3,436 research outputs found
Structure of the full-length TRPV2 channel by cryo-EM.
Transient receptor potential (TRP) proteins form a superfamily Ca(2+)-permeable cation channels regulated by a range of chemical and physical stimuli. Structural analysis of a 'minimal' TRP vanilloid subtype 1 (TRPV1) elucidated a mechanism of channel activation by agonists through changes in its outer pore region. Though homologous to TRPV1, other TRPV channels (TRPV2-6) are insensitive to TRPV1 activators including heat and vanilloids. To further understand the structural basis of TRPV channel function, we determined the structure of full-length TRPV2 at ∼5 Å resolution by cryo-electron microscopy. Like TRPV1, TRPV2 contains two constrictions, one each in the pore-forming upper and lower gates. The agonist-free full-length TRPV2 has wider upper and lower gates compared with closed and agonist-activated TRPV1. We propose these newly revealed TRPV2 structural features contribute to diversity of TRPV channels
Comparison of Post-injection Site Pain Between Technetium Sulfur Colloid and Technetium Tilmanocept in Breast Cancer Patients Undergoing Sentinel Lymph Node Biopsy.
BackgroundNo prior studies have examined injection pain associated with Technetium-99m Tilmanocept (TcTM).MethodsThis was a randomized, double-blinded study comparing postinjection site pain between filtered Technetium Sulfur Colloid (fTcSC) and TcTM in breast cancer lymphoscintigraphy. Pain was evaluated with a visual analogue scale (VAS) (0-100 mm) and the short-form McGill Pain Questionnaire (SF-MPQ). The primary endpoint was mean difference in VAS scores at 1-min postinjection between fTcSC and TcTM. Secondary endpoints included a comparison of SF-MPQ scores between the groups at 5 min postinjection and construction of a linear mixed effects model to evaluate the changes in pain during the 5-min postinjection period.ResultsFifty-two patients underwent injection (27-fTcSC, 25-TcTM). At 1-min postinjection, patients who received fTcSC experienced a mean change in pain of 16.8 mm (standard deviation (SD) 19.5) compared with 0.2 mm (SD 7.3) in TcTM (p = 0.0002). At 5 min postinjection, the mean total score on the SF-MPQ was 2.8 (SD 3.0) for fTcSC versus 2.1 (SD 2.5) for TcTM (p = 0.36). In the mixed effects model, injection agent (p < 0.001), time (p < 0.001) and their interaction (p < 0.001) were associated with change in pain during the 5-min postinjection period. The model found fTcSC resulted in significantly more pain of 15.2 mm (p < 0.001), 11.3 mm (p = 0.001), and 7.5 mm (p = 0.013) at 1, 2, and 3 min postinjection, respectively.ConclusionsInjection with fTcSC causes significantly more pain during the first 3 min postinjection compared with TcTM in women undergoing lymphoscintigraphy for breast cancer
HST astrometry in the Orion Nebula Cluster: census of low-mass runaways
We present a catalog of high-precision proper motions in the Orion Nebula
Cluster (ONC), based on Treasury Program observations with the Hubble Space
Telescope's (HST) ACS/WFC camera. Our catalog contains 2,454 objects in the
magnitude range of , thus probing the stellar masses
of the ONC from 0.4 down to 0.02 over an area
of 550 arcmin. We provide a number of internal velocity dispersion
estimates for the ONC that indicate a weak dependence on the stellar location
and mass. There is good agreement with the published velocity dispersion
estimates, although nearly all of them (including ours at
and mas yr) might be biased by the overlapping young
stellar populations of Orion A. We identified 4 new ONC candidate runaways
based on HST and the Gaia DR2 data, all with masses less than 1
. The total census of known candidate runaway sources is 10 -- one of
the largest samples ever found in any Milky Way open star cluster.
Surprisingly, none of them has the tangential velocity exceeding 20 km
s. If most of them indeed originated in the ONC, it may compel
re-examination of dynamical processes in very young star clusters. It appears
that the mass function of the ONC is not significantly affected by the lost
runaways.Comment: 16 pages, 10 figures, 5 tables. Accepted for publication in A
Magnetic light
In this paper we report on the observation of novel and highly unusual
magnetic state of light. It appears that in small holes light quanta behave as
small magnets so that light propagation through such holes may be affected by
magnetic field. When arrays of such holes are made, magnetic light of the
individual holes forms novel and highly unusual two-dimensional magnetic light
material. Magnetic light may soon become a great new tool for quantum
communication and computing.Comment: Submitted to Phys.Rev.Lett., 3 figure
Small-x QCD studies with CMS at the LHC
The capabilities of the CMS experiment to study the low-x parton structure
and QCD evolution in the proton and the nucleus at LHC energies are presented
through four different measurements, to be carried out in Pb-Pb at sqrt(s_NN) =
5.5 TeV: (i) the charged hadron rapidity density and (ii) the
ultraperipheral (photo)production of Upsilon; and in p-p at sqrt(s) = 14 TeV:
(iii) inclusive forward jets and (iv) Mueller-Navelet dijets (separated by
8).Comment: Quark Matter'06 Proceedings. To appear in J.Phys.
Fast 18F Labeling of a Near-Infrared Fluorophore Enables Positron Emission Tomography and Optical Imaging of Sentinel Lymph Nodes
We combine a novel boronate trap for F− with a near-infrared fluorophore into a single molecule. Attachment to targeting ligands enables localization by positron emission tomography (PET) and near-infrared fluorescence (NIRF). Our first application of this generic tag is to label Lymphoseek (tilmanocept), an agent designed for receptor-specific sentinel lymph node (SLN) mapping. The new conjugate incorporates 18F− in a single, aqueous step, targets mouse SLN rapidly (1 h) with reduced distal lymph node accumulation, permits PET or scintigraphic imaging of SLN, and enables NIRF-guided excision and histological verification even after 18F decay. This embodiment is superior to current SLN mapping agents such as nontargeted [99mTc]sulfur colloids and Isosulfan Blue, as well as the phase III targeted ligand [99mTc]SPECT Lymphoseek counterpart, species that are visible by SPECT or visible absorbance separately. Facile incorporation of 18F into a NIRF probe should promote many synergistic PET and NIRF combinations
Comparative evaluation of [(99m)tc]tilmanocept for sentinel lymph node mapping in breast cancer patients: results of two phase 3 trials.
BackgroundSentinel lymph node (SLN) surgery is used worldwide for staging breast cancer patients and helps limit axillary lymph node dissection. [(99m)Tc]Tilmanocept is a novel receptor-targeted radiopharmaceutical evaluated in 2 open-label, nonrandomized, within-patient, phase 3 trials designed to assess the lymphatic mapping performance.MethodsA total of 13 centers contributed 148 patients with breast cancer. Each patient received [(99m)Tc]tilmanocept and vital blue dye (VBD). Lymph nodes identified intraoperatively as radioactive and/or blue stained were excised and histologically examined. The primary endpoint, concordance (lower boundary set point at 90 %), was the proportion of nodes detected by VBD and [(99m)Tc]tilmanocept.ResultsA total of 13 centers contributed 148 patients who were injected with both agents. Intraoperatively, 207 of 209 nodes detected by VBD were also detected by [(99m)Tc]tilmanocept for a concordance rate of 99.04 % (p < 0.0001). [(99m)Tc]tilmanocept detected a total of 320 nodes, of which 207 (64.7 %) were detected by VBD. [(99m)Tc]Tilmanocept detected at least 1 SLN in more patients (146) than did VBD (131, p < 0.0001). In 129 of 131 patients with ≥1 blue node, all blue nodes were radioactive. Of 33 pathology-positive nodes (18.2 % patient pathology rate), [(99m)Tc]tilmanocept detected 31 of 33, whereas VBD detected only 25 of 33 (p = 0.0312). No pathology-positive SLNs were detected exclusively by VBD. No serious adverse events were attributed to [(99m)Tc]tilmanocept.Conclusion[(99m)Tc]Tilmanocept demonstrated success in detecting a SLN while meeting the primary endpoint. Interestingly, [(99m)Tc]tilmanocept was additionally noted to identify more SLNs in more patients. This localization represented a higher number of metastatic breast cancer lymph nodes than that of VBD
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