197 research outputs found
Peri-Implant Bone Loss of External Hexagon and Morse Taper in Patients Wearing Immediately Loaded Overdentures
Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells
It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions
Effect of light-activation with different light-curing units and time intervals on resin cement bond strength to intraradicular dentin
Flavonoids in Kidney Health and Disease
This review summarizes the latest advances in knowledge on the effects of flavonoids on
renal function in health and disease. Flavonoids have antihypertensive, antidiabetic, and
antiinflammatory effects, among other therapeutic activities. Many of them also exert
renoprotective actions that may be of interest in diseases such as glomerulonephritis,
diabetic nephropathy, and chemically-induced kidney insufficiency. They affect several
renal factors that promote diuresis and natriuresis, which may contribute to their
well-known antihypertensive effect. Flavonoids prevent or attenuate the renal injury
associated with arterial hypertension, both by decreasing blood pressure and by acting
directly on the renal parenchyma. These outcomes derive from their interference with
multiple signaling pathways known to produce renal injury and are independent of their
blood pressure-lowering effects. Oral administration of flavonoids prevents or ameliorates
adverse effects on the kidney of elevated fructose consumption, high fat diet, and
types I and 2 diabetes. These compounds attenuate the hyperglycemia-disrupted renal
endothelial barrier function, urinarymicroalbumin excretion, and glomerular hyperfiltration
that results from a reduction of podocyte injury, a determinant factor for albuminuria
in diabetic nephropathy. Several flavonoids have shown renal protective effects against
many nephrotoxic agents that frequently cause acute kidney injury (AKI) or chronic kidney
disease (CKD), such as LPS, gentamycin, alcohol, nicotine, lead or cadmium. Flavonoids
also improve cisplatin- or methotrexate-induced renal damage, demonstrating important
actions in chemotherapy, anticancer and renoprotective effects. A beneficial prophylactic
effect of flavonoids has been also observed against AKI induced by surgical procedures
such as ischemia/reperfusion (I/R) or cardiopulmonary bypass. In several murine models
of CKD, impaired kidney function was significantly improved by the administration of
flavonoids from different sources, alone or in combination with stem cells. In humans,
cocoa flavanols were found to have vasculoprotective effects in patients on hemodialysis.
Moreover, flavonoids develop antitumor activity against renal carcinoma cells with no
toxic effects on normal cells, suggesting a potential therapeutic role in patients with renal
carcinoma.This study was supported by grants from the Carlos III Health
Institute of Spain, and the Red de Investigación Renal REDinREN
number 5 012/0021. FEDER una manera de hacer Europa
Homocysteine and Familial Longevity: The Leiden Longevity Study
Homocysteine concentrations are a read-out of methionine metabolism and have been related to changes in lifespan in animal models. In humans, high homocysteine concentrations are an important predictor of age related disease. We aimed to explore the association of homocysteine with familial longevity by testing whether homocysteine is lower in individuals that are genetically enriched for longevity. We measured concentrations of total homocysteine in 1907 subjects from the Leiden Longevity Study consisting of 1309 offspring of nonagenarian siblings, who are enriched with familial factors promoting longevity, and 598 partners thereof as population controls. We found that homocysteine was related to age, creatinine, folate, vitamin B levels and medical history of hypertension and stroke in both groups (all p<0.001). However, levels of homocysteine did not differ between offspring enriched for longevity and their partners, and no differences in the age-related rise in homocysteine levels were found between groups (p for interaction 0.63). The results suggest that homocysteine metabolism is not likely to predict familial longevity
Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar
We study the process with
initial-state-radiation events produced at the PEP-II asymmetric-energy
collider. The data were recorded with the BaBar detector at center-of-mass
energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454
. We investigate the mass
distribution in the region from 3.5 to 5.5 . Below 3.7
the signal dominates, and above 4
there is a significant peak due to the Y(4260). A fit to
the data in the range 3.74 -- 5.50 yields a mass value
(stat) (syst) and a width value (stat)(syst) for this state. We do not
confirm the report from the Belle collaboration of a broad structure at 4.01
. In addition, we investigate the system
which results from Y(4260) decay
Stochastic Gravity: Theory and Applications
Whereas semiclassical gravity is based on the semiclassical Einstein equation
with sources given by the expectation value of the stress-energy tensor of
quantum fields, stochastic semiclassical gravity is based on the
Einstein-Langevin equation, which has in addition sources due to the noise
kernel. In the first part, we describe the fundamentals of this new theory via
two approaches: the axiomatic and the functional. In the second part, we
describe three applications of stochastic gravity theory. First, we consider
metric perturbations in a Minkowski spacetime, compute the two-point
correlation functions of these perturbations and prove that Minkowski spacetime
is a stable solution of semiclassical gravity. Second, we discuss structure
formation from the stochastic gravity viewpoint. Third, we discuss the
backreaction of Hawking radiation in the gravitational background of a black
hole and describe the metric fluctuations near the event horizon of an
evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews
in Relativity gr-qc/0307032 ; it includes new sections on the Validity of
Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric
Fluctuations of an Evaporating Black Hol
Strong mucosal immune responses in SIV infected macaques contribute to viral control and preserved CD4+ T-cell levels in blood and mucosal tissues
<p>Abstract</p> <p>Background</p> <p>Since there is still no protective HIV vaccine available, better insights into immune mechanism of persons effectively controlling HIV replication in the absence of any therapy should contribute to improve further vaccine designs. However, little is known about the mucosal immune response of this small unique group of patients. Using the SIV-macaque-model for AIDS, we had the rare opportunity to analyze 14 SIV-infected rhesus macaques durably controlling viral replication (controllers). We investigated the virological and immunological profile of blood and three different mucosal tissues and compared their data to those of uninfected and animals progressing to AIDS-like disease (progressors).</p> <p>Results</p> <p>Lymphocytes from blood, bronchoalveolar lavage (BAL), and duodenal and colonic biopsies were phenotypically characterized by polychromatic flow cytometry. In controllers, we observed higher levels of CD4+, CD4+CCR5+ and Gag-specific CD8+ T-cells as well as lower immune activation in blood and all mucosal sites compared to progressors. However, we could also demonstrate that immunological changes are distinct between these three mucosal sites.</p> <p>Intracellular cytokine staining demonstrated a significantly higher systemic and mucosal CD8+ Gag-specific cellular immune response in controllers than in progressors. Most remarkable was the polyfunctional cytokine profile of CD8+ lymphocytes in BAL of controllers, which significantly dominated over their blood response. The overall suppression of viral replication in the controllers was confirmed by almost no detectable viral RNA in blood and all mucosal tissues investigated.</p> <p>Conclusion</p> <p>A strong and complex virus-specific CD8+ T-cell response in blood and especially in mucosal tissue of SIV-infected macaques was associated with low immune activation and an efficient suppression of viral replication. This likely afforded a repopulation of CD4+ T-cells in different mucosal compartments to almost normal levels. We conclude, that a robust SIV-specific mucosal immune response seems to be essential for establishing and maintaining the controller status and consequently for long-term survival.</p
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