Periodontal pathogen Aggregatibacter actinomycetemcomitans JP2 correlates with colonic leukocytes decrease and gut microbiome imbalance in mice.

AIM: Evidence suggests that translocation of oral pathogens through the oral-gut axis may induce intestinal dysbiosis. This study aimed to evaluate the impact of a highly leukotoxic Aggregatibacter actinomycetemcomitans (Aa) strain on the gut microbiota, intestinal mucosal integrity and immune system in healthy mice. METHODS: Eight-week-old male C57BL6 mice were divided into control (n = 16) and JP2 groups (n = 19), which received intragastric gavage with PBS and with a suspension of Aa JP2 (HK921), respectively, twice a week for 4 weeks. Colonic lamina propria, fecal material, serum, gingival tissues, and mandibles were obtained for analyses of leukocyte populations, inflammatory mediators, mucosal integrity, alveolar bone loss, and gut microbiota. Differences between groups for these parameters were examined by non-parametric tests. RESULTS: The gut microbial richness and the number of colonic macrophages, neutrophils, and monocytes were significantly lower in Aa JP2-infected mice than in controls (p < .05). In contrast, infected animals showed higher abundance of Clostridiaceae, Lactobacillus taiwanensis, Helicobacter rodentium, higher levels of IL-6 expression in colonic tissues, and higher splenic MPO activity than controls (p < .05). No differences in tight junction expression, serum endotoxin levels, and colonic inflammatory cytokines were observed between groups. Infected animals presented also slightly more alveolar bone loss and gingival IL-6 levels than controls (p < .05). CONCLUSION: Based on this model, intragastric administration of Aa JP2 is associated with changes in the gut ecosystem of healthy hosts, characterized by less live/recruited myeloid cells, enrichment of the gut microbiota with pathobionts and decrease in commensals. Negligible levels of colonic pro-inflammatory cytokines, and no signs of mucosal barrier disruption were related to these changes.

Cafeteria Diet Can Affect Bone Microarchitecture in Sedentary and Trained Male Rats.

INTRODUCTION: Poor eating habits and a sedentary lifestyle can impair health. Regular physical activity improves the quality of life and is essential for bone health. Therefore, the present study aimed to evaluate the effects of the cafeteria diet on bone quality of sedentary and exercised rats. METHODS: Sixty young male Wistar rats were divided into six groups (n=10) according to diet composition and activity level, being: SD+CON, standard diet and control; SD+SED, standard diet and sedentary; SD+EX, standard diet and exercised; CD+CON, cafeteria diet and control; CD+SED, cafeteria diet and sedentary; CD+EX, cafeteria diet and exercised. The exercise protocol consisted of 10 ladder-climbing sessions/day, 5 days/week, and the sedentary rats were maintained in individual cages with limited mobility. Body mass and food intake were evaluated weekly. After 10 weeks, the animals were euthanized, and white adipose tissue was collected. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and micro-computed tomography analyses. RESULTS: The cafeteria diet increased adipose tissue (p<0.001), decreased bone mineral density (p=0.004), and impaired biomechanical properties (p<0.05) and histomorphometry parameters (p=0.044). The sedentarism decreased bone mineral density (p<0.001) and biomechanical properties (p<0.05), and the exercise did not improve bone properties. CONCLUSION: In this experimental model, it was concluded that the cafeteria diet and a sedentary lifestyle negatively affect bone, and ladder-climbing exercise could not prevent the effects of the unhealthy diet.

Molecular parallelisms between pigmentation in the avian iris and the integument of ectothermic vertebrates.

Birds exhibit striking variation in eye color that arises from interactions between specialized pigment cells named chromatophores. The types of chromatophores present in the avian iris are lacking from the integument of birds or mammals, but are remarkably similar to those found in the skin of ectothermic vertebrates. To investigate molecular mechanisms associated with eye coloration in birds, we took advantage of a Mendelian mutation found in domestic pigeons that alters the deposition of yellow pterin pigments in the iris. Using a combination of genome-wide association analysis and linkage information in pedigrees, we mapped variation in eye coloration in pigeons to a small genomic region of ~8.5kb. This interval contained a single gene, SLC2A11B, which has been previously implicated in skin pigmentation and chromatophore differentiation in fish. Loss of yellow pigmentation is likely caused by a point mutation that introduces a premature STOP codon and leads to lower expression of SLC2A11B through nonsense-mediated mRNA decay. There were no substantial changes in overall gene expression profiles between both iris types as well as in genes directly associated with pterin metabolism and/or chromatophore differentiation. Our findings demonstrate that SLC2A11B is required for the expression of pterin-based pigmentation in the avian iris. They further highlight common molecular mechanisms underlying the production of coloration in the iris of birds and skin of ectothermic vertebrates.

Chronic alcohol and nicotine consumption as catalyst for systemic inflammatory storm and bone destruction in apical periodontitis.

AIM: To assess the periapical alveolar bone pattern and the serum levels of proinflammatory cytokines, biochemical markers and metabolites in rats subjected to chronic alcohol and nicotine consumption and induced apical periodontitis. METHODOLOGY: Twenty-eight male Wistar rats were divided into four groups: Control, Alcohol, Nicotine and Alcohol+Nicotine. The alcohol groups were exposed to self-administration of a 25% alcohol solution, while the other groups were given only filtered water. The nicotine groups received daily intraperitoneal injections of a nicotine solution (0.19 µL of nicotine/mL), whereas the other groups received saline solution. Periapical lesions were induced by exposing the pulps of the left mandibular first molars for 28 days. After euthanasia, the mandibles were removed and the percentage bone volume, bone mineral density, trabecular thickness, trabecular separation and trabecular number of the periapical bone were measured using micro-computed tomography images. Serum samples were collected for analysis of proinflammatory cytokines (IL-1ß, IL-4, IL-6 and TNF-α), biochemical and metabolomic analysis. Statistical analysis was performed with a significance level of 5%. Nonparametric data were analysed using the Kruskal-Wallis test followed by Dunn's test, while one-way anova followed by Tukey's test was performed for parametric data. RESULTS: The groups exposed to alcohol or nicotine consumption exhibited an altered bone pattern indicating lower bone density and higher levels of IL-1ß, IL-6 and TNF-α compared to the Control group (p < .05). Significant differences were observed among the groups in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, cholesterol, triglycerides, urea, creatinine, albumin, uric acid, bilirubin and calcium. Metabolomic analysis revealed significant differences in glycine, phosphocholine, lysine, lactate, valine, pyruvate and lipids (CH2 CH2 CO), n(CH2 ) and n(CH3 ). Most of these parameters were even more altered in the simultaneous consumption of both substances compared to single consumption. CONCLUSION: Alcohol and nicotine chronic consumption altered several metabolic markers, impaired liver and kidney function, increased the production of systemic proinflammatory mediators and harmed the periapical bone microarchitecture in the presence of apical periodontitis. The simultaneous consumption of alcohol and nicotine intensified these detrimental effects.

The effect of root canal preparation tapers on planktonic bacteria and biofilm reduction in the apical third: A correlative microtomography and microbiological laboratory study.

AIM: To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. METHODOLOGY: After microtomography analysis for morphological standardization of the canals, 48 mandibular molar roots, each containing two canals (96 canals), were contaminated with E. faecalis and C. albicans and divided into four groups (n = 11) for canal instrumentation using ProDesign Logic 2 files with different tapers G (.03): # 25.03; G (.04): # 25.04; G (.05): # 25.05; and G (.06): # 25.06 and irrigation with 2.5% sodium hypochlorite. Four roots were examined under a scanning electron microscope (SEM) to qualitatively assess biofilm formation. Eight roots were used as the negative control group (samples were not contaminated). Bacteriological samples were taken exclusively from the apical third of the roots before and after chemical-mechanical preparation and bacterial counts were determined (CFU/mL). The final micro-CT scan was used to quantify the volume variation and unprepared canal area in the apical third. Statistical analysis was performed using the Kruskal-Wallis, Student-Newman-Keuls and Wilcoxon tests for analysis of microbiological data. anova and the Tukey or Games-Howell test were used for analysis of micro-CT data and Spearman's test for correlations (α = 5%). RESULTS: All groups showed a significant reduction in bacteria (p < .05), with no statistically significant difference between groups. There was no significant difference in per cent volume increase between groups. The unprepared area (Δ%) was affected by the file used (p = .026) and was significantly lower for G (.06) compared to G (.03). There was no statistically significant correlation among bacterial reduction, volume and unprepared area (p > .05). CONCLUSION: The different preparation tapers influenced root canal shaping in the apical third but did not improve decontamination in this region.

Intracanal removal and apical extrusion of filling material after retreatment using rotary or reciprocating instruments: A new approach using human cadavers.

AIM: This study compared intracanal removal of filling as well as the frequency and volume of extruded material after retreatment with either HyFlex or Reciproc instruments in mandibular teeth from cadavers. METHODOLOGY: The root canals of 14 pairs of contralateral single-rooted teeth in mandibles of cadavers were instrumented with Reciproc R40 and filled using lateral compaction. The mandibles were scanned in a micro-computed tomographic (micro-CT) device before and after retreatment procedures. The contralateral teeth were assigned to two groups (n = 14) according to the retreatment protocol using either HyFlex or Reciproc instrument systems. In the HyFlex group, the HyFlex Remover instrument was worked 3 mm short of the working length (WL), followed by HyFlex CM 40.04 and 50.04 at the WL. In the Reciproc group, the R50 instrument was worked up at the coronal two thirds, followed by two more cycles until the WL was reached. Pre- and post-operative micro-CT images were analysed for extrusion and intracanal removal of filling material. RESULTS: After retreatment, extrusion of filling material occurred in 11 (78%) and 14 (100%) teeth from HyFlex and Reciproc groups respectively (p > .05). A similar volume of extruded material was observed after retreatment with both systems (p > .05). A significant decrease in the intracanal filling volume was verified after retreatment with both tested systems (p < .05). However, residual filling material was found in all root canals, regardless of the system. The amount of filling material removed (HyFlex = 80.8%; Reciproc = 65.9%) and the operation time was similar between systems (p > .05). CONCLUSIONS: A high frequency of filling material extrusion was observed after retreatment with the two systems in a cadaver model, with no significant difference between them. Both protocols obtained similar efficacy in filling material removal procedures, although none completely cleaned the canals.

Digital flashcards and medical physiology performance: a dose-dependent effect.

Use of digital flashcards promotes active recall, spaced repetition, and self-assessment academic principles. This work explores the association and dose-dependent effect of this study method and locomotor (LP) and cardiovascular physiology (CP) grades. A single-faculty cohort study of medical LP and CP students was conducted, and 155 and 676 flashcards, respectively, were created through Moodle. An exploratory analysis examined three exam results (2019), and a confirmatory study used a fourth exam (2021) in another CP cohort. Of 685 students enrolled, 558 participated in the exploratory analysis: 319 (69%) for LP and 311 (84%) for CP, of which 203 LP and 267 CP students were flashcard users. Median grades were higher among flashcard users, and the number of cards reviewed was positively correlated with grades (r = 0.275 to 0.388 for LP and r = 0.239 to 0.432 for CP, P < 0.001). Multiple linear regression models confirmed a positive dose-dependent association between results and the number of flashcards studied: for every 100 LP cards reviewed, exam grades increased 0.44-0.75 on a 0-20 scale range (P < 0.001), and for every 1,000 CP flashcards, results raised 0.81-1.08 values (P < 0.05). These findings were confirmed in the 2021 CP cohort of 269 participants, of whom 67% were flashcard users. Digital flashcard revision has a consistent positive dose-dependent association on LP and CP grades.NEW & NOTEWORTHY Implementing flashcard-based strategies is a feasible way to promote active recall, spaced repetition, and self-assessment, and students are highly adherent to these initiatives. There is a positive dose-dependent association between the number of flashcards reviewed and physiology grades. These results are consistent across different physiology subjects, under different cohorts, over short and medium terms.

Stress distribution on teeth restored with veneers using various incisal preparation designs: A 3D finite element analysis study.

STATEMENT OF PROBLEM: The type of veneer preparation is often chosen according to the patient's tooth structure and occlusion. Taking biomechanics into account in this decision-making process provides the clinician with more technical information on how to improve the clinical longevity of restorations. However, biomechanical analyses of veneer preparation designs are sparse. PURPOSE: The purpose of this 3-dimensional (3D) finite element analysis with microcomputed tomography (µCT) data obtained from realistic models was to assess the influence of different preparations for ceramic and composite resin veneers on restoration and resin layer stress distribution. MATERIAL AND METHODS: Four replicas of a central incisor were printed and prepared for laminate veneers with 4 different incisal edge designs: shoulder (SH), palatal chamfer (PC), palatal chamfer and oblique fracture involving the distal angle (OF-PC), and palatal chamfer involving horizontal incisal fracture (IF-PC). After fabrication and cementation of the veneers, the restored replicas were assessed with µCT, and 3D finite element models were built. A 100-N load was applied on the palatal surface at 60 and 125 degrees relative to the longitudinal axis. Maximum principal stress and stress distribution on the veneers, cement layer, and tooth structure were calculated and analyzed. RESULTS: The SH preparation exhibited better stress distribution than the PC preparation, and the cement layer and the veneer were subjected to lower stress. The IF-PC preparation had better stress distribution than the OF-PC. The shoulder and IF-PC showed higher stress on laminate veneers, but lower stress on the cement layer. Ceramic veneers exhibited lower stress than composite resin veneers. CONCLUSIONS: The different incisal preparations for laminate veneers influenced stress distribution on restorations and on the resin cement layer. The shoulder type preparation showed better stress distribution and the composite resin veneers showed unfavorable results compared with the ceramic veneers.

Clinical relevance of the blanking period on late recurrence after catheter ablation of atrial fibrillation.

INTRODUCTION: Recurrence of atrial fibrillation (AF) within the blanking period after catheter ablation (CA) is traditionally classified as a transient and benign event. However, recent findings suggest that early recurrence (ER) is associated with late recurrence (LR), challenging the predefined "blanking period". We aimed to determine the clinical and procedural predictors of ER and LR after CA and establish the risk of LR in patients who experience ER. METHODS AND RESULTS: Retrospective single-centre study including all patients who underwent a first procedure of AF CA between 2017 and 2019. ER was defined as any recurrence of AF, atrial flutter or atrial tachycardia >30 s within 90 days after CA and LR as any recurrence after 90 days of CA. A total of 399 patients were included, 37% women, median age of 58 years [49-66] and 77% had paroxysmal AF. Median follow-up was 33 months (from 13 to 61). ER after CA was present in 14% of the patients, and LR was reported in 32%. Among patients who experienced ER, 84% also had LR (p < .001). Patients with ER had a higher prevalence of moderate/severe valvular heart disease, persistent AF, previous electrical cardioversion, a larger left atrium, higher coronary artery calcium score, and higher rates of intraprocedural electrical cardioversion and cardiac fibrosis on eletroanatomical mapping compared with patients without ER. After covariate adjustment, ER and female sex were defined as independent predictors of LR (hazard ratio [HR] 4.69; 95% confidence interval [CI], 2.99-7.35; p < .001 and HR 2.73; 95% CI, 1.47-5.10; p = .002, respectively). CONCLUSION: The risk of LR after an index procedure of CA was significantly higher in patients with ER (five-fold increased risk). These results support the imperative need to clarify the clinical role of the blanking period.

Full genotype characterization of Brazilian canine G3P[3] strains during a 10-year survey (2012-2021) of rotavirus infection in domestic dogs and cats.

There is a dearth of information on the molecular epidemiology of rotaviruses in pets in Brazil. The aim of this study was to monitor rotavirus infections in household dogs and cats, determine full-genotype constellations, and obtain data on evolutionary relationships. Between 2012 and 2021, 600 fecal samples from dogs and cats (516 and 84, respectively) were collected at small animal clinics in São Paulo state, Brazil. Rotavirus screening was conducted using ELISA, PAGE, RT-PCR, sequencing, and phylogenetic analysis. Rotavirus type A (RVA) was detected in 0.5% (3/600) of the animals. No non-RVA types were detected. The three canine RVA strains were found to have a novel genetic constellation, G3-P[3] -I2-R3-C2-M3-A9-N2-T3-E3-H6, which has never been reported in dogs. As expected, all of the viral genes, except those encoding NSP2 and VP7, were closely related to the corresponding genes from canine, feline, and canine-like-human RVA strains. A novel N2 (NSP2) lineage was identified, grouping together Brazilian canine, human, rat and bovine strains, suggesting that genetic reassortment had occurred. Uruguayan G3 strains obtained from sewage contained VP7 genes that were phylogenetically close to those of the Brazilian canine strains, which suggests that these strains are widely distributed in pet populations in South American countries. For the NSP2 (I2), NSP3 (T3), NSP4 (E3), NSP5 (H6), VP1 (R3), VP3 (M3), and VP6 (I2) segments, phylogenetic analysis revealed possibly new lineages. The epidemiological and genetic data presented here point out the necessity for collaborative efforts to implement the One Health strategy in the field of RVA research and to provide an updated understanding of RVA strains circulating canines in Brazil.

Atypical antipsychotics olanzapine and clozapine increase bone loss in female rats with experimental periodontitis.

BACKGROUND AND OBJECTIVES: Periodontitis is a highly prevalent disease in psychiatric patients, including those undergoing symptomatic treatment with second-generation antipsychotics. Some of these drugs, such as clozapine (CLO) and olanzapine (OLA), have prominent metabolic effects such as weight gain, hyperglycemia, and dyslipidemia, which are risk factors for periodontitis. In addition to the metabolic effects, there are reports of changes in salivary flow, gingival bleeding, and caries. In this context, we aimed to evaluate if the metabolic effects of OLA and CLO alter periodontal parameters in an animal model of periodontitis without the environmental and psychosocial biases inherent to human diseases. METHODS: In the first set of experiments, male and female adult Wistar rats received oral administration of CLO, OLA, or vehicle for 45 days. They were evaluated for body mass composition and weight gain, blood glucose parameters (fasting and glucose tolerance and insulin resistance tests), and lipid profile (HDL, total cholesterol, and triglycerides). In a second set of experiments, the same measurements were performed in female rats exposed to the antipsychotics for 45 days and ligature-induced periodontitis on the 30th day of treatment. Macroscopic measurements of exposed roots, microtomography in the furcation region of the first molar, and histological evaluation of the region between the first and second molars were evaluated to assess bone loss. Additionally, gingival measurements of myeloperoxidase activity and pro-inflammatory cytokine TNF-α were made. RESULTS: Only females exposed to OLA had more significant weight gain than controls. They also exhibited differences in glucose metabolism. Ligature-induced periodontitis produced intense bone retraction without changing the density of the remaining structures. The bone loss was even higher in rats with periodontitis treated with OLA or CLO and was accompanied by a local increase in TNF-α caused by CLO. These animals, however, did not exhibit the same metabolic impairments observed for animals without periodontitis. CONCLUSION: The use of clozapine and olanzapine may be a risk factor for periodontal disease, independent of systemic metabolic alterations.

Impact of Coronary Artery Calcium Score Screening on Cardiovascular Risk Stratification of Patients with Atrial Fibrillation Undergoing Ablation.

INTRODUCTION: There is a well-established association between atrial fibrillation (AF) and coronary artery disease. Coronary artery calcium score (CACS) is a helpful tool to refine cardiovascular (CV) risk stratification and inform on the best strategies for primary CV prevention. This study aims to evaluate the impact of opportunistic screening with CACS on risk stratification and decision of preventive therapies, in patients with AF. METHODS: Cross-sectional study including patients with AF or atrial flutter undergoing cardiac computed tomography for ablation procedure planning, from 2017 to 2019. Baseline clinical and demographical data were collected. CACS was assessed in patients without coronary artery disease using the Agatston method. RESULTS: A total of 474 patients were included (93% with AF, mean age of 58 ± 10 years, 62% male). CACS >0 was present in 254 (54%) patients. According to CACS and the Society of Cardiovascular Computed Tomography recommendations, 25% of the patients would be candidates for statin therapy and 17% would be candidates for changes in the current statin intensity; in 11 patients (8%), acetylsalicylic acid would be recommended. CONCLUSION: In our study, more than half of the patients undergoing cardiac computed tomography before AF catheter ablation had CACS above zero. Our findings suggest that an opportunistic evaluation of CACS at the time of ablation can be an important tool to improve CV risk stratification, with important clinical and therapeutic implications.

Dentine Mineral Changes Induced by Polyalkenoate Cements after Different Selective Caries Removal Techniques: An in vitro Study.

This study aimed at evaluating the mineral variation induced by polyalkenoate cements in residual dentine after different caries removal methods. Ten extracted sound molars were selected, and five cavities were prepared on the occlusal surface of each specimen. Carious lesions were generated using a microbial protocol, while the caries removal was performed using bur, hand excavator, or two papain-based chemo-mechanical agents. One cavity was left unexcavated in each tooth. Cavities were restored using a zinc polycarboxylate cement (ZPC; n = 25), or a glass ionomer cement (GIC) was used (n = 25). Subsequently, the specimens were stored under simulated pulpal pressure for 45 days. Micro-CT scanning was performed after caries formation, removal, and restoration. Cavity volumes (mm3) and mineral density (MD) changes were calculated. Remineralisation ability was investigated by scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FTIR). Statistical analysis was performed (5% significance level). Baseline caries, cavity volume, and MD increase after caries removal were similar to all excavation groups (p > 0.05). MD was higher in ZPC compared to GIC (p < 0.05). SEM revealed that the chemo-mechanical techniques produced a smoother dentine surface compared to mechanical methods. FTIR showed silicon-based minerals in GIC-treated dentine, while ZPC-treated presented mineral deposits characterised by amorphous calcium phosphate. In both cases, the presence of carbonates was detected on dentine surfaces. All caries removal techniques performed similarly in terms of carious dentine excavation. ZPC can be used as dentine replacement material after caries removal as it may induce higher MD increase in residual dentine via deposition of calcium phosphates, compared to GIC.

Twitter promotion is associated with higher citation rates of cardiovascular articles: the ESC Journals Randomized Study.

The association between the dissemination of scientific articles on Twitter and online visibility (as assessed by the Altmetric Score) is still controversial, and the impact on citation rates has never been rigorously addressed for cardiovascular medicine journals using a randomized design. The ESC Journals Study randomized 695 papers published in the ESC Journal Family (March 2018-May 2019) for promotion on Twitter or to a control arm (with no active tweeting from ESC channels) and aimed to assess whether Twitter promotion was associated with an increase in citation rates (primary endpoint) and of the Altmetric Score. This is the final analysis including 694 articles (one paper excluded due to retraction). After a median follow-up of 994 days (interquartile range: 936-1063 days), Twitter promotion of articles was associated with a 1.12 (95% confidence interval: 1.08-1.15) higher rate of citations, and this effect was independent of the type of article. Altmetric Attention Score and number of users tweeting were positive predictors for the number of citations. A social media strategy of Twitter promotion for cardiovascular medicine papers seems to be associated with increased online visibility and higher numbers of citations.

Instrumentation time and effectiveness of hand and rotary files in a prototyped second mandibular primary molar: A micro-CT study.

BACKGROUND: Eccentric instruments have been proposed as more effective and less time-consuming for endodontic instrumentation. AIM: To compare biomechanical outcomes of different instrumentation systems and time undertaken for instrumentation in resin prototypes. DESIGN: Sixty standardized prototypes of mandibular second primary molars were instrumented according to the following systems: K-files, ProTaper Next (PTN), XP-endo Shaper (XPS), XP-endo Finisher (XPF), XP-Clean (XPC), and Sequence Baby File (SBF; n = 10/each). Irrigation was performed with saline with simultaneous aspiration, and time spent was recorded. The prototypes were micro-CT-scanned before and after the instrumentation, and image sets were reconstructed and registered. Non-instrumented areas, accumulated debris, removed root material volume, and canal transportation were quantified. Data were analyzed through ANOVA, the Kruskal-Wallis test, and the Wilcoxon signed-rank test (α = 5%). RESULTS: K-files and SBF resulted in more instrumentation time (p < .05). SBF, XPC and PTN removed less root dentine (p < .05), but PTN left more untouched areas (p < .05). Accumulated debris were lower for XPC and SBF (p < .05). Canal transportation was similar among the groups. CONCLUSION: Rotary systems reduced instrumentation time, whereas SBF and XPC resulted in more conservative instrumentation, with less debris accumulation and non-instrumented areas. A dedicated paediatric endodontic system (SBF) outperformed eccentric instruments in terms of effectiveness.

Influence of conservative endodontic access cavities on instrumentation of oval-shaped straight root canals.

AIM: To evaluate the influence of the design of endodontic access cavities on the percentage of unprepared areas of canal walls and flexural fatigue of instruments activated by reciprocating movement in oval-shaped straight root canals of extracted teeth. METHODOLOGY: Forty-two mandibular incisors with oval canals were scanned by a microcomputed tomography (micro-CT) device for homogeneous selection and distribution of the samples. Then, the teeth were divided into two groups (n = 21) according to the design of access cavity being tested: ultraconservative endodontic access cavity (UltraAC) and traditional access cavity. The canals were accessed with the aid of a surgical microscope, instrumented with the WaveOne Gold Medium system and irrigated with 2.5% NaOCl and 17% EDTA. The unprepared areas of the canal wall were analysed by overlaying images before and after instrumentation and expressed as percentages. micro-CT data were analysed using t-test, Mann-Whitney and Wilcoxon tests. The endodontic instruments used during instrumentation were subjected to static flexural fatigue testing using an artificial stainless steel canal with a 60° angle of curvature and a radius of 5 mm, located 5 mm from the tip of the instrument. The instruments were activated until fracture occurred, and the time in seconds for the fracture was recorded using a digital timer. The number of cycles to fracture was calculated and analysed statistically. For flexural fatigue data, an anova test complemented by a Tukey range test was used. The significance level of 5% was used for all analyses. RESULTS: There was no significant difference between the groups related to unprepared areas by the instrument during canal preparation (p > .05). The difference in flexural fatigue resistance between the groups was not significant. CONCLUSION: The use of UltraAC did not interfere with the canal instrumentation of extracted mandibular incisors with straight and oval canals. There was no difference in the flexural fatigue resistance of the instruments in relation to access cavity design.

Micro-tomographic analysis of the root trunk and pre-furcation area of the first mandibular molars.

This study analyzed the root trunk (RT) and the pre-furcation area (PFA) of mandibular first molars. Thirty lower first mandibular molars extracted due to advanced periodontal disease were evaluated in a high-energy spiral computerized micro-tomography. Two gutta-percha markings on the cementoenamel junction (CEJ) and at the furcation entrance (FE) at buccal and lingual surfaces served as reference points for measurements of RT length, and PFA width and depth, at the levels of CEJ, 1 mm apical to CEJ, 2 mm apical to CEJ, and at the FE. The mean RT length was 2.49 mm at buccal and 3.18 mm at lingual sides. The mean widths of the PFA at CEJ, at 1 and 2 mm apical to CEJ, and at FE were 2.9, 3.4, 3.9 and 4.3 mm, respectively, while the mean depths were 0.19, 0.32, 0.57 and 1.1 mm, respectively. The PFA coincided with CEJ in 10 buccal and 10 lingual surfaces, representing 33.33% of the sample. There was a negative correlation between RT length and PFA dimensions. This study concludes that the RT length was smaller than previous studies. From the CEJ up to the furcation entrance, the PFA showed a progressive increase in width and depth. The coincidence of the PFA area beginning at the CEJ in 1/3, and the negative correlation between RT length and PFA dimensions may represent greater risk factor for the early development of furcation lesions.

Pre milling debranning of wheat with a commercial system to improve flour quality.

In the present study wheat (Triticum aestivum) cultivars were treated with industrial debranning step pre-milling both in a laboratory and a commercial mill to evaluate the benefits of this technology. Different levels of removal of wheat external layers were made (0 to 6%) and the results showed improved color of the flours (0.22 L* value units). Ash contents increased by 8.6% with debranning level, as a result of incorporating high ash aleurone layer in the resulted flour. The α-amylase activity was reduced by 33.8% and 19.8%, for the wheat and flour, respectively. Another benefit was the dropping of 70.6% of the deoxynivalenol (DON) levels. The experimental baking of flours produced with a wheat mix made up 40% Quartzo, 40% Baguette and 20% CD 150 varieties in a commercial mill after debranning resulted in breads with lighter crumb and crust color.

Genetic Basis of De Novo Appearance of Carotenoid Ornamentation in Bare Parts of Canaries.

Unlike wild and domestic canaries (Serinus canaria), or any of the three dozen species of finches in genus Serinus, the domestic urucum breed of canaries exhibits bright red bills and legs. This novel trait offers a unique opportunity to understand the mechanisms of bare-part coloration in birds. To identify the mutation producing the colorful phenotype, we resequenced the genome of urucum canaries and performed a range of analyses to search for genotype-to-phenotype associations across the genome. We identified a nonsynonymous mutation in the gene BCO2 (beta-carotene oxygenase 2, also known as BCDO2), an enzyme involved in the cleavage and breakdown of full-length carotenoids into short apocarotenoids. Protein structural models and in vitro functional assays indicate that the urucum mutation abrogates the carotenoid-cleavage activity of BCO2. Consistent with the predicted loss of carotenoid-cleavage activity, urucum canaries tended to have increased levels of full-length carotenoid pigments in bill tissue and reduced levels of carotenoid-cleavage products (apocarotenoids) in retinal tissue compared with other breeds of canaries. We hypothesize that carotenoid-based bare-part coloration might be readily gained, modified, or lost through simple switches in the enzymatic activity or regulation of BCO2 and this gene may be an important mediator in the evolution of bare-part coloration among bird species.

Cardiac rehabilitation in elderly myocardial infarction survivors: focus on circulatory power.

Exercise-based cardiac rehabilitation (EBCR) is paramount after an acute myocardial infarction (AMI). Older individuals have been reported as having a worse prognosis after an AMI, and some series have reported differences in the functional response to EBCR. The peak circulatory power (CP), a non-invasive parameter, has been described as a surrogate for the cardiac power, showing promising results as a comprehensive measure of the cardiovascular response. Whilst this, data concerning the impact of EBCR on CP, particularly among elderly individuals, remains elusive. To address this issue, an observational, retrospective study including all patients admitted due to an AMI who completed a phase II EBCR programme between 11/2012 and 4/2017, was conducted, with CP being analysed by a symptom-limited cardiopulmonary exercise test. A total of 379 patients, 30% aged ≥65 years-old, were included. CP significantly improved after the EBCR programme (in all patients, as well as in both subgroups). Older patients presented lower CP than their younger counterparts at the beginning and the end of the programme, while presenting smaller improvements (122 ± 540 vs 293 ± 638 mmHg mL/kg/min, p = 0.013). This was maintained after adjusting for several potential confounding factors. A contemporary ECBR programme was associated with significant improvements in CP among AMI patients. Though those aged ≥65 years-old presented smaller improvements in CP than younger individuals, these still presented significant increases in this parameter. These results highlight the importance of EBCR in this challenging higher risk group of patients.