142 research outputs found
Does contrast echocardiography induce increases in markers of myocardial necrosis, inflammation and oxidative stress suggesting myocardial injury?
BACKGROUND: Contrast echocardiography is a precise tool for the non-invasive assessment of myocardial function and perfusion. Side effects of contrast echocardiography resulting from contrast-agent induced myocardial micro-lesions have been found in animals. The goal of this study is to measure markers of myocardial necrosis, inflammation and oxidative stress in humans to evaluate potential side-effects of contrast echocardiography. METHODS: 20 patients who underwent contrast echocardiography with Optison as the contrast medium were investigated. To evaluate myocardial micro-necrosis, inflammation and oxidative stress, cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, -8 and thiobarbituric acid reactive substances (TBARS) were measured at baseline and at 2, 4, 8 and 24 hours after contrast echocardiography. RESULTS: At baseline, 50% of the patients had cTnI and TBARS values outside the reference range. TNF-α, IL-6, IL-8 levels were within the reference range. Patients with cTnI above the RR clustered to significantly higher levels of TNF-α and IL-6. After contrast echocardiography, no statistically significant increase of cTnI, cytokines and TBARS was found. However, for nearly 50% of the patients, the intra-individual cTnI kinetics crossed the critical difference (threefold of methodical variation) which indicates a marker increase. This was neither predicted by the baseline levels of the cytokines nor the markers of oxidative stress. CONCLUSION: There are no clinically relevant increases in serum markers for micro-necrosis, inflammation and oxidative stress in humans after contrast echocardiography. Future studies have to address whether cTnI increase in some patients represent a subset with increased risk for side effects after contrast echocardiography
Significance of lobular intraepithelial neoplasia at margins of breast conservation specimens: a report of 38 cases and literature review
<p>Abstract</p> <p>Background</p> <p>Presence of lobular intraepithelial neoplasia (LIN) is not routinely reported as part of margin assessment in breast conservation therapy (BCT) as in ductal carcinoma in situ (DCIS). With new emerging evidence of LIN as possible precursor lesion, the hypothesis is that LIN at the margin may increase the risk of local recurrence with BCT. The aim is to determine whether there is an increase incidence of recurrence when LIN is found at surgical margins on BCT.</p> <p>Methods</p> <p>We retrospectively reviewed a total of 1,334 BCT at a single institution in a 10 year period. Inclusion criteria are positive margin with LIN from primary BCT containing invasive and/or in situ carcinoma with comparison to the negative control group who had similar diseases with negative margin for LIN.</p> <p>Results</p> <p>We identified 38 cases (2.8%) with LIN either lobular carcinoma in situ/atypical lobular hyperplasia (LCIS/ALH) at a margin on initial BCT with 36% recurrence rate. Of the 38 cases: 5 (13%) were lost to follow-up, 12 (32%) had no further procedures performed and 21 (55%) had re-excision. Out of 21 patients who had re-excisions, 12 (57%) had residual invasive carcinoma or DCIS, three (14%) had pleomorphic LCIS and 4 (19%) showed residual classic type LCIS. 71% had significant residual disease (local recurrence) and 29% had no residual disease. A negative control group consisted of 38 cases. We found two patients with bone or brain metastasis and one local recurrence. Clinical follow up periods range from 1 to 109 months.</p> <p>Conclusions</p> <p>LIN found at a margin on BCT showed a significant recurrent ipsilateral disease. Our study supports the view that LIN seen at the margin may play a role in recurrence.</p
(Re)Storying Obama: An Examination of Recently Published Informational Texts
American publishers have published numerous children’s books about Barack Obama over the past several years; most take the form of informational biographies. This article reports on a research project aimed at how these books incorporate sociohistorical narratives, particularly those related to the civil rights movement. Though the features of the books might cause the reader to presume political neutrality, the books link readers to distinct Discourses (Gee, 1996), suggesting particular ideologies. In this article, we identified the following differences: (1) specific happenings from Obama’s life were included in some texts while omitted in others; (2) when the events were included, how they were framed differed; and (3) the narrative constructions of the events varied. We use the differences amongst these texts to argue for the importance of critical literacy in elementary classrooms
Loss of Sialic Acid Binding Domain Redirects Protein σ1 to Enhance M Cell-Directed Vaccination
Ovalbumin (OVA) genetically fused to protein sigma 1 (pσ1) results in tolerance to both OVA and pσ1. Pσ1 binds in a multi-step fashion, involving both protein- and carbohydrate-based receptors. To assess the relative pσ1 components responsible for inducing tolerance and the importance of its sialic binding domain (SABD) for immunization, modified OVA-pσ1, termed OVA-pσ1(short), was deleted of its SABD, but with its M cell targeting moiety intact, and was found to be immunostimulatory and enhanced CD4+ and CD8+ T cell proliferation. When used to nasally immunize mice given with and without cholera toxin (CT) adjuvant, elevated SIgA and serum IgG responses were induced, and OVA-pσ1(s) was more efficient for immunization than native OVA+CT. The immune antibodies (Abs) were derived from elevated Ab-forming cells in the upper respiratory tissues and submaxillary glands and were supported by mixed Th cell responses. Thus, these studies show that pσ1(s) can be fused to vaccines to effectively elicit improved SIgA responses
Unintended learning in primary school practical science lessons from Polanyi’s perspective of intellectual passion
This study explored, from the perspective of intellectual passion developed by
Michael Polanyi, the unintended learning that occurred in primary practical science lessons.
We use the term ‘unintended’ learning to distinguish it from ‘intended’ learning that
appears in teachers’ learning objectives. Data were collected using video and audio
recordings of a sample of twenty-four whole class practical science lessons, taught by five
teachers, in Korean primary schools with 10- to 12-year-old students. In addition, video
and audio recordings were made for each small group of students working together in order
to capture their activities and intra-group discourse. Pre-lesson interviews with the teachers
were undertaken and audio-recorded to ascertain their intended learning objectives.
Selected key vignettes, including unintended learning, were analysed from the perspective
of intellectual passion developed by Polanyi. What we found in this study is that unintended
learning could occur when students got interested in something in the first place and
could maintain their interest. In addition, students could get conceptual knowledge when
they tried to connect their experience to their related prior knowledge. It was also found
that the processes of intended learning and of unintended learning were different. Intended
learning was characterized by having been planned by the teacher who then sought to
generate students’ interest in it. In contrast, unintended learning originated from students’
spontaneous interest and curiosity as a result of unplanned opportunities. Whilst teachers’
persuasive passion comes first in the process of intended learning, students’ heuristic
passion comes first in the process of unintended learning. Based on these findings, we argue that teachers need to be more aware that unintended learning, on the part of individual
students, can occur during their lesson and to be able to better use this opportunity
so that this unintended learning can be shared by the whole class. Furthermore, we argue
that teachers’ deliberate action and a more interactive classroom culture are necessary in
order to allow students to develop, in addition to heuristic passion, persuasive passion
towards their unintended learning
Composition Influences the Pathway but not the Outcome of the Metabolic Response of Bacterioplankton to Resource Shifts
Bacterioplankton community metabolism is central to the functioning of aquatic ecosystems, and strongly reactive to changes in the environment, yet the processes underlying this response remain unclear. Here we explore the role that community composition plays in shaping the bacterial metabolic response to resource gradients that occur along aquatic ecotones in a complex watershed in Québec. Our results show that the response is mediated by complex shifts in community structure, and structural equation analysis confirmed two main pathways, one involving adjustments in the level of activity of existing phylotypes, and the other the replacement of the dominant phylotypes. These contrasting response pathways were not determined by the type or the intensity of the gradients involved, as we had hypothesized, but rather it would appear that some compositional configurations may be intrinsically more plastic than others. Our results suggest that community composition determines this overall level of community plasticity, but that composition itself may be driven by factors independent of the environmental gradients themselves, such that the response of bacterial communities to a given type of gradient may alternate between the adjustment and replacement pathways. We conclude that community composition influences the pathways of response in these bacterial communities, but not the metabolic outcome itself, which is driven by the environment, and which can be attained through multiple alternative configurations
Reframing professional development through understanding authentic professional learning
Continuing to learn is universally accepted and expected by professionals and other stakeholders across all professions. However, despite changes in response to research findings about how professionals learn, many professional development practices still focus on delivering content rather than enhancing learning. In exploring reasons for the continuation of didactic practices in professional development, this article critiques the usual conceptualization of professional development through a review of recent literature across professions. An alternative conceptualization is proposed, based on philosophical assumptions congruent with evidence about professional learning from seminal educational research of the past two decades. An argument is presented for a shift in discourse and focus from delivering and evaluating professional development programs to understanding and supporting authentic professional learning
State of the art of immunoassay methods for B-type natriuretic peptides: An update
The aim of this review article is to give an update on the state of the art of the immunoassay
methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides.
Using chromatographic procedures, several studies reported an increasing number of
circulating peptides related to BNP in human plasma of patients with heart failure. These
peptides may have reduced or even no biological activity. Furthermore, other studies have
suggested that, using immunoassays that are considered specific for BNP, the precursor of the
peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of
patients with heart failure. Because BNP immunoassay methods show large (up to 50%)
systematic differences in values, the use of identical decision values for all immunoassay
methods, as suggested by the most recent international guidelines, seems unreasonable. Since
proBNP significantly cross-reacts with all commercial immunoassay methods considered
specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of
glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians
should take into account that there are large systematic differences between methods when
they compare results from different laboratories that use different BNP immunoassays. On the
other hand, clinical laboratories should take part in external quality assessment (EQA) programs
to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors
believe that the development of more specific methods for the active peptide, BNP1–32, should
reduce the systematic differences between methods and result in better harmonization of
results
Enrichment of Omnivorous Cercozoan Nanoflagellates from Coastal Baltic Sea Waters
Free-living nano-sized flagellates are important bacterivores in aquatic habitats. However, some slightly larger forms can also be omnivorous, i.e., forage upon both bacterial and eukaryotic resources. This hitherto largely ignored feeding mode may have pronounced implications for the interpretation of experiments about protistan bacterivory. We followed the response of an uncultured group of omnivorous cercozoan nanoflagellates from the Novel Clade 2 (Cerc_BAL02) to experimental food web manipulation in samples from the Gulf of Gdańsk (Southern Baltic Sea). Seawater was either prefiltered through 5 µm filters to exclude larger predators of nanoflagellates (F-treatment), or prefiltered and subsequently 1∶10 diluted with sterile seawater (F+D-treatment) to stimulate the growth of both, flagellates and bacteria. Initially, Cerc_BAL02 were rapidly enriched under both conditions. They foraged on both, eukaryotic prey and bacteria, and were highly competitive at low concentrations of food. However, these omnivores were later only successful in the F+D treatment, where they eventually represented almost one fifth of all aplastidic nanoflagellates. By contrast, their numbers stagnated in the F-treatment, possibly due to top-down control by a concomitant bloom of other, unidentified flagellates. In analogy with observations about the enrichment of opportunistically growing bacteria in comparable experimental setups we suggest that the low numbers of omnivorous Cerc_Bal02 flagellates in waters of the Gulf of Gdańsk might also be related to their vulnerability to grazing pressure
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