Diabetes mellitus may increase bone loss after occlusal trauma and experimental periodontitis

Background: Diabetes mellitus (DM) involves metabolic changes that can negatively influence periodontal tissues, resulting in more prevalent and severe periodontitis and impaired bone formation. Occlusal trauma (OT) is an injury of the supportive periodontium that results in bone loss. It can be hypothesized that DM would increase bone loss after OT, mainly when associated with periodontitis. Thus, the aim of the present study is to evaluate the influence of DM on bone response in the furcation area of teeth subjected to OT in the presence, or absence, of experimental periodontitis (EP) in the rat model. Methods: Thirty-two male Wistar rats were assigned to four groups: 1) group 1 (G1): DM+OT+EP (n = 8); 2) group 2 (G2): DM+OT (n = 8); 3) group 3 (G3): OT+EP (n = 8); and 4) group 4 (G4): OT (n = 8). G1 and G2 received a single intraperitoneal injection of streptozotocin (STZ). After 10 days, G1 and G3 were subjected to EP by ligature placement. Fifteen days after the start of EP, OT was induced by the creation of a premature contact. The animals were euthanized 35 days after DM induction. Results: DM enhanced bone loss in the presence of OT combined with EP, but did not increase bone loss in teeth subjected to OT alone. EP caused greater bone loss when associated with OT. Conclusion: Within the limits of this animal study, it can be concluded that DM enhances bone loss in the presence of occlusal trauma associated with EP.     

Influence of exposure time to saliva and antioxidant treatment on bond strength to enamel after tooth bleaching: an in situ study

Objectives

This study evaluated the influence of different exposure times to saliva in situ in comparison with an antioxidant treatment on composite resin bond strength to human enamel restored after tooth bleaching.

Material and Methods

Forty human teeth specimens measuring 5x5 mm were prepared and randomly allocated into 5 groups with 8 specimens each: Gct (control group, restored on unbleached enamel); Gbl (restored immediately after bleaching); Gsa (bleached, treated with 10% sodium ascorbate gel for 60 min and restored); G7d (bleached, exposed to saliva in situ for 7 days and restored); and G14d (bleached, exposed to saliva in situ for 14 days and restored). Restored samples were cut into 0.8 mm² sticks that were tested in microtensile. Specimens were microscopically analyzed and failure modes were classified as adhesive, cohesive, or mixed. Pretest and cohesive failures were not considered in the statistical analysis, which was performed with one-way ANOVA and Tukey''s post-hoc test (α=0.05), with the dental specimen considered as the experimental unit.

Results

Mean bond strength results found for Gbl in comparison with Gct indicated that bleaching significantly reduced enamel adhesiveness (P<0.01). However, no statistically significant differences were found between Gct, Gsa and G7d (P>0.05). Bond strength found for G14d was significantly higher than for Gsa (P<0.01). Fractures modes were predominantly of a mixed type.

Conclusions

Bonding strength to bleached enamel was immediately restored with the application of sodium ascorbate and exposure to human saliva in situ for at least 7 days. Best results were obtained with exposure to human saliva in situ for 14 days. Treatment with sodium ascorbate gel for 60 min may be recommended in cases patients cannot wait for at least 7 days for adhesive techniques to be performed.     

Heterologous Expression and Functional Characterization of the Exogenously Acquired Aminoglycoside Resistance Methyltransferases RmtD,RmtD2, and RmtG

The exogenously acquired 16S rRNA methyltransferases RmtD, RmtD2, and RmtG were cloned and heterologously expressed in Escherichia coli, and the recombinant proteins were purified to near homogeneity. Each methyltransferase conferred an aminoglycoside resistance profile consistent with m⁷G1405 modification, and this activity was confirmed by in vitro 30S methylation assays. Analyses of protein structure and interaction with S-adenosyl-l-methionine suggest that the molecular mechanisms of substrate recognition and catalysis are conserved across the 16S rRNA (m⁷G1405) methyltransferase family.     

Reproducibility of the items on the Stroke Specific Quality of Life questionnaire that evaluate the participation component of the International Classification of Functioning,Disability and Health

Purpose: To evaluate the reproducibility of the Stroke Specific Quality of Life (SS-QOL) items that address the participation component of the International Classification of Functioning, Disability and Health (ICF) and analyse the correlation between the subscore of these 26 items and the total SS-QOL score.

Methods: Seventy-five stroke survivors participated in this study. Reproducibility was evaluated using the intraclass correlation coefficient (ICC_2,1), standard error of measurement (SEM), minimum detectable change (MDC) and the Bland–Altman plot. The correlation between the subscore of the 26 items and the total SS-QOL score was analysed using Spearman’s correlation coefficients (rho) and simple linear regression. An alpha risk?≤?0.05 was considered for all analyses.

Results: The SS-QOL items that address the participation component of the ICF demonstrated excellent reliability (intra-rater ICC_2,1?=?0.96; inter-rater ICC_2,1?=?0.95). The SEM and MDC were adequate. The Bland–Altman plot demonstrated satisfactory agreement. A significant and strong correlation (rho?=?0.83) was found between the 26 SS-QOL items that address participation and the total SS-QOL score. Moreover, the evaluation of participation was found to explain 73% of the evaluation of health-related quality of life.

Conclusion: The 26 SS-QOL items that address the participation component of the ICF demonstrated adequate reproducibility. Thus, participation, which represents the social aspects of functionality, can be adequately evaluated with these items.

• Implications for Rehabilitation

• The 26 Stroke Specific Quality of Life items that address participation proved to be reproducible for the analysis of social participation following a stroke.

• The findings can lead to a better understanding of the social participation of individuals with chronic hemiparesis and assist in the establishment of adequate treatment for such individuals.

• The rehabilitation process can be directed towards more specific goals focused on the patient expectations, thereby contributing to greater humanization and effectiveness of treatment to improve social participation following a stroke.

     

Comparison Between Pre-Exhaustion and Traditional Exercise Order on Muscle Activation and Performance in Trained Men

The purpose of this study was to measure the acute effects of pre-exhaustion vs. traditional exercise order on neuromuscular performance and sEMG in trained men. Fourteen young, healthy, resistance trained men (age: 25.5 ± 4.0 years, height: 174.9 ± 4.1 cm, and total body mass: 80.0 ± 11.1 kg) took part of this study. All tests were randomized and counterbalanced for all subjects and experimental conditions. Volunteers attended one session in the laboratory. First, they performed ten repetition maximum (10RM) tests for each exercise (bench press and triceps pushdown) separately. Secondly, they performed all three conditions at 10RM: pre-test (bench press and triceps pushdown, separately), pre-exhaustion (triceps pushdown+bench press, PE) and traditional (bench press+triceps pushdown, TR), and rested 30 minutes between conditions. Results showed that pre-test was significantly greater than PE (p = 0.031) but not different than TR, for total volume load lifted. There was a significant difference between the pre-test and the time-course of lactate measures (p = 0.07). For bench press muscle activity of the pectoralis major, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). Also, for muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.001, PE: p = 0.005, and TR: p = 0.006). For triceps pushdown, muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). For RPE, there were no significant differences between PE and TR (p = 0.15). Our results suggest that exercise order decreases repetitions performed, however, neuromuscular fatigue, lactate, and RPE are not impacted. The lack of difference in total volume load lifted between PE and TR might explain, at least in part, the similar metabolic and perceptual responses.

Key points

• The effects of different exercise order schemes (e.g. PE and TR) on muscle activity and strength performance indicated that similar responses were observed when comparing these schemes.
• Strength and conditioning coaches should consider these results when prescribing resistance training programs.
• The primary target (e.g. muscle group) of the training session should trained first, when fatigue level low, in order to maximize training outcomes.

Key words: Exercise performance, resistance training, biomechanics     

Polycyclic aromatic hydrocarbon patterns in the city of Rio de Janeiro

In this study, the concentrations of 16 Polycyclic Aromatic Hydrocarbon (PAH), considered priority by US EPA (US Environmental Protection Agency), in fine particulate matter (PM_2.5), were determined in a forest reserve and in an urban area in the city of Rio de Janeiro. The PM_2.5 samples were collected in the Tijuca Forest (TF) and on the Maracanã campus of the State University of Rio de Janeiro (UERJ), using PM_2.5 high-volume air samplers, from November 2015 to April 2016. The organic matter was extracted, separated by liquid chromatography, and analyzed by gas chromatography-mass spectrometry (GC-MS). The mean total PAH (excluding naphthalene, acenaphthene, and acenaphthylene) concentrations were 0.46?±?0.61 ng m^?3 and 1.12?±?0.71 ng m^?3 in PM_2.5 collected at TF and UERJ, respectively. The diagnostic ratios suggested vehicular sources for both sites with no clear distinction between light and heavy vehicular sources. Cluster and principal component analyses were also used to clarify the possible PAH sources. Simulations of air mass trajectories confirmed the transport of pollutants from the city to the forest. Mutagenicity tests revealed that the PM collected in the UERJ presented mutagenic positive activity, likely for nitro-PAH and amino-PAH, which may be related to vehicular emissions. For the TF, although the forest was impacted by the pollutants, no positive activity was detected. Correlation and cluster analyses showed different PAH distributions for the TF and UERJ sites, which indicates that the TF receives the air masses from the city but is also impacted by local emissions.     

Impact of untreated dental caries severity on the quality of life of preschool children and their families: a cross-sectional study

Purpose

Untreated dental caries is a persistent oral problem among preschool children. Although there is vast evidence regarding the impact of dental caries on oral health-related quality of life (OHRQoL) in this age group, evidence on the impact of untreated caries severity is scarce. The purpose of this study was to investigate the impact of untreated caries severity on the OHRQoL of preschool children and their families.

Methods

A cross-sectional study was conducted with 563 individuals in the city of Goiania, Brazil. Data were collected through interviews with parents/caregivers and clinical examinations of their children. The OHRQoL was measured by the Brazilian version of the Early Childhood Oral Health Impact Scale. Untreated dental caries severity was assessed using validated indices. Other independent variables were socioeconomic, toothache prevalence, and the questionnaire respondent. Statistical analysis involved bivariate comparisons and Poisson regression analyses.

Results

A higher prevalence of impact on OHRQoL was found among preschool children with untreated dental caries with clinical consequences (PR 1.31; 95% CI 1.01–1.70) compared to those without caries; those aged 5 years (PR 1.47; 95% CI 1.18–1.82), compared to those aged two; and those with a toothache (PR 1.54; 95% CI 1.34–1.76), compared to those without toothache. Moreover, fathers (PR 0.71; 95% CI 0.55–0.92) and other respondents (PR 0.70; 95% CI 0.52–0.96) perceived less impact on the OHRQoL in comparison to mothers.

Conclusions

Severe untreated dental caries with clinical consequences had a negative impact on the children’s OHRQoL, regardless of toothache and socioeconomic factors.

     

Orofacial lesions in treated southeast Brazilian leprosy patients: a cross-sectional study

AIM: The aim of the present study was to clinically evaluate the oral mucosa lesions of leprosy patients during and after multi-drug therapy. METHODS: Clinical examination, medical and dental history examination was performed in 100 leprosy patients. RESULTS: The results revealed that 71 patients, 50 men and 21 women, exibited oral lesions. The most frequent lesions were: fissured tongue (18 cases), inflammatory papillary hyperplasia (16 cases), chronic atrophic candidiasis (10 cases), fibroma (10 cases), erythematous candidiasis (eight cases), and traumatic ulceration (seven cases). CONCLUSION: We conclude that leprosy-related lesions are not present in patients undergoing treatment for leprosy, probably due to response to multidrug therapy.