity of methane-oxidizing bacteria in the Gulf of Mexico
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