Micro-computed tomography and histology to explore internal morphology in decapod larvae

Traditionally, the internal morphology of crustacean larvae has been studied using destructive techniques such as dissection and microscopy. The present study combines advances in microcomputed tomography (micro-CT) and histology to study the internal morphology of decapod larvae, using the common spider crab (Maja brachydactyla Balss, 1922) as a model and resolving the individual limitations of these techniques. The synergy of micro-CT and histology allows the organs to be easily identified, revealing simultaneously the gross morphology (shape, size, and location) and histological organization (tissue arrangement and cell identification). Micro-CT shows mainly the exoskeleton, musculature, digestive and nervous systems, and secondarily the circulatory and respiratory systems, while histology distinguishes several cell types and confirms the organ identity. Micro-CT resolves a discrepancy in the literature regarding the nervous system of crab larvae. The major changes occur in the metamorphosis to the megalopa stage, specifically the formation of the gastric mill, the shortening of the abdominal nerve cord, the curving of the abdomen beneath the cephalothorax, and the development of functional pereiopods, pleopods, and lamellate gills. The combination of micro-CT and histology provides better results than either one alone.Financial support was provided by the Spanish Ministry of Economy and Competitiveness through the INIA project (grant number RTA2011-00004-00-00) to G.G. and a pre-doctoral fellowship to D.C. (FPI-INIA)

Empirical Analysis of the Assessment of Innovation Effects in U.S. Merger Cases

In this empirical study all mergers that have been challenged by the U.S. antitrust agencies FTC and DOJ between 1995 and 2008 were analyzed in regard to the question to what extent and how the agencies assessed the innovation effects of mergers. Theoretical background is the still open question how negative effects of mergers on innovation should be taken into account in merger policy. Although we can show in our study that in one third of all challenged mergers also innovation concerns were raised, the results also point to a still existing large degree of uneasiness and inconsistencies of the agencies in regard to the assessment of innovation effects. A particularly interesting result is that - despite the wide-spread rejection of the "innovation market approach" in the antitrust debate - the agencies used more an innovationspecific assessment approach that includes also innovation in the market definition than the pure traditional product market concept. Additionally, we also found significant differences between the assessment approaches of the FTC and the DOJ

Interference of partial visual analysis of root filling quality and apical status on retreatment decisions

OBJECTIVE: The presence of periapical radiolucency has been used as a criterion for endodontic treatment failure. However, in addition to the inherent limitations of radiographic examinations, radiographic interpretations are extremely subjective. Thus, this study investigated the effect of partial analysis of root filling quality and periapical status on retreatment decisions by general dentists. MATERIAL AND METHODS: Twelve digitalized periapical radiographs were analyzed by 10 observers. The study was conducted at three time points at 1-week intervals. Radiographs edited with the Adobe Photoshop CS4 software were analyzed at three time points: first, only root filling quality was analyzed; second, only the periapical areas of the teeth under study were visualized; finally, observers analyzed the unedited radiographic image. Spearman's coefficient was used to analyze the correlations between the scores assigned when the periapical area was not visible and when the unedited radiograph was analyzed, as well as between the scores assigned when root fillings where not visible and when the unedited radiograph was analyzed. Sensitivity, specificity, positive and negative predictive values between partial images and unedited radiographs were also used to analyze retreatment decisions. The level of significance was set at 5%. RESULTS: The visualization of the root filling on the unedited radiograph affected the interpretation of the periapical status and the technical quality of the fillings has a greater influence on the general dentist's decision to prescribe endodontic retreatment than the periapical condition. CONCLUSION: In order to make endodontic diagnosis, radiographic interpretation process should not only emphasize technical aspects, but also consider biological factors

Estudo longitudinal do sucesso clínico-radiográfico de dentes tratados com medicação intracanal de hidróxido de cálcio

INTRODUÇÃO: O tratamento endodôntico é de fundamental importância para abolir a infecção presente em dentes que apresentam necrose pulpar. OBJETIVO: O objetivo do presente estudo foi avaliar clínica e radiograficamente a eficácia dos tratamentos de canais radiculares de dentes com lesão periapical crônica, efetuados pelos graduandos em Odontologia, da Faculdade de Odontologia de Araçatuba - UNESP. MATERIAL E MÉTODO: Foram selecionados 100 pacientes que possuíam dentes com lesão periapical crônica para serem tratados. Após o preparo biomecânico, os canais radiculares receberam uma medicação intracanal de hidróxido de cálcio durante o período de 14 dias. Os canais radiculares foram obturados com cimento endodôntico à base de hidróxido de cálcio. Foi realizada a proservação por um período entre oito e 11 meses. RESULTADO: A análise dos resultados permitiu constatar a porcentagem de 78,46% dos casos com reparo total da lesão periapical e de 21,54% dos casos em que não houve evidências de reparo. CONCLUSÃO: Ocorreu reparo das lesões periapicais nos dentes tratados pelos graduandos da Faculdade de Odontologia de Araçatuba - UNESP.INTRODUCTION: Root canal treatment plays a fundamental role in abolishing infections in teeth showing pulp necrosis. OBJECTIVE: We aimed to evaluate the clinical and radiographic efficacy of root canal treatment for teeth with chronic periapical lesions, which was performed by students of Undergraduate Dentistry, Faculty of Dentistry, Campus Araçatuba - UNESP. MATERIAL and METHOD: We selected 100 patients who had teeth with chronic periapical lesions. After biomechanical preparation, the root canal receiving of calcium hydroxide intracanal dressing during the 14 days. The root canals were filled with a calcium hydroxide-based endodontic sealer. Follow-up examinations were performed for at least 8 months. RESULT: An analysis of the results showed total repair in 78.46% of the cases and no evidence of repair in 21.54% of the cases. CONCLUSION: Repair occurred in the teeth with chronic periapical lesions treated by students of Undergraduate Dentistry, Faculty of Dentistry, Campus Araçatuba - UNESP.UNESP Faculdade de Odontologia Departamento de Odontologia RestauradoraUNESP Faculdade de Odontologia Departamento de Patologia e Propedêutica ClínicaUNESP Faculdade de Odontologia Departamento de Odontologia RestauradoraUNESP Faculdade de Odontologia Departamento de Patologia e Propedêutica Clínic

Distinct cytokine profiles of circulating mononuclear cells stimulated with Staphylococcus aureus enterotoxin A in vitro during early and late episodes of chronic osteomyelitis

We investigated the cytokine profile of peripheral mononuclear cells from chronic osteomyelitis (OST) patients following in vitro stimulation with staphylococcal enterotoxin A (SEA). We demonstrate that stimulation with SEA induced prominent lymphocyte proliferation and high levels of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and IL-10 secretion in both OST and non-infected individuals (NI). Even though stimulation with SEA had no impact on IL-6 production in either patient group, the baseline level of IL-6 production by cells from OST patients was always significantly less than that produced by cells from NI. After classifying the osteomyelitic episodes based on the time after the last reactivation event as "early" (1-4 months) or "late" osteomyelitis (5-12 months), we found that increased levels of TNF-α and IL-4 in combination with decreased levels of IL-6 were observed in the early episodes. By contrast, increased levels of IL-10, IL-2 and IL-6 were hallmarks of late episodes. Our data demonstrate that early osteomyelitic episodes are accompanied by an increased frequency of "high producers" of TNF-α and IL-4, whereas late events are characterised by increased frequencies of "high producers" of IL-10, IL-6 and IL-2. These findings demonstrate the distinct cytokine profiles in chronic osteomyelitis, with a distinct regulation of IL-6 production during early and late episodes

Tannerella forsythia, a periodontal pathogen entering the genomic era

Several questions need to be addressed to evaluate whether Tannerella forsythia is to be considered a periodontal pathogen. T. forsythia has been detected in periodontal health and disease, so could it be a pathogen? The species was not detected in many studies despite finding other putative pathogens, so could it be important in pathogenicity? The challenges of working with T. forsythia include its fastidious and anaerobic growth requirements for cultural detection. Thus, studies associating T. forsythia with periodontal and other oral infections have used noncultural approaches (immunoassays and DNA-based assays) in addition to cultural approaches. We feel the timing of this review represents an interesting transition period in our understanding of the relationships of species with infection. Information from the recently released full genome sequence data of T. forsythia will provide new approaches and tools that can be directed to assess pathogenicity. Furthermore, molecular assessment of gene expression will provide a new understanding of the pathogenical potential of the species, and its effect on the host. T. forsythia, was described in reviews focusing on periodontal pathogens associated with herpesvirus detection (200), species for which genome projects were underway (41), members of polybacterial periodontal pathogenic consortium (91), and participants in periodontal microbial ecology (202). We will describe the history, taxonomy, and characteristics of T. forsythia, and related species or phylotypes in the genus Tannerella. To assess the pathogenic potential of T. forsythia, we first describe species associations with periodontal and other infections, including animal models, as has been the traditional approach arising from Koch’s postulates (203). Criteria for pathogenicity were expanded to incorporate sequence- derived information (58), and again more recently to include molecular signatures of pathogens and disease (170). We used sequence and genome-derived information, in addition to biofilm, pathogenic mediators, and host responses, to further explore the pathogenic potential of T. forsythia

Is the Google Platform a Two-Sided Market?

Probably not. Or, at least, it is a sui generis two-sided market. Unlike other platforms, such as Microsoft Windows operating system, credit cards, or night clubs, where a single transaction is performed via the platform, two different transactions take place on Google. Users look for search results, while advertisers look for users' eyeballs. Whilst operating systems, credit cards, and night clubs would be meaningless if either of the two sides were missing, search engines (like TV or newspapers) can exist under different market configurations. Indeed, in search engines network externalities run only from the number of users to advertisers, and not the other way around. This thesis is supported by the analysis of the existing literature on two-sided markets and the applications carried out so far to the economics of search engines. According to this analysis, a new construction of the relevant market where Google operates is proposed. Google operates as a retailer of eyeballs, or users' attention. In the upstream market, on one side, it buys well-profiled eyeballs from large retailers, i.e. major websites, at a positive price (Traffic Acquisition Costs); on the other side, it buys eyeballs from single consumers in exchange of search services (in-kind payment). Then, it sells well-profiled eyeballs to advertisers in the downstream market. Based on this market construction, the allegations against Google are analysed as alleged violations of competition law along this vertical chain

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study

Postoperative pain is a frequent complication associated with root canal treatment, especially during apical instrumentation of tooth with preexisting periradicular inflammation OBJECTIVES: The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. MATERIAL AND METHODS: Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal–Wallis test. RESULTS: There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). CONCLUSION: All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques