65 research outputs found
Effects of manure history and nitrogen fertilizer rate on sugar beet production in the northwest U.S.
Past manure applications effects on sugarbeet production needs to be assessed in the areas where manure applications to crop land are common. A study was conducted in Kimberly, Idaho in 2014 and 2016 to assess the effects of manure application history and N rates on sugarbeet production on a Portneuf silt loam (coarse-silty mixed mesic Durixerollic Calciorthid) soil. From 2004 to 2009, manure was applied to plots every two years (M1, total application = 60 tons per acre), every year (M2 total application = 106 tons per acre), or no manure (F, commercial fertilizer only). In spring 2014, the manure main plots were split in half with one half receiving a commercial fertilizer N rate treatment superimposed on the main plots in 2014 and the other half receiving the superimposed N rate treatments in 2016. In 2014 and 2016, the commercial fertilizer N rates were 0, 30, 56, 77, 100, 141, 180, and 202 pounds per acre. The study design was a randomized block split-plot with manure history as the main plot and N rate as the subplot. During both years of the study, N rate did not affect sugarbeet yields, but M1 and M2 treatments had higher sugarbeet root yields compared to the F treatment. Averaged across all N rates, root yields from both manured treatments were 12% and 36% greater than the F treatment in 2014 and 2016, respectively, although sugar yield was only significantly greater in 2016. Manure applications will impact sugarbeet production for several years after manure applications have ceased
Interleukin-6 Receptor Antagonists in Critically Ill Patients with Covid-19.
BACKGROUND: The efficacy of interleukin-6 receptor antagonists in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear. METHODS: We evaluated tocilizumab and sarilumab in an ongoing international, multifactorial, adaptive platform trial. Adult patients with Covid-19, within 24 hours after starting organ support in the intensive care unit (ICU), were randomly assigned to receive tocilizumab (8 mg per kilogram of body weight), sarilumab (400 mg), or standard care (control). The primary outcome was respiratory and cardiovascular organ support-free days, on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support to day 21. The trial uses a Bayesian statistical model with predefined criteria for superiority, efficacy, equivalence, or futility. An odds ratio greater than 1 represented improved survival, more organ support-free days, or both. RESULTS: Both tocilizumab and sarilumab met the predefined criteria for efficacy. At that time, 353 patients had been assigned to tocilizumab, 48 to sarilumab, and 402 to control. The median number of organ support-free days was 10 (interquartile range, -1 to 16) in the tocilizumab group, 11 (interquartile range, 0 to 16) in the sarilumab group, and 0 (interquartile range, -1 to 15) in the control group. The median adjusted cumulative odds ratios were 1.64 (95% credible interval, 1.25 to 2.14) for tocilizumab and 1.76 (95% credible interval, 1.17 to 2.91) for sarilumab as compared with control, yielding posterior probabilities of superiority to control of more than 99.9% and of 99.5%, respectively. An analysis of 90-day survival showed improved survival in the pooled interleukin-6 receptor antagonist groups, yielding a hazard ratio for the comparison with the control group of 1.61 (95% credible interval, 1.25 to 2.08) and a posterior probability of superiority of more than 99.9%. All secondary analyses supported efficacy of these interleukin-6 receptor antagonists. CONCLUSIONS: In critically ill patients with Covid-19 receiving organ support in ICUs, treatment with the interleukin-6 receptor antagonists tocilizumab and sarilumab improved outcomes, including survival. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.)
Galaxy bulges and their massive black holes: a review
With references to both key and oft-forgotten pioneering works, this article
starts by presenting a review into how we came to believe in the existence of
massive black holes at the centres of galaxies. It then presents the historical
development of the near-linear (black hole)-(host spheroid) mass relation,
before explaining why this has recently been dramatically revised. Past
disagreement over the slope of the (black hole)-(velocity dispersion) relation
is also explained, and the discovery of sub-structure within the (black
hole)-(velocity dispersion) diagram is discussed. As the search for the
fundamental connection between massive black holes and their host galaxies
continues, the competing array of additional black hole mass scaling relations
for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590
references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic
Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer
Publishin
Over-expression of CD200 in Acute Myeloid Leukemia Mediates the Expansion of Regulatory T-lymphocytes and Directly Inhibits Natural Killer Cell Tumor Immunity
CD200 is a type-1 transmembrane glycoprotein which suppresses inflammatory and autoimmune responses by signalling through its cognate transmembrane receptor homologue (CD200R). Normally, CD200 expression is restricted to immune privileged sites where it enhances immune tolerance through mechanisms that include modulating the expansion of FOXP3+ regulatory T-lymphocytes (T-regs) and suppressing macrophage cytolytic activity. Furthermore, leukocyte associated CD200 has been reported to suppress Natural Killer (NK) cell activity in vivo. Pathologically, we have previously shown that CD200 over-expression on leukemic blasts in around 50% of acute myeloid leukemia (AML) patients is significantly associated with a poor overall survival (Tonks et al, Leukemia, 2007). Given the existing evidence that T-reg frequency and NK cell function influence blast clearance and long-term survival in AML, we investigated the possibility that CD200 expression in AML may be directly suppressing anti-tumor immunity in this disease. Here we present evidence that CD200+ AML can suppress host anti-tumor responses by augmenting the frequency of AML patient T-regs and by direct inhibition of NK cell anti-tumor activity. We also show that targeting the interaction between CD200 and its receptor might provide a new strategy for the treatment of AML. Bone marrow aspirates from 91 diagnostic AML patients were analysed by multiparameter flow cytometry for blast CD200 protein expression. We found that the level of blast CD200 expression directly correlated with an increased frequency of T-regs (CD4+CD25++FoxP3+; R=0.78, p=0.0008). Measuring 3H-thymidine incorporation, we show that T-regs isolated from AML patients by MACSÂź separation inhibited T-cell proliferation (induced by CD3 and CD28 stimulation) at ratios <0.1%, thus confirming that patients T-regs were functional. In contrast to T-regs, NK cell frequency (CD45+CD19âCD3âCD56+) did not correlate with the level of AML blast CD200 expression (R=0.15, p=0.851), however, NK cell subpopulation bivariate analysis using CD56 and CD16 demonstrated that the CD56dimCD16+ (the principle active NK population) was significantly reduced by over 50% in CD200+ AML patients (36±5% compared to 15±5%, p=0.009). Furthermore, CD200 expression on target cells appeared to have a direct effect on the cytotoxic activity of NK cells; co-culture of NK cells with CD200+ targets resulted in decreased CD107a expression (a marker for cytolytic granules) in NK cells (23±4% vs 12±5%, p=0.038) and decreased apoptosis of the target cells (19±1% vs 10±1%, p=0.041). Since CD200R was detected on NK cells in AML patients, it was likely that CD200 was having a direct effect on suppression of NK cytotoxicity. This was supported by the significant recovery of NK cytolytic activity against CD200+ blasts in the presence of a CD200 blocking antibody (5±1% vs 11±2% CD107a+ NK cells, p=0.046) whereas there was no change seen with CD200â blasts (19±4% vs 19±3%). In conclusion, these findings suggest that CD200 expression on leukemic blasts plays an influential role in suppressing anti-tumor immunity in AML patients through modulating the expansion of functionally suppressive T-regs and directly suppressing NK cell cytolytic activity. In this study blocking CD200 interaction with its receptor was able to recover a significant proportion of patient NK activity, making CD200 a potential therapeutic target for CD200+ AML
CD200 Inhibits Memory Th1 Cell Function in Acute Myeloid Leukaemia (AML)
CD200 is a cell-surface glycoprotein that is normally expressed in tissues of the immune system, where its role is to protect immune privileged sites. We previously established CD200 to be frequently over-expressed and associated with poor AML patient outcome. In
this study, we investigated the possibility that CD200 expression may mediate suppression of T-cell function in this disease. Using multiparameter flow cytometry, we compared PMA/ionomycin stimulated CD8+ T-cell cytotoxic potential (CD107a expression) and the frequency
of intracellular TNFa, IL-2 and IFNc producing CD4+/CD8+
memory T-cells between CD200hi and CD200lo patients. We demonstrated that both the magnitude of the CD8+ memory cytotoxic T-cell response and the Th1 cytokine producing CD4+ memory helper T-cells was significantly inhibited in CD200hi AML patients (P < 0.05). Further, using ELISPOT assays to measure IFNg release we showed that the Th1 memory response to common viral antigens was significantly reduced by 75% in CD200hi versus CD200lo AML patients(P < 0.05). Recovery of IFNc release in response to recall antigens
was observed in CD4+ memory T-cells incubated with a
blocking antibody to CD200R. In conclusion, this study shows a correlation between T-cell dysfunction and expression of CD200 which suggests targeting this axis could be therapeutically beneficial for AML CD200hi patients
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