726 research outputs found
Circulating bile acids and adenoma recurrence in the context of adherence to a high-fiber, high-fruit and vegetable, and low-fat dietary intervention
INTRODUCTION: Diet may affect bile acid (BA) metabolism and signaling. In turn, BA concentrations may be associated with cancer risk. We investigated (i) associations of BA concentrations with adenoma recurrence and (ii) the effect of a high-fiber, high-fruit and vegetable, and low-fat dietary intervention on serum BA concentrations. METHODS: The Polyp Prevention Trial is a 4-year randomized, controlled trial that investigated the effect of a high-fiber, high-fruit and vegetable, and low-fat diet on colorectal adenoma recurrence. Among 170 participants who reported adhering to the intervention and 198 comparable control arm participants, we measured 15 BAs in baseline, year 2, and year 3 serum using targeted, quantitative liquid chromatography-tandem mass spectrometry. We estimated associations of BAs with adenoma recurrence using multivariable logistic regression and the effect of the dietary intervention on BA concentrations using repeated-measures linear mixed-effects models. In a subset (N = 65), we investigated associations of BAs with 16S rRNA gene sequenced rectal tissue microbiome characteristics. RESULTS: Baseline total BA concentrations were positively associated with adenoma recurrence (odds ratio Q3 vs Q1 = 2.17; 95% confidence interval = 1.19-4.04; Ptrend = 0.03). Although we found no effect of the dietary intervention on BA concentrations, pretrial dietary fiber intake was inversely associated with total baseline BAs (Spearman = -0.15; PFDR = 0.02). BA concentrations were associated with potential colorectal neoplasm-related microbiome features (lower alpha diversity and higher Bacteroides abundance). DISCUSSION: Baseline circulating BAs were positively associated with adenoma recurrence. Although the dietary intervention did not modify BA concentrations, long-term fiber intake may be associated with lower concentrations of BAs that are associated with higher risk of adenoma recurrence
The double Caldeira-Leggett model: Derivation and solutions of the master equations, reservoir-induced interactions and decoherence
In this paper we analyze the double Caldeira-Leggett model: the path integral
approach to two interacting dissipative harmonic oscillators. Assuming a
general form of the interaction between the oscillators, we consider two
different situations: i) when each oscillator is coupled to its own reservoir,
and ii) when both oscillators are coupled to a common reservoir. After deriving
and solving the master equation for each case, we analyze the decoherence
process of particular entanglements in the positional space of both
oscillators. To analyze the decoherence mechanism we have derived a general
decay function for the off-diagonal peaks of the density matrix, which applies
both to a common and separate reservoirs. We have also identified the expected
interaction between the two dissipative oscillators induced by their common
reservoir. Such reservoir-induced interaction, which gives rise to interesting
collective damping effects, such as the emergence of relaxation- and
decoherence-free subspaces, is shown to be blurred by the high-temperature
regime considered in this study. However, we find that different interactions
between the dissipative oscillators, described by rotating or counter-rotating
terms, result in different decay rates for the interference terms of the
density matrix.Comment: 42 pages, 7 figures, new discussion added, typos adde
Internal kinematics of spiral galaxies in distant clusters IV. Gas kinematics of spiral galaxies in intermediate redshift clusters and in the field
(Abridged) We trace the interaction processes of galaxies at intermediate
redshift by measuring the irregularity of their ionized gas kinematics, and
investigate these irregularities as a function of the environment (cluster
versus field) and of morphological type (spiral versus irregular). Our sample
consists of 92 distant galaxies. 16 cluster (z~0.3 and z~0.5) and 29 field
galaxies (mean z=0.44) of these have velocity fields with sufficient signal to
be analyzed. We find that the fraction of galaxies that have irregular gas
kinematics is remarkably similar in galaxy clusters and in the field at
intermediate redshifts. The distribution of the field and cluster galaxies in
(ir)regularity parameters space is also similar. On the other hand galaxies
with small central concentration of light, that we see in the field sample, are
absent in the cluster sample. We find that field galaxies at intermediate
redshifts have more irregular velocity fields as well as more clumpy and less
centrally concentrated light distributions than their local counterparts.
Comparison with a SINS sample of 11 z ~ 2 galaxies shows that these distant
galaxies have more irregular gas kinematics than our intermediate redshift
cluster and field sample. We do not find a dependence of the irregularities in
gas kinematics on morphological type. We find that two different indicators of
star formation correlate with irregularity in the gas kinematics. More
irregular gas kinematics, also more clumpy and less centrally concentrated
light distributions of spiral field galaxies at intermediate redshifts in
comparison to their local counterparts indicate that these galaxies are
probably still in the process of building their disks via mechanisms such as
accretion and mergers. On the other hand, they have less irregular gas
kinematics compared to galaxies at z ~ 2.Comment: Accepted for publication in A&A, high resolution version available at
http://www.astro.rug.nl/~kutdemir/13262/13262_hr.p
The impact of residents' informedness and involvement on their perceptions of tourism impacts: The case of Bled
The tourism development debate includes many studies on how residents perceive positive or negative tourism impacts, based on sustainability, as understood by a three-pillar concept. However, so far studies were very limited in addressing certain requirements for sustainable tourism, such as informed stakeholdersâ participation and cooperation â which represent the subject of this study. The survey that was undertaken follows previous ones in using the established three-pillar sustainability concept in order to define impacts of tourism. Further, it adds to tourism research by surveying informedness and developmental involvement. A four-dimensional informednessâinvolvement tourism grid is used to segment residents and their perceptions on tourism impacts in each segment are analysed. The model is empirically applied to the Slovenian lake and mountain destination of Bled. The findings confirm that highly informed and highly involved residents had better perceptions of tourism than all other groups, whereas those residents who were lowly informed and lowly involved had more negative perceptions of tourism. The survey contributes by expanding knowledge on resident perceptions of tourism by adding in the aspects of informedness and involvement. The proposed model can be applied to any destination to help manage residentsâ opinions and consequently their support for tourism development
Optical multiband surface photometry of a sample of Seyfert galaxies. I. Large-scale morphology and local environment analysis of matched Seyfert and inactive galaxy samples
Parallel analysis of the large-scale morphology and local environment of
matched active and control galaxy samples plays an important role in studies of
the fueling of active galactic nuclei. We carry out a detailed morphological
characterization of a sample of 35 Seyfert galaxies and a matched sample of
inactive galaxies in order to compare the evidence of non-axisymmetric
perturbation of the potential and, in the second part of this paper, to be able
to perform a multicomponent photometric decomposition of the Seyfert galaxies.
We constructed contour maps, BVRcIc profiles of the surface brightness,
ellipticity, and position angle, as well as colour index profiles. We further
used colour index images, residual images, and structure maps, which helped
clarify the morphology of the galaxies. We studied the presence of close
companions using literature data. By straightening out the morphological status
of some of the objects, we derived an improved morphological classification and
built a solid basis for a further multicomponent decomposition of the Seyfert
sample. We report hitherto undetected (to our knowledge) structural components
in some Seyfert galaxies - a bar (Ark 479), an oval/lens (Mrk 595), rings (Ark
120, Mrk 376), a nuclear bar and ring (Mrk 352), and nuclear dust lanes (Mrk
590). We compared the large-scale morphology and local environment of the
Seyfert sample to those of the control one and found that (1) the two samples
show similar incidences of bars, rings, asymmetries, and close companions; (2)
the Seyfert bars are generally weaker than the bars of the control galaxies;
(3) the bulk of the two samples shows morphological evidence of
non-axisymmetric perturbations of the potential or close companions; (4) the
fueling of Seyfert nuclei is not directly related to the large-scale morphology
and local environment of their host galaxies.Comment: Accepted for publication in A&
Successful management of multiple permanent pacemaker complications â infection, 13 year old silent lead perforation and exteriorisation following failed percutaneous extraction, superior vena cava obstruction, tricuspid valve endocarditis, pulmonary embolism and prosthetic tricuspid valve thrombosis
A 59 year old man underwent mechanical tricuspid valve replacement and removal of pacemaker generator along with 4 pacemaker leads for pacemaker endocarditis and superior vena cava obstruction after an earlier percutaneous extraction had to be abandoned, 13 years ago, due to cardiac arrest, accompanied by silent, unsuspected right atrial perforation and exteriorisation of lead. Postoperative course was complicated by tricuspid valve thrombosis and secondary pulmonary embolism requiring TPA thrombolysis which was instantly successful. A review of literature of pacemaker endocarditis and tricuspid thrombosis along with the relevant management strategies is presented. We believe this case report is unusual on account of non operative management of right atrial lead perforation following an unsuccessful attempt at percutaneous removal of right sided infected pacemaker leads and the incidental discovery of the perforated lead 13 years later at sternotomy, presentation of pacemaker endocarditis with a massive load of vegetations along the entire pacemaker lead tract in superior vena cava, right atrial endocardium, tricuspid valve and right ventricular endocardium, leading to a functional and structural SVC obstruction, requirement of an unusually large dose of warfarin postoperatively occasioned, in all probability, by antibiotic drug interactions, presentation of tricuspid prosthetic valve thrombosis uniquely as vasovagal syncope and isolated hypoxia and near instantaneous resolution of tricuspid prosthetic valve thrombosis with Alteplase thrombolysis
The clinical features of the piriformis syndrome: a systematic review
Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis
Allergic reaction related to ramipril use: a case report
<p>Abstract</p> <p>Background</p> <p>Angiotensin-converting enzyme (ACE) inhibitors are widely prescribed for patients with diabetes as a nephroprotector drug or to treat hypertension. Generally they are safe for clinical practice, but the relationship between these drugs and angioedema is known. The exact mechanism for ACE inhibitors-induced angioedema is not clear and it is still a matter of discussion.</p> <p>Case Report</p> <p>We reported a case of a 23-year-old black female with an 11 year history of type 1 diabetes, regularly monitored in the department of diabetes, in use of 0,98 UI/kg/day of human insulin, which presented an allergic reaction 24 h after ramipril use. The drug had been prescribed to treat diabetic nephropathy. There was no previous history of drug induced or alimentary allergy. The patient was instructed to discontinue the use of ramipril and oral antihistaminic drug and topical corticosteroid were prescribed. Skin biopsies were performed and confirmed the clinical hypothesis of pharmacodermy. The evaluation of ACE polymorphism identified <it>DD </it>genotype. Six months after the withdrawal of ramipril the patient was prescribed the angiotensin-II receptor blocker (ARB) losartan as nephroprotector. She remained well without adverse reactions.</p> <p>Conclusions</p> <p>ACE inhibitors-induced angioedema is uncommon and the clinical presentation is variable with lips, tongue, oropharinge, and larynge as the most common locations. The presence of angioedema during treatment requires the immediate cessation of treatment due to the risk of possible severe complications. The case reported presented moderate symptoms, with the development of early onset edema in uncommon regions. ACE <it>DD </it>genotype had been associated with angioedema-ACE inhibitors induced. In patients who have experienced ACE inhibitor-related angioedema, ARB should be used cautiously used. However in the case of our patient, the prescription of losartan as nefroprotector did not result in any recurrent adverse effect.</p
A web-based library consult service for evidence-based medicine: Technical development
BACKGROUND: Incorporating evidence based medicine (EBM) into clinical practice requires clinicians to learn to efficiently gain access to clinical evidence and effectively appraise its validity. Even using current electronic systems, selecting literature-based data to solve a single patient-related problem can require more time than practicing physicians or residents can spare. Clinical librarians, as informationists, are uniquely suited to assist physicians in this endeavor. RESULTS: To improve support for evidence-based practice, we have developed a web-based EBM library consult service application (LCS). Librarians use the LCS system to provide full text evidence-based literature with critical appraisal in response to a clinical question asked by a remote physician. LCS uses an entirely Free/Open Source Software platform and will be released under a Free Software license. In the first year of the LCS project, the software was successfully developed and a reference implementation put into active use. Two years of evaluation of the clinical, educational, and attitudinal impact on physician-users and librarian staff are underway, and expected to lead to refinement and wide dissemination of the system. CONCLUSION: A web-based EBM library consult model may provide a useful way for informationists to assist clinicians, and is feasible to implement
- âŠ