45 research outputs found
DP-4-colorability of two classes of planar graphs
DP-coloring (also known as correspondence coloring) is a generalization of
list coloring introduced recently by Dvo\v{r}\'ak and Postle (2017). In this
paper, we prove that every planar graph without -cycles adjacent to
-cycles is DP--colorable for and . As a consequence, we obtain
two new classes of -choosable planar graphs. We use identification of
verticec in the proof, and actually prove stronger statements that every
pre-coloring of some short cycles can be extended to the whole graph.Comment: 12 page
Ginkgolide B Reduces Atherogenesis and Vascular Inflammation in ApoE−/− Mice
To investigate whether ginkgolide B (a platelet-activating factor inhibitor) affects vascular inflammation in atherosclerosis-prone apolipoprotein E-deficient (ApoE(-/-)) mice.Human platelets were used to evaluate the effects of ginkgolide B on platelet aggregation and signal transduction. Ginkgolide B attenuated platelet aggregation and inhibited phosphatidylinositol 3 kinase (PI3K) activation and Akt phosphorylation in thrombin- and collagen-activated platelets. ApoE(-/-) mice were administered a high-cholesterol diet for 8 weeks. Plasma platelet factor 4 (PF4) and RANTES (regulated upon activation, normal T-cell expressed, and secreted protein) were then measured using an enzyme-linked immunosorbent assay. Scanning electron microscopy and immunohistochemistry were used to determine atherosclerotic lesions. Ginkgolide B decreased plasma PF4 and RANTES levels in ApoE(-/-) mice. Scanning electron microscopic examination showed that ginkgolide B reduced aortic plaque in ApoE(-/-) mice. Immunohistochemistry analysis demonstrated that ginkgolide B diminished P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE(-/-) mice. Moreover, ginkgolide B suppressed macrophage and vascular cell adhesion protein 1 (VCAM-1) expression in aorta lesions in ApoE(-/-) mice. Similar effects were observed in aspirin-treated ApoE(-/-) mice.Ginkgolide B significantly reduced atherosclerotic lesions and P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE-/- mice. The efficacy of ginkgolide B was similar to aspirin. These results provide direct evidence that ginkgolide B inhibits atherosclerosis, which may be associated with inhibition of the PI3K/Akt pathway in activated platelets
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Spine surgeon specialty differences in single-level percutaneous kyphoplasty
Background
Percutaneous kyphoplasty (PKP) is a procedure performed by a spine surgeon who undergoes either orthopedic or neurosurgical training. The relationship between short-term adverse outcomes and spine specialty is presently unknown. To compare short-term adverse outcomes of single-level PKP when performed by neurosurgeons and orthopedic surgeons in order to develop more concretely preventive strategies for patients under consideration for single-level PKP.
Methods
We evaluated patients who underwent single-level PKP from 2012 to 2014 through the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). We used univariate analysis and multivariate logistic regression to assess the association between spine surgeon specialty and short-term adverse events, including postoperative complication and unplanned readmission, and to identify different independent risk predictors between two specialties.
Results
Of 2248 patients who underwent single-level PKP procedure, 1229 patients (54.7%) had their operations completed by a neurosurgeon. There were no significant differences in the development of the majority of postoperative complications and the occurrence of unplanned readmission between the neurosurgical cohort (NC) and the orthopedic cohort (OC). A difference in the postoperative blood transfusion rate (0.7% NS vs. 1.7% OC, P = 0.039) was noted and may due to the differences in comorbidities between patients. Multivariate regression analysis revealed different independent predictors of postoperative adverse events for the two spine specialties.
Conclusions
By comparing a large range of demographic feature, preoperative comorbidities, and intraoperative factors, we find that short-term adverse events in single-level PKP patients does not affect by spine surgeon specialty, except that the OC had higher postoperative blood transfusion rate. In addition, the different perioperative predictors of postoperative complications and unplanned readmissions were identified between the two specialties. These findings can lead to better evidence-based patient counseling and provide valuable information for medical evaluation and potentially devise methods to reduce patients’ risk
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Efficacy and safety of erythropoietin for traumatic brain injury
Background
Recent studies regarding the effects of erythropoietin (EPO) for treating traumatic brain injury (TBI) have been inconsistent. This study conducts a meta-analysis of randomized controlled trials (RCTs) to assess the safety and efficacy of EPO for TBI patients at various follow-up time points.
Methods
A literature search was performed using PubMed, Web of Science, MEDLINE, Embase, Google Scholar and the Cochrane Library for RCTs studying EPO in TBI patients published through March 2019. Non-English manuscripts and non-human studies were excluded. The assessed outcomes include mortality, neurological recovery and associated adverse effects. Dichotomous variables are presented as risk ratios (RR) with a 95% confidence interval (CI).
Results
A total of seven RCTs involving 1197 TBI patients (611 treated with EPO, 586 treated with placebo) were included in this study. Compared to the placebo arm, treatment with EPO did not improve acute hospital mortality or short-term mortality. However, there was a significant improvement in mid-term (6 months) follow-up survival rates. EPO administration was not associated with neurological function improvement. Regarding adverse effects, EPO treatment did not increase the incidence of thromboembolic events or other associated adverse events.
Conclusions
This meta-analysis indicates a slight mortality benefit for TBI patients treated with EPO at mid-term follow-up. EPO does not improve in-hospital mortality, nor does it increase adverse events including thrombotic, cardiovascular and other associated complications. Our analysis did not demonstrate a significant beneficial effect of EPO intervention on the recovery of neurological function. Future RCTs are required to further characterize the use of EPO in TBI
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Correction to: Characterization of bone morphology in CCN5/WISP2 knockout mice.
In the original publication's title CCN5/WISP5 should have been CCN5/WISP2
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Characterization of bone morphology in CCN5/WISP5 knockout mice.
CCN5/WISP2 is part of the CCN family of matricellular proteins, but is distinct in that it lacks the C-terminal (CT) domain. Although CCN5 has been shown to impact cell proliferation and differentiation in vitro, its role in vivo is unclear. We therefore generated mice using ES cells developed by the Knockout Mouse Project (KOMP) in which exons 2-5, which encode the all of the conserved protein coding regions, are replaced by a lacZ cassette. Ccn5 LacZ/LacZ mice were viable and apparently normal. Based on previous studies showing that CCN5 impacts osteoblast proliferation and differentiation, we performed an analysis of adult bone phenotype. LacZ expression was examined in adult bone, and was found to be strong within the periosteum, but not in trabecular bone or bone marrow. Micro-CT analysis revealed no apparent changes in bone mineral density (BMD) or bone tissue volume (BV/TV) in Ccn5 LacZ/LacZ mice. These studies indicate that CCN5 is not required for normal bone formation, but they do not rule out a role in mechanotransduction or repair processes. The availability of Ccn5 LacZ mice enables studies of CCN5 expression and function in multiple tissues
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Characterization of bone morphology in CCN5/WISP5 knockout mice.
CCN5/WISP2 is part of the CCN family of matricellular proteins, but is distinct in that it lacks the C-terminal (CT) domain. Although CCN5 has been shown to impact cell proliferation and differentiation in vitro, its role in vivo is unclear. We therefore generated mice using ES cells developed by the Knockout Mouse Project (KOMP) in which exons 2-5, which encode the all of the conserved protein coding regions, are replaced by a lacZ cassette. Ccn5 LacZ/LacZ mice were viable and apparently normal. Based on previous studies showing that CCN5 impacts osteoblast proliferation and differentiation, we performed an analysis of adult bone phenotype. LacZ expression was examined in adult bone, and was found to be strong within the periosteum, but not in trabecular bone or bone marrow. Micro-CT analysis revealed no apparent changes in bone mineral density (BMD) or bone tissue volume (BV/TV) in Ccn5 LacZ/LacZ mice. These studies indicate that CCN5 is not required for normal bone formation, but they do not rule out a role in mechanotransduction or repair processes. The availability of Ccn5 LacZ mice enables studies of CCN5 expression and function in multiple tissues
Correction to: Characterization of bone morphology in CCN5/WISP2 knockout mice.
In the original publication's title CCN5/WISP5 should have been CCN5/WISP2