Tooth discolouration and internal bleaching after the use of triple antibiotic paste.

AIM: To assess the discolouration of teeth with closed and open apices after placement of triple antibiotic paste (TAP, ciprofloxacin, metronidazole and minocycline) in the pulp chamber and whether discolouration could be reversed by internal bleaching procedures. METHODOLOGY: Twenty extracted human mandibular premolars were divided into 2 groups (n = 10): teeth with closed apices (CA) and teeth with open apices (OA). After conventional access, the TAP was sealed in the pulp chamber for 3 weeks. The paste was removed by a rinse with sodium hypochlorite (NaOCl) and a mixture of sodium perborate and distilled water was sealed in the pulp chamber for 1, 2 and 3 weeks. The shade was measured by a spectrophotometer at six time periods: baseline (T0), after 3 weeks of placement of TAP (T1), after removal of TAP with a NaOCl rinse (T2) and after 1 (T3), 2 (T4) and 3 (T5) weeks of internal bleaching with sodium perborate paste. Data were collected based on the CIELAB-CIE1976 (L*a*b*) system and analysed using t-tests and anova. RESULTS: A significant decrease in the mean values of L* (lightness) was observed after treatment with TAP (T1, P < 0.05). Considerable increases in these values after bleaching with sodium perborate (T3 < T4 < T5) were found in both groups. The only significant difference in the intergroup analysis was between T1 and T2, in which ΔE values in the OA group were higher (P = 0.04). CONCLUSIONS: TAP discoloured the tooth structure, but discolouration could be reversed with sodium perborate paste. In general, teeth with closed and open apices had the same rates of discolouration and bleaching.

A micro-computed tomography evaluation of long-oval canal preparation using reciprocating or rotary systems.

AIM: To evaluate, using micro-computed tomography, the preparation of long-oval root canals using a single reciprocating system versus a multiple-file rotary system. METHODOLOGY: Distal canals of thirty mandibular molars were selected and randomly assigned to one of two instrument groups (n = 15): Reciproc 40 (VDW, Munich, Germany) or BioRaCe system (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The teeth were scanned before and after preparation of the canal by a SkyScan 1172 micro-computed tomography scanner at 11-µm resolution. Morphometric variations were measured by volume increases and by the remaining untreated canal surface area in the entire canal and as well as in each third of the canal. Data were compared using the Mann-Whitney test. RESULTS: The Reciproc system left significantly more areas untouched (P < 0.001) in the cervical and middle thirds (18.14% and 21.82%) as compared to BioRaCe (8.14% and 11.35%). The Reciproc system had the greatest increase in volume of both the entire canal and the apical third (P < 0.5). CONCLUSIONS: Neither technique was able to completely prepare the outline of long-oval canals. The Reciproc system removed more tooth structure. The BioRaCe left fewer untouched dentine walls in the more coronal thirds of the canal, whilst Reciproc left fewer in the apical third.

Antioxidant and orofacial anti-nociceptive activities of the stem bark aqueous extract of Anadenanthera colubrina (Velloso) Brenan (Fabaceae).

The anti-nociceptive and antioxidant activities of the Anadenantheracolubrina stem bark aqueous extract (AEAC) were investigated. AEAC (30 µg/mL) reduced 94.8% of 2,2-diphenyl-1-picrylhydrazyl radical and prevented 64% (200 µg/mL) of lipid peroxidation caused by 2,2'-azobis(2-methylpropionamidine) dihydrochloride-induced peroxyl radicals. AEAC treatment (200 and 400 mg/kg) significantly (p < 0.001) reduced mice orofacial nociception in the first (61.4% and 62.6%, respectively) and second (48.9% and 61.9%, respectively) phases of the formalin test. Nociception caused by glutamate was significantly (p < 0.001) reduced by up to 79% at 400 mg/kg, while 56-60% of the nociceptive behaviour induced by capsaicin was significantly inhibited by AEAC (100-400 mg/kg). Mice treated with AEAC did not show changes in motor performance in the Rota-rod apparatus. It appears that AEAC is of pharmacological importance in treating pain due to its anti-nociceptive effects, which were shown to be mediated by central and peripheral mechanisms.

Efficacy of reciprocating and rotary techniques for removing filling material during root canal retreatment.

AIM: To compare the efficacy of reciprocating and rotary techniques with that of hand files for removing gutta-percha and sealer from root canals. METHODOLOGY: The root canals of fifty-four human extracted maxillary central incisors were cleaned and shaped using a crown-down technique to a size 40 and filled with gutta-percha and a zinc oxide-eugenol-based sealer using a lateral compaction technique. Teeth were divided into three groups according to the technique used for removing the root filling material: group I - Gates-Glidden burs and stainless steel hand files up to size 50; group II - rotary technique with NiTi Mtwo R files and additional Mtwo files to size 50, 0.04 taper; group III - reciprocating technique with the Reciproc instrument R50, size 50, 0.05 taper. Chloroform was used as a solvent in all groups. Teeth were then split longitudinally and photographed under 8× magnification. The images were transferred to a computer, and the total canal space and remaining filling material were quantified. The ratio of remaining filling material to root canal periphery was computed with the aid of Image Tool 3.0 software. The mean percentages of remaining filling material and time required to remove it were compared using the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). RESULTS: The mean percentage of remaining filling material was significantly higher (P < 0.05) in group II, with Mtwo rotary files (12.17%), than in group I, with the hand file technique (7.19%), and group III, with Reciproc instruments (4.57%), which were statistically similar (P > 0.05). The time required to remove filling material was significantly shorter (P < 0.05) in group III (194 s), followed by group II (365 s) and group I (725 s) (P < 0.05). CONCLUSION: Remaining endodontic filling material was observed on the canal walls of all teeth regardless of the technique used. Hand files combined with Gates-Glidden burs (group I) and the reciprocating technique (group III) removed more filling material from the canal walls than the Mtwo R files. The reciprocating technique was the most rapid method for removing gutta-percha and sealer, followed by the rotary technique and the hand file technique.

Endothelial nitric oxide synthase gene variant modulates the relationship between serum cholesterol levels and blood pressure in the general population: new evidence for a direct effect of lipids in arterial blood pressure.

BACKGROUND: A causal relationship between plasma cholesterol and blood pressure remains poorly understood. It has been postulated that the decrease in nitric oxide (NO) availability is a potential mechanism by which hypercholesterolemia may stimulate blood pressure elevation. However, evidence supporting the role of the L-arginine-NO pathway on the relationship between hypertension and hypercholesterolemia is still lacking. METHODS AND RESULTS: We tested for an association of the expressed NO synthase (eNOS) Glu298Asp gene variant and plasma levels of lipids and lipoproteins in the determination of systolic blood pressure levels in a 1577 individuals randomly selected from the general population. Significant interactions could be disclosed either between the Glu298Asp gene variant and total-cholesterol (p = 0.02), log-transformed triglycerides (p = 0.004) or non-HDL-cholesterol (p = 0.003) in the determination of systolic blood pressure. In addition, although the presence of the AspAsp genotype did not significantly increase the risk of hypertension in individuals in the 50% lowest percentile of total-cholesterol, presence of this genotype significantly increased the risk of hypertension in individuals in the 50% highest percentile. Finally, in a multiple logistic regression model adjusting for age, sex, diabetes, ethnicity, smoking status and BMI, the AspAsp genotype significantly increased the risk of hypertension only in individuals with total-cholesterol above 209 mg/dL (p = 0.05, odds ratios (OR) = 2.0). CONCLUSION: Taken together, these results provide evidence supporting the role of the eNOS Glu298Asp gene variant in modulating blood pressure through a relationship with lipid levels.

Vacinação anti-rabica / Antirabies vaccination

A raiva é conhecida desde tempos remotos da História da Humanidade, existindo farta literatura e mitologia em relação à mesma. Também conhecida como hidrofobia, a doença é uma antropozoonose causada pelo vírus da Raiva. Está presente em quase todos os países do mundo, exceto em regiões insulares, onde não existe reservatório natural para o vírus ou a doença não foi introduzida, e em regiões onde a mesma foi erradicada a partir de medidas de controle, como Japão, Reino Unido, Hawai, Oceania, Ilhas do Caribe, Austrália, Uruguai e alguns países da Europa.

Baroreceptor reflex function in rats submitted to chronic inhibition of nitric oxide synthesis.

1. The chronic inhibition of nitric oxide synthesis by N omega-nitro-L-arginine-methyl ester (L-NAME) leads to arterial hypertension accompanied by a significant increase in cardiac sympathetic tone and an almost complete abolition of the vagal tone in conscious adult male Wistar rats. The main aim of the present study was to examine the baroreceptor heart rate reflex function in L-NAME-treated rats (N = 10). 2. Spontaneous daily oral intake of L-NAME (1 mg/ml for 6 days) caused marked hypertension and tachycardia (176 +/- 5 mmHg and 418 +/- 16 bpm), when compared to untreated rats (111 +/- 2 mmHg and 354 +/- 8 bpm). 3. Baroreflex gain was determined in conscious freely moving rats by sigmoidal curve fitting analysis using alternate intravenous injections of phenylephrine (0.2-10.0 micrograms/kg) and sodium nitroprusside (0.5-20.0 micrograms/kg) to produce pressor-induced bradycardia and depressor-induced tachycardia, respectively. The baroreflex gain (sensitivity) was significantly enhanced in L-NAME-treated rats compared to control rats (10.9 +/- 2.5 vs 4.5 +/- 0.3 bpm/mmHg, respectively) mainly due to exaggerated reflex bradycardia responses to increases in arterial hypertension. 4. The data indicate that chronic inhibition of nitric oxide synthesis enhances the bradycardic component of the baroreflex function.

Baroreceptor reflex function in rats submitted to chronic inhibition of nitric oxide synthesis

1. The chronic inhibition of nitric oxide synthesis by N omega-nitro-L-arginine-methyl ester (L-NAME) leads to arterial hypertension accompanied by a significant increase in cardiac sympathetic tone and an almost complete abolition of the vagal tone in conscious adult male Wistar rats. The main aim of the present study was to examine the baroreceptor heart rate reflex function in L-NAME-treated rats (N = 10). 2. Spontaneous daily oral intake of L-NAME (1 mg/ml for 6 days) caused marked hypertension and tachycardia (176 +/- 5 mmHg and 418 +/- 16 bpm), when compared to untreated rats (111 +/- 2 mmHg and 354 +/- 8 bpm). 3. Baroreflex gain was determined in conscious freely moving rats by sigmoidal curve fitting analysis using alternate intravenous injections of phenylephrine (0.2-10.0 micrograms/kg) and sodium nitroprusside (0.5-20.0 micrograms/kg) to produce pressor-induced bradycardia and depressor-induced tachycardia, respectively. The baroreflex gain (sensitivity) was significantly enhanced in L-NAME-treated rats compared to control rats (10.9 +/- 2.5 vs 4.5 +/- 0.3 bpm/mmHg, respectively) mainly due to exaggerated reflex bradycardia responses to increases in arterial hypertension. 4. The data indicate that chronic inhibition of nitric oxide synthesis enhances the bradycardic component of the baroreflex function

Evidence that the autonomic nervous system plays a major role in the L-NAME-induced hypertension in conscious rats.

The present study was designed to investigate the role of the autonomic nervous system in experimental hypertension induced by chronic administration of N-nitro-L-arginine methyl ester (L-NAME) in the drinking water (1 mg/mL) over 6 days. L-NAME ingestion caused a large rise in resting mean arterial pressure (MAP) (175 +/- 5 mm Hg) and heart rate (HR) (440 +/- 17 beats per minute) compared to nontreated control rats (resting MAP: 112 +/- 2 mm Hg and HR: 345 +/- 8 beats per minute). Ganglionic blockade induced by trimethaphan (5 mg/kg, intravenously) caused a significantly (P < .01) greater decrease in MAP (delta -86 +/- 7 mm Hg) compared to control rats MAP (delta -44 +/- 4 mm Hg). This strongly suggests that the level of central sympathetic tone in L-NAME-treated rats is much greater than in nontreated rats. Using atenolol and atropine alone and combined, the level of resting sympathetic drive to the heart was found to be significantly increased in L-NAME-treated rats compared to control rats. However, vagal tone to the heart was found to be virtually abolished in L-NAME-treated rats compared to control rats. These results indicate that an increase in central sympathetic drive plays an important role in the hypertension induced by chronic inhibition of nitric oxide synthesis with L-NAME.

Cardiovascular diseases and alimentary comparison study: preliminary analysis from Brazil.

The Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study (1) was designed to study the relationship of dietary factors to blood pressure (BP) and other major cardiovascular disease (CVD) in widely different populations of both industralized and developing countries. The primary aim of the research was to test specific hypotheses linking the intake of certain dietary constituents, e.g., sodium (Na), potassium (K), calcium (Ca), and protein, to BP (core study). The final aim was to contribute to the scientific information base required to guide the formulation of dietary goals for the primary prevention of CVD. The results of the preliminary analysis of data from Brazil in 57 inhabitants (22 men and 35 women) suggest a nonsignificant statistical correlation of Na intake estimated by urinary Na excretion and diastolic BP (DBP) and systolic BP (SBP) (p greater than 0.05), K intake estimated by urinary K excretion for DBP and SBP (p greater than 0.05), and taurine intake estimated by taurine urinary excretion for DBP and SBP (p greater than 0.05). A positive correlation was found between body mass index (BMI) and BP (p less than 0.01), for both DBP and SBP.

Metastases intracranianas. Estudo de 147 casos. / Intracranial metastases: Study of 147 cases

Sao analisados 147 casos de metastases intracranianas quanto a distribuicao etaria, manifestacoes clinicas, topografia, orgaos de origem, tipos histologicos e resultados obtidos pelas terapeuticas instituidas. Os criterios de selecao para o tratamento cirurgico sao comentados