792 research outputs found
Adjuvant Intravesical Chemohyperthermia Versus Passive Chemotherapy in Patients with Intermediate-risk Non–muscle-invasive Bladder Cancer (HIVEC-II): A Phase 2, Open-label, Randomised Controlled Trial
Background: Adjuvant intravesical chemotherapy following tumour resection is recommended for intermediate-risk non–muscle-invasive bladder cancer (NMIBC). Objective: To assess the efficacy and safety of adjuvant intravesical chemohyperthermia (CHT) for intermediate-risk NMIBC. Design, setting, and participants: HIVEC-II is an open-label, phase 2 randomised controlled trial of CHT versus chemotherapy alone in patients with intermediate-risk NMIBC recruited at 15 centres between May 2014 and December 2017 (ISRCTN 23639415). Randomisation was stratified by treating hospital. Interventions: Patients were randomly assigned (1:1) to adjuvant CHT with mitomycin C at 43°C or to room-temperature mitomycin C (control). Both treatment arms received six weekly instillations of 40 mg of mitomycin C lasting for 60 min. Outcome measurements and statistical analysis: The primary endpoint was 24-mo disease-free survival as determined via cystoscopy and urinary cytology. Analysis was by intention to treat. Results: A total of 259 patients (131 CHT vs 128 control) were randomised. At 24 mo, 42 patients (32%) in the CHT group and 49 (38%) in the control group had experienced recurrence. Disease-free survival at 24 mo was 61% (95% confidence interval [CI] 51–69%) in the CHT arm and 60% (95% CI 50–68%) in the control arm (hazard ratio [HR] 0.92, 95% CI 0.62–1.37; log-rank p = 0.8). Progression-free survival was higher in the control arm (HR 3.44, 95% CI 1.09–10.82; log-rank p = 0.02) on intention-to-treat analysis but was not significantly higher on per-protocol analysis (HR 2.87, 95% CI 0.83–9.98; log-rank p = 0.06). Overall survival was similar (HR 2.55, 95% CI 0.77–8.40; log-rank p = 0.09). Patients undergoing CHT were less likely to complete their treatment (n =75, 59% vs n = 111, 89%). Adverse events were reported by 164 patients (87 CHT vs 77 control). Major (grade III) adverse events were rare (13 CHT vs 7 control). Conclusions: CHT cannot be recommended over chemotherapy alone for intermediate-risk NMIBC. Adverse events following CHT were of low grade and short-lived, although patients were less likely to complete their treatment. Patient summary: The HIVEC-II trial investigated the role of heated chemotherapy instillations in the bladder for treatment of intermediate-risk non–muscle-invasive bladder cancer. We found no cancer control benefit from heated chemotherapy instillations over room-temperature chemotherapy. Adverse events following heated chemotherapy were low grade and short-lived, although these patients were less likely to complete their treatment
Cosmology of a Scalar Field Coupled to Matter and an Isotropy-Violating Maxwell Field
Motivated by the couplings of the dilaton in four-dimensional effective
actions, we investigate the cosmological consequences of a scalar field coupled
both to matter and a Maxwell-type vector field. The vector field has a
background isotropy-violating component. New anisotropic scaling solutions
which can be responsible for the matter and dark energy dominated epochs are
identified and explored. For a large parameter region the universe expands
almost isotropically. Using that the CMB quadrupole is extremely sensitive to
shear, we constrain the ratio of the matter coupling to the vector coupling to
be less than 10^(-5). Moreover, we identify a large parameter region,
corresponding to a strong vector coupling regime, yielding exciting and viable
cosmologies close to the LCDM limit.Comment: Refs. added, some clarifications. Published in JHEP10(2012)06
Inflation with stable anisotropic hair: is it cosmologically viable?
Recently an inflationary model with a vector field coupled to the inflaton
was proposed and the phenomenology studied for the Bianchi type I spacetime. It
was found that the model demonstrates a counter-example to the cosmic no-hair
theorem since there exists a stable anisotropically inflationary fix-point. One
of the great triumphs of inflation, however, is that it explains the observed
flatness and isotropy of the universe today without requiring special initial
conditions. Any acceptable model for inflation should thus explain these
observations in a satisfactory way. To check whether the model meets this
requirement, we introduce curvature to the background geometry and consider
axisymmetric spacetimes of Bianchi type II,III and the Kantowski-Sachs metric.
We show that the anisotropic Bianchi type I fix-point is an attractor for the
entire family of such spacetimes. The model is predictive in the sense that the
universe gets close to this fix-point after a few e-folds for a wide range of
initial conditions. If inflation lasts for N e-folds, the curvature at the end
of inflation is typically of order exp(-2N). The anisotropy in the expansion
rate at the end of inflation, on the other hand, while being small on the
one-percent level, is highly significant. We show that after the end of
inflation there will be a period of isotropization lasting for about 2N/3
e-folds. After that the shear scales as the curvature and becomes dominant
around N e-folds after the end of inflation. For plausible bounds on the reheat
temperature the minimum number of e-folds during inflation, required for
consistency with the isotropy of the supernova Ia data, lays in the interval
(21,48). Thus the results obtained for our restricted class of spacetimes
indicates that inflation with anisotropic hair is cosmologically viable.Comment: 25 pages, 3 figures; v2: Minor changes, refs added; v3: JHEP version
(proof-reading corrections
New Constraints (and Motivations) for Abelian Gauge Bosons in the MeV-TeV Mass Range
We survey the phenomenological constraints on abelian gauge bosons having
masses in the MeV to multi-GeV mass range (using precision electroweak
measurements, neutrino-electron and neutrino-nucleon scattering, electron and
muon anomalous magnetic moments, upsilon decay, beam dump experiments, atomic
parity violation, low-energy neutron scattering and primordial
nucleosynthesis). We compute their implications for the three parameters that
in general describe the low-energy properties of such bosons: their mass and
their two possible types of dimensionless couplings (direct couplings to
ordinary fermions and kinetic mixing with Standard Model hypercharge). We argue
that gauge bosons with very small couplings to ordinary fermions in this mass
range are natural in string compactifications and are likely to be generic in
theories for which the gravity scale is systematically smaller than the Planck
mass - such as in extra-dimensional models - because of the necessity to
suppress proton decay. Furthermore, because its couplings are weak, in the
low-energy theory relevant to experiments at and below TeV scales the charge
gauged by the new boson can appear to be broken, both by classical effects and
by anomalies. In particular, if the new gauge charge appears to be anomalous,
anomaly cancellation does not also require the introduction of new light
fermions in the low-energy theory. Furthermore, the charge can appear to be
conserved in the low-energy theory, despite the corresponding gauge boson
having a mass. Our results reduce to those of other authors in the special
cases where there is no kinetic mixing or there is no direct coupling to
ordinary fermions, such as for recently proposed dark-matter scenarios.Comment: 49 pages + appendix, 21 figures. This is the final version which
appears in JHE
MHC Class I Endosomal and Lysosomal Trafficking Coincides with Exogenous Antigen Loading in Dendritic Cells
BACKGROUND: Cross-presentation by dendritic cells (DCs) is a crucial prerequisite for effective priming of cytotoxic T-cell responses against bacterial, viral and tumor antigens; however, this antigen presentation pathway remains poorly defined. METHODOLOGY/PRINCIPAL FINDINGS: In order to develop a comprehensive understanding of this process, we tested the hypothesis that the internalization of MHC class I molecules (MHC-I) from the cell surface is directly involved in cross-presentation pathway and the loading of antigenic peptides. Here we provide the first examination of the internalization of MHC-I in DCs and we demonstrate that the cytoplasmic domain of MHC-I appears to act as an addressin domain to route MHC-I to both endosomal and lysosomal compartments of DCs, where it is demonstrated that loading of peptides derived from exogenously-derived proteins occurs. Furthermore, by chasing MHC-I from the cell surface of normal and transgenic DCs expressing mutant forms of MHC-I, we observe that a tyrosine-based endocytic trafficking motif is required for the constitutive internalization of MHC-I molecules from the cell surface into early endosomes and subsequently deep into lysosomal peptide-loading compartments. Finally, our data support the concept that multiple pathways of peptide loading of cross-presented antigens may exist depending on the chemical nature and size of the antigen requiring processing. CONCLUSIONS/SIGNIFICANCE: We conclude that DCs have 'hijacked' and adapted a common vacuolar/endocytic intracellular trafficking pathway to facilitate MHC I access to the endosomal and lysosomal compartments where antigen processing and loading and antigen cross-presentation takes place
Geographical variation in radiological services: a nationwide survey
BACKGROUND: Geographical variation in health care services challenges the basic principle of fair allocation of health care resources. This study aimed to investigate geographical variation in the use of X-ray, CT, MRI and Ultrasound examinations in Norway, the contribution from public and private institutions, and the impact of accessibility and socioeconomic factors on variation in examination rates. METHODS: A nationwide survey of activity in all radiological institutions for the year 2002 was used to compare the rates per thousand of examinations in the counties. The data format was files/printouts where the examinations were recorded according to a code system. RESULTS: Overall rates per thousand of radiological examinations varied by a factor of 2.4. The use of MRI varied from 170 to 2, and CT from 216 to 56 examinations per 1000 inhabitants. Single MRI examinations (knee, cervical spine and head/brain) ranged high in variation, as did certain other spine examinations. For examination of specific organs, the counties' use of one modality was positively correlated with the use of other modalities. Private institutions accounted for 28% of all examinations, and tended towards performing a higher proportion of single examinations with high variability. Indicators of accessibility correlated positively to variation in examination rates, partly due to the figures from the county of Oslo. Correlations between examination rates and socioeconomic factors were also highly influenced by the figures from this county. CONCLUSION: The counties use of radiological services varied substantially, especially CT and MRI examinations. A likely cause of the variation is differences in accessibility. The coexistence of public and private institutions may be a source of variability, along with socioeconomic factors. The findings represent a challenge to the objective of equality in access to health care services, and indicate a potential for better allocation of overall health care resources. PREVIOUS PUBLICATION: The data applied in this article was originally published in Norwegian in: Børretzen I, Lysdahl KB, Olerud HM: Radiologi i Noreg – undersøkingsfrekvens per 2002, tidstrendar, geografisk variasjon og befolkningsdose. StrålevernRapport 2006:6. Østerås: The Norwegian Radiation Protection Authority. The Norwegian Radiation Protection Authority has given the authors permission to republish the data
Recurrent and Founder Mutations in the Netherlands: the Long-QT Syndrome
Background and objective The long-QT syndrome (LQTS) is associated with premature sudden cardiac deaths affecting whole families and is caused by mutations in genes encoding for cardiac proteins. When the same mutation is found in different families (recurrent mutations), this may imply either a common ancestor (founder) or multiple de novo mutations. We aimed to review recurrent mutations in patients with LQTS. Methods By use of our databases, we investigated the number of mutations that were found recurrently (at least three times) in LQT type 1-3 patients in the Netherlands. We studied familial links in the apparently unrelated probands, and we visualised the geographical distribution of these probands. Our results were compared with published literature of founder effects in LQTS outside the Netherlands. Results We counted 14 recurrent LQT mutations in the Netherlands. There are 326 identified carriers of one of these mutations. For three of these mutations, familial links were found between apparently unrelated probands. Conclusion Whereas true LQT founder mutations are described elsewhere in the world, we cannot yet demonstrate a real founder effect of these recurrent mutations in the Netherlands. Further studies on the prevalence of these mutations are indicated, and haplotype-sharing of the mutation carriers is pertinent to provide more evidence for founder mutation-based LQTS pathology in our countr
The Mycobacterium tuberculosis Phagosome Is a HLA-I Processing Competent Organelle
Mycobacterium tuberculosis (Mtb) resides in a long-lived phagosomal compartment that resists maturation. The manner by which Mtb antigens are processed and presented on MHC Class I molecules is poorly understood. Using human dendritic cells and IFN-γ release by CD8+ T cell clones, we examined the processing and presentation pathway for two Mtb–derived antigens, each presented by a distinct HLA-I allele (HLA-Ia versus HLA-Ib). Presentation of both antigens is blocked by the retrotranslocation inhibitor exotoxin A. Inhibitor studies demonstrate that, after reaching the cytosol, both antigens require proteasomal degradation and TAP transport, but differ in the requirement for ER–golgi egress and new protein synthesis. Specifically, presentation by HLA-B8 but not HLA-E requires newly synthesized HLA-I and transport through the ER–golgi. Phenotypic analysis of the Mtb phagosome by flow organellometry revealed the presence of Class I and loading accessory molecules, including TAP and PDI. Furthermore, loaded HLA-I:peptide complexes are present within the Mtb phagosome, with a pronounced bias towards HLA-E:peptide complexes. In addition, protein analysis also reveals that HLA-E is enriched within the Mtb phagosome compared to HLA-A2. Together, these data suggest that the phagosome, through acquisition of ER–localized machinery and as a site of HLA-I loading, plays a vital role in the presentation of Mtb–derived antigens, similar to that described for presentation of latex bead-associated antigens. This is, to our knowledge, the first description of this presentation pathway for an intracellular pathogen. Moreover, these data suggest that HLA-E may play a unique role in the presentation of phagosomal antigens
Distinguishing Family from Friends
Kinship and friendship are key human relationships. Increasingly, data suggest that people are not less altruistic toward friends than close kin. Some accounts suggest that psychologically we do not distinguish between them; countering this is evidence that kinship provides a unique explanatory factor. Using the Implicit Association Test, we examined how people implicitly think about close friends versus close kin in three contexts. In Experiment 1, we examined generic attitudinal dispositions toward friends and family. In Experiment 2, attitude similarity as a marker of family and friends was examined, and in Experiments 3 and 4, strength of in-group membership for family and friends was examined. Findings show that differences exist in implicit cognitive associations toward family and friends. There is some evidence that people hold more positive general dispositions toward friends, associate attitude similarity more with friends, consider family as more representative of the in-group than friends, but see friends as more in-group than distant kin
Quantitative Whole Body Biodistribution of Fluorescent-Labeled Agents by Non-Invasive Tomographic Imaging
When small molecules or proteins are injected into live animals, their physical and chemical properties will significantly affect pharmacokinetics, tissue penetration, and the ultimate routes of metabolism and clearance. Fluorescence molecular tomography (FMT) offers the ability to non-invasively image and quantify temporal changes in fluorescence throughout the major organ systems of living animals, in a manner analogous to traditional approaches with radiolabeled agents. This approach is best used with biotherapeutics (therapeutic antibodies, or other large proteins) or large-scaffold drug-delivery vectors, that are minimally affected by low-level fluorophore conjugation. Application to small molecule drugs should take into account the significant impact of fluorophore labeling on size and physicochemical properties, however, the presents studies show that this technique is readily applied to small molecule agents developed for far-red (FR) or near infrared (NIR) imaging. Quantification by non-invasive FMT correlated well with both fluorescence from tissue homogenates as well as with planar (2D) fluorescence reflectance imaging of excised intact organs (r2 = 0.996 and 0.969, respectively). Dynamic FMT imaging (multiple times from 0 to 24 h) performed in live mice after the injection of four different FR/NIR-labeled agents, including immunoglobulin, 20–50 nm nanoparticles, a large vascular imaging agent, and a small molecule integrin antagonist, showed clear differences in the percentage of injected dose per gram of tissue (%ID/g) in liver, kidney, and bladder signal. Nanoparticles and IgG1 favored liver over kidney signal, the small molecule integrin-binding agent favored rapid kidney and bladder clearance, and the vascular agent, showed both liver and kidney clearance. Further assessment of the volume of distribution of these agents by fluorescent volume added information regarding their biodistribution and highlighted the relatively poor extravasation into tissue by IgG1. These studies demonstrate the ability of quantitative FMT imaging of FR/NIR agents to non-invasively visualize and quantify the biodistribution of different agents over time
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