Proteomic profile of root canal contents in teeth with post-treatment endodontic disease.

AIM: To characterize the proteome of 20 root canals in teeth with post-treatment endodontic disease using mass spectrometry and to correlate the identified proteins with clinical features. METHODOLOGY: Twenty patients with radiographic evidence of apical periodontitis and need for root canal re-treatment were selected. Samples from the root canal contents were collected and processed using two-dimensional capillary nano-flow liquid chromatography and electrospray ionization tandem mass spectrometry. The acquired spectra were separately searched against specific protein database. The results obtained were analysed using descriptive statistics. Additionally, Pearson's chi-square test or one-sided Fisher's exact test, as appropriate, was chosen to examine the null hypothesis that there is no relationship between each clinical feature and the presence of specific microbial or human proteins. Significance levels were set at 5% (P < 0.05). RESULTS: A total of 1153 human and 720 microbial UniProt accession numbers corresponding to proteins were recovered. The greater prevalence of proteins was related to biological functions, such as cellular and metabolic processes. A considerable number of microbial proteins with clinical relevance functions, such as pathogenesis/virulence, proteolysis, cell adhesion and drug resistance, were detected. Common endodontic pathogens related to post-treatment endodontic disease such as Enterococcus spp., Propionibacterium spp. and Streptococcus spp. were associated with 23, 40 and 94 distinct proteins, respectively. As for human proteins, many factors related to the immune system process were detected. No significant correlations were found between microbial and human proteins and the clinical features investigated (P > 0.05). CONCLUSIONS: A considerable number of microbial and human proteins were identified using proteomic analyses, being mainly related to processes indicating cell viability. No significant correlation was found between proteins and clinical features. These findings suggest a network of important microbial pathogenic functions that may be responsible for the host immune system response.

The value of practice: A critique of interactional expertise.

Collins and Evans have proposed a 'normative theory of expertise' as a way to solve the 'problem of demarcation' in public debates involving technical matters. Their argument is that all citizens have the right to participate in the 'political' phases of such debates, while only three types of experts should have a voice in the 'technical' phases. In this article, Collins and Evans' typology of expertise--in particular, the idea of 'interactional expertise'--is the focus of a detailed empirical, methodological and philosophical analysis. As a result, we reaffirm the difference between practitioners and non-practitioners, contesting the four central claims about interactional expertise--namely, that (1) the idea of interactional expertise has been proven empirically, (2) it is possible to develop interactional expertise through 'linguistic socialization alone', (3) the idea of interactional expertise supports the 'the minimal embodiment thesis' that the individual human body or, more broadly, 'embodiment' is not as relevant as linguistic socialization for acquiring a language and (4) interactional experts have the same linguistic fluency, understanding and judgemental abilities of practitioners within discursive settings. Instead, we argue, individuals' abilities and understandings vary according to the 'type of immersion' they have experienced within a given practice and whether they bring with them another 'perspective'. Acknowledging these differences helps with demarcation but does not solve the 'problem of demarcation'. Every experience is perspectival and cannot handle, alone, the intertwined and complex issues found in public debates involving technical matters. The challenge, then, concerns the ways to mediate interactions between actors with distinct perspectives, experiences and abilities.

Framework for the assessment of the safety culture in the oil and gas industry.

Approaches to safety culture assessment may have many limits if supported exclusively by quantitative methods. Based on this, a research team developed a quantitative-qualitative approach to assess the maturity of the safety culture on an oil platform. To that end, the team sought to develop and test a method consisting of an initial ethnographic phase followed by four other distinct phases: definition of homogeneous groups; production of customized questionnaires; quantitative evaluation; and qualitative assessment. The results show the emergence of trends, from pre-defined themes in safety culture to specific levels of maturity for each of the homogeneous groups. At the same time, it was perceived that the maturity level of the groups is defined from the daily work practices developed by each one of them. This experience allowed us to propose a framework for assessing the maturity levels of safety culture for the oil and gas industry.

Effect of Lippia alba (Mill.) N.E. Brown Essential Oil on the Human Umbilical Artery.

Lippia alba is popularly known as lemon balm, with its essential oil (EO) cited for displaying antimicrobial, sedative, and vasorelaxant effects. Yet, its action on isolated human vessels has not been described in the literature. Thus, we evaluated the vasorelaxant effect of essential oil of L. alba (EOLa) on human umbilical arteries (HUA) isolated in organ baths. HUA rings were isolated, subjected to contractions induced by potassium chloride (KCl), serotonin (5-HT), or histamine (HIST) to record the isometric tension, and then treated with EOLa (30-1000 µg/mL). The EOLa showed a more prominent inhibitory effect on the pharmacomechanical coupling contraction via HIST with an EC50 value of 277.1 ± 8.5 µg/mL and maximum relaxant effect at 600 µg/mL. The addition of tetraethylammonium (TEA) or 4-aminopyridine (4-AP) in HUA preparations did not inhibit EOLa total relaxant effect at 1000 µg/mL. In the presence of gliblenclamide (GLI), the oil relaxed the HUA rings by 90.8% at maximum concentration. The EOLa was also investigated for its effects on voltage-operated calcium channels (VOCCs), where the HUA preincubation with this oil at 1000 µg/mL inhibited BaCl2 (0.1-30 mM)-induced contractions. This study demonstrates for the first time that EOla has a vasorelaxant effect on HUA and its particular blockade of VOCCs.