1,122 research outputs found

    Bladder cancer, a unique model to understand cancer immunity and develop immunotherapy approaches

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    International audienceWith the mechanistic understanding of immune checkpoints and success in checkpoint blockade using antibodies for the treatment of certain cancers, immunotherapy has become one of the hottest areas in cancer research, with promise of long-lasting therapeutic effect. Currently, however, only a proportion of cancers have a good response to checkpoint inhibition immunotherapy. Better understanding of the cancer response and resistance mechanisms is essential to fully explore the potential of immunotherapy to cure the majority of cancers. Bladder cancer, one of the most common and aggressive malignant diseases, has been successfully treated both at early and advanced stages by different immunotherapeutic approaches, bacillus Calmette-Guérin (BCG) intravesical instillation and anti-PD-1/PD-L1 immune checkpoint blockade, respectively. Therefore, it provides a good model to investigate cancer immune response mechanisms and to improve the efficiency of immunotherapy. Here, we review bladder cancer immunotherapy with equal weight on BCG and anti-PD-1/PD-L1 therapies and demonstrate why and how bladder cancer can be used as a model to study the predictors and mechanisms of cancer immune response and shine light on further development of immunotherapy approaches and response predictive biomarkers to improve immunotherapy of bladder cancer and other malignancies. We review the success of BCG and anti-PD-1/PD-L1 treatment of bladder cancer, the underlying mechanisms and the therapeutic response predictors, including the limits to our knowledge. We then highlight briefly the adaptation of immunotherapy approaches and predictors developed in other cancers for bladder cancer therapy. Finally, we explore the potential of using bladder cancer as a model to investigate cancer immune response mechanisms and new therapeutic approaches, which may be translated into immunotherapy of other human cancers

    A [4Fe-4S]-Fe(CO)(CN)-L-cysteine intermediate is the first organometallic precursor in [FeFe] hydrogenase H-cluster bioassembly.

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    Biosynthesis of the [FeFe] hydrogenase active site (the 'H-cluster') requires the interplay of multiple proteins and small molecules. Among them, the radical S-adenosylmethionine enzyme HydG, a tyrosine lyase, has been proposed to generate a complex that contains an Fe(CO)2(CN) moiety that is eventually incorporated into the H-cluster. Here we describe the characterization of an intermediate in the HydG reaction: a [4Fe-4S][(Cys)Fe(CO)(CN)] species, 'Complex A', in which a CO, a CN- and a cysteine (Cys) molecule bind to the unique 'dangler' Fe site of the auxiliary [5Fe-4S] cluster of HydG. The identification of this intermediate-the first organometallic precursor to the H-cluster-validates the previously hypothesized HydG reaction cycle and provides a basis for elucidating the biosynthetic origin of other moieties of the H-cluster

    Ultrafast entangling gates between nuclear spins using photo-excited triplet states

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    The representation of information within the spins of electrons and nuclei has been powerful in the ongoing development of quantum computers. Although nuclear spins are advantageous as quantum bits (qubits) due to their long coherence lifetimes (exceeding seconds), they exhibit very slow spin interactions and have weak polarisation. A coupled electron spin can be used to polarise the nuclear spin and create fast single-qubit gates, however, the permanent presence of electron spins is a source of nuclear decoherence. Here we show how a transient electron spin, arising from the optically excited triplet state of C60, can be used to hyperpolarise, manipulate and measure two nearby nuclear spins. Implementing a scheme which uses the spinor nature of the electron, we performed an entangling gate in hundreds of nanoseconds: five orders of magnitude faster than the liquid-state J coupling. This approach can be widely applied to systems comprising an electron spin coupled to multiple nuclear spins, such as NV centres, while the successful use of a transient electron spin motivates the design of new molecules able to exploit photo-excited triplet states.Comment: 5 pages, 3 figure

    Controlling spin relaxation with a cavity

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    Spontaneous emission of radiation is one of the fundamental mechanisms by which an excited quantum system returns to equilibrium. For spins, however, spontaneous emission is generally negligible compared to other non-radiative relaxation processes because of the weak coupling between the magnetic dipole and the electromagnetic field. In 1946, Purcell realized that the spontaneous emission rate can be strongly enhanced by placing the quantum system in a resonant cavity -an effect which has since been used extensively to control the lifetime of atoms and semiconducting heterostructures coupled to microwave or optical cavities, underpinning single-photon sources. Here we report the first application of these ideas to spins in solids. By coupling donor spins in silicon to a superconducting microwave cavity of high quality factor and small mode volume, we reach for the first time the regime where spontaneous emission constitutes the dominant spin relaxation mechanism. The relaxation rate is increased by three orders of magnitude when the spins are tuned to the cavity resonance, showing that energy relaxation can be engineered and controlled on-demand. Our results provide a novel and general way to initialise spin systems into their ground state, with applications in magnetic resonance and quantum information processing. They also demonstrate that, contrary to popular belief, the coupling between the magnetic dipole of a spin and the electromagnetic field can be enhanced up to the point where quantum fluctuations have a dramatic effect on the spin dynamics; as such our work represents an important step towards the coherent magnetic coupling of individual spins to microwave photons.Comment: 8 pages, 6 figures, 1 tabl

    Parascedosporium and its relatives: phylogeny and ecological trends

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    The genus Scedosporium and its relatives comprising microascalean anamorphs with slimy conidia were studied. Graphium and Parascedosporium also belong to this complex, while teleomorphs are found in Pseudallescheria, Petriella, Petriellopsis, and Lophotrichus. Species complexes were clearly resolved by rDNA ITS sequencing. Significantly different ecological trends were observed between resolved species aggregates. The Pseudallescheria and Scedosporium prolificans clades were the only lineages with a marked opportunistic potential to mammals, while Petriella species were associated primarily with soil enriched by, e.g. dung. A consistent association with bark beetles was observed in the Graphium clade. The ex-type strain of Rhinocladium lesnei, CBS 108.10 was incorrectly implicated by Vuillemin (1910) in a case of human mycetoma; its sequence was identical to that of the ex-type strain of Parascedosporium tectonae, CBS 127.84

    Early Stage Biomineralization in the Periostracum of the ‘Living Fossil’ Bivalve Neotrigonia

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    A detailed investigation of the shell formation of the palaeoheterodont ‘living fossil’ Neotrigonia concentrated on the timing and manufacture of the calcified ‘bosses’ which stud the outside of all trigonioid bivalves (extant and fossil) has been conducted. Electron microscopy and optical microscopy revealed that Neotrigonia spp. have a spiral-shaped periostracal groove. The periostracum itself is secreted by the basal cell, as a thin dark pellicle, becoming progressively transformed into a thin dark layer by additions of secretions from the internal outer mantle fold. Later, intense secretion of the internal surface of the outer mantle fold forms a translucent layer, which becomes transformed by tanning into a dark layer. The initiation of calcified bosses occurred at a very early stage of periostracum formation, deep within the periostracal groove immediately below the initialmost dark layer. At this stage, they consist of a series of polycyclically twinned crystals. The bosses grow as the periostracum traverse through the periostracal groove, in coordination with the thickening of the dark periostracal layer and until, upon reaching the mantle edge, they impinge upon each other and become transformed into large prisms separated by dark periostracal walls. In conclusion, the initial bosses and the external part of the prismatic layer are fully intraperiostracal. With later growth, the prisms transform into fibrous aggregates, although the details of the process are unknown. This reinforces the relationships with other groups that have the ability to form intraperiostracal calcifications, for example the unionoids with which the trigonioids form the clade Paleoheterodonta. The presence of similar structures in anomalodesmatans and other euheterodonts raises the question of whether this indicates a relationship or represents a convergence. The identification of very early calcification within an organic sheet has interesting implications for our understanding of how shells may have evolved.Coordinated Research Projects CGL2010-20748-C02-01 (AGC, EMH) and 02 (CS) (DGI, Spanish MICINN); the Research Group RNM363 (Consejería de Economía, Investigación, Ciencia y Empleo, Junta de Andalucía); and the FP7 COST Action TD0903 of the European Community

    Pilot, randomized, placebo-controlled clinical field study to evaluate the effectiveness of bupivacaine liposome injectable suspension for the provision of post-surgical analgesia in dogs undergoing stifle surgery

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    Abstract Background Local anesthetics are an important component of perioperative pain management, but the duration of action of available products is limited. We hypothesized that a single local infiltration of a novel bupivacaine liposome injectable suspension (AT-003) would provide clinically effective analgesia over a 72-h period. In a masked, randomized, placebo-controlled, multi-center pilot field study, dogs undergoing lateral retinacular suture placement for cranial cruciate insufficiency were randomly assigned to surgical site infiltration with AT-003 (5.3 mg/kg) or an equivalent volume of saline. Infiltration of the surgical site was done prior to closure. Primary outcome measure was the Glasgow Composite Measure Pain Scale (CMPS-SF) assessed prior to surgery and at 2, 4, 8, 12, 24, 30, 36, 48, 54, 60 and 72 h following surgery by trained individuals. Provision for rescue analgesia was employed. Repeated measures analysis of variance were utilized to test for possible differences between treatment groups and a success/failure analysis was also employed, based on the need for rescue analgesia. Results Forty-six dogs were enrolled and evaluated. For CMPS-SF scores there was a significant overall treatment effect (p = 0.0027) in favor of AT-003. There were significantly more successes in the AT-003 group compared to placebo over each time period (p = 0.0001 for 0–24 h, p = 0.0349 for 0–48 h, and p = 0.0240 for 0-72 h). No significant adverse events were seen. Conclusions AT-003 (bupivacaine liposome injectable suspension) provided measurable local analgesia over a 72-h period following post-stifle surgery surgical site tissue infiltration. Further work is indicated to develop this product for clinical use

    The Cosmological Baryon Density from the Deuterium Abundance at a redshift z = 3.57

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    We present a measurement of the deuterium to hydrogen ratio in a quasar absorption system at redshift z = 3.57 towards QSO 1937-1009. We use a two component fit, with redshifts determined from unsaturated metal lines, to fit the hydrogen and deuterium features simultaneously. We find a low value of D/H = 2.3 \pm 0.6 \times 10^{-5}, which does not agree with other measurements of high D/H (Songaila et al. 1994, Carswell et al. 1994). The absorption system is very metal poor, with metallicities less than 1/100 solar. Standard models of chemical evolution show the astration of deuterium is limited to a few percent from primordial for systems this metal-poor, so we believe our value represents the primordial one. Using predictions of standard big-bang nucleosynthesis and measurements of the cosmic microwave background, our measurement gives the density of baryons in units of the critical density, Ωbh2=0.024±0.006\Omega_b h^2 = 0.024 \pm 0.006, where H_0 = 100 h km s^{-1] Mpc^{-1}.Comment: 10 pages, 2 Figures, also available at http://nately.ucsd.edu/ ; submitted to Natur
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