Karen Barros Parron Fernandes

Acute stress affects the global DNA methylation profile in rat brain: Modulation by physical exercise

The vulnerability of epigenetic marks of brain cells to environmental stimuli and its implication for health have been recently debated. Thus, we used the rat model of acute restraint stress (ARS) to evaluate the impact of stress on the global DNA methylation and on the expression of the Dnmt1 and Bdnf genes of hippocampus, cortex, hypothalamus and periaqueductal gray (PAG). Furthermore, we verified the potential of physical exercise to modulate epigenetic responses evoked by ARS. Sedentary male Wistar rats were submitted to ARS at the 75th postnatal day (PND), whereas animals from a physically active group were previously submitted to swimming sessions (35-74th PND) and to ARS at the 75th PND. Global DNA methylation profile was quantified using an ELISA-based method and the quantitative expression of the Dnmt1 and Bdnf genes was evaluated by real-time PCR. ARS induced a decrease in global DNA methylation in hippocampus, cortex and PAG of sedentary animals and an increased expression of Bdnf in PAG. No change in DNA methylation was associated with ARS in the exercised animals, although it was associated with abnormal expression of Dnmt1 and Bdnf in cortex, hypothalamus and PAG. Our data reveal that ARS evokes adaptive changes in global DNA methylation of rat brain that are independent of the expression of the Dnmt1 gene but might be linked to abnormal expression of the Bdnf gene in the PAG. Furthermore, our evidence indicates that physical exercise has the potential to modulate changes in DNA methylation and gene expression consequent to ARS.

Factors related to oral health-related quality of life of independent brazilian elderly.

The aim of this cross-sectional study was to assess the factors associated with the impact of oral health on the quality of life in a sample of 504 Brazilian independent elderly. Data collection included oral examinations and structured interviews. The simplified form of the Oral Health Impact Profile (OHIP-14) was used to measure OHRQoL. Information on sociodemographic characteristics, use of dental services, and subjective measures of health was collected. Poisson regression within a hierarchical model was used to data analyses. The following variables were associated with a negative impact on OHRQoL: female gender (PR = 1.40; CI 95%: 1.11–1.77); lower class (PR = 1.58; CI 95%: 1.13–2.20); up to 3 occluding pairs of posterior teeth (PR = 1.88; CI 95%: 1.13–3.14); at least one untreated caries (PR = 1.28; CI 95%: 1.06–1.54); curative reasons for the last dental appointment (PR = 1.52; CI 95%: 1.15–2.00); poor self-perception of oral health (PR = 2.49; CI 95%: 1.92–3.24); and poor perception of dental care provided (PR = 1.34; CI 95%: 1.12–1.59). The younger elderly also noticed this negative impact. These findings showed that the clinical, sociodemographic, and subjective factors evaluated exerted a negative impact on OHRQoL in elderly people. Health authorities must address all these factors when planning interventions on oral health for this population.

Prenatal dental care: evaluation of professional knowledge of obstetricians and dentists in the cities of Londrina/PR and Bauru/SP, Brazil, 2004

The purpose of this study was to assess the current knowledge and recommendations of obstetricians and dentists as to the dental care to pregnant patients in the cities of Londrina/PR and Bauru/SP, Brazil. Questionnaires were distributed to professionals of both cities, arguing on the following issues: oral health during pregnancy; contact between prenatal care and dental care providers; prenatal fluoride supplementation; selection of therapeutic agents for local anesthesia, pain control and treatment of infection; and dental procedures that can be performed during each trimester. Data were analyzed by frequency of responses and statistical analyses were carried out using X2 (type of workplace/service) and t test (time since graduation), significant if p<0.05. Seventy-nine obstetricians and 37 dentists responded the questionnaires. Most physicians referred the patient to dental care only when a source of dental problem was mentioned, limiting the adoption of a preventive approach. Forty-three percent of dentists and 34% of obstetricians did not know the potential contribution of periodontal infection as a risk factor for preterm low birth-weight babies. There was divergence from scientific literature as to the recommendation of local anesthetics (dentists and obstetricians), prenatal fluoride supplementation (obstetricians) and dental radiographs (dentists). The findings of this survey with dentists and obstetricians showed that dental management during pregnancy still presents some deviations from scientific literature recommendations, indicating the need to update these health care professionals in order to establish guidelines for prenatal dental care.

Prevalence of developmental defects of enamel in children and adolescents with asthma

OBJECTIVE This study aimed to evaluate the prevalence of developmental defects of enamel (DDEs) in relation to asthma severity, symptom onset and pharmacological treatment in pediatric asthma patients. METHODS Children and adolescents (68 asthma patients and 68 controls), 5-15 years of age and residents of the city of Londrina, Brazil, were enrolled in the study. Medical and dental histories were collected through the use of a structured questionnaire. Each participant underwent a dental examination in which the examiner employed the DDE index. RESULTS Of the 68 asthma group subjects, 61 (89.7%) presented dental enamel defects, compared with only 26 (38.2%) of those in the control group. Using multivariate logistic regression analysis, we estimated the risk of DDEs in permanent dentition to be 11 times higher in pediatric subjects with asthma than in those without (OR = 11.88, p = 0.0001). The occurrence of dental enamel defects correlated with greater asthma severity (p = 0.0001) and earlier symptom onset (p = 0.0001). However, dental enamel defects did not correlate with the initiation of treatment (p = 0.08) or the frequency of medication use (p = 0.93). CONCLUSIONS Pediatric patients with severe, early-onset asthma are at increased risk of dental enamel defects and therefore require priority dental care.

The paraventricular nucleus of hypothalamus mediates the pressor response to noradrenergic stimulation of the medial prefrontal cortex in unanesthetized rats

The medial prefrontal cortex (MPFC) is a structure that is also involved in cardiovascular modulation. The injection of norepinephrine (NE) into the prelimbic (PL) area of the MPFC of unanesthetized rats evokes a pressor response which is mediated by acute vasopressin release. Vasopressin is synthesized by magnocellular cells of the paraventricular (PVN) and supraoptic nucleus (SON) of the hypothalamus. In the present study, we endeavored to determine which vasopressin-synthesizing hypothalamic nucleus is involved in the pressor pathway activated after NE injection into the PL area of the MPFC. We report here that lidocaine microinjection into the SON did not change the pressor response evoked by NE injection into the PL. However, the response to NE was blocked by prior injection of lidocaine or CoCl(2) into the PVN, indicating that this area is responsible for the mediation of this pressor response. A neuroanatomic experiment in which the neuronal tracer biotinylated dextran amine (BDA) was microinjected into the MPFC showed a lack of axons or neuronal cell bodies in the PVN, indicating that there are no direct connections between the PL area of the MPFC and the PVN. The results suggest that the PVN is involved in the mediation of the pressor response to NE in the PL area and that this pathway must relay in other brain structures before reaching the PVN.

Anti-inflammatory and analgesic effects of low-level laser therapy on the postoperative healing process

[Purpose] This study aimed to evaluate the anti-inflammatory and analgesic effects of intraoral application of low-level laser therapy (660 nm) to control pain, swelling and interincisal opening following the extraction of mandibular third molars. [Subjects and Methods] Ten patients underwent removal of lower third molars using the same surgical protocol and pharmacological approach. In the postoperative period, all patients received four consecutive daily sessions of low-level laser therapy, beginning 24 hours after the surgery. Intraoral applications using the diode laser with 660 nm wavelength in the continuous scan mode were performed covering the entire surgical area, which was divided into four quadrants, each of 1 cm2 area at a distance of 1 cm. The energy applied at each point was 5 J/cm2 during 8 seconds. [Results] The swelling and interincisal opening returned to normal 24 hours after the first low-level laser therapy application (Friedman test). Moreover, the pain intensity was reduced on the third postoperative day, according to the Friedman test. [Conclusion] Low-level laser therapy (660 nm), at the dosimetry used in this study, was effective in reducing postoperative pain and swelling following oral surgery.

Postural balance and physical activity in daily life (PADL) in physically independent older adults with different levels of aerobic exercise capacity

Balance impairs with aging and may cause mobility limitations and functional decline. We aimed to evaluate postural balance and PADL in physically independent older adults with different levels of exercise capacity. One hundred fifty seven physically independent individuals, aged 60 years or older were evaluated. Postural balance assessment was performed during one-legged stance test using a force-platform and maximum exercise capacity with the incremental shuttle walking test (ISWT). PADL was assessed subjectively by the modified Baecke questionnaire and objectively using a pedometer. Based on the performance achieved in the ISWT, according to the percentage of the predicted value, the older adults were separated into 3 groups: low performance group (LP group, ISWT < 80% predicted, n = 32, 19 women), normal performance group (NP group, 80 ≤ ISWT ≤ 100% predicted, n = 30, 22 women) and high performance group (HP group, ISWT > 100% predicted, n = 95, 67 women). The HP group showed better postural balance when compared to LP groups (p < 0.001) and also higher levels of PADL measured with pedometer (p < 0.001). There was a modest correlation (r = 0.45) between exercise capacity and PADL in the LP group and a weak correlation between exercise capacity and balance (r = -28) in the HP group. Physically independent older adults with more preserved exercise capacity have better postural balance and higher levels of PADL in comparison to those older adults who show a poorer condition in terms of exercise capacity.

Dental caries status and salivary properties of asthmatic children and adolescents

AIMS This study aimed to investigate the dental caries status and salivary properties in 3- to 15-year-old children/adolescents. METHODS The sample was split in two groups: asthma group (AG), composed of 65 patients who attended Public Health Service; asthma-free group (AFG), composed of 65 nonasthmatic children/adolescents recruited in two public schools. Stimulated salivary samples were collected for 3 min. Buffering capacity and pH were ascertained in each salivary sample. A single trained and calibrated examiner (kappa = 0.98) performed the dental caries examination according to WHO criteria. RESULTS The AFG showed salivary flow rate (1.10 ± 0.63 mL/min) higher (P = 0.002) than AG (0.80 ± 0.50 mL/min). An inverse relationship was observed between asthma severity and salivary flow rate (Phi coefficient, rφ: 0.79, P = 0.0001). Children with moderate or severe asthma showed an increased risk for reduced salivary flow rate (OR: 17.15, P < 0.001). No association was observed between drug use frequency (P > 0.05) and drug type (P > 0.05) with salivary flow rate. Buffering capacity was similar in both groups. No significant differences were encountered in dental caries experience between AFG and AG groups. CONCLUSIONS Although asthma can cause reduction in flow rate, the illness did not seem to influence dental caries experience in children with access to proper dental care.

Cariogenic Microorganisms and Oral Conditions in Asthmatic Children

This study evaluated the caries risk of asthmatic patients on the basis of mutans streptococci (MS) and lactobacilli levels in saliva samples as well as the index of oral hygiene and dental caries (DMFT index). The study population was composed of 80 asthmatic children, aged 3–15 years, who use specific medication, and 80 matched, healthy control children. The parents were interviewed about oral health-related factors. The World Health Organization criteria were used for dental examinations. The Köhler and Bratthal methodology was used to detect salivary MS levels and dilutions of saliva were done for lactobacilli counting. No differences between asthma and control groups were observed for caries prevalence in children aged 3–6 and 7–10 years, except in severe cases in the younger group. However, higher caries prevalence for permanent dentition was observed in 11- to 15-year-old asthmatic children. An increased dental biofilm was observed in the asthma group, as well as salivary levels of MS. No differences were observed in levels of lactobacilli. No statistical correlations were found between medication, frequency of treatment, method of consumption and caries experience, dental biofilm and salivary levels of MS or lactobacilli. However, there was a correlation between MS levels and treatment duration. The logistic regression revealed that MS level is an important risk factor for increased caries experience. Asthma should be evaluated as a risk factor for caries experience because it can increase the levels of MS and the dental biofilm.

In vitro assessment of solvent evaporation from commercial adhesive systems compared to experimental systems

Solvents should be properly evaporated after application to dental substrates. The aim of this study was to assess the evaporation of commercial, experimental and neat solvents. The tested null hypotheses were that there are no differences in solvent evaporation regardless of its formulation and over time. Evaporation from commercial adhesive systems (Scotchbond Multipurpose Primer, Scotchbond Multipurpose Adhesive, Prime & Bond NT, Multi Bond, Excite, Single Bond 2, Adhese Primer, Adhese Bond, Xeno III A and Xeno III B) and experimental primers (35% HEMA plus 65% acetone or ethanol or water v/v) were compared to neat solvents (acetone, ethanol and water). Samples (10 microL) of these products were dripped into glass containers placed on a digital precision balance. Evaporation was assessed at 0, 5, 10, 15, 30, 60, 120, 300 and 600 s times to calculate mass loss. Data were analyzed statistically by ANOVA and Bonferronis correction (a=0.05). Acetone-based products exhibited a remarkable capacity to evaporate spontaneously over time. Neat acetone evaporated significantly more than the HEMA-mixtures and the commercial formulations (p<0.05). The incorporation of monomers and other ingredients in the commercial formulations seem to reduce the evaporation capacity. Solvent evaporation was time and material-dependent.