Influence of Manganese Oxide on the Esthetic Efficacy and Toxicity Caused by Conventional In-office Tooth Bleaching Therapy.

OBJECTIVE: This study aimed to evaluate the esthetic efficacy, cytotoxicity, and kinetics of decomposition of hydrogen peroxide (H2O2) present in a commercial bleaching gel with 35% H2O2 (BG35%) chemically activated with manganese oxide (MnO2). METHODS AND MATERIALS: After incorporating 2 mg/mL, 6 mg/mL, and 10 mg/mL of MnO2 into BG35%, the stability of pH and temperature of the products were analyzed. To assess the esthetic efficacy (ΔE and ΔWI), the BG35%s with MnO2 were applied for 45 minutes on enamel/dentin discs (DiE/D). BG35% or no treatment were used as positive (PC) and negative (NC) controls, respectively. To analyze the cell viability (CV) and oxidative stress (OXS), the same bleaching protocols were performed on DiE/D adapted to artificial pulp chambers. The extracts (culture medium + gel components that diffused through the discs) were applied to pulp cells and submitted to H2O2 quantification. BG35% with MnO2 that showed the best results was evaluated relative to kinetic decomposition of H2O2, with consequent generation of free radicals (FR) and hydroxyl radicals (OH•). The data were submitted to the one-way analysis of variance complemented by Tukey post-test (α=0.05). Data on kinetics of H2O2 decomposition were submitted to the Student's-t test (α=0.05). RESULTS: All the BG35%s with MnO2 showed stability of pH and temperature, and the gel with 10 mg/mL of this activator had an esthetic efficacy 31% higher than that of the PC (p<0.05). Reduction in OXS and trans-amelodentinal diffusion of H2O2 occurred when all the BG35%s with MnO2 were used. The addition of 6 and 10 mg/mL of MnO2 to BG35% increased the CV in comparison with PC, confirmed by the cell morphology analysis. An increase in FR and OH• formation was observed when 10 mg/mL of MnO2 was added to BG35%. CONCLUSION: Catalysis of BG35% with MnO2 minimized the trans-amelodentinal diffusion of H2O2 and toxicity of the product to pulp cells. BG35% containing 10 mg/mL of MnO2 potentiated the decomposition of H2O2, enhancing the generation of FR and OH•, as well as the efficacy of the in-office tooth therapy.

Dopamine depletion in wistar rats with epilepsy.

The dopamine content in cerebral structures has been related to neuronal excitability and several approaches have been used to study this phenomenon during seizure vulnerability period. In the present work, we describe the effects of dopamine depletion after the administration of 6-hidroxidopamine (6-OHDA) into the substantia nigra pars compacta of male rats submitted to the pilocarpine model of epilepsy. Susceptibility to pilocarpine-induced status epilepticus (SE), as well as spontaneous and recurrent seizures (SRSs) frequency during the chronic period of the model were determined. Since the hippocampus is one of main structures in the development of this experimental model of epilepsy, the dopamine levels in this region were also determined after drug administration. In the first experiment, 62% (15/24) of 6-OHDA pre-treated rats and 45% (11/24) of those receiving ascorbic acid as control solution progressed to motor limbic seizures evolving to SE, after the administration of pilocarpine. Severeness of seizures during the model´s the acute period, was significantly higher in epileptic experimental rats (56.52%), than in controls (4.16%). In the second experiment, the frequency of seizures in the model's chronic phase did not significantly change between groups. Our data show that dopamine may play an important role on seizure severity in the pilo's model acute period, which seems to be due to dopamine inhibitory action on motor expression of seizure.

Effect of Time and Temperature of Air Jet on the Mechanical and Biological Behavior of a Universal Adhesive System.

OBJECTIVES: To evaluate the influence of heat application on the degree of conversion (DC) of the 3M Single Bond Universal Adhesive System, as well as its transdentinal cytotoxicity and microtensile bond strength to dentin. METHODS: Experimental groups were established according to the time and temperature of the air jet: G1: 5 seconds-25°C; G2: 10 seconds-25°C; G3: 20 seconds-25°C; G4: 5 seconds-50°C; G5: 10 seconds-50°C; G6: 20 seconds-50°C. In control group (G7), no treatment was performed. The DC was assessed using the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. For the transdentinal cytotoxicity test, dentin discs fitted in artificial pulp chambers (APC) received the application of the adhesive system and the air jets. For the microtensile bond strength, healthy molars were restored and submitted to the microtensile test after 24 hours and 6 months, respectively. RESULTS: Significant reduction in viability of Mouse Dental Papilla Cell-23 (MDPC-23), which exhibited morphological changes, was observed in all experimental groups compared to control (p<0.05). Although all tested protocols resulted in transdentinal diffusion of 2-hydroxyethyl methacrylate (HEMA), the group G6 presented the highest degree of monomeric conversion and the lowest cytotoxic effect, with higher dentin bond strength values in comparison to group G1 (p<0.05). CONCLUSIONS: Applying an air blast at 50°C for 20 seconds increases the DC and microtensile bond strength of the 3M Single Bond Universal Adhesive System to dentin, as well as reduces the transdentinal cytotoxicity of the material to pulp cells.

Effects of Enzymatic Activation of Bleaching Gels on Hydrogen Peroxide Degradation Rates, Bleaching Effectiveness, and Cytotoxicity.

OBJECTIVES: The aim of this study was to evaluate the effect of horseradish peroxidase (HRP) on the release of free radicals, bleaching effectiveness, and indirect cytotoxicity of a 35% hydrogen peroxide (HP) bleaching gel. METHODS AND MATERIALS: First, HP degradation rates and free radical release were evaluated for 35% HP in contact or not with HRP (10 mg/mL). The bleaching gel associated or not with HRP was then applied (3 × 15 minutes) to enamel/dentin discs adapted to artificial pulp chambers, and the culture medium in contact with dentin surfaces (extract) was collected and exposed to cultured odontoblast-like cells. Membrane damage and viability of cells as well as oxidative stress were evaluated. Residual HP/free radical diffusion was quantified, and bleaching effectiveness (ΔE) was assessed. Unbleached discs served as negative controls. RESULTS: The addition of HRP to the 35% HP bleaching gel enhanced the release of free radicals in comparison with plain HP gel. The 35% HP-mediated cytotoxicity significantly decreased with HRP in the bleaching gel and was associated with reduced HP/free radical diffusion through the enamel/dentin discs. ΔE values increased every bleaching session for HRP-containing gel relative to positive control, accelerating the whitening outcome. CONCLUSION: The enzymatic activation of a 35% HP bleaching gel with HRP accelerated HP degradation mediated by intensification of free radical release. This effect optimized whitening outcome as well as minimized residual HP and free radical diffusion through enamel and dentin, decreasing the harmful effects on odontoblast-like cells.

Interactive effects of ApoE polymorphism, alcohol and smoking on age-related trends of blood pressure levels in elderly men: the Bambuì Cohort Study of Ageing (1997-2008).

Data from a population-based prospective study were used to examine longitudinal changes in blood pressure (BP) and seek interactions between apolipoprotein E (ApoE) genotypes, smoking and alcohol in a cohort of 557 elderly Brazilian men. Repeated BP measurements were obtained in four waves, and multi-level random-effects pattern-mixture models were used to evaluate age-related BP trajectories while accounting for non-ignorable dropouts/deaths and handling heterogeneities as random parameter variations. Alcohol was associated with high systolic BP in ε2 carriers and those with the ε3/3 genotype, but not in ε4 carriers. This was dependent on age and smoking habits: at the age of 60, expected systolic BP in alcohol drinking ε2 carriers was 16.5 mm Hg higher than in the reference group of non-smokers/non-drinkers if they were not smokers (P=0.049), and 28.6 mm Hg higher if they were also smokers (P=0.004). The youngest smoking/non-drinking ε2 carriers had lower systolic BP, but it increased rapidly and led to higher expected levels among older carriers. Alcohol consumption, alone or together with smoking, interacts with the effects of ApoE genotype on systolic BP, probably nullifying the more favourable lipid profile of ε2 carriers. The interactions of gene-modifiable risk factors have major public health implications.

Uric acid and fibrinogen: age-modulated relationships with blood pressure components.

Data from a cross-sectional population-based study carried out in the town of Bollate (Milan) were used to verify whether there is an age-modulated relationship between the components of blood pressure (BP) and plasma uric acid and fibrinogen levels. Changes in uric acid and fibrinogen levels in relation to diastolic BP (DBP), systolic BP (SBP), mean arterial pressure (MAP) and pulse pressure (PP) in 820 subjects aged 42-59 years and in 509 subjects aged 60-74 years were estimated from general linear models adjusted by the clinical, lifestyle and biological variables traditionally associated with cardiovascular risk. Uric acid levels significantly increased with DBP and MAP only in the middle-aged group without metabolic syndrome or diabetes, and were even in those who were pre-hypertensive. On the contrary, fibrinogen levels significantly increased with SBP and PP only among the elderly with metabolic syndrome or diabetes, and were particularly high among those with stage 2 hypertension. These findings add evidence concerning an age-modulated relationship between the levels of uric acid and fibrinogen and the steady and pulsatile components of BP and it is possibly related to the different mechanisms underlying increased BP: renal factors in middle-aged subjects and vascular abnormalities in the elderly.

Phenotypic and genotypic variant of MDR-Mycobacterium tuberculosis multiple isolates in the same tuberculosis episode, Rio de Janeiro, Brazil

Assuming that the IS6110-restriction fragment length polymorphism (RFLP) changes at a constant rate of 3.2 years, this methodology was applied to demonstrate, for the first time, variant patterns of Mycobacterium tuberculosis (MTB) in multiple isolates obtained at short time intervals from sputum and blood of an HIV+ patient with multiple admissions to the Emergency Room and to the multidrug-resistant tuberculosis (MDR-TB) Reference Center of a secondary-care hospital in Rio de Janeiro, Brazil. In sputum, the IS6110-RFLP appeared in isolates with two variant patterns with 10 and 13 IS6110 copies. However, blood presented only the pattern corresponding to 10 copies, suggesting compartmentalization. With regard to the exact match of 10 of 13 bands, this may be a subpopulation with the same clonal origin and this may be related to the IS6110 transposition. A susceptibility test demonstrated an MDR profile (INH R, RIF R, SM R, and EMB R), with the sputum isolate also exhibiting EMB S (R = resistant; S = sensitive). A gene mutation confirmed resistance only to streptomycin. There was agreement between the results of the phenotypic test and the clinical response to MDR-TB treatment, suggesting serious implications with regard to treatment administration based exclusively on molecular methods, and calling attention to the fact that more effective control strategies against the emergence of MDR strains must be implemented by the TB control program to prevent transmission of MDR-MTB strains at health facilities in areas highly endemic for TB.

Phenotypic and genotypic variant of MDR-Mycobacterium tuberculosis multiple isolates in the same tuberculosis episode, Rio de Janeiro, Brazil.

Assuming that the IS6110-restriction fragment length polymorphism (RFLP) changes at a constant rate of 3.2 years, this methodology was applied to demonstrate, for the first time, variant patterns of Mycobacterium tuberculosis (MTB) in multiple isolates obtained at short time intervals from sputum and blood of an HIV+ patient with multiple admissions to the Emergency Room and to the multidrug-resistant tuberculosis (MDR-TB) Reference Center of a secondary-care hospital in Rio de Janeiro, Brazil. In sputum, the IS6110-RFLP appeared in isolates with two variant patterns with 10 and 13 IS6110 copies. However, blood presented only the pattern corresponding to 10 copies, suggesting compartmentalization. With regard to the exact match of 10 of 13 bands, this may be a subpopulation with the same clonal origin and this may be related to the IS6110 transposition. A susceptibility test demonstrated an MDR profile (INH(R), RIF(R), SM(R), and EMB(R), with the sputum isolate also exhibiting EMB(S) (R = resistant; S = sensitive). A gene mutation confirmed resistance only to streptomycin. There was agreement between the results of the phenotypic test and the clinical response to MDR-TB treatment, suggesting serious implications with regard to treatment administration based exclusively on molecular methods, and calling attention to the fact that more effective control strategies against the emergence of MDR strains must be implemented by the TB control program to prevent transmission of MDR-MTB strains at health facilities in areas highly endemic for TB.

Features of metabolic syndrome in non-diabetic Italians and Brazilians: a discriminant analysis.

This aim of this study was to compare the characteristics of metabolic syndrome (MetS) in a Brazilian and an Italian population. The subjects were non-diabetic men and women aged 40-74 years from population-based surveys: 1242 from Brazil and 1198 from Italy. Logistic regression models were used to compare adjusted prevalence rates and make a discrimination analysis to distinguish the subjects with a diagnosis of MetS in the two groups. Dyslipidemia [low high-density lipoprotein (HDL)-cholesterol] and impaired fasting glucose were more prevalent among the Brazilians, and increased blood pressure and abdominal obesity (in men) among the Italians. Generally, the Italians showed higher prevalence of overall obesity and high pulse-pressure, and the Brazilians had higher prevalence of metabolic markers of insulin resistance. Among the subjects with the syndrome, HDL-cholesterol was the most discriminant factor, followed by plasma uric acid levels (which were higher in the Brazilians). The Italian men had a larger waist circumference and the Italian women higher body mass index values than the Brazilians. Italians had higher systolic and lower diastolic pressure values. The patterns of the metabolic alterations seemed to be more linked to insulin resistance among Brazilian subjects, whereas obesity seemed to play a more important role among the Italians. Although they are not sufficient to support the hypothesis of differences in the underlying pathophysiological processes between these groups, our results illustrate the difficulty of using a single unifying definition of MetS, and suggest that different benefits may be obtained from treatments targeting obesity, blood pressure or insulin resistance.

Lifestyle correlates of anthropometric estimates of body adiposity in an Italian middle-aged and elderly population: a covariance analysis.

OBJECTIVE: To study the relationship between behavioural factors, body adiposity and muscle mass. SUBJECTS AND METHODS: A total of 1415 Italian individuals (705 men and 710 women) aged 40-74 years from a population-based survey carried out in the town of Bollate (Milan). Analysis of covariance was used to refine and improve the precision of the comparisons. RESULTS: Men: Smoking and sedentary behaviour were related to larger waist circumference (WC) and smaller hip circumference (HC). Increased WC was also associated with high-fat diet and moderate-to-heavy drinking (compared to light drinkers). Those more educated (completed high school) were leaner and ex-smokers had higher body mass index (BMI) than non-smokers. Women: BMI was inversely related with education, the more educated having also lower muscle mass. The light drinkers were leaner and moderate-to-heavy drinkers had less muscle mass than abstainers. Moderate-to-heavy drinkers had larger WC than light drinkers. A strong negative trend was found in the relationship between dietary fibre and WC. Overall adiposity (BMI) and, more weakly, HC and peripheral subcutaneous fat increased with more TV watching, whereas BMI lowered, together with WC and muscle mass (as measured by the mid-arm circumference), with more walking/cycling. CONCLUSIONS: Modifiable habits such as smoking (men) and moderate-to-heavy alcohol drinking are associated with a pattern that is particularly deleterious to health: increased intra-abdominal fat and less muscle mass. Prevention strategies should be simultaneously aimed at promoting physical activities and reducing sedentary behaviours. A low-fat, fibre-rich diet seems to be closely related to a healthy distribution of body fat.

Circadian variation of the cell proliferation in the jejunal epithelium of rats at weaning phase.

Circadian variation in cell proliferation of the jejunal epithelium of 18-day-old rats was studied using the 2-h arrested metaphase score and crypt isolation method. A continuous decrease in the arrested metaphases occurred from 07.00 h to 13.00 h. From 17.00 h arrested metaphase values increased and were maintained at the higher level during the dark period as showed by Cosinor analyses (P < 0.05). These results indicate that in the young rat there is already a circadian variation in jejunal epithelial cell proliferation as early as 18 days. We can even suggest that the presence of a circadian rhythm at weaning contributes to the steady state of cell proliferation in the intestinal epithelium observed in adult life.

Dietary and nutritional patterns in an elderly rural population in Northern and Southern Italy: (I). A cluster analysis of food consumption.

OBJECTIVE: To describe the food consumption patterns of Italian elderly subjects and the factors associated with different dietary habits. DESIGN: Cross-sectional study. SETTING: Population-based study. SUBJECTS: A total of 847 men and 1465 women aged 65 y or older, living in rural areas in the province of Pavia (Northern Italy) and near Cosenza (Southern Italy) in 1992-1993. INTERVENTIONS: The dietary information was collected by means of a quantitative food-frequency questionnaire, with cluster analysis being used to segregate the subjects on the basis of similarities in their food consumption. A generalised logistic regression model including residence, age, living status, education, physical activity and degree of disability was fitted to assess the factors associated with different food consumption habits. RESULTS: Six dietary clusters were selected for men and seven for women. The largest cluster for both genders was "small eaters" (46% of men and 51% of women); "big eaters", "light diet" and "alcohol" clusters were also identified for both genders. The men were also grouped into "balanced diet" and "cheese" clusters, and the women into "sweet", "greens" and "butter" clusters. CONCLUSIONS: In addition to the influence of the area of residence--residents in Northern Italy consume greater amounts of animal fats, sugar and alcoholic beverages, and those living in Southern Italy have a greater intake of fruit, vegetables, fish and olive oil--all of the other studied variables predicted the probabilities of falling into a specific dietary cluster. SPONSORSHIP: National Research Council (Italy)--Invecchiamento Project No. 95.01048. PF40.

Dietary and nutritional patterns in an elderly rural population in Northern and Southern Italy: (II). Nutritional profiles associated with food behaviours.

OBJECTIVE: To describe the nutritional profiles of the food consumption patterns identified in an elderly Italian rural population. DESIGN: Cross-sectional study. SETTING: : Population-based study. SUBJECTS: A total of 847 men and 1465 women aged 65 y or older, resident in rural areas in the province of Pavia (Northern Italy) and near Cosenza (Southern Italy) in 1992-1993. INTERVENTIONS: A cluster analysis segregated the subjects into six groups for men and seven for women on the basis of similarities in their food intake (see companion paper). The mean daily energy, macronutrient, mineral and vitamin intakes were calculated for the sample as a whole and for each cluster, and then compared with the age- and gender-specific recommended daily allowances for the Italian population. RESULTS: The largest cluster ("small eaters", which included about half of the population) had an insufficient intake of essential fatty acids, calcium, potassium, zinc (men), iron (women), thiamin, riboflavin, niacin, beta-carotene, and vitamins A, D and E. The most noticeable characteristics of some of the other clusters were a high intake of fats, a high proportion of total energy provided by sugars, a high intake of vitamin C, folic acid and beta-carotene, and a high alcohol consumption. Furthermore, sodium intake was too high in all of the clusters and vitamin D intake was generally inadequate. CONCLUSIONS: The dietary habits of elderly Italians living in rural areas combine elements of the Mediterranean and "wealthy" diets. SPONSORSHIP: National Research Council (Italy) - Invecchiamento Project no. 95.01048.PF40.

Recent trends in the HIV epidemic among injecting drug users in Northern Italy, 1993-1999.

OBJECTIVE: To monitor and describe the time trends of the HIV epidemic among intravenous drug users (IDU) attending drug dependence treatment centres (DDTC) in Northern Italy. DESIGN: A cohort of all seronegative IDU attending DDTC in Lombardy between 1993 and 1999; all had been tested for HIV at least twice. Periodic sample interview surveys were done to assess risk behaviours. METHODS: The incidence rates of HIV infection were calculated using the person-year (PY) method and expressed as the number of cases per 1000 PY at risk. Background HIV prevalence was calculated by dividing the number of positive cases by the total number of IDU tested at all DDTC in Lombardy. RESULTS: Between 1993 and 1999, 135 seroconversions occurred in 7945 subjects followed for 19 671 PY, yielding an incidence rate of 6.9/1000 PY. Ninety seroconversions occurred among the 6563 males and 45 seroconversions among 1382 females (incidence rates 5.5 and 14.0, respectively). Among the males, the incidence of HIV was 4.5 in those aged less than 25 years and 5.8 in those aged 25 years or more. Among the females, the corresponding figures were 21.1 and 10.3. HIV prevalence decreased over time, and it was higher among females. Sexual behaviours at risk were more common among females. CONCLUSIONS: The incidence of HIV infection among IDU in Northern Italy was stable between 1993 and 1999. The higher incidence and prevalence among females and the different prevalence of risk behaviours between genders suggest an increasing role of heterosexual transmission.

The prevalence of dementia and cognitive deficit in a rural population of 2442 residents in northern Italy. A door-to-door survey.

A population study to estimate the prevalence of dementia was carried out amongst the residents of four rural towns near Pavia in northern Italy. The population included a 40% sample of the residents between 65 and 69 years old and all residents of 70 years old or older. A door-to-door neuropsychological screening was followed by neurological examination on individuals scoring low at the screening. Of the 1670 subjects who completed the screening, 42.3% scored under the cut-off point. The prevalence of cognitive deficit was higher in women, even accounting for age. Of those who scored under the cut-off point, 336 underwent neurological examination, yielding a prevalence of dementia of 15% (from 1.6% between the ages of 65 and 69; 35% at the age of 85) in women and 5% (from 7% between the ages of 75 and 79; 27% at the age of 85 or more) in men.

Nutrition and cognitive deficit in the elderly: a population study.

OBJECTIVE: To investigate the association between a healthy diet indicator and the prevalence of cognitive impairment in the elderly. DESIGN: Cross-sectional study. SETTING: Population based. SUBJECTS: A total of 1651 subjects (560 men and 1091 women) including everybody aged 70 y or more, and a random sample of people (about 40%) aged 65-69 y resident in four rural towns in the province of Pavia, Italy in 1992-1993. INTERVENTIONS: The healthy diet indicator based on the WHO guidelines for the prevention of chronic diseases was calculated as reported by Huijbregts et al (1998; Eur. J. Clin. Nutr. 52, 826-831). Food intake was estimated by means of a 180-item food-frequency questionnaire and nutrient intake was calculated using the food composition database compiled for epidemiologic studies in Italy. The cognitive function was categorized into four levels-normal cognition, mild, moderate and severe cognitive deficit-according to the neuropsychological test score. The relationship between the dietary and the ordinal cognitive function variables was studied using the proportional-odds model. RESULTS: After adjustment for age, sex, education, total energy intake, cigarette smoking, alcohol consumption and physical activity, a better healthy diet score was associated with a lower prevalence of cognitive deficit. The cumulative odds ratio was 0.85 (95% CI 0.77-0.93). CONCLUSIONS: Our results suggest an association between a globally satisfactory diet and better cognitive performance in the elderly. However, the specific aspects of a 'healthy diet' for the elderly should be clarified. SPONSORSHIP: National Research Council (Italy), 'Invecchiamento' Project no. 95.01048.PF40.

Statistical analysis of correlated binary data in ophthalmology: a weighted logistic regression approach.

Ophthalmological studies often deal with correlated binary outcome variables. We propose a weighted logistic regression method to account for the intraclass correlations between eyes. Using simulation studies, we compared this method with two standard logistic regression approaches: a) based on eyes as the unit of analysis and b) treating individuals classified as cases if at least one eye is affected. The considered approaches were evaluated in terms of type I error, power and estimation properties. The simulation results reveal that the subject-based approach can lead to substantial bias in regression coefficient estimates when the correlation between eyes is heterogeneous across groups or when it is low, and that power is directly affected by this bias. Furthermore, the standard eye-based approach, which ignores intrasubject correlations, leads to inflated type I error rates. The proposed weighted approach performed well in all of the situations considered. This is a simple method which can be implemented using any current statistical or epidemiological package that includes logistic regression analysis.

[Patterns in nursing supervision at hospitals in Feira de Santana-Ba]. / Padrão de Supervisão da Enfermeira em Hospitais de Feira de Santana-BA.

This is an exploratory descriptive study about Nurse Supervision Pattern (NSP) performed in Feira de Santana-Bahia-Brazil, in 1994, which aims at describing supervision pattern and identifying interference factors. A questionnaire and descriptive statistics have been used. Supervision pattern proved that the kind of hospital is a factor that interferes on NSP. Based on literature, percentual exam of results and author's professional experience, it asserted that sex, academic graduation, earnings, health politics, planning and technical administrative structure are conditional factors for NSP, as well as lack of professional autonomy, interference of political parties, deficiency of material and human resources, low salaries, unsuitable environment and unsatisfactory interpersonal relationships mentioned by the subjects.