247 research outputs found

    Functional binding interaction identified between the axonal CAM L1 and members of the ERM family

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    Ayeast two-hybrid library was screened using the cytoplasmic domain of the axonal cell adhesion molecule L1 to identify binding partners that may be involved in the regulation of L1 function. The intracellular domain of L1 bound to ezrin, a member of the ezrin, radixin, and moesin (ERM) family of membrane–cytoskeleton linking proteins, at a site overlapping that for AP2, a clathrin adaptor. Binding of bacterial fusion proteins confirmed this interaction. To determine whether ERM proteins interact with L1 in vivo, extracellular antibodies to L1 were used to force cluster the protein on cultured hippocampal neurons and PC12 cells, which were then immunolabeled for ERM proteins. Confocal analysis revealed a precise pattern of codistribution between ERMs and L1 clusters in axons and PC12 neurites, whereas ERMs in dendrites and spectrin labeling remained evenly distributed. Transfection of hippocampal neurons grown on an L1 substrate with a dominant negative ERM construct resulted in extensive and abnormal elaboration of membrane protrusions and an increase in axon branching, highlighting the importance of the ERM–actin interaction in axon development. Together, our data indicate that L1 binds directly to members of the ERM family and suggest this association may coordinate aspects of axonal morphogenesis

    Chronic pain and opioid analgesic use : a case report

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    Opioids are often ineffective for managing chronic non-malignant pain. If prescribed, this should be as part of an opioid trial with clear aims of therapy, tapering/stopping if it is ineffective, or if it is causing adverse effects. Clinical guidance is available but there are many gaps in the evidence

    Deep sequencing of the vaginal microbiota of women with HIV

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    Background:Women living with HIV and co-infected with bacterial vaginosis (BV) are at higher risk for transmitting HIV to a partner or newborn. It is poorly understood which bacterial communities constitute BV or the normal vaginal microbiota among this population and how the microbiota associated with BV responds to antibiotic treatment. Methods and Findings: The vaginal microbiota of 132 HIV positive Tanzanian women, including 39 who received metronidazole treatment for BV, were profiled using Illumina to sequence the V6 region of the 16S rRNA gene. Of note, Gardnerella vaginalis and Lactobacillus iners were detected in each sample constituting core members of the vaginal microbiota. Eight major clusters were detected with relatively uniform microbiota compositions. Two clusters dominated by L. iners or L. crispatus were strongly associated with a normal microbiota. The L. crispatus dominated microbiota were associated with low pH, but when L. crispatus was not present, a large fraction of L. iners was required to predict a low pH. Four clusters were strongly associated with BV, and were dominated by Prevotella bivia, Lachnospiraceae, or a mixture of different species. Metronidazole treatment reduced the microbial diversity and perturbed the BV-associated microbiota, but rarely resulted in the establishment of a lactobacilli-dominated microbiota. Conclusions: Illumina based microbial profiling enabled high though-put analyses of microbial samples at a high phylogenetic resolution. The vaginal microbiota among women living with HIV in Sub-Saharan Africa constitutes several profiles associated with a normal microbiota or BV. Recurrence of BV frequently constitutes a different BV-associated profile than before antibiotic treatment

    Clastic Polygonal Networks Around Lyot Crater, Mars: Possible Formation Mechanisms From Morphometric Analysis

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    Polygonal networks of patterned ground are a common feature in cold-climate environments. They can form through the thermal contraction of ice-cemented sediment (i.e. formed from fractures), or the freezing and thawing of ground ice (i.e. formed by patterns of clasts, or ground deformation). The characteristics of these landforms provide information about environmental conditions. Analogous polygonal forms have been observed on Mars leading to inferences about environmental conditions. We have identified clastic polygonal features located around Lyot crater, Mars (50°N, 30°E). These polygons are unusually large (> 100 m diameter) compared to terrestrial clastic polygons, and contain very large clasts, some of which are up to 15 metres in diameter. The polygons are distributed in a wide arc around the eastern side of Lyot crater, at a consistent distance from the crater rim. Using high-resolution imaging data, we digitised these features to extract morphological information. These data are compared to existing terrestrial and Martian polygon data to look for similarities and differences and to inform hypotheses concerning possible formation mechanisms. Our results show the clastic polygons do not have any morphometric features that indicate they are similar to terrestrial sorted, clastic polygons formed by freeze-thaw processes. They are too large, do not show the expected variation in form with slope, and have clasts that do not scale in size with polygon diameter. However, the clastic networks are similar in network morphology to thermal contraction cracks, and there is a potential direct Martian analogue in a sub-type of thermal contraction polygons located in Utopia Planitia. Based upon our observations, we reject the hypothesis that polygons located around Lyot formed as freeze-thaw polygons and instead an alternative mechanism is put forward: they result from the infilling of earlier thermal contraction cracks by wind-blown material, which then became compressed and/or cemented resulting in a resistant fill. Erosion then leads to preservation of these polygons in positive relief, while later weathering results in the fracturing of the fill material to form angular clasts. These results suggest that there was an extensive area of ice-rich terrain, the extent of which is linked to ejecta from Lyot crater

    Clinical activity of ipilimumab for metastatic uveal melanoma: a retrospective review of the Dana-Farber Cancer Institute, Massachusetts General Hospital, Memorial Sloan-Kettering Cancer Center, and University Hospital of Lausanne experience.

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    BACKGROUND: Uveal melanoma exhibits a high incidence of metastases; and, to date, there is no systemic therapy that clearly improves outcomes. The anticytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) antibody ipilimumab is a standard of care for metastatic melanoma; however, the clinical activity of CTLA-4 inhibition in patients with metastatic uveal melanoma is poorly defined. METHODS: To assess ipilimumab in this setting, the authors performed a multicenter, retrospective analysis of 4 hospitals in the United States and Europe. Clinical characteristics, toxicities, and radiographic disease burden, as determined by central, blinded radiology review, were evaluated. RESULTS: Thirty-nine patients with uveal melanoma were identified, including 34 patients who received 3 mg/kg ipilimumab and 5 who received 10 mg/kg ipilimumab. Immune-related response criteria and modified World Health Organization criteria were used to assess the response rate (RR) and the combined response plus stable disease (SD) rate after 12 weeks, after 23 weeks, and overall (median follow-up, 50.4 weeks [12.6 months]). At week 12, the RR was 2.6%, and the response plus SD rate was 46.%; at week 23, the RR was 2.6%, and the response plus SD rate was 28.2%. There was 1 complete response and 1 late partial response (at 100 weeks after initial SD) for an immune-related RR of 5.1%. Immune-related adverse events were observed in 28 patients (71.8%) and included 7 (17.9%) grade 3 and 4 events. Immune-related adverse events were more frequent in patients who received 10 mg/kg ipilimumab than in those who received 3 mg/kg ipilimumab. The median overall survival from the first dose of ipilimumab was 9.6 months (95% confidence interval, 6.3-13.4 months; range, 1.6-41.6 months). Performance status, lactate dehydrogenase level, and an absolute lymphocyte count ≥ 1000 cells/μL at week 7 were associated significantly with survival. CONCLUSIONS: In this multicenter, retrospective analysis of 4 hospitals in the United States and Europe of patients with uveal melanoma, durable responses to ipilimumab and manageable toxicity were observed

    Symmetric invariants and cohomology of groups

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46235/1/208_2005_Article_BF01446902.pd

    Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

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    We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

    Observation of the Ξc+\Xi_c^+ Charmed Baryon Decays to Σ+Kπ+\Sigma^+ K^-\pi^+, Σ+Kˉ0\Sigma^+ \bar{K}^{*0}, and ΛKπ+π+\Lambda K^-\pi^+\pi^+

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    We have observed two new decay modes of the charmed baryon Ξc+\Xi_c^+ into Σ+Kπ+\Sigma^+ K^-\pi^+ and Σ+Kˉ0\Sigma^+ \bar{K}^{*0} using data collected with the CLEO II detector. We also present the first measurement of the branching fraction for the previously observed decay mode Ξc+ΛKπ+π+\Xi_c^+\to\Lambda K^-\pi^+\pi^+. The branching fractions for these three modes relative to Ξc+Ξπ+π+\Xi_c^+\to\Xi^-\pi^+\pi^+ are measured to be 1.18±0.26±0.171.18 \pm 0.26 \pm 0.17, 0.92±0.27±0.140.92 \pm 0.27 \pm 0.14, and 0.58±0.16±0.070.58 \pm 0.16 \pm 0.07, respectively.Comment: 12 page uuencoded postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Measurement of the Mass Splittings between the bbˉχb,J(1P)b\bar{b}\chi_{b,J}(1P) States

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    We present new measurements of photon energies and branching fractions for the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the chi_b states are determined from the measured radiative photon energies. The ratio of mass splittings between the chi_b substates, r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information on the nature of the bbbar confining potential. We find r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN
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