193 research outputs found
No change in calculated creatinine clearance after tenofovir initiation among Thai patients
Objectives Thai patients have a lower average body weight than patients from western Europe or the USA. Tenofovir is largely prescribed at the standard dosage of 300 mg once daily: therefore, the per kilogram dose is higher in Thailand than in the USA. We asked the question whether this higher per kilogram dose was associated with more nephrotoxicity. Methods Thai patients from the Staccato trial were treated with tenofovir/lamivudine combined with ritonavir-boosted saquinavir. Creatinine values were measured before the start of tenofovir and then every 12 weeks. Renal function was assessed using the Cockcroft-Gault formula and the MDRD formula. To compare CLCR before and after tenofovir, the t-paired or Wilcoxon signed rank tests were used. One-way analysis of variance and Spearman's correlation coefficient were used to study CLCR longitudinally. Results CLCR remained stable after a median of 21 weeks on tenofovir (difference of +1.06 mL/min; 95% CI −2.7-4.8, P = 0.58), even among patients with underlying diseases. The mean CLCR remained stable across time (P = 0.17). Conclusions We did not find renal dysfunction on tenofovir among Thai patients included in the Staccato trial. Tenofovir could be safely prescribed at a standard dosage of 300 mg once daily in the Thai populatio
Search for radiative pumping lines of OH masers: I. The 34.6um absorption line towards 1612 MHz OH maser sources
The 1612 MHz hydroxyl maser in circumstellar envelopes has long been thought
to be pumped by 34.6um photons. Only recently, the Infrared Space Observatory
has made possible spectroscopic observations which enable the direct
confirmation of this pumping mechanism in a few cases. To look for the presence
of this pumping line, we have searched the Infrared Space Observatory Data
Archive and found 178 spectra with data around 34.6um for 87 galactic 1612MHz
masers. The analysis performed showed that the noise level and the spectral
resolution of the spectra are the most important factors affecting the
detection of the 34.6um absorption line. Only 5 objects from the sample (3 red
supergiants and 2 galactic center sources) are found to show clear 34.6um
absorption (all of them already known) while two additional objects only
tentatively show this line. The 3 supergiants show similar pump rates and their
masers might be purely radiatively pumped. The pump rates of OH masers in late
type stars are found to be about 0.05, only 1/5 of the theoretical value of
0.25 derived by Elitzur (1992). We have also found 16 maser sources which,
according to the analysis assuming Elitzur's pump rate, should show the 34.6
m absorption line but do not. These non-detections can be tentatively
explained by far-infrared photon pumping, clumpy nature of the OH masing region
or a limb-filling emission effect in the OH shell.Comment: 11 pages, 8 figures, 3 table
Circuit dissection of the role of somatostatin in itch and pain
Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide
Control of mechanical pain hypersensitivity in mice through ligand-targeted photoablation of TrkB-positive sensory neurons
Mechanical allodynia is a major symptom of neuropathic pain whereby innocuous touch evokes severe pain. Here we identify a population of peripheral sensory neurons expressing TrkB that are both necessary and sufficient for producing pain from light touch after nerve injury in mice. Mice in which TrkB-Cre-expressing neurons are ablated are less sensitive to the lightest touch under basal conditions, and fail to develop mechanical allodynia in a model of neuropathic pain. Moreover, selective optogenetic activation of these neurons after nerve injury evokes marked nociceptive behavior. Using a phototherapeutic approach based upon BDNF, the ligand for TrkB, we perform molecule-guided laser ablation of these neurons and achieve long-term retraction of TrkB-positive neurons from the skin and pronounced reversal of mechanical allodynia across multiple types of neuropathic pain. Thus we identify the peripheral neurons which transmit pain from light touch and uncover a novel pharmacological strategy for its treatment
Imagined people, behaviour and future mobility: Insights from visions of electric vehicles and car clubs in the United Kingdom
This study focuses on imagined futures of personal mobility in the United Kingdom in the context of the need to reduce greenhouse gas emissions from transport. Focusing on two innovations, electric vehicles and car clubs, the study investigates how people, behaviour and mobility are imagined in a range of visioning documents about the future up to 2050, a timeline that is critically important for emission reduction targets. We find that people are imagined primarily as consumers in line with the rational actor paradigm, with many visions focusing on low-carbon vehicles as a sustainability solution. This simple technological substitution vision does not play to the strengths of electric vehicles, and diminishes their transformative potential. There are fewer car club visions; these show less car ownership, but retain high mobility and an economic growth perspective. Our findings support the idea that much future mobility visioning is used to support the status quo, rather than to explore a variety of futures with diverse portrayal of people, behaviour and mobility
Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy
A Dual Infection Pseudorabies Virus Conditional Reporter Approach to Identify Projections to Collateralized Neurons in Complex Neural Circuits
Replication and transneuronal transport of pseudorabies virus (PRV) are widely used to define the organization of neural circuits in rodent brain. Here we report a dual infection approach that highlights connections to neurons that collateralize within complex networks. The method combines Cre recombinase (Cre) expression from a PRV recombinant (PRV-267) and Cre-dependent reporter gene expression from a second infecting strain of PRV (PRV-263). PRV-267 expresses both Cre and a monomeric red fluorescent protein (mRFP) fused to viral capsid protein VP26 (VP26-mRFP) that accumulates in infected cell nuclei. PRV-263 carries a Brainbow cassette and expresses a red (dTomato) reporter that fills the cytoplasm. However, in the presence of Cre, the dTomato gene is recombined from the cassette, eliminating expression of the red reporter and liberating expression of either yellow (EYFP) or cyan (mCerulean) cytoplasmic reporters. We conducted proof-of-principle experiments using a well-characterized model in which separate injection of recombinant viruses into the left and right kidneys produces infection of neurons in the renal preautonomic network. Neurons dedicated to one kidney expressed the unique reporters characteristic of PRV-263 (cytoplasmic dTomato) or PRV-267 (nuclear VP26-mRFP). Dual infected neurons expressed VP26-mRFP and the cyan or yellow cytoplasmic reporters activated by Cre-mediated recombination of the Brainbow cassette. Differential expression of cyan or yellow reporters in neurons lacking VP26-mRFP provided a unique marker of neurons synaptically connected to dual infected neurons, a synaptic relationship that cannot be distinguished using other dual infection tracing approaches. These data demonstrate Cre-enabled conditional reporter expression in polysynaptic circuits that permits the identification of collateralized neurons and their presynaptic partners
Genetic Evidence for Involvement of Neuronally Expressed S1P1 Receptor in Nociceptor Sensitization and Inflammatory Pain
Sphingosine-1-phosphate (S1P) is a key regulator of immune response. Immune cells, epithelia and blood cells generate high levels of S1P in inflamed tissue. However, it is not known if S1P acts on the endings of nociceptive neurons, thereby contributing to the generation of inflammatory pain. We found that the S1P1 receptor for S1P is expressed in subpopulations of sensory neurons including nociceptors. Both S1P and agonists at the S1P1 receptor induced hypersensitivity to noxious thermal stimulation in vitro and in vivo. S1P-induced hypersensitivity was strongly attenuated in mice lacking TRPV1 channels. S1P and inflammation-induced hypersensitivity was significantly reduced in mice with a conditional nociceptor-specific deletion of the S1P1 receptor. Our data show that neuronally expressed S1P1 receptors play a significant role in regulating nociceptor function and that S1P/S1P1 signaling may be a key player in the onset of thermal hypersensitivity and hyperalgesia associated with inflammation
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