305 research outputs found
Counteraction of HCV-induced oxidative stress concurs to establish chronic infection in liver cell cultures
Hepatitis C virus (HCV) is a blood-borne pathogen causing acute and chronic hepatitis. A significant number of people chronically
infected with HCV develop cirrhosis and/or liver cancer. The pathophysiologic mechanisms of hepatocyte damage associated with
chronic HCV infection are not fully understood yet, mainly due to the lack of an in vitro system able to recapitulate the stages of
infection in vivo. Several studies underline that HCV virus replication depends on redox-sensitive cellular pathways; in addition, it
is known that virus itself induces alterations of the cellular redox state. However, the exact interplay between HCV replication and
oxidative stress has not been elucidated. In particular, the role of reduced glutathione (GSH) in HCV replication and infection is
still not clear. We set up an in vitro system, based on low m.o.i. of Huh7.5 cell line with a HCV infectious clone (J6/JFH1), that
reproduced the acute and persistent phases of HCV infection up to 76 days of culture. We demonstrated that the acute phase of
HCV infection is characterized by the elevated levels of reactive oxygen species (ROS) associated in part with an increase of
NADPH-oxidase transcripts and activity and a depletion of GSH accompanied by high rates of viral replication and apoptotic
cell death. Conversely, the chronic phase is characterized by a reestablishment of reduced environment due to a decreased ROS
production and increased GSH content in infected cells that might concur to the establishment of viral persistence. Treatment
with the prooxidant auranofin of the persistently infected cultures induced the increase of viral RNA titer, suggesting that a
prooxidant state could favor the reactivation of HCV viral replication that in turn caused cell damage and death. Our results
suggest that targeting the redox-sensitive host-cells pathways essential for viral replication and/or persistence may represent a
promising option for contrasting HCV infection
Local Rule-Based Explanations of Black Box Decision Systems
The recent years have witnessed the rise of accurate but obscure decision
systems which hide the logic of their internal decision processes to the users.
The lack of explanations for the decisions of black box systems is a key
ethical issue, and a limitation to the adoption of machine learning components
in socially sensitive and safety-critical contexts. %Therefore, we need
explanations that reveals the reasons why a predictor takes a certain decision.
In this paper we focus on the problem of black box outcome explanation, i.e.,
explaining the reasons of the decision taken on a specific instance. We propose
LORE, an agnostic method able to provide interpretable and faithful
explanations. LORE first leans a local interpretable predictor on a synthetic
neighborhood generated by a genetic algorithm. Then it derives from the logic
of the local interpretable predictor a meaningful explanation consisting of: a
decision rule, which explains the reasons of the decision; and a set of
counterfactual rules, suggesting the changes in the instance's features that
lead to a different outcome. Wide experiments show that LORE outperforms
existing methods and baselines both in the quality of explanations and in the
accuracy in mimicking the black box
Three-dimension-printed custom-made prosthetic reconstructions: from revision surgery to oncologic reconstructions
Background
The use of custom-made 3D-printed prostheses for reconstruction of severe bone defects in selected cases is increasing. The aims of this study were to evaluate (1) the feasibility of surgical reconstruction with these prostheses in oncologic and non-oncologic settings and (2) the functional results, complications, and outcomes at short-term follow-up.
Methods
We analyzed 13 prospectively collected patients treated between June 2016 and January 2018. Diagnoses were primary bone tumour (7 patients), metastasis (3 patients), and revision of total hip arthroplasty (3 patients). Pelvis was the most frequent site of reconstruction (7 cases). Functional results were assessed with MSTS score and complications according to Henderson et al. Statistical analysis was performed using Kaplan-Meier and log-rank test curves.
Results
At a mean follow-up of 13.7 months (range, 6 \u2013 26 months), all patients except one were alive. Oncologic outcomes show seven patients NED (no evidence of disease), one NED after treatment of metastasis, one patient died of disease, and another one was alive with disease. Overall survival was 100% and 80% at one and two years, respectively. Seven complications occurred in five patients (38.5%). Survival to all complications was 62% at two years of follow-up. Functional outcome was good or excellent in all cases with a mean score of 80.3%.
Conclusion
3D-printed custom-made prostheses represent a promising reconstructive technique in musculoskeletal oncology and challenging revision surgery. Preliminary results were satisfactory. Further studies are needed to evaluate prosthetic design, fixation methods, and stability of the implants at long-ter
Effect of essential fatty acid deficiency on the lipid composition of the Yoshida ascites hepatoma (AH 130) and of the liver and blood plasma from host and normal rats.
In order to study the response of a poorly differentiated tumor to nutritional manipulation, the Yoshida ascites hepatoma (AH 130) was grown in rats fed an essential fatty acid (EFA)-deficient diet and in rats fed a control diet. Hepatomas, livers, and blood plasma from host rats and normal rats were studied as to the effects of EFA deficiency on the lipid composition. Normal rats fed an EFA-deficient diet showed an increased concentration of triglycerides and cholesteryl esters in the liver and a reduced level of total phospholipids in plasma. Host rats fed the EFA-deficient diet showed a lower concentration of triglycerides in the liver when compared with the host rats fed a control diet. In addition, EFA-deficient host rats had reduced levels of plasma free fatty acids and triglycerides. These latter were markedly high in host rats under normal dietetic conditions. As compared to the livers of either host rats or normal rats fed the control diet, the Yoshida hepatoma cells had a lower content of total phospholipids and free fatty acids as well as a higher level of free cholesterol; they also showed a typical fatty acid pattern in their phospholipids. The main characteristics of this pattern were a high content of oleic and palmitoleic acids and a low level of C20 and C22 polyunsaturated fatty acids. Exposure of Yoshida hepatoma cells to an EFA-deficient environment resulted in a decrease in the concentration of total phospholipids and free fatty acids and in changes in the fatty acid composition similar to those observed in the livers of normal and host rats. These changes suggest that, under the experimental conditions used, the Yoshida hepatoma cells are responsive to EFA deficiency
Instabilities in two flavor quark matter
I discuss briefly the instabilities of two flavor quark matter, paying
attention to the gradient instability which develops in the g2SC phase in the
Goldstone sector.Comment: 6 pages. Talk given at QCD@Work07, Martina Franca (Italy). Some typos
corrected, one reference adde
Instabilities in two flavor quark matter
I discuss briefly the instabilities of two flavor quark matter, paying
attention to the gradient instability which develops in the g2SC phase in the
Goldstone sector.Comment: 6 pages. Talk given at QCD@Work07, Martina Franca (Italy). Some typos
corrected, one reference adde
Engineered exosomes boost the HCV NS3-specific CD8+ T lymphocyte immunity in humans
AbstractAt the present, no anti-Hepatitis C virus (HCV) HCV vaccine is available, and many patients failed the treatment with new class of HCV inhibitors. In HCV infection, both experimental and clinic evidences indicate that a strong CTL-immune response could have significant therapeutic effects. We developed an innovative anti-HCV CD8+ T immunogen based on the uploading in engineered exosomes of full-length HCV-NS3 protein. HCV NS3 exosomes appeared immunogenic when injected in mice, as proven by the detection of a memory CD8+ T lymphocyte pool two weeks after the last of three immunizations. On the other hand, dendritic cells isolated from PBMCs of HCV infected patients activate autologous HCV NS3-specific CD8+ T lymphocytes upon challenge with HCV NS3 exosomes. These results provide the proof-of-principle that engineered exosomes can boost the CD8+ T cell immunity in HCV-infected patients, thus representing a suitable option for patients resisting the therapies with recently discovered HCV inhibitors
Cortical and subcortical brain alterations in Juvenile Absence Epilepsy
Despite the common assumption that genetic generalized epilepsies are characterized by a macroscopically normal brain on magnetic resonance imaging, subtle structural brain alterations have been detected by advanced neuroimaging techniques in Childhood Absence Epilepsy syndrome. We applied quantitative structural MRI analysis to a group of adolescents and adults with Juvenile Absence Epilepsy (JAE) in order to investigate micro-structural brain changes using different brain measures. We examined grey matter volumes, cortical thickness, surface areas, and subcortical volumes in 24 patients with JAE compared to 24 healthy controls; whole-brain voxel-based morphometry (VBM) and Freesurfer analyses were used. When compared to healthy controls, patients revealed both grey matter volume and surface area reduction in bilateral frontal regions, anterior cingulate, and right mesial-temporal lobe. Correlation analysis with disease duration showed that longer disease was correlated with reduced surface area in right pre- and post-central gyrus. A possible effect of valproate treatment on brain structures was excluded. Our results indicate that subtle structural brain changes are detectable in JAE and are mainly located in anterior nodes of regions known to be crucial for awareness, attention and memory
Mitochondria, Oxidative Stress, cAMP Signalling and Apoptosis: A Crossroads in Lymphocytes of Multiple Sclerosis, a Possible Role of Nutraceutics
Multiple sclerosis (MS) is a complex inflammatory and neurodegenerative chronic disease that involves the immune and central nervous systems (CNS). The pathogenesis involves the loss of blood–brain barrier integrity, resulting in the invasion of lymphocytes into the CNS with consequent tissue damage. The MS etiology is probably a combination of immunological, genetic, and environmental factors. It has been proposed that T lymphocytes have a main role in the onset and propagation of MS, leading to the inflammation of white matter and myelin sheath destruction. Cyclic AMP (cAMP), mitochondrial dysfunction, and oxidative stress exert a role in the alteration of T lymphocytes homeostasis and are involved in the apoptosis resistance of immune cells with the consequent development of autoimmune diseases. The defective apoptosis of autoreactive lymphocytes in patients with MS, allows these cells to perpetuate, within the CNS, a continuous cycle of inflammation. In this review, we discuss the involvement in MS of cAMP pathway, mitochondria, reactive oxygen species (ROS), apoptosis, and their interaction in the alteration of T lymphocytes homeostasis. In addition, we discuss a series of nutraceutical compounds that could influence these aspect
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