1,721,054 research outputs found
Harmonization protocols for thyroid stimulating hormone (TSH) immunoassays: different approaches based on the consensus mean value
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microRNA(interference) networks are embedded in the gene regulatory networks
No full textmicroRNAs (miRNAs) are a class of endogenous 22-25 nt single-stranded RNA molecules that regulate gene expression post-transcriptionally. They are highly conserved among species with distinct temporal and spatial patterns of expression, each of them potentially interacting with hundreds of messenger RNAs. Since miRNAs, like transcription factors (TFs), are trans-acting factors that interact with cis-regulatory elements, they potentially generate a complex combinatorial code. Moreover, as TFs and genes containing binding sites for TFs have a high probability of being targeted by miRNAs, the basic interplay miRNA/TF renders miRNAs key components of gene regulatory networks. Several biological processes, including diseases such as cancer, have been causatively associated to disturbances of miRNAs/TF interplay both in vitro and in vivo. These aspects, cumulatively, indicate that miRNAs and transcription factors have a crucial role in determining cellular behaviour, highlighting the role of small RNA molecules in regulatory mechanisms and indicating other routes in the evolutionary path of gene expression
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
Mutual information preconditioning improves Bayesian networks learning of medical databases
No full textThe influence of the ovarian cycle on the first-step laboratory screening for primary aldosteronism
No full textObjectives: to investigate the influence of the ovarian cycle on aldosterone in low renin hypertensive
women. Primary aldosteronism is in fact increasingly recognized as a cause of arterial hypertension and
aldosterone has been reported to vary in normal women during the ovarian cycle, usually increasing in the
luteal phase.
Methods: hormonal levels (LH, FSH, 17 beta-estradiol, progesterone, aldosterone, PRA) were measured at
weekly intervals during one menstrual cycle in 26 uncomplicated mild hypertensive women with known
low renin levels, after discontinuation of antihypertensive treatment. Statistical analysis was performed by
Friedman test, Bonferroni adjusted Wilcoxon test, Fisher exact-test or Chi-square test with continuity
correction, as appropriate.
Results: Aldosterone and PRA increased from the 7th day (follicular phase) to the 21st day (luteal phase)
from 11.2 to 17.8 ng/dL and from 0.23 to 0.35 ng/mL/hr, respectively, (p=0.004), with no significant
changes in aldosterone/PRA ratio (ARR) but with an increase in the number of patients with aldosterone
levels >15ng/dL (8/26 vs 19/25, p=0.018) or with an ARR >30 if combined with either a minimum PRA
value of 0.5 ng/ml/hr or an aldosterone level of >15 ng/dL (7/26 vs 16/25 and 7/26 vs 17/25 respectively,
p<0.05). Aldosterone was positively correlated with PRA and progesterone levels.
Conclusion: Hyperaldosteronism frequently occurs during the luteal phase of the ovarian cycle in low
renin hypertensive women (possibly linked to a progesterone effect); the ovarian cycle may thus be a
factor of variability in the performance of parameters and cut-off points commonly used in the first-step
laboratory screening for primary aldosteronism
The Biological Effects of Diagnostic Cardiac Imaging RID A-6953-2008
No full textIn this paper the authors deal with the main imaging techniques available to clinical cardiologists, with a brief overview of biophysical and biological aspects which are of relevance for the assessment of health effects related to the exposure of patients to both ionizing and non ionizing radiation. A main contribute is the reviewing published evidence on biological effects of radiation, trying to compose a balanced issue in order to increase awareness and knowledge about radiation exposure from cardiac imaging and implications for health risk
Accuracy of point-of-care ultrasound to identify the source of infection in septic patients: a prospective study-comment
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