626 research outputs found
Cytotoxic CD4 T Cells in Antiviral Immunity
CD4 T cells that acquire cytotoxic phenotype and function have been repeatedly identified in humans, mice, and other species in response to many diverse pathogens. Since CD4 cytotoxic T cells are able to recognize antigenic determinants unique from those recognized by the parallel CD8 cytotoxic T cells, they can potentially contribute additional immune surveillance and direct effector function by lysing infected or malignant cells. Here, we briefly review much of what is known about the generation of cytotoxic CD4 T cells and describe our current understanding of their role in antiviral immunity. Furthering our understanding of the many roles of CD4 T cells during an anti-viral response is important for developing effective vaccine strategies that promote long-lasting protective immunity
TRYMS : the ethical and practical considerations of a double-blind placebo controlled randomised clinical trial
Bimaterial Composites via Colloidal Rolling Techniques: III, Mechanical Properties
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65273/1/j.1151-2916.1999.tb02261.x.pd
Testosterone replacement in young male cancer survivors (TRYMS) - pragmatic adaptation of trial design for a trial struggling with recruitment
Time evolution of the Rabi Hamiltonian from the unexcited vacuum
The Rabi Hamiltonian describes a single mode of electromagnetic radiation
interacting with a two-level atom. Using the coupled cluster method, we
investigate the time evolution of this system from an initially empty field
mode and an unexcited atom. We give results for the atomic inversion and field
occupation, and find that the virtual processes cause the field to be squeezed.
No anti-bunching occurs.Comment: 25 pages, 8 figures, RevTe
Testosterone replacement in young male cancer survivors: A 6-month double-blind randomised placebo-controlled trial
Background
Young male cancer survivors have lower testosterone levels, higher fat mass, and worse quality of life (QoL) than age-matched healthy controls. Low testosterone in cancer survivors can be due to orchidectomy or effects of chemotherapy and radiotherapy. We have undertaken a double-blind, placebo-controlled, 6-month trial of testosterone replacement in young male cancer survivors with borderline low testosterone (7–12 nmol/l).
Methods and findings
This was a multicentre United Kingdom study conducted in secondary care hospital outpatients. Male survivors of testicular cancer, lymphoma, and leukaemia aged 25–50 years with morning total serum testosterone 7–12 nmol/l were recruited. A total of 136 men were randomised between July 2012 and February 2015 (42.6% aged 25–37 years, 57.4% 38–50 years, 88% testicular cancer, 10% lymphoma, matched for body mass index [BMI]). Participants were randomised 1:1 to receive testosterone (Tostran 2% gel) or placebo for 26 weeks. A dose titration was performed after 2 weeks. The coprimary end points were trunk fat mass and SF36 Physical Functioning score (SF36-PF) at 26 weeks by intention to treat. At 26 weeks, testosterone treatment compared with placebo was associated with decreased trunk fat mass (−0.9 kg, 95% CI −1.6 to −0.3, p = 0.0073), decreased whole-body fat mass (−1.8 kg, 95% CI −2.9 to −0.7, p = 0.0016), and increased lean body mass (1.5 kg, 95% CI 0.9–2.1, p < 0.001). Decrease in fat mass was greatest in those with a high truncal fat mass at baseline. There was no treatment effect on SF36-PF or any other QoL scores. Testosterone treatment was well tolerated. The limitations of our study were as follows: a relatively short duration of treatment, only three cancer groups included, and no hard end point data such as cardiovascular events.
Conclusions
In young male cancer survivors with low-normal morning total serum testosterone, replacement with testosterone is associated with an improvement in body composition.
Trial registration
ISRCTN: 70274195, EudraCT: 2011-000677-31
Broad-band Jet Emission in Young and Powerful Radio Sources: the Case of the CSS Quasar 3C 186
We present the X-ray analysis of a deep ~200 ksec Chandra observation of the
compact steep spectrum radio-loud quasar 3C 186 (z=1.06) and investigate the
contribution of the unresolved radio jet to the total X-ray emission. The
spectral analysis is not conclusive on the origin of the bulk of the X-ray
emission. In order to examine the jet contribution to the X-ray flux, we model
the quasar spectral energy distribution (SED), adopting several scenarios for
the jet emission. For the values of the main physical parameters favored by the
observables, a dominant role of the jet emission in the X-ray band is ruled out
when a single zone (leptonic) scenario is adopted, even including the
contribution of the external photon fields as seed photons for inverse Compton
emission. We then consider a structured jet, with the blazar component that-
although not directly visible in the X-ray band - provides an intense field of
seed synchrotron photons Compton-scattered by electrons in a mildly
relativistic knot. In this case the whole X-ray emission can be accounted for
if we assume a blazar luminosity within the range observed from flat spectrum
radio quasars. The X-ray radiative efficiency of such (structured) jet is
intimately related to the presence of a complex velocity structure. The jet
emission can provide a significant contribution in X-rays if it decelerates
within the host galaxy, on kiloparsec scales. We discuss the implications of
this model in terms of jet dynamics and interaction with the ambient medium.Comment: 17 pages, 5 figures, 4 tables. Accepted for publication in Ap
Life-history evolution and elevated natural mortality in a population of Atlantic cod (Gadus morhua)
Fisheries-induced evolution has been hypothesized to delay the recovery of collapsed fish stocks through effects on their productivity. The cod stock in the southern Gulf of St. Lawrence (SGSL) collapsed in the early 1990s and has shown no recovery since then, due mainly to high natural mortality of adult cod. Age and size at maturation of SGSL cod decreased sharply over time in cohorts produced in the 1950s and 1960s, likely reflecting an evolutionary response to intensified fishing, and have remained low since then, despite severe reductions in fishing mortality over the past 15 years. A predicted consequence of early maturation is increased natural mortality due to higher costs to reproduction. Early maturation may be a cause of increases in natural mortality of SGSL cod in the 1970s but does not appear to be related to the much larger increases since then. Instead, the current high natural mortality of SGSL cod appears to be primarily a cause, rather than a consequence, of the continued early maturation in this population, now replacing fishing mortality as the agent of selection favouring early maturity. This striking example of the failure to reverse fisheries-induced evolution by relaxing fishing pressure emphasizes the need for management strategies that minimize the chances of harvest-induced genetic change
Results of the SEL-I-METRY Phase II Trial on Resensitization of Advanced Iodine Refractory Differentiated Thyroid Cancer to Radioiodine Therapy.
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