88 research outputs found
Influence of Internode Length on Degradability of Lucerne Stems
Lignification of plant tissues restricts degradation of forages by ruminants. The undegradable lignified middle lamella/primary cell wall prevents rumen microbes from accessing undamaged adjacent plant cells. In contrast, walls of non-lignified tissues are completely degradable. Preliminary observations of how deeply rumen microbes could degrade different tissues within 20- to 30-mm long lucerne (Medicago sativa L.) stem pieces indicated a two-fold range in depth of degradation among stem samples. Studies were undertaken to determine if extent of cell wall degradation in lucerne was influenced by length of stem internodes
Induction of Thyroid Gene Expression and Radioiodine Uptake in Melanoma Cells: Novel Therapeutic Implications
Both the MAP kinase and PI3K/Akt pathways play an important role in the pathogenesis of melanoma. We conducted the present study to test the hypothesis that targeting the two pathways to potently induce cell inhibition accompanied with thyroid iodide-handling gene expression for adjunct radioiodine ablation could be a novel effective therapeutic strategy for melanoma. We used specific shRNA approaches and inhibitors to individually or dually suppress the MAP kinase and PI3K/Akt pathways and examined the effects on a variety of molecular and cellular responses of melanoma cells that harbored activating genetic alterations in the two pathways. Suppression of the MAP kinase and PI3K/Akt pathways showed potent anti-melanoma cell effects, including the inhibition of cell proliferation, transformation and invasion, induction of G0/G1 cell cycle arrest and, when the two pathways were dually suppressed, cell apoptosis. Remarkably, suppression of the two pathways, particularly simultaneous suppression of them, also induced expression of genes that are normally expressed in the thyroid gland, such as the genes for sodium/iodide symporter and thyroid-stimulating hormone receptor. Melanoma cells were consequently conferred the ability to take up radioiodide. We conclude that dually targeting the MAP kinase and PI3K/Akt pathways for potent cell inhibition coupled with induction of thyroid gene expression for adjunct radioiodine ablation therapy may prove to be a novel and effective therapeutic strategy for melanoma
Using redundancy to cope with failures in a delay tolerant network
We consider the problem of routing in a delay tolerant net-work (DTN) in the presence of path failures. Previous work on DTN routing has focused on using precisely known network dy-namics, which does not account for message losses due to link failures, buffer overruns, path selection errors, unscheduled de-lays, or other problems. We show how to split, replicate, and erasure code message fragments over multiple delivery paths to optimize the probability of successful message delivery. We provide a formulation of this problem and solve it for two cases: a 0/1 (Bernoulli) path delivery model where messages are ei-ther fully lost or delivered, and a Gaussian path delivery model where only a fraction of a message may be delivered. Ideas from the modern portfolio theory literature are borrowed to solve the underlying optimization problem. Our approach is directly relevant to solving similar problems that arise in replica place-ment in distributed file systems and virtual node placement in DHTs. In three different simulated DTN scenarios covering a wide range of applications, we show the effectiveness of our ap-proach in handling failures
Interferon β-1a in relapsing multiple sclerosis: four-year extension of the European IFNβ-1a Dose-C omparison Study
Background: Multiple sclerosis (MS) is a chronic disease requiring long-term monitoring of treatment. Objective: To assess the four-year clinical efficacy of intramuscular (IM) IFNb-1a in patients with relapsing MS from the European IFNb-1a Dose-C omparison Study. Methods: Patients who completed 36 months of treatment (Part 1) of the European IFNb-1a Dose-C omparison Study were given the option to continue double-blind treatment with IFNb-1a 30 mcg or 60 mcg IM once weekly (Part 2). Analyses of 48-month data were performed on sustained disability progression, relapses, and neutralizing antibody (NA b) formation. Results: O f 608/802 subjects who completed 36 months of treatment, 493 subjects continued treatment and 446 completed 48 months of treatment and follow-up. IFNb-1a 30 mcg and 60 mcg IM once weekly were equally effective for up to 48 months. There were no significant differences between doses over 48 months on any of the clinical endpoints, including rate of disability progression, cumulative percentage of patients who progressed (48 and 43, respectively), and annual relapse rates; relapses tended to decrease over 48 months. The incidence of patients who were positive for NAbs at any time during the study was low in both treatment groups. Conclusion: C ompared with 60-mcg IM IFNb-1a once weekly, a dose of 30 mcg IM IFNb-1a once weekly maintains the same clinical efficacy over four years
Factors associated with excessive bleeding in cardiopulmonary bypass patients: a nested case-control study
<p>Abstract</p> <p>Introduction</p> <p>Excessive bleeding (EB) after cardiopulmonary bypass (CPB) may lead to increased mortality, morbidity, transfusion requirements and re-intervention. Less than 50% of patients undergoing re-intervention exhibit surgical sources of bleeding. We studied clinical and genetic factors associated with EB.</p> <p>Methods</p> <p>We performed a nested case-control study of 26 patients who did not receive antifibrinolytic prophylaxis. Variables were collected preoperatively, at intensive care unit (ICU) admission, at 4 and 24 hours post-CPB. EB was defined as 24-hour blood loss of >1 l post-CPB. Associations of EB with genetic, demographic, and clinical factors were analyzed, using SPSS-12.2 for statistical purposes.</p> <p>Results</p> <p>EB incidence was 50%, associated with body mass index (BMI)< 26.4 (25–28) Kg/m<sup>2</sup>, (<it>P </it>= 0.03), lower preoperative levels of plasminogen activator inhibitor-1 (PAI-1) (<it>P </it>= 0.01), lower body temperature during CPB (<it>P </it>= 0.037) and at ICU admission (<it>P </it>= 0.029), and internal mammary artery graft (<it>P </it>= 0.03) in bypass surgery. We found a significant association between EB and 5G homozygotes for PAI-1, after adjusting for BMI (F = 6.07; <it>P </it>= 0.02) and temperature during CPB (F = 8.84; <it>P </it>= 0.007). EB patients showed higher consumption of complement, coagulation, fibrinolysis and hemoderivatives, with significantly lower leptin levels at all postoperative time points (<it>P </it>= 0.01, <it>P </it>< 0.01 and <it>P </it>< 0.01).</p> <p>Conclusion</p> <p>Excessive postoperative bleeding in CPB patients was associated with demographics, particularly less pronounced BMI, and surgical factors together with serine protease activation.</p
PAI-1 and t-PA/PAI-1 complex potential markers of fibrinolytic bleeding after cardiac surgery employing cardiopulmonary bypass
Background: Enhanced bleeding remains a serious problem after cardiac surgery, and fibrinolysis is often involved. We speculate that lower plasma concentrations of plasminogen activator inhibitor - 1 (PAI-1) preoperatively and tissue plasminogen activator/PAI-1 (t-PA/PAI-1) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding.Methods: Totally 88 adult patients (mean age 66 ± 10 years) scheduled for cardiac surgery, were enrolled into a prospective study. Blood samples were collected pre-operatively, on admission to the recovery and at 6 and 24 hours postoperatively. Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study. The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage (CTD): Group I > 500ml, Group II ≤ 500ml. Associations between CTD, PAI-1, t-PA/PAI-1 complex and D-dimer were analyzed with SPSS.Results: Nine patients were excluded because of surgical bleeding. Of the 79 remaining patients, 38 were allocated to Group I and 41 to Group II. The CTD volumes correlated with the preoperative plasma levels of PAI-1 (r = - 0.3, P = 0.009). Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups (P < 0.001 and P = 0.012, respectively). Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively.Conclusions: Lower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery.publishersversionPeer reviewe
The Developmental Significance of Adolescent Romantic Relationships: Parent and Peer Predictors of Engagement and Quality at Age 15
From a longitudinal sample (n = 957; 49.9% male; 77.3% White/non-Hispanic) of participants studied from infancy through age 15, adolescents’ depth of engagement in, and quality of romantic relationships were predicted from early and contemporaneous parent–child interactive quality and peer social competence. High quality maternal parenting and peer experiences prior to and during adolescence tended to be negatively associated with the depth of engagement in this domain for the full sample, yet positively associated with the quality of adolescents’ romantic relationships for the sub-set of individuals currently dating at age 15. Results reconcile contrasting views of the origins of romantic relationship engagement and quality and the positive versus negative developmental salience of romantic relationships in adolescence
[18F]2-Fluoro-2-deoxy-D-glucose incorporation by AGS gastric adenocarcinoma cells in vitro during response to epirubicin, cisplatin and 5-fluorouracil
Decreased tumour [18F]2-fluoro-2-deoxy-D-glucose (18FDG) incorporation is related to response however its significance at the cell level in gastro-oesophageal cancer and how it relates to cell death is unknown. Here human gastric adenocarcinoma (AGS) cells were treated with lethal dose 10 and 50 (LD10 and LD50), determined by using the MTT assay, of the three drugs, epirubicin, 5-fluorouracil and cisplatin, commonly used in the treatment of patients with gastro-oesophageal cancer. 18FDG incorporation was determined after 48 and 72 h of treatment with each drug and related to drug-induced changes in glucose transport, hexokinase activity, cell cycle distribution and annexin V-PE binding (a measure of apoptosis). Treatment of cells for 48 and 72 h with LD50 doses of cisplatin resulted in reductions in 18FDG incorporation of 27 and 25% respectively and of 5-fluorouracil reduced 18FDG incorporation by 34 and 33% respectively: epirubicin treatment reduced incorporation by 30 and 69% respectively. Cells that had been treated for 72 h with each drug were incubated in drug-free media for a further 6 days to determine their ability to recover. Comparison of the ability to recover from the chemotherapy agent, with 18FDG incorporation before the recovery period allowed an assessment of the predictive ability of 18FDG incorporation. Cells treated with either 5-fluorouracil or cisplatin demonstrated recovery on removal of the drug. In contrast, cells treated with epirubicin did not recover corresponding with the greatest 72 h treatment decrease in 18FDG incorporation. In contrast to adherent cells treated with cisplatin or 5-fluorouracil, adherent epirubicin-treated cells also exhibited very high levels of apoptosis. Glucose transport was decreased after each treatment whilst hexokinase activity was only decreased after 72 h of treatment with each drug. There was no consistent relationship observed between 18FDG incorporation and cell cycle distribution. Our results show that at the tumour cell level in gastric tumour cells, decreased 18FDG incorporation and glucose transport, accompanies therapeutic growth inhibition. 18FDG incorporation is particularly diminished in cells exhibiting apoptosis
Contact & connect—an intervention to reduce depression stigma and symptoms in construction workers: protocol for a randomised controlled trial
Structural evolution of wheat chromosomes 4A, 5A, and 7B and its impact on recombination
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