1,251 research outputs found
Role of glutathionylation in infection and inflammation
Glutathionylation, that is, the formation of mixed disulfides between protein cysteines and
glutathione (GSH) cysteines, is a reversible post-translational modification catalyzed by dierent
cellular oxidoreductases, by which the redox state of the cell modulates protein function. So far, most
studies on the identification of glutathionylated proteins have focused on cellular proteins, including
proteins involved in host response to infection, but there is a growing number of reports showing
that microbial proteins also undergo glutathionylation, with modification of their characteristics and
functions. In the present review, we highlight the signaling role of GSH through glutathionylation,
particularly focusing on microbial (viral and bacterial) glutathionylated proteins (GSSPs) and host
GSSPs involved in the immune/inflammatory response to infection; moreover, we discuss the
biological role of the process in microbial infections and related host responses
Glutathione increase by the n-butanoyl glutathione derivative (GSH-C4) inhibits viral replication and induces a predominant Th1 immune profile in old mice infected with influenza virus
During aging, glutathione (GSH) content declines and the immune system undergoes a
deficiency in the induction of Th1 response. Reduced secretion of Th1 cytokines, which is
associated with GSH depletion, could weaken the host defenses against viral infections.
We first evaluated the concentration of GSH and cysteine in organs of old mice; then, the
effect of the administration of the N-butanoyl GSH derivative (GSH-C4) on the response of
aged mice infected with influenza A PR8/H1N1 virus was studied through the determination
of GSH concentration in organs, lung viral titer, IgA and IgG1/IgG2a production and
Th1/Th2 cytokine profile.
Old mice had lower GSH than young mice in organs. Also the gene expression of
endoplasmic reticulum (ER) stress markers involved in GSH metabolism and folding of
proteins, i.e. Nrf2 and PDI, was reduced. Following infection, GSH content remained low
and neither infection nor GSH-C4 treatment affected Nrf2 expression. In contrast, PDI
expression was upregulated during infection and appeared counterbalanced by GSH-C4.
Moreover, the treatment with GSH-C4 increased GSH content in organs, reduced viral
replication and induced a predominant Th1 response.
In conclusion, GSH-C4 treatment could be used in the elderly to contrast influenza virus
infection by inducing immune response, in particular the Th1 profile
The Clustering of Extremely Red Objects
We measure the clustering of Extremely Red Objects (EROs) in ~8 deg^2 of the
NOAO Deep Wide Field Survey Bo\"otes field in order to establish robust links
between ERO z~1.2 and local galaxy z<0.1 populations. Three different color
selection criteria from the literature are analyzed to assess the consequences
of using different criteria for selecting EROs. Specifically, our samples are
(R-K_s)>5.0 (28,724 galaxies), (I-K_s)>4.0 (22,451 galaxies) and (I-[3.6])>5.0
(64,370 galaxies). Magnitude-limited samples show the correlation length (r_0)
to increase for more luminous EROs, implying a correlation with stellar mass.
We can separate star-forming and passive ERO populations using the (K_s-[24])
and ([3.6]-[24]) colors to K_s=18.4 and [3.6]=17.5, respectively. Star-forming
and passive EROs in magnitude limited samples have different clustering
properties and host dark halo masses, and cannot be simply understood as a
single population. Based on the clustering, we find that bright passive EROs
are the likely progenitors of >4L^* elliptical galaxies. Bright EROs with
ongoing star formation were found to occupy denser environments than
star-forming galaxies in the local Universe, making these the likely
progenitors of >L^* local ellipticals. This suggests that the progenitors of
massive >4L^* local ellipticals had stopped forming stars by z>1.2, but that
the progenitors of less massive ellipticals (down to L^*) can still show
significant star formation at this epoch.Comment: 19 pages, 16 figures, 4 tables, Accepted to ApJ 27th November 201
Skeletal Anomaly Monitoring in Rainbow Trout (Oncorhynchus mykiss, Walbaum 1792) Reared under Different Conditions
The incidence of skeletal anomalies could be used as an indicator of the "quality" of rearing conditions as these anomalies are thought to result from the inability of homeostatic mechanisms to compensate for environmentally-induced stress and/or altered genetic factors. Identification of rearing conditions that lower the rate of anomalies can be an important step toward profitable aquaculture as malformed market-size fish have to be discarded, thus reducing fish farmers' profits. In this study, the occurrence of skeletal anomalies in adult rainbow trout grown under intensive and organic conditions was monitored. As organic aquaculture animal production is in its early stages, organic broodstock is not available in sufficient quantities. Non-organic juveniles could, therefore, be used for on-growing purposes in organic aquaculture production cycle. Thus, the adult fish analysed in this study experienced intensive conditions during juvenile rearing. Significant differences in the pattern of anomalies were detected between organically and intensively-ongrown specimens, although the occurrence of severe, commercially important anomalies, affecting 2-12.5% of individuals, was comparable in the two systems. Thus, organic aquaculture needs to be improved in order to significantly reduce the incidence of severe anomalies in rainbow trout
Electrophysiology Model for a Human Heart with Ischemic Scar and Realistic Purkinje Network
The role of Purkinje fibres in the onset of arrhythmias is controversial and computer simulations may shed light on possible arrhythmic mechanisms involving the Purkinje fibres. However, few computational modelling studies currently include a detailed Purkinje network as part of the model. We present a coupled Purkinje-myocardium electrophysiology model that includes an explicit model for the ischemic scar plus a detailed Purkinje network, and compare simulated activation times to those obtained by electro-anatomical mapping in vivo during sinus rhythm pacing. The results illustrate the importance of using sufficiently dense Purkinje networks in patient-specific studies to capture correctly the myocardial early activation that may be influenced by surviving Purkinje fibres in the infarct region
Efficient Numerical Schemes for Computing Cardiac Electrical Activation over Realistic Purkinje Networks: Method and Verification
We present a numerical solver for the fast conduction system in the heart using both a CPU and a hybrid CPU/GPU implementation. To verify both implementations, we construct analytical solutions and show that the L2-error is similar in both implementations and decreases linearly with the spatial step size. Finally, we test the performance of the implementations with networks of varying complexity, where the hybrid implementation is, on average, 5.8 times faster
Non-B HIV type 1 subtypes among men who have sex with men in Rome, Italy
An increase in the circulation of HIV-1 non-B subtypes has been observed in recent years in Western European countries. Due to the lack of data on the circulation of HIV-1 non-B subtypes among European HIV-1-infected men who have sex with men (MSM), a biomolecular study was conducted in Rome, Italy. HIV-1 partial pol gene sequences from 111 MSM individuals (76 drug naive and 35 drug experienced) were collected during the years 2004-2006. All these sequences were analyzed using the REGA HIV-1 Subtyping Tool, and aligned using CLUSTAL X followed by manual editing using the Bioedit software. A BLAST search for non-B subtype sequences was also performed. Twenty-six (23.4%) MSM were not Italians. Eight individuals (7.2%) were diagnosed as HIV infected before 1991, 20 (18.0%) between 1991 and 1999, and 83 (74.8%) from 2000 to 2006. Fifteen (15/111, 13.5%) individuals were infected with the non-B subtype. The percentage of infection with HIV-1 non-B subtypes was 8.2% (7/85) among Italian MSM and 30.8% (8/26) among the non-Italians (OR = 4.95 95% IC: 1.40-17.87). Individuals infected with the non-B subtype were significantly younger than those infected with the HIV-1 B subtype (28 years vs. 34 years, p = 0.003). The CRFs were more prevalent (8.1%) than pure subtypes (5.4%), which were distributed as follows: subtype C (2.6%), subtype A1 (1.7%), and subtype F1 (0.9%). Major mutations conferring resistance to antiretroviral drugs (ARV) were not found among HIV-1 non-B subtype drug-naive patients but were found in two ARV-experienced individuals. The data show that viral diversity is likely increasing in a population group that had been previously characterized by the circulation of HIV-1 subtype B. © Copyright 2009, Mary Ann Liebert, Inc
Demonstration and Comparison of Operation of Photomultiplier Tubes at Liquid Argon Temperature
Liquified noble gases are widely used as a target in direct Dark Matter
searches. Signals from scintillation in the liquid, following energy deposition
from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should
be recorded down to very low energies by photosensors suitably designed to
operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter
searches currently implement photo multiplier tubes for signal read-out. In the
last few years PMTs with photocathodes operating down to liquid Argon
temperatures (87 K) have been specially developed with increasing Quantum
Efficiency characteristics. The most recent of these, Hamamatsu Photonics Mod.
R11065 with peak QE up to about 35%, has been extensively tested within the R&D
program of the WArP Collaboration. During these testes the Hamamatsu PMTs
showed superb performance and allowed obtaining a light yield around 7
phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12%
range, sufficient for detection of events down to few keVee of energy
deposition. This shows that this new type of PMT is suited for experimental
applications, in particular for new direct Dark Matter searches with LAr-based
experiments
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