1,367 research outputs found
Gastrointestinal neuromuscular apparatus: An underestimated target of gut microbiota
Over the last few years, the importance of the resident
intestinal microbiota in the pathogenesis of several gastro-
intestinal diseases has been largely investigated. Growing
evidence suggest that microbiota can influence gastro-
intestinal motility. The current working hypothesis is that
dysbiosis-driven mucosal alterations induce the production
of several inflammatory/immune mediators which affect
gut neuro-muscular functions. Besides these indirect
mucosal-mediated effects, the present review highlights
that recent evidence suggests that microbiota can directly
affect enteric nerves and smooth muscle cells functions
through its metabolic products or bacterial molecular
components translocated from the intestinal lumen. Toll-
like receptors, the bacterial recognition receptors, are
expressed both on enteric nerves and smooth muscle and
are emerging as potential mediators between microbiota
and the enteric neuromuscular apparatus. Furthermore,
the ongoing studies on probiotics support the hypothesis
that the neuromuscular apparatus may represent a target
of intervention, thus opening new physiopathological and
therapeutic scenarios
Interjet Energy Flow/Event Shape Correlations
We identify a class of perturbatively computable measures of interjet energy
flow, which can be associated with well-defined color flow at short distances.
As an illustration, we calculate correlations between event shapes and the flow
of energy, Q_Omega, into an interjet angular region, Omega, in high-energy
two-jet e^+e^- -annihilation events. Laplace transforms with respect to the
event shapes suppress states with radiation at intermediate energy scales, so
that we may compute systematically logarithms of interjet energy flow. This
method provides a set of predictions on energy radiated between jets, as a
function of event shape and of the choice of the region Omega in which the
energy is measured. Non-global logarithms appear as corrections. We apply our
method to a continuous class of event shapes.Comment: 9 pages, 5 figures. Based on talk given by C.F. Berger at TH-2002,
International Conference on Theoretical Physics, Theme 2: "QCD, Hadron
dynamics, etc.", Paris, France, 2002. Slight changes to text, reference adde
Exaggerated Sexual Swellings and the Probability of Conception in Wild Sanje Mangabeys (Cercocebus sanjei)
© 2017, The Author(s). Females of several catarrhine primate species exhibit exaggerated sexual swellings that change in size and coloration during the menstrual cycle and, in some species, gestation. Although their function remains under debate, studies indicate that swellings may contain information males could use to discern ovulation and the probability that a cycle will be conceptive. Here we combine visual ratings of swellings with hormonal data for a group of Sanje mangabeys (18 adult, 3 adolescent females) to determine if their swellings provide reliable information on female fertility. In all cases where ovulation was detected (N=7), it occurred during maximum tumescence, and in 83.3% during the first two days of the âshiny phase,â a period during maximum tumescence when the swelling was brightest. There were no significant differences in maximum tumescence and shiny phase duration among cycles of different probability of conception, although there was a trend toward conceptive cycles exhibiting shorter shiny phases than nonconceptive ones. Only 25% (N=4) of postconceptive swellings developed the shiny phase, and adolescents displayed the longest maximum tumescence and shiny phases. The conspicuous nature of the shiny phase and the frequent overlap between its onset and ovulation suggest that its presence serves as a general signal of ovulation and that the cycle has a high probability of being conceptive. It also suggests that swellings in some Sanje mangabeys are more accurate signals of fertility than in other primates
Examining the Effect of Kindlin-3 Binding Site Mutation on LFA-1-ICAM-1 Bonds by Force Measuring Optical Tweezers
Integrins in effector T cells are crucial for cell adhesion and play a central role in cell-mediated immunity. Leukocyte adhesion deficiency (LAD) type III, a genetic condition that can cause death in early childhood, highlights the importance of integrin/kindlin interactions for immune system function. A TTT/AAA mutation in the cytoplasmic domain of the beta 2 integrin significantly reduces kindlin-3 binding to the beta 2 tail, abolishes leukocyte adhesion to intercellular adhesion molecule 1 (ICAM-1), and decreases T cell trafficking in vivo. However, how kindlin-3 affects integrin function in T cells remains incompletely understood. We present an examination of LFA-1/ICAM-1 bonds in both wild-type effector T cells and those with a kindlin-3 binding site mutation. Adhesion assays show that effector T cells carrying the kindlin-3 binding site mutation display significantly reduced adhesion to the integrin ligand ICAM-1. Using optical trapping, combined with back focal plane interferometry, we measured a bond rupture force of 17.85 +/- 0.63 pN at a force loading rate of 30.21 +/- 4.35 pN/s, for single integrins expressed on wild-type cells. Interestingly, a significant drop in rupture force of bonds was found for TTT/AAA-mutant cells, with a measured rupture force of 10.08 +/- 0.88pN at the same pulling rate. Therefore, kindlin-3 binding to the cytoplasmic tail of the beta 2-tail directly affects catch bond formation and bond strength of integrin-ligand bonds. As a consequence of this reduced binding, CD8+ T cell activation in vitro is also significantly reduced.Peer reviewe
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