4,974 research outputs found
Methodologies for self-organising systems:a SPEM approach
We define âSPEM fragmentsâ of five methods for developing self-organising multi-agent systems. Self-organising traffic lights controllers provide an application scenario
Why Can\u27t We Be Friends? The Banning of Teacher-Student Communication Via Social Media and the Freedom of Speech
Is Latent Equine Herpesvirus Type 1 (EHV-1) Reactivated by Triggering Activation of the Unfolded Protein Response in Equine Peripheral Blood Leukocytes?
Equine Herpesvirus type 1 (EHV-1) is a worldwide threat to the health of horses. It can cause mild respiratory disease, abortions and deaths of newborn foals as well as a potentially fatal neurologic disorder known as Equine Herpesvirus Myeloencephalopathy (EHM). The virus is maintained in populations by stress-induced periodic reactivation of virus in long-term latently infected horses and transmission of the reactivated virus to susceptible individuals. In horses, peripheral blood leukocytes (PBLs) are thought to be an important site for EHV-1 latent genomes. Since the Unfolded Protein Response (UPR) is a cellular response to a variety of stressors that has been linked to reactivation of herpes simplex virus in humans, a virus closely related to EHV-1, I tested the hypothesis that latent EHV-1 relies on the UPR as a pluripotent stress sensor and uses it to reactivate lytic gene expression.
Since little work has been done in defining the UPR in horses, I first successfully developed a quantitative real-time polymerase chain reaction (RT-qPCR) assay to detect and quantitate transcripts for selected UPR genes in equine dermal (E.Derm) cells and PBLs. Activation of the UPR was achieved in both cell types using thapsigargin and a difference in gene expression after activation of the UPR in two equine cell types was found. A nested PCR assay to detect and distinguish latent EHV-1 and EHV-4 was evaluated and the sensitivity of the technique to detect EHV-1 was determined. I discovered that the nested PCR technique was not sensitive enough to detect the estimated one latent viral genome in 50,000 PBLs.
Lytic EHV-1 infection was characterized by single step growth curve in E.Derm cells and consistent detection of temporal EHV-1 gene expression by RT-qPCR was achieved. The relationship between EHV-1 gene expression and UPR gene expression during lytic infection was investigated. While EHV-1 infection had no effect on UPR gene expression, activation of the UPR appeared to decrease the expression of EHV-1 genes temporarily and reversibly during the first 4 h after infection. Finally, detection of EHV-1 in PBLs from horses presumed to be latently infected by co-cultivation with E. Derm cells permissive to EHV-1 infection was attempted. To detect viral DNA, PBLs were stimulated with thapsigargin or interleukin 2 (IL-2) which was previously reported to induce reactivation of latent EHV-1. I was not able to reproduce previously published experiments of reactivation in vitro of latent EHV-1 by stimulation with IL-2, and virus reactivation did not occur after stimulation of PBLs with thapsigargin.
In summary, a RT-qPCR assay to measure the expression of equine UPR genes was developed and activation of the UPR by treatment of E.Derm cells and PBLs with thapsigargin was successfully achieved. A difference in gene expression after activation of the UPR in two equine cell types was found. In contrast to what has been reported for other alphaherpesviruses, there appears to be no, or only little, interaction between the UPR and EHV-1 during viral infection. Detection of latent EHV-1 genomes in PBLs was not achieved by using a nested PCR, as this technique was not sensitive enough to detect the estimated one latent viral genome in 50,000 PBLs. Finally, latent EHV-1 was not detected in presumed latently infected PBLs or reactivated by triggering the UPR in equine PBLs
The Endocannabinoid System in Energy Homeostasis and the Etiopathology of Metabolic Disorders
Endocannabinoids and cannabinoid CB1 receptors are known to play a generalized role in energy homeostasis. However, clinical trials with the first generation of CB1 blockers, now discontinued due to psychiatric side effects, were originally designed to reduce food intake and body weight rather than the metabolic risk factors associated with obesity. In this review, we discuss how, in addition to promoting energy intake, endocannabinoids control lipid and glucose metabolism in several peripheral organs, particularly the liver and adipose tissue. Direct actions in skeletal muscle and pancreas are also emerging. This knowledge may help in the design of future therapies for the metabolic syndrome
Regarding âUnderstanding the âScopeâ of the Problem: Why Laparoscopy Is Considered Safe during the COVID-19 Pandemicâ
SARS-CoV-2 range in size from 0.06 to 0.125 ÎŒm, falling squarely within the particle-size range that HEPA filters capture with extraordinary efficiency: 0.01 micron and above. It is incorrect to state that HEPA filters are not able to catch particles below 0.3 micron, like SARS-CoV-2 virus.
This belief is based on a misunderstanding of how HEPA filters work. The particles size of 0.3 micron is used as a standard to measure the effectiveness of HEPA filters, but this does not mean they are not able to catch smaller particles. A paper from the NASA1 well explains that HEPA filters are highly effective in capturing a very high proportion, up to 100%, of nanoparticulate contaminants, ranging in size from 0.1 to 0.001 micron (diffusion regime) because they donât fly straight, collide with other fast-moving molecules, move around in random pathways and hit the filter fibers remaining stuck in them. This is known as the Brownian movement. The intersecting regime has just a small drop in efficiency that affects the particles of around 0.3 ÎŒm, defined as most penetrating particle size (MPPS). This value for a typical HEPA filter varies from 0.2 to 0.3 micron, depending on flow rate, and lowering the flow speed, a simple HEPA will perform as an ULPA filter
Release of anandamide from blood cells
Background: Endogenous ligands of cannabinoid receptors ( endocannabinoids), in particular anandamide ( arachidonylethanolamide), have been recognized as being of crucial importance in a variety of physiological functions. Plasma concentrations of anandamide have been measured in a number of investigations; however, discrepant data on "normal'' anandamide plasma concentrations were reported. Since this might be caused by pre-analytical variables, we investigated the impact of different sample handling conditions on measured plasma anandamide concentrations. Methods: Blood samples were taken from healthy volunteers in EDTA- or heparin-containing tubes; whole blood samples were kept at +4 degrees C, room temperature, or 37 degrees C, respectively, for up to 120 min before obtaining plasma by centrifugation. Plasma anandamide concentrations were measured by an isotope-dilution liquid chromatography tandem mass spectrometry ( LC-MS/MS) method. Results: A marked time- and temperature-dependent increase in plasma anandamide concentrations ex vivo was observed in both EDTA- and heparin-containing tubes. Mean anandamide concentrations approximately doubled when EDTA samples were kept at 4 degrees C for 60 min before centrifugation {[}immediately centrifuged, 1.3 mg/L ( SD 0.3 mg/L); 2.8 mg/L ( SD 0.5 mg/L) after storage for 60 min; n=12). After storage of heparinized whole-blood samples for 120 min at 37 degrees C, a mean plasma anandamide concentration of 11.9 mg/L ( SD 1.8 mg/L) was found. In cell-free plasma, no increase in anandamide concentrations was found. Conclusion: Anandamide is released from blood cells ex vivo at a very high rate; therefore, strictly standardized pre-analytical protocols have to be applied for plasma anandamide determination
Basic fibroblast growth factor mediates carotid plaque instability through metalloproteinase-2 and â9 expression
OBJECTIVE(S): We hypothesized that basic fibroblast growth factor (bFGF) may exert a role in carotid plaque instability by regulating the expression of matrix metalloproteinases (MMP). METHODS: Plaques obtained from 40 consecutive patients undergoing carotid endarterectomy were preoperatively classified as soft or hard. Serum bFGF was pre- and postoperatively measured. The release of MMP-2 and MMP-9 in the blood serum, and the activity, production and expression in the carotid specimens was analyzed. Specific anti-bFGF inhibition tests were performed in vitro on human umbilical artery smooth muscle cells (HUASMC) to evaluate the role of bFGF in the activity, production and expression of MMP-2 and -9. RESULTS: Twenty-one (53%) patients had a soft carotid plaque and 19 (48%) a hard plaque. Preoperative bFGF serum levels were higher in patients with soft plaques [soft=34 (28-39) pg/mL and hard=20 (17-22) pg/mL-p<0.001] and postoperatively returned to normal values (when compared to 10 healthy volunteers). The serum levels of MMP-2 in patients' with soft plaques were higher than those in patients' with hard plaques [soft=1222 (1190-1252) ng/mL and hard=748 (656-793)ng/mL-p<0.0001]. MMP-9 serum values were 26 (22-29) ng/mL for soft plaques and 18 (15-21) ng/mL for hard plaques (p<0.0001). We found increased activity, production and expression of MMP-2 and -9 in soft plaques compared to hard plaques (p<0.001). In vitro inhibition tests on HUASMC showed the direct influence of bFGF on the activity, production and expression of MMP-2 and -9 (p<0.001). CONCLUSIONS: bFGF seems to exert a key role in carotid plaque instability regulating the activity, production and expression of MMP thus altering the physiologic homeostasis of the carotid plaque
Minimal flavor-changing models and muon after the measurement
There has been a steady interest in flavor anomalies and their global fits as
ideal probes of new physics. If the anomalies are real, one promising
explanation is a new gauge boson with flavor-changing coupling to bottom
and strange quarks and a flavor-conserving coupling to muons and, possibly,
electrons. We point out that direct production of such a , emerging from
the collision of and quarks, may offer a complementary window into
these phenomena because collider searches already provide competitive
constraints. On top of that, we analyse the same scenario in relation to
another long-standing discrepancy between theory and experiment that concerns
the anomalous magnetic moment of the muon. By scanning the allowed
coupling strengths in the low-mass region, we assess the compatibility of the
signals from LHCb with the searches in the high energy LHC data and the
measurements of the anomalous magnetic moment of the involved leptons. We also
argue that observations of the latter can break the degeneracy pattern in the
Wilson coefficients and presented by LHCb data. The model
we consider is compatible with the new measurement of , therefore it
can potentially account for the long-standing deviations observed in
-physics.Comment: 13 pages, 5 figures. Missing factors corrected in eqs. 2.7-2.9 with
slight updates in fig.
Growth factors and experimental arterial grafts
Background: The production of growth factors from several experimental arterial conduits was determined.
Methods: We implanted 105 experimental arterial grafts that were 1 cm long in the abdominal aorta of Lewis rats (average
weight, 250 g). Five different types of grafts were analyzed: arterial isografts, vein grafts, arterial allografts, and polytetrafluoroethylene
(PTFE) grafts with normal or decreased compliance. Animals were killed humanely 4 weeks after
surgery and the production of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), transforming
growth factor-b, tumor necrosis factor-a, and interleukin-1 was analyzed.
Results: Myointimal hyperplasia (MH) was evident in vein grafts, arterial allografts, and PTFE grafts, but not in arterial
isografts. Growth factor production was increased for grafts prone to develop MH like vein, PTFE grafts, and arterial
allografts. PDGF and bFGF were increased significantly for PTFE and vein grafts, but not for arterial allografts. The
importance of bFGF and PGDF was confirmed by the capability of antibody to PDGF and to bFGF to reduce the
mitogenic activity of smooth muscle cells, in vivo and in vitro, for PTFE and vein grafts, but not for arterial allografts, in
which a predominant role was played by interleukin-1 and tumor necrosis factor-a.
Conclusions: Agents able to neutralize this increased production of growth factors, either directly or by competition with
their receptors, can prevent MH formation. (J Vasc Surg 2016;64:1444-9.)
Clinical Relevance: Arterial grafts release growth factors, which can lead to myointimal hyperplasia formation and
atherosclerosis progression in the arterial tree. Both phenomena can cause graft occlusion. Inhibition of growth factor release by arterial grafts can improve their clinical effectiveness
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