1,721,111 research outputs found
Bacterial detection in asyntomatic patient radicular cysts and odontogenic keratocysts
No full textOdontogenic cysts of the jaws include various pathological entities, traditionally classified into two different groups: developmental cysts (dentigerous, keratocysts, etc.) and inflammatory cysts (radicular, etc.). Radicular cysts (RCs) comprise about 52% to 68% of all the cysts affecting the human jaws, followed by dentigerous and odontogenic keratocysts (OKCs). OKCs are neoplastic lesions, classified by the WHO Working Group as benign tumours with odontogenic epithelium. Through the years, there have been conflicting reports regarding the presence of microorganisms in odontogenic cysts. Some studies suggest that bacteria are not found in RCs and do not normally penetrate into the lamina. Meghji et al. (1996) found higher level of endotoxin in RCs than in OKCs, but no aerobe and anaerobe bacteria with microbiologically sterile cystic fluid. However, other studies have shown that some odontogenic cysts do indeed contain microorganisms and may not be sterile.
Since no exhaustive results are available in this research-area, the purpose of this study was to detect the potential bacteria into cystic fluid from non-ruptured RCs and OKCs of asyntomatic patients, with information about of the microbial load. Cystic fluids samples from RCs (12 patients) and OKCs (6 patients) were cultured in anaerobic and aerobic conditions to detect microorganisms. Cultures were positive in 17 of 18 cases within 3 weeks.
Microbiological samples generally yielded mean total bacterial counts higher than or nearly close to 1x105 cfu/ml. A total of 12 different species were isolated and identified both in RCs and in OKCs fluid including facultative and obligate anaerobe groups.
These data are in disagreement with Meghji et al. study showing that all the cysts fluids were negative for anaerobes after 72 h of incubation. Better knowledge about the microorganism content in jaw cyst lesions should help to improve the selection of antibiotics in oral surgery practice
Use of Pinus sylvestris L. (Pinaceae), Origanum vulgare L. (Lamiaceae), and Thymus vulgaris L. (Lamiaceae) essential oils and their main components to enhance itraconazole activity against azole susceptible/not-susceptible Cryptococcus neoformans strains
Full text linkAbstract
Background:
Cryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health care. To date, there are very few molecules with any activity towards Cryptococcus neoformans, leading to heightened interest in finding new alternatives or adjuvants to conventional drugs for the
treatment of mycosis caused by this yeast. Since the essential oils (EOs) are considered as a potential rich source of bioactive antimicrobial compounds, we evaluated the antifungal activity of Origanum vulgare (oregano), Pinus sylvestris (pine), and Thymus vulgaris
(thyme red) EOs, and their components (α-pinene, carvacrol, thymol) compared with fluconazole, itraconazole, and voriconazole, against C.neoformans clinical strains. Then, we investigated the effect of EOs and components in combination with itraconazole.
Methods:
EO composition was analysed by Gas chromatography-mass spectrometry (GC-MS). A broth microdilution method was used to evaluate the susceptibility of C.neoformans to azoles, EOs and components. Checkerboard tests, isobolograms and time-kill assays were carried out for combination studies.
Results: C.neoformans isolates were susceptible to azoles, while one C.neoformans exhibited a reduced susceptibility to all test edazole drugs. All EOs exerted a good inhibitory activity against all C.neoformans strains. Pine EO was the most effective. Among components, thymol exerted the most remark able activity. By checkerboard testing and isobolographic analysis, combinations of itraconazole with oregano, pine, or thyme EOs, and carvacrol were found to be synergistic (FICI ≤ 0.5) against azole susceptible C.neoformans. Regarding the azole not susceptible C.neoformans strain, the synergistic effect with itraconazole was observed with thyme EO (chemotype: thymol 26.52%; carvacrol 7.85%), and carvacrol. Time-kill assays confirmed the synergistic effects of itraconazole and oregano or thyme EO against azole susceptible C.neoformans.
Binary mixtures of itraconazole/thyme EO or carvacrol yielded additive effects on the azole not susceptible C.neoformans.
Conclusions: Our findings highlight the potential effectiveness of thyme, oregano EOs, and carvacrol as natural and cost-effective adjuvants when used in combination with itraconazole. Identification of EOs exerting these effects could be one of the feasible ways to overcome drug resistance, reducing drug concentration and side effects
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
Antimicrobial efficacy of cryotreatment against Enterococcus faecalis in root canals [*G.Banche is the corresponding author]
Full text linkDispelling 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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