137 research outputs found
On the Lyapunov functional of Leslie-Gower predator-prey models with time-delay and Holling's functional responses
The global stability on the dynamical behavior of the Leslie-Gower predator-prey system with delayed prey specific growth is analyzed by constructing the corresponding Lyapunov functional. Three different types of famous Holling's functional responses are considered in the present study. The sufficient conditions for the global stability analysis of the unique positive equilibrium point are derived accordingly. A numerical example is presented to illustrate the effect of different Holling-Type functional responses on the global stability of the Leislie-Gower predator-prey model
Moderate strength (0.23â0.28 T) static magnetic fields (SMF) modulate signaling and differentiation in human embryonic cells
<p>Abstract</p> <p>Background</p> <p>Compelling evidence exists that magnetic fields modulate living systems. To date, however, rigorous studies have focused on identifying the molecular-level biosensor (e.g., radical ion pairs or membranes) or on the behavior of whole animals leaving a gap in understanding how molecular effects are translated into tissue-wide and organism-level responses. This study begins to bridge this gulf by investigating static magnetic fields (SMF) through global mRNA profiling in human embryonic cells coupled with software analysis to identify the affected signaling pathways.</p> <p>Results</p> <p>Software analysis of gene expression in cells exposed to 0.23â0.28 T SMF showed that nine signaling networks responded to SMF; of these, detailed biochemical validation was performed for the network linked to the inflammatory cytokine IL-6. We found the short-term (<24 h) activation of IL-6 involved the coordinate up-regulation of toll-like receptor-4 (TLR4) with complementary changes to NEU3 and ST3GAL5 that reduced ganglioside GM3 in a manner that augmented the activation of TLR4 and IL-6. Loss of GM3 also provided a plausible mechanism for the attenuation of cellular responses to SMF that occurred over longer exposure periods. Finally, SMF-mediated responses were manifest at the cellular level as morphological changes and biochemical markers indicative of pre-oligodendrocyte differentiation.</p> <p>Conclusion</p> <p>This study provides a framework describing how magnetic exposure is transduced from a plausible molecular biosensor (lipid membranes) to cell-level responses that include differentiation toward neural lineages. In addition, SMF provided a stimulus that uncovered new relationships â that exist even in the absence of magnetic fields â between gangliosides, the time-dependent regulation of IL-6 signaling by these glycosphingolipids, and the fate of embryonic cells.</p
Targeting extracellular DNA to deliver IGF-1 to the injured heart.
There is a great need for the development of therapeutic strategies that can target biomolecules to damaged myocardium. Necrosis of myocardium during a myocardial infarction (MI) is characterized by extracellular release of DNA, which can serve as a potential target for ischemic tissue. Hoechst, a histological stain that binds to double-stranded DNA can be conjugated to a variety of molecules. Insulin-like growth factor-1 (IGF-1), a small protein/polypeptide with a short circulating-half life is cardioprotective following MI but its clinical use is limited by poor delivery, as intra-myocardial injections have poor retention and chronic systemic presence has adverse side effects. Here, we present a novel delivery vehicle for IGF-1, via its conjugation to Hoechst for targeting infarcted tissue. Using a mouse model of ischemia-reperfusion, we demonstrate that intravenous delivery of Hoechst-IGF-1 results in activation of Akt, a downstream target of IGF-1 and protects from cardiac fibrosis and dysfunction following MI
On the Lyapunov functional of Leslie-Gower predator-prey models with time-delay and Holling's functional responses
Label-free isolation of prostate circulating tumor cells using Vortex microfluidic technology.
There has been increased interest in utilizing non-invasive "liquid biopsies" to identify biomarkers for cancer prognosis and monitoring, and to isolate genetic material that can predict response to targeted therapies. Circulating tumor cells (CTCs) have emerged as such a biomarker providing both genetic and phenotypic information about tumor evolution, potentially from both primary and metastatic sites. Currently, available CTC isolation approaches, including immunoaffinity and size-based filtration, have focused on high capture efficiency but with lower purity and often long and manual sample preparation, which limits the use of captured CTCs for downstream analyses. Here, we describe the use of the microfluidic Vortex Chip for size-based isolation of CTCs from 22 patients with advanced prostate cancer and, from an enumeration study on 18 of these patients, find that we can capture CTCs with high purity (from 1.74 to 37.59%) and efficiency (from 1.88 to 93.75 CTCs/7.5âmL) in less than 1âh. Interestingly, more atypical large circulating cells were identified in five age-matched healthy donors (46-77 years old; 1.25-2.50 CTCs/7.5âmL) than in five healthy donors <30 years old (21-27 years old; 0.00 CTC/7.5âmL). Using a threshold calculated from the five age-matched healthy donors (3.37 CTCs/mL), we identified CTCs in 80% of the prostate cancer patients. We also found that a fraction of the cells collected (11.5%) did not express epithelial prostate markers (cytokeratin and/or prostate-specific antigen) and that some instead expressed markers of epithelial-mesenchymal transition, i.e., vimentin and N-cadherin. We also show that the purity and DNA yield of isolated cells is amenable to targeted amplification and next-generation sequencing, without whole genome amplification, identifying unique mutations in 10 of 15 samples and 0 of 4 healthy samples
Mortality associated with the use of non-vitamin K antagonist oral anticoagulants in cancer patients:Dabigatran versus rivaroxaban
Abstract Objective This study assesses the mortality outcomes of nonâvitamin K antagonist oral anticoagulants (NOACs) in cancer patients with venous thromboembolism (VTE) and atrial fibrillation (AF). Methods Medical records of cancer patients receiving NOACs for VTE or AF between January 1, 2011, and December 31, 2016, were retrieved from Taiwan's National Health Institute Research Database. NOACs were compared using the inverse probability of treatment weighting (IPTW) method. The primary outcome was cancerârelated death. Secondary outcomes were allâcause mortality, major bleeding, and gastrointestinal (GI) bleeding. Results Among 202,754 patients who received anticoagulants, 3591 patients (dabigatran: 907; rivaroxaban: 2684) with active cancers were studied. Patients who received dabigatran were associated with lower risks of cancerârelated death at one year (HRÂ =Â 0.71, 95% CIÂ =Â 0.54â0.93) and at the end of followâups (HRÂ =Â 0.79, 95% CIÂ =Â 0.64â0.98) compared with rivaroxaban. Patients who received dabigatran were also associated with lower risks of allâcause mortality (HRÂ =Â 0.81, 95% CIÂ =Â 0.67â0.97), major bleeding (HRÂ =Â 0.64, 95% CIÂ =Â 0.47â0.88), and GI bleeding (HRÂ =Â 0.57, 95% CIÂ =Â 0.39â0.84) at the end of followâups compared with rivaroxaban. Conclusion Compared with rivaroxaban, the use of dabigatran may be associated with a lower risk of cancerârelated death and allâcause mortality
The effectiveness of adjunct mindfulness-based intervention in treatment of bipolar disorder: A systematic review and meta-analysis
BACKGROUND: Mindfulness-based interventions (MBIs) have been increasingly used as an adjunctive treatment to pharmacotherapy for a few psychiatric disorders. However, few studies have investigated the efficacy of MBIs in bipolar disorder (BD). METHODS: We performed a systematic review and meta-analysis to evaluate the efficacy of MBIs as an adjunctive treatment in BD. Major electronic databases were independently searched by two authors for controlled and uncontrolled studies which examined the effects of MBIs on psychiatric symptoms in subjects with BD. Data from original studies were synthesized by using a random effects model. RESULTS: Twelve trials were eligible for inclusion into current meta-analysis, including three controlled studies (n=132) and nine uncontrolled studies (n=142). In within-group analysis, MBIs significantly reduced depressive (7 studies, n=100, Hedges' g=0.58, p<0.001) and anxiety (4 studies, n=68, Hedges' g=0.34, p=0.043) symptoms, but not manic symptoms (6 studies, n=89, Hedges' g=0.09, p=0.488) and cognition (3 studies, n=43, Hedges' g=0.35, p=0.171), compared to baseline. In between-group analysis (intervention group versus waiting list group, all patients with BD), MBIs did not reduce depressive (3 studies, n=132, Hedges' g=0.46, p=0.315) or anxiety (3 studies, n=132, Hedges' g=0.33, p=0.578) symptoms. LIMITATIONS: Only three controlled trials compared MBIs to control conditions. CONCLUSIONS: Our meta-analysis showed significantly beneficial effects on depressive and anxiety symptoms of BD patients in within-group analysis. However, this significance was not observed in comparison with the control groups. Further clinical trials are warranted to investigate the differences in the benefits of MBIs between treatment and control subjects
Relationship between depression and frailty in older adults: A systematic review and meta-analysis
Aim
Depression and frailty are prevalent and burdensome in older age. However, the relationships between these entities are unclear and no quantitative meta-analysis exists. We conducted a systematic review and meta-analysis to investigate the associations between depression and frailty.
Methods
Two authors searched major electronic databases from inception until November-2016 for cross- sectional/longitudinal studies investigating depression and frailty. The strength of the reciprocal associations between frailty and depression was assessed through odds ratios (ORs) adjusted for potential confounders.
Results
From 2306 non duplicated hits, 24 studies were included. The overall prevalence of depression in 8023 people with frailty was 38.60% (95% CI 30.07 to 47.10, I2=94%). Those with frailty were at increased odds of having depression (OR adjusted for publication bias 4.42, 95%CI 2.66-7.35, k=11), also after adjusting for potential confounders (OR=2.64; 95%CI: 1.59-4.37, I2=55%, k=4). The prevalence of frailty in 2167 people with depression was 40.40% (95%CI 27.00-55.30, I2=97%). People with depression were at increased odds of having frailty (OR=4.07, 95%CI 1.93-8.55, k=8). The pooled OR for incident frailty, adjusted for a median of 7 confounders, was 3.72 (95%CI 1.95-7.08, I2=98%, k=4), whilst in two studies frailty increased the risk of incident depression with an OR=1.90 (95%CI 1.55-2.32, I2=0%).
Conclusion
This meta-analysis points to a reciprocal interaction between depression and frailty in older adults. Specifically, each condition is associated with an increased prevalence and incidence of the other, and may be a risk factor for the development of the other. However, further prospective investigations are warranted
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