1,720,974 research outputs found
Influence of core body temperature on Tryptophan metabolism, kynurenines, and estimated IDO activity in critically ill patients receiving target temperature management following cardiac arrest.
No full textBACKGROUND/AIMS
Temperature control improves neurological prognosis in comatose cardiac arrest (CA) survivors. Previous reports demonstrate that most affected patients show signs of significant systemic inflammation. In an effort to better characterize potential temperature-related effects on key inflammatory pathways, we investigate the course of Tryptophan (Trp) levels, Tryptophan catabolites (including kynurenines) and indoleamine-2,3-dioxygenase (IDO)-activity in post CA patients.
MATERIAL/METHODS
In an observational blinded endpoint analysis, a total of n=270 serial samples from 20 post CA patients (63.1±16.6 yrs., 45% shockable rhythm, mean time to return of spontaneous circulation (ROSC) 26.6±16.0min) treated with target temperature management (TTM) were analyzed. Core body temperatures, course of Trp, Trp catabolites (incl. kynurenines), and estimated IDO-activity were followed up for a maximum of 7 days after ROSC. Patients were followed up until hospital discharge or death and functional outcome was recorded.
RESULTS
Over the 7-day observational interval, marked changes in Trp serum levels and IDO-activity were noted. In general, Trp serum levels but not IDO-activity seemed to parallel with the course of core body temperature. In explorative analyses, a correlation of Trp (rho=0.271 (95%-CI: 0.16-0.38, p<0.0001) and IDO-activity (rho=-0.155, 95%-CI: -0.27 to -0.037, p=0.01) with core body temperature was observed. Linear mixed effect models revealed a positive significant association of core body temperature with Trp serum levels (Likelihood ratio test χ(2)=6.35, p=0.012). In patients with good (vs. unfavorable) outcome, a tendency toward higher Trp serum levels, lower IDO-activity, and lower Kynurenic acid levels was noted.
CONCLUSIONS
We observed significant changes in Trp catabolism and IDO-activity that appeared temperature associated in post CA patients. Under hypothermia, decreased serum levels of Trp and increased IDO-activity were noted. We speculate from our data that IDO-induction during hypothermia contributes to the previously described increased susceptibility to infection or sepsis under reduced temperatures
A Unique Helicate Comprised of Four Cytosine Nucleobases and Four Metal Entities (PtII, PtII, AuIII, AuI). Implications for the Interactions of Linearly Coordinated Metal Ions with Nucleotide Duplexes
No full textReaction of trans-[Pt(CH3NH2)2(1-MeC-N3)2]X2 (1-MeC =1-methylcytosine; X = NO3– or ClO4–) with Na[AuCl4] in strongly alkaline aqueous solution yields an asymmetrical double helicate containing two central PtII as well as AuIII and AuI atoms, four 1-methylcytosinato bridges (1-MeC–-N3,N4), two terminal methylamine and two bridging methylamido ligands, [Au2Pt2(CH3NH2)2(CH3NH)2(1-MeC–)4]Cl2·2H2O (2). The four 1-MeC– ligands, which are pairwise oriented in head-head fashion, are deprotonated at their N4 positions
and cross-linked by the gold ions
A nutritional program to improve outcome of very low birth weight infants
No full textBackground & aims: The growth of very low birth weight infants does not match intrauterine trajectories, likely due to inappropriate caloric intake. We therefore investigated whether modification of the standard nutritional schedule can impact postnatal growth. Methods: We introduced a set of evidence-based strategies in a study group of infants (n = 123): 1) higher maximum intake of intravenous amino acids and lipids; 2) prioritisation of earlier enteral feeding; 3) faster attainment of full enteral feeds; 4) daily adjustment of enteral feeds according to growth trajectory; and 5) utilisation of an electronic pre-structured prescription ordering system that tracks individual growth and energy intake. These infants were compared with a control group (n = 115) in a pre/post retrospective cohort study. Results: The study group achieved a higher caloric intake, attained full enteral feeds 5 days earlier, and returned to their birth weight more rapidly than the control group. At 36 weeks postmenstrual age, infants who had been born at <30 weeks were heavier (6,260 g) but had a similar percentage fat mass. Those born at <28 weeks had a larger head circumference (Delta 1.4 cm) and lower sepsis rate (7.8%). Conclusions: Optimization of early postnatal nutrition and daily adjustment of milk intake according to weight gain improved growth, without any unfavourable outcomes for body composition and neuro-developmental follow-up. (C) 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved
Increased Activity of the Immunoregulatory Enzyme Indoleamine-2,3-Dioxygenase (IDO) with Consecutive Tryptophan Depletion Predicts Death in Patients with Neuroendocrine Neoplasia.
Full text linkBACKGROUND/AIMS
Data from a considerable number of malignancies demonstrate that depletion of the essential amino acid tryptophan via induction of the immuno-regulatory enzyme Indoleamine-2,3-dioxygenase (IDO) serves as an important tumour escape strategy and is of prognostic importance. Here we investigate the predictive value of the activity of IDO as well as levels of tryptophan and respective downstream catabolites in a large cohort of patients with neuroendocrine neoplasia (NEN).
METHODS
142 consecutive Caucasian patients (62 male, aged 60.3 ± 11.9 years) with histologically confirmed NEN were systematically analysed in a retrospective blinded endpoint analysis. Patients were followed up for a mean period of about 3.9 ± 1.9 years. Clinical outcome, levels of established biomarkers, and tryptophan degradation markers (assessed using tandem mass spectrometry) including estimated IDO-activity were recorded. Cox-proportional hazards regression models were performed for the assessment of prognostic power.
RESULTS
We found that baseline tryptophan levels were significantly lower and IDO-activity was significantly increased in non-survivors. The risk for death inclined stepwise and was highest in patients in the upper tertile of IDO-activity. Cox-proportional regression models identified IDO-activity as an independent predictor for death.
CONCLUSIONS
In this retrospective analysis, we observed that baseline activity of the immunoregulatory enzyme IDO was significantly increased in non-survivors. IDO-activity was identified as an independent predictor for death in this cohort of NEN patients. Whether IDO-activity or tryptophan depletion serves to guide future therapeutic interventions in NEN remains to be established
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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