1,720,954 research outputs found
EPIDEMIOLOGIA DELLE INFEZIONI DA CANDIDA
Full text linkCandida is reported as an important cause of bloodstream infections (BSI) in critical patients such as cancer patients, surgical patients and premature neonates. Neonates are frequently infected or colonised during the stay in the nursery or during the delivery from Candida vaginitis that is a frequent event in pregnant women, particularly during the third trimester. Candidemia is an important challenge for public health as it is associated with severe complications, high mortality, increased length of hospital stay and great economical cost. Most of Candida BSIs develop from an endogenous source such as the colonised gut.
One of the aims of this study was to assess the epidemiology of candidemia and antifungal susceptibility profiles of Candida isolates in Lombardy hospitals through a prospective survey and to evaluate the changes compared to results of a previous survey performed 10 years before in the same region.
A prospective laboratory–based surveillance of candidemia was performed in 2009. The compared data reveal a threefold increase in incidence ( from 0.38 to 1,19 per 1000 admissions), aging of infected patients, an increase in surgical patients (63.8% vs.56%) and decline in crude mortality (from 35 to 27.1%). C. albicans was confirmed as the prevalent species causing candidemia although the rate was a little lower respect the previous survey (52.1% vs. 58.5%). C. glabrata was the second species with a statistically significant increase from 12.8% to 20.3%. Susceptibility testing confirmed the broad spectrum activity of amphotericin B and echinocandins. Decreased susceptibility or resistance to fluconazole was found in 24.9% of the tested isolates. The rate of high biofilm producers among Candida isolates was relevant (25.7%), however no correlation between this micribiological parameter and outcome could be demonstrated.
In a previous study performed in collaboration with Massey University a particular cluster of C. albicans named General Purpose Genotype (GPG) was found more virulent than others in causing candidemia in neonates and was associated with higher mortality rate in this population. The number of cases was low and we wanted to better investigate this association by enlarging the population number. However the introduction of antifungal prophylaxis in the neonatal intensive care units lowered the number of candidemia in this patients population. Therefore we decided to investigate the prevalence of the cluster as cause of vaginitis in pregnant women that is the principal way of infection at birth. GPG strains were detected in 32% of the pregnant women with C. albicans vaginitis and in 34.7% of not-pregnant women. The prevalence of GPG among isolates from African and North African women was statistically significant (62.5% versus 18.2%).
In addition it was investigated the presence of GPG in isolates from patients affected by alimentary tract colonization. The overall prevalence of the cluster was 32.7% without difference among men and women. A similar prevalence of the cluster among isolates causing colonization or candidemia was observed in neonates (34,8% vs. 33.3%). On the contrary in adult patients hospitalized in intensive care unites the rates were statistically different (42.9% vs. 11.9%).
Patients with alimentary tract colonization in different sites were selected for the molecular identification of the strains by multilocus system typing. This was designed to verify if different body sites were colonized by the same strain as predictive tool of deep infection. This part of the study was performed at Massey University. However, due to problems regarding the growth of the strains, only the extraction and the amplification of the DNA was performed until now and the sequencing is in progress.
GPG+ and GPG- isolates were also analyzed to detect differences in susceptibility to antifungal drugs. A decrease susceptibility to fluconazole (geometrical mean 1.53mg/l vs. 0.67mg/l) and a higher rate of resistance to 5-fluorocytosine (30% vs. 0%), were detected in GPG+ isolates.
A boric acid-5-fluorocytosine based cream was suggested by guidelines for the treatment of vaginal candidosis, especially in pregnant women. Our results suggest to looking for GPG strains among vaginal isolates to avoid clinical failures with possible evolution to a chronic infection, more difficult to eradicate, and the possible vertical contamination of the newborns by a strains associated with high crude mortality rate
Sensibilità in vitro agli antifungini di isolati clinici di Cryptococcus Neoformans
No full textObiettivi: determinare la sensibilità in vitro agli antifungini di isolati clinici di Cryptococcus neoformans raccolti tra il 2010 e il 2016 dal “FIMUA Cryptococcosis network” e calcolare i valori di cutoff epidemiologico (ECV).
Metodi. Centottantatre isolati di C. neoformans (77 di genotipo VNI, 1 VNII, 47 VNIV, 56 ibridi VNIII) sono stati sottoposti a saggi di sensibilità in vitro a fluconazolo (FLZ), itraconazolo (ITZ), voriconazolo (VRZ) e 5-fluorocitosina (5-FC) mediante la metodica della microdiluizione in brodo descritta da Zaragoza et al. (Antimicrob. Agents Chemother. 2011): terreno di crescita yeast nitrogen base (YNB) + glucosio (0,5%) portato a pH 7.0 con NaOH, inoculo finale di 104 CFU/ml, incubazione a 30°C ed in agitazione (14000 rpm) ogni 30 min. La 5-FC è stata saggiata in YNB + glucosio (2%), pH 5.6 (Viviani M.A., J. Chemother. 2003). La lettura è stata effettuata dopo 48 h mediante spettrofotometro a λ di 492 nm. E’ stata considerata l’inibizione del 50% della crescita rispetto al controllo (MIC 50). Sono stati calcolati la media geometrica (GM) e l’ECV, definito come la MIC (mg/L) che comprende almeno il 95% degli isolati (Pfaller M.A., Drug Resist Update 2010).
Risultati. I range di MIC, ECV e % di isolati con MIC≤ECV sono riportati in tabella.
Nei 3 genotipi sono stati osservati differenti pattern di sensibilità. Gli isolati VNIV hanno mostrato valori di MIC di tutti gli azoli inferiori rispetto agli altri genotipi: FLZ GM 1,45 vs 2,89 per VNIII e 2,5 per VNI, VRZ GM 0,03 vs 0,06 per VNIII e 0,05 per VNI, e ITZ GM 0,04 vs 0,09 per VNIII and 0,12 per VNI. I tre isolati con MIC>ECV per FLZ erano di genotipo VNIII, 2 di questi avevano anche MIC di VRZ superiore all’ECV. Un altro ceppo VNIII e due ceppi VNI avevano MIC>ECV per VRZ. Solamente un ceppo VNI aveva un valore di MIC una diluizione superiore rispetto all’ECV per ITZ. Tre isolati VNI e uno VNIV avevano MIC>ECV per 5-FC.
Conclusioni. I risultati di questo studio su isolati wild-type di C. neoformans confermano la bassa frequenza di resistenza agli antifungini. La conoscenza della distribuzione delle MIC degli isolati wild-type di C. neoformans e l’ECV sono utili per monitorare la resistenza e determinare i breakpoint clinici
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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