145 research outputs found

    Reproductive success and contaminant associations in tree swallows (\u3ci\u3eTachycineta bicolor\u3c/i\u3e) used to assess a Beneficial Use Impairment in U.S. and Binational Great Lakes’ Areas of Concern

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    During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological variables and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure rates. Four of 5 ecological variables (Female Age, Date within season, Year, and Site) were important explanatory variables. Of the 11 contaminants, only total dioxin and furan toxic equivalents (TEQs) explained a significant amount of the egg failure probabilities. Neither total PCBs nor PCB TEQs explained the variation in egg failure rates. In a separate analysis, polycyclic aromatic hydrocarbon exposure in nestling diet, used as a proxy for female diet during egg laying, was significantly correlated with the daily probability of egg failure. The 8 sites within AOCs which had poorer reproduction when compared to 10 non-AOC sites, the measure of impaired reproduction as defined by the Great Lakes Restoration Initiative, were associated with exposure to dioxins and furan TEQs, PAHs, or depredation. Only 2 sites had poorer reproduction than the poorest performing non-AOC. Using a classic (non-modeling) approach to estimating reproductive success, 82% of nests hatched at least 1 egg, and 75% of eggs laid, excluding those collected for contaminant analyses, hatched

    Multi-omics responses in tree swallow (\u3ci\u3eTachycineta bicolor\u3c/i\u3e) nestlings from the Maumee Area of Concern, Maumee River, Ohio

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    A multi-omics approach was utilized to identify altered biological responses and functions, and to prioritize contaminants to assess the risks of chemical mixtures in the Maumee Area of Concern (AOC), Maumee River, OH, USA. The Maumee AOC is designated by the United States Environmental Protection Agency as having significant beneficial use impairments, including degradation of fish and wildlife populations, bird or animal deformities or reproduction problems, and loss of fish and wildlife habitat. Tree swallow (Tachycineta bicolor) nestlings were collected at five sites along the Maumee River, which included wastewater treatment plants (WWTPs) and industrial land-use sites. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo p dioxins and furans (PCDD/Fs), and chlorinated pesticide concentrations were elevated in Maumee tree swallows, relative to a remote reference site, Star Lake, WI, USA. Liver tissue was utilized for non-targeted transcriptome and targeted metabolome evaluation. A significantly differentially expressed gene cluster related to a downregulation in cell growth and cell cycle regulation was identified when comparing all Maumee River sites with the reference site. There was an upregulation of lipogenesis genes, such as PPAR signaling (HMGCS2, SLC22A5), biosynthesis of unsaturated fatty acids (FASN, SCD, ELOVL2, and FADS2), and higher lipogenesis related metabolites, such as docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) at two industrial land-use sites, Ironhead and Maumee, relative to WWTP sites (Perrysburg and SideCut), and the reference site. Toledo Water, in the vicinity of the other two industrial sites and also adjacent to a WWTP, showed a mix of signals between industrial land-use and WWTP land-use. PAHs, oxychlordane, and PBDEs were determined to be the most likely causes of the differentiation in biological responses, including de novo lipogenesis and biosynthesis of unsaturated fatty acids

    Histologic tissue response to furcation perforation repair using mineral trioxide aggregate or dental pulp stem cells loaded onto treated dentin matrix or tricalcium phosphate

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    Objectives The aim of this study is to compare the effect of treated dentine matrix (TDM) and tricalcium phosphate (TCP) scaffolds on odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs) in furcation perforations created in the pulp chamber floor of premolar teeth in dogs. Material and methods DPSCs were isolated and cultured from the dental pulp of the maxillary left second and third premolars of dogs. The DPSCs were loaded on TCP (SC+TCP) and TDM (SC+TDM) scaffolds and inserted into intentionally perforated pulp chamber floors of premolars in dogs; six teeth were used for each group. Three more groups of six specimens were created, and mineral trioxide aggregate (MTA), TDM, and TCP were inserted into the perforations to act as controls. An intact premolar and no treatment in the perforation site were used as positive and negative controls respectively. After 3 months, the animals were sacrificed and the type of inflammation, presence of dentine, continuation and type of cementum, type of connective tissue, and presence of foreign body reaction were evaluated, and significant differences were between groups determined using the Fisher’s exact test. The evaluation of the amount of inflammation and the percentage of new bone formation was evaluated using the Mann-Whitney U test. Results The negative control group was associated with severe inflammation and granulation tissue formation. In the positive control group, intact periodontal tissues and no inflammation were observed. Dentine bridge formation was not seen in specimens of any group. The specimens in the SC+TDM group were associated with significantly more bone formation than other groups (P < 0.001). The amount of inflammation was less than 10 % in specimens of all groups with the exception of three specimens in the TCP group that were categorized as 10–30 %. Chronic inflammation without foreign body reactions was the major pattern of inflammation in groups. Formation of cementum with a cellular and continuous appearance was seen in all specimens. Conclusions SC+TDM was associated with significantly more bone formation when used to repair uninfected furcation perforations in the premolar teeth of dogs. Clinical relevance Application of TDM as a biological scaffold in combination with DPSCs may offer an advantage during the repair of root perforation defects

    Desempenho de sistemas endodĂ´nticos rotatĂłrios constante e progressivo no preparo do canal radicular

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    Objective The aim of this study was to compare the performance of two nickel-titanium rotary systems regarding the preparation time, final shape of canal, incidence of aberration, transportation, and fracture of instrument. Methods A total of 40 simulated canals in resin blocks with 30o curves and a length of 17 mm were divided randomly into two groups: preparation with ProTaper and BioRaCe systems up to F5 and BR5 respectively. Pre- and post-operative canal images were taken and superimposed in order to identify aberrations, transportation, and to take measurements of the canal width. In addition, the preparation time and instrument fractures were recorded. The data were analyzed using Student's t test. Results There is no difference (p>.05) comparing the systems regarding preparation time, canal aberration, and instrument fracture rates. The progressive tapered instruments of ProTaper prepared significantly larger canal widths in the apical third (p0,05). Os instrumentos progressivos do ProTaper resultou em canais significativamente mais largos no terço apical (p<0,05). Conclusão Os dois sistemas rotatórios avaliados resultaram em preparo endodôntico seguro, com poucas alteraçþes e fratura de instrumento

    Cemental tear: Literature review, proposed classification and recommendations for treatment

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    Cemental tears are an important condition of relevance to Endodontics but are often overlooked. A cemental tear is the partial or complete detachment of the cementum from the cemento-dentinal junction or along the incremental line within the body of cementum. The limited attention received is most likely due to the limited awareness amongst dental professionals and challenges in accurately diagnosing them, resulting in misdiagnosis and erroneous treatment. The aim of this review is to describe the: (i) epidemiology and predisposing factors; (ii) clinical, radiographic and histological features and (iii) the clinical management and treatment outcomes of cemental tear. The review included 37 articles published in English that comprised eight observational studies and 29 case reports. The prevalence of cemental tears was reported to be lower than 2%; whilst the incidence remains unknown. Internal factors due to the inherent structural weakness of cementum and its interface with the dentine, and external factors that are associated with stress have been proposed as the two mechanisms responsible for the development and propagation of cemental tears. Predisposing factors that have been implicated were tooth type, gender, age, previous root canal treatment, history of dental trauma, occlusal trauma and excessive occlusal force; however, evidence is limited. Common clinical and radiographic manifestations of cemental tears resemble the presentations of primary endodontic diseases, primary periodontal diseases and combined endodontic–periodontal lesions. Clinical management tended to focus on complete removal of the torn fragments and periodontal treatment, often combined with regenerative treatment. In this article, a new classification for cemental tears is developed that consists of classes 0 to 6 and stages A, B, C and D based on the: (i) location and accessibility of the torn cemental fragment; (ii) the pattern and extension of the associated bony defect in relation to the root length and (iii) the number of root surface/s affected by the cemental tear/s and the associated bony defect. Recommendations for treatment strategies are also provided and linked to the classification to aid in streamlining the process of treatment decision making

    Exposure and Effects of Perfluoroalkyl Substances in Tree Swallows Nesting in Minnesota and Wisconsin, USA

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    The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor). Concentrations of PFASs were quantified as were reproductive success end points. The sample egg method was used wherein an egg sample is collected, and the hatching success of the remaining eggs in the nest is assessed. The association between PFAS exposure and reproductive success was assessed by site comparisons, logistic regression analysis, and multistate modeling, a technique not previously used in this context. There was a negative association between concentrations of perfluorooctane sulfonate (PFOS) in eggs and hatching success. The concentration at which effects became evident (150–200 ng/g wet weight) was far lower than effect levels found in laboratory feeding trials or egg injection studies of other avian species. This discrepancy was likely because behavioral effects and other extrinsic factors are not accounted for in these laboratory studies and the possibility that tree swallows are unusually sensitive to PFASs. The results from multistate modeling and simple logistic regression analyses were nearly identical. Multistate modeling provides a better method to examine possible effects of additional covariates and assessment of models using Akaike information criteria analyses. There was a credible association between PFOS concentrations in plasma and eggs, so extrapolation between these two commonly sampled tissues can be performed

    Management of patients receiving novel antithrombotic treatment in endodontic practice: Review and clinical recommendations

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    Cardiovascular diseases are a major component of non-communicable diseases and death, with thrombosis constituting the most common underlying pathosis of the three major cardiovascular disorders: ischaemic heart disease (acute coronary syndrome), stroke and venous thromboembolism (VTE). The introduction of direct oral anticoagulants (DOACs) in recent years has necessitated a more complex approach to periprocedural and perioperative anticoagulation management and the need for revised management strategies and protocols. Currently, patients taking classic oral anticoagulants are advised to stop taking the drugs and have their INR values checked 72 h prior to dental surgery (e.g., apical surgery, tooth extraction, and periodontal surgery) and checked again 24 h prior to the procedure to ensure it is within the therapeutic range. However, the current incorporation of these novel DOACs in routine medical practice requires changes in the way patients are managed preoperatively in dentistry, and specifically in endodontic surgery. The methodology applied in this review included searching for relevant articles in the PubMed database using keywords listed in the Entree Terms databases. Articles published on human blood clotting mechanism, antithrombotic drugs, as well as treatment guidelines and recommendations for dentistry were retrieved. In addition, textbooks and guidelines that may not have surfaced in the online search were searched manually. The aim of this paper was to review the mechanisms of action of classic and novel antithrombotic medications and their impact on endodontic treatment and the management of local haemostasis in endodontics

    A bibliometric analysis of the top 100 most-cited case reports and case series in Endodontic journals

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    Aim To identify the top 100 most-cited case reports and case series published in Endodontic journals and to analyse their bibliometric characteristics. Methodology The Clarivate Analytics’ Web of Science (WoS), Scopus and PubMed databases were used to identify the top 100 most-cited case reports and case series in Endodontic journals. Complete bibliographic records of the selected case reports and case series were exported in plain text or BibTeX format and imported into the R environment for statistical computing and graphics. The following parameters were then analysed: names and affiliations of the authors, title, year of publication, journal of publication, first author, corresponding author, literature cited within reports, language, citation counts, impact factor of the journal, keywords, Keywords Plus and research topic. Results In total, 88 case reports and 12 case series published in English between 1977 and 2016 were identified as the most-cited reports in the field of Endodontics. The terms “case report(s)” or “case series” were not included in the title of 57 articles. The number of authors per report ranged from one to seven, with the average number of co-authors per report being 3.14. The most-cited author was M Trope (University of Pennsylvania, USA). The University of Washington and Private Practice, Cetraro, Italy, were the most productive institutions. The country whose case reports received the largest total number of citations was the United States. The largest number of the most-cited reports appeared in 2002, 2004 and 2007 (n = 7, respectively). According to the WoS database, the total number of citations ranged from 42 to 453, with the average number of citations per report being 79.97. The majority of the top 100 most-cited articles were published in the Journal of Endodontics and the International Endodontic Journal. The most frequently used author keywords were revascularization and mineral trioxide aggregate. The majority of the case reports and case series dealt with topics related to pulp regeneration. Conclusion This bibliometric study provides a comprehensive overview on the progress, trends and current directions in clinical practice within the field of Endodontics

    Factors that influence the outcome of pulpotomy in permanent teeth

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    The promotion of minimally invasive treatments focussed on the maintenance of pulp vitality has become a priority area in Endodontics. These vital pulp treatments (VPT) include partial and full pulpotomy, during which diseased coronal pulp tissue is removed prior to placement of a capping biomaterial and restoration. Traditionally, pulpotomies were confined to the treatment of carious primary and traumatized permanent teeth. However, these treatments have now been proposed as definitive solutions for cariously exposed permanent teeth with mild symptoms or even symptoms indicative of irreversible disease. Until recently, it was recommended that carious exposure of mature permanent teeth be managed by root canal treatment. The promotion of pulpotomy as an alternative treatment has opened up a wave of laboratory and clinical research aimed at improving therapies or evaluating clinical outcomes. In modern evidence‐based endodontics, it is imperative that the outcomes of both partial and full pulpotomy are considered and important prognostic factors identified, so that improvements can be made to aid clinical decision‐making and to direct new research. In this narrative review, the outcomes of partial and full pulpotomy are discussed, before analysis of patient, intraoperative and postoperative factors that influence the outcome of the pulpotomy procedure. The review highlights that although partial and full pulpotomy for the treatment of even pulpal disease are highly successful procedures, this is based on low‐quality evidence with a lack of prospective, comparative trials investigating potential prognostic factors. Based on current evidence, it appears that age, gender, tooth type, root development and intraoperative pulpal haemorrhage do not impact significantly on pulpotomy outcome, whilst others such as caries depth, inflammatory status of the pulp, capping material, level of inflammatory pulpal‐biomarkers and the final restoration integrity do. Other factors, including the influence of exposure type, periodontal condition, pulpal lavage, magnification, operator experience, isolation of the operating field and type of pulpotomy, require further experimental investigation before definitive conclusions can be made relating to the success of the pulpotomy procedure. Finally, there is not only a need for future well‐designed prospective research addressing these issues but also a widening of our understanding of outcome to include patient‐reported as well as clinician‐reported outcomes

    Human Melanoma-Associated Mast Cells Display a Distinct Transcriptional Signature Characterized by an Upregulation of the Complement Component 3 That Correlates With Poor Prognosis

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    Cutaneous melanoma is one of the most aggressive human malignancies and shows increasing incidence. Mast cells (MCs), long-lived tissue-resident cells that are particularly abundant in human skin where they regulate both innate and adaptive immunity, are associated with melanoma stroma (MAMCs). Thus, MAMCs could impact melanoma development, progression, and metastasis by secreting proteases, pro-angiogenic factors, and both pro-inflammatory and immuno-inhibitory mediators. To interrogate the as-yet poorly characterized role of human MAMCs, we have purified MCs from melanoma skin biopsies and performed RNA-seq analysis. Here, we demonstrate that MAMCs display a unique transcriptome signature defined by the downregulation of the FcξRI signaling pathway, a distinct expression pattern of proteases and pro-angiogenic factors, and a profound upregulation of complement component C3. Furthermore, in melanoma tissue, we observe a significantly increased number of C3+^{+} MCs in stage IV melanoma. Moreover, in patients, C3 expression significantly correlates with the MC-specific marker TPSAB1, and the high expression of both markers is linked with poorer melanoma survival. In vitro, we show that melanoma cell supernatants and tumor microenvironment (TME) mediators such as TGF-β, IL-33, and IL-1β induce some of the changes found in MAMCs and significantly modulate C3 expression and activity in MCs. Taken together, these data suggest that melanoma-secreted cytokines such as TGF-β and IL-1β contribute to the melanoma microenvironment by upregulating C3 expression in MAMCs, thus inducing an MC phenotype switch that negatively impacts melanoma prognosis
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