1,720,971 research outputs found
Predittori di danno polmonare in fibrosi cistica: indagine su infezione e infiammazione
Full text linkBackground: Inflammation and infection are cornerstones in Cystic fibrosis (CF) lung disease. The research about a biomarker related to disease progression, tracking respiratory exacerbations and effectiveness of antibiotic therapy, is fervent.
Aim: this PhD work aimed to investigate:
-if plasma and exhaled breath condensate (EBC) levels of Asymmetric dimethilarginine (ADMA) and related metabolites, reportedly related to inflammation in asthma, could associate to disease history, especially respiratory exacerbation onset and effectiveness of treatment;
-if lung MRI sequence diffusion weighted imaging (DWI), known to depict tissue inflammation, could discriminate between stable disease and exacerbation, and highlight treatment effectiveness; and if morphological MRI may be influenced by chronic colonization of the airways by P. aeruginosa;
-if chronic colonization of the airways by P. aeruginosa may be characterized by an evolution in antibiotic resistance, especially in pediatric CF population;
Methods: 4 studies were elaborated
-a perspective study on pediatric CF patients, divided into stable and exacerbated patients; clinical data, EBC and plasma were collected in stable group at enrollment, and in exacerbated group before and after antibiotic treatment; ADMA and related metabolites were measured in plasma and EBC through Ultra performance liquidi cromatography, coupled with tandem mass spectrometry, and compared to healthy controls;
-a perspective study on pediatric CF patients, in which EBC and clinical data were collected every month for 6 month or till exacerbation; ADMA and related metabolites were measured and correlation with clinical data was tested;
-a perspective study on patients divided into stable and exacerbated; spirometry and RMN were performed in exacerbated patients before and after antibiotic treatment and in stable patients at enrollment and after 2 weeks;
-a retrospective study about a 4-year period, based upon extraction of clinical and microbiologic data about antibiotic sensitivity of P.aeruginosa in CF patients chronically colonized by P.aeruginosa.
Results:
-an univocal marker of inflammation could not be identified in EBC; given the absence of differences in ADMA levels among patient groups and healthy controls, and the increase of Citrullin levels in CF compared with controls, a dysregulation of ADMA metabolism was suspected;
-various metabolites were higher in plasma of CF patients than in controls; ADMA was increased in exacerbated patients before antibiotic treatment and decreased to levels similar to stable patients after antibiotic treatment; Aginine was increased in all groups, with a further increase after antibiotic treatment;
-DWI tracked respiratory exacerbation and effectiveness of treatment; a good correlation to clinical and spirometric parameters was proved; inter and intra-observer agreement were very good; morphologic MRI showed correlation with spirometry and colonization of the airways by P. aeruginosa;
-the prevalence of antibiotic sensitivity of P. aeruginosa showed an evolution during the 4-year study period; a decrease in sensitivity especially to fluoroquinolones was proved; sensitivity diminished to a greater extent in pediatic population; increased minimum inhibitory concentrations were found in pediatric patients who underwent more antibiotic courses per year.
Conclusions: CF has great phenotipic variability among patients and many factors may influence airways conditions, so a marker can hardly describe this complexity. Moreover, inflammatory pathways alterations are still not completely understood, and deserve futher investigations, given our findings in EBC. Findings on plasma highlighted ADMA role and depicted systemic alterations of the disease. A novel method as metabolomics could enlighten different aspects of the disease in future and help in the stratification of patients. Thoracic MRI with DWI sequence has shown a promising role in inflammation localization and quantification and surely deserves further detailed studies as clinical and research outcome measure
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
Imported malaria in an italian paediatric department, 1996-2012
No full textImported malaria is progressively increasing in Italy in the last two decades. A significant number of malaria
cases is registered every year in North-eastern Italy due to the high immigration rate. Most cases are non -
immune African children born in Italy and visiting friends and relatives (VFR) in endemic areas without
proper chemioprophylaxis.
We described 65 paediatric cases of imported malaria (age range: 7 mo-15 yrs),admitted to our Paediatric
Department during the period 1996-2012. 39 (60%) were long-term immigrants VFR, 24 (38%) were new
immigrants arriving in Italy for the first time, 1 was Indian adopted child and 1 an Italian child visiting Africa
with parents for tourism. 64 children came back from Sub-Saharan Africa, while only one child came from
Asia. Non-appropriate prophylaxis was reported in all cases.
Up to 2009 Plasmodium falciparum was the only isolated parasite while, during the last 3 years, 7 cases of
mixed malaria (P. falciparum, P. ovale, P. malariae and P. vivax) were observed.
All the cases were treated with quinine and since 2011 with Artemisinin derivatives, according to WHO
Guidelines.
All patients survived, nobody reported neurological sequelae. We emphasize a case of severe malaria
complicated with rhabdomyolysis and acute renal failure due to delayed diagnosis.
These epidemiological data demonstrate how important should be the information about chemoprophylaxis
in long-term immigrants in order to prevent imported malaria.
Early diagnosis of malaria reduces severe complications: we recommend physicians to suspect this infection
in all febrile children coming from malaria endemic areas
Efficacy of Elexacaftor–Tezacaftor–Ivacaftor on chronic rhinosinusitis in cystic fibrosis
No full textPurpose: Our work aims to add evidence on the effectiveness of Elexacaftor-Tezacaftor-Ivacaftor on chronic rhinosinusitis in cystic fibrosis. Materials and methods: We conducted an observational retrospective cohort study at the Cystic Fibrosis Center of a tertiary care hospital to investigate the effect of Elexacaftor-Tezacaftor-Ivacaftor on chronic rhinosinusitis in cystic fibrosis patients, aged 12 or older. The study's endpoints were the change in the occurrence of acute exacerbations of chronic rhinosinusitis, and the variation of the endoscopic and radiologic findings scored using the Lund-Kennedy endoscopic scale, Lund-Mackay, and modified Lund-Mackay radiologic scales, in patients who underwent both pre-treatment and post-treatment examinations. Results: The study population comprised 136 patients, of which 28 underwent both pre-treatment and post-treatment nasal endoscopy and 15 had pre- and post-treatment CT scans. Elexacaftor-Tezacaftor-Ivacaftor provided a significant improvement in chronic rhinosinusitis. The mean number of acute exacerbations of chronic rhinosinusitis per year in the pre-treatment time was 0.55 versus 0.35 during the treatment ( p < 0.0021). The Lund-Kennedy scale had a pre-treatment average score of 4.21 points versus 1.5 points after the start of Elexacaftor-Tezacaftor-Ivacaftor ( p < 0.0001). The average Lund-Mackay and modified Lund-Mackay scores in the pre-treatment time were respectively 14.6 and 16.45 points; and after the start of the therapy, they became 5.87 and 6.73 ( p < 0.0001). Conclusion: Elexacaftor-Tezacaftor-Ivacaftor was associated with fewer acute exacerbations of chronic rhinosinusitis, and a significant improvement of chronic rhinosinusitis evaluated endoscopically and radiologically. To our knowledge, this is the first study investigating the change in the occurrence of acute exacerbation of chronic rhinosinusitis in patients affected by cystic fibrosis in therapy with Elexacaftor-Tezacaftor-Ivacaftor
Malaria and salmonella infection: relationship or casuality?
No full textIntroduction: In Sub-Saharan Africa, non-Typhoid Salmonella (NTS) bacteriemia is a common and often
fatal complication of Plasmodium falciparum malaria. Thus WHO protocols recommend to treat children with
severe malaria also with broad-spectrum antibiotics.
Case report: We describe the case of a four year old boy, born in Italy, admitted to our Department for
severe Plasmodium falciparum malaria after visiting relatives in Burkina Faso. The child presented high
fever, diarrhea and vomiting. Intravenous quinine therapy was promptly administrated with improvement of
the conditions and decrease of fever after 24 hours. During the third day of hospitalization the temperature
abruptly raised and child's conditions worsened. Laboratory testing showed increased CRP level (280 mg/L)
and decreased total White Blood Cells count (6940/mm3). Blood smear examination was negative for
Plasmodia while blood culture resulted positive for Salmonella enteritidis. The patient was treated with
parenteral ceftriaxone for 10 days and oral quinine for one week with a complete recovery.
Discussion: Recent studies in mice (Cunnington et al.,2012) showed that the increased risk for developing
NTS bacteriemia during malaria is caused by the hemolysis of red cells infected by Plasmodium.
Intravascular hemolysis releases heme which induces heme oxigenase-1 leading to reduced macrophage
antimicrobial activity and consequently impaired resistance to NTS with increased bacterial replication.
Conclusion: Concurrent malaria and salmonella infections are frequently described in endemic areas. This
vulnerability to NTS in malaria infection is being assessed in literature. In Medicine coexisting pathologies
are rarely explained by casuality
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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