10 research outputs found
Protective Intestinal Effects of Pituitary Adenylate Cyclase Activating Polypeptide
Pituitary adenylate cyclase activating polypeptide (PACAP) is an
endogenous neuropeptide widely distributed throughout the body, including the
gastrointestinal tract. Several effects have been described in human and animal
intestines. Among others, PACAP infl uences secretion of intestinal glands, blood
fl ow, and smooth muscle contraction. PACAP is a well-known cytoprotective peptide
with strong anti-apoptotic, anti-infl ammatory, and antioxidant effects. The
present review gives an overview of the intestinal protective actions of this neuropeptide.
Exogenous PACAP treatment was protective in a rat model of small bowel
autotransplantation. Radioimmunoassay (RIA) analysis of the intestinal tissue showed that endogenous PACAP levels gradually decreased with longer-lasting
ischemic periods, prevented by PACAP addition. PACAP counteracted deleterious
effects of ischemia on oxidative stress markers and cytokines. Another series of
experiments investigated the role of endogenous PACAP in intestines in PACAP
knockout (KO) mice. Warm ischemia–reperfusion injury and cold preservation models
showed that the lack of PACAP caused a higher vulnerability against ischemic
periods. Changes were more severe in PACAP KO mice at all examined time points.
This fi nding was supported by increased levels of oxidative stress markers and
decreased expression of antioxidant molecules. PACAP was proven to be protective
not only in ischemic but also in infl ammatory bowel diseases. A recent study showed
that PACAP treatment prolonged survival of Toxoplasma gondii infected mice suffering
from acute ileitis and was able to reduce the ileal expression of proinfl ammatory
cytokines. We completed the present review with recent clinical results obtained
in patients suffering from infl ammatory bowel diseases. It was found that PACAP
levels were altered depending on the activity, type of the disease, and antibiotic
therapy, suggesting its probable role in infl ammatory events of the intestine
Applying code specialization to FFT libraries for integral parameters
Code specialization is an approach that can be used to improve the sequence of optimizations to be performed by the compiler. The performance of code after specialization may vary, depending upon the structure of the application. For FFT libraries, the specialization of code with different parameters may cause an increase in code size, thereby impacting overall behavior of applications executing in environment with small instruction caches. In this article, we propose a new approach for specializing FFT code that can be effectively used to improve performance while limiting the code increase by incorporating dynamic specialization. Our approach makes use of a static compile time analysis and adapts a single version of code to multiple values through runtime specialization. This technique has been applied to different FFT libraries over Itanium IA-64 platform using icc compiler v 9.0. For highly efficient libraries, we are able to achieve speedup of more than 80 % with small increase in code size
Evaluation de la pertinence des radiographies du thorax en réanimation adultes dans un CHU.
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