Antimicrobial activity of an L-amino acid oxidase isolated from Bothrops leucurus snake venom

Some snake venom proteins present enzymatic activities, such as L-amino acid oxidase (LAAO). The aim of this paper was to investigate the effect of Bothrops leucurus total venom (BleuTV) and its fraction LAAO (BleuLAAO) on bacteria, yeast, and promastigote forms of Leishmania amazonensis and Leishmania chagasi, and epimastigote forms of Trypanosoma cruzi. BleuTV was isolated with a Protein Pack 5PW® (Waters Corporation, USA), and several fractions were obtained. BleuLAAO was purified to high molecular homogeneity, and its N-terminal amino acid sequence shared a high degree of amino acid conservation with other LAAOs. BleuTV inhibited Staphylococcus aureus growth in a dose-dependent manner, with a minimum inhibitory concentration (MIC) of 25 ìg/mL, which corresponded to its minimum lethal concentration (MLC). BleuTV also inhibited the growth of promastigote forms of L. chagasi and L. amazonensis, with respective IC50 values of 1.94 ìg/mL and 5.49 ìg/mL. Furthermore, it repressed T. cruzi growth with an IC50 of 1.14 ìg/mL. However, BleuLAAO did not inhibit the growth of the microorganisms studied and was not toxic to macrophages. BleuTV had low toxicity against macrophages at the concentrations studied. In conclusion, whole venom from Bothrops leucurus inhibited the growth of some microorganisms, including S. aureus, Leishmania sp., and T. cruzi.(AU)

Antimicrobial activity of an L-amino acid oxidase isolated from Bothrops leucurus snake venom

Some snake venom proteins present enzymatic activities, such as L-amino acid oxidase (LAAO). The aim of this paper was to investigate the effect of Bothrops leucurus total venom (BleuTV) and its fraction LAAO (BleuLAAO) on bacteria, yeast, and promastigote forms of Leishmania amazonensis and Leishmania chagasi, and epimastigote forms of Trypanosoma cruzi. BleuTV was isolated with a Protein Pack 5PW® (Waters Corporation, USA), and several fractions were obtained. BleuLAAO was purified to high molecular homogeneity, and its N-terminal amino acid sequence shared a high degree of amino acid conservation with other LAAOs. BleuTV inhibited Staphylococcus aureus growth in a dose-dependent manner, with a minimum inhibitory concentration (MIC) of 25 ìg/mL, which corresponded to its minimum lethal concentration (MLC). BleuTV also inhibited the growth of promastigote forms of L. chagasi and L. amazonensis, with respective IC50 values of 1.94 ìg/mL and 5.49 ìg/mL. Furthermore, it repressed T. cruzi growth with an IC50 of 1.14 ìg/mL. However, BleuLAAO did not inhibit the growth of the microorganisms studied and was not toxic to macrophages. BleuTV had low toxicity against macrophages at the concentrations studied. In conclusion, whole venom from Bothrops leucurus inhibited the growth of some microorganisms, including S. aureus, Leishmania sp., and T. cruzi.

Comparison of the percentage of gutta-percha-filled area obtained by Thermafil and System B.

The aim of this study was to determine the percentage of gutta-percha-filled area (GPFA) obtained by Thermafil and System B techniques using light microscopy and digital image processing. Forty-five human mandibular first molars were prepared and obturated as follows: Group 1: lateral condensation (n = 15); Group 2: System B (n = 15); and Group 3: Thermafil system (n = 15). Horizontal sections were cut 4 and 6 mm from the apical foramen of each tooth. The samples were metallographically prepared and taken through photomicrographs. Using digital analysis, the cross-sectional area of the canal and the gutta-percha areas were measured. The GPFA data obtained for the three groups were analysed using the non-parametric Friedman and Wilcoxon Signed-Ranks tests. Significant differences were found between Group 3 and Group 2-Group 1. No significant difference was found between Group 2 and Group 1. The Thermafil system produced significantly higher GPFAs than lateral condensation and System B techniques (P < 0.01). This result suggests that the Thermafil system can reduce sealer and voids.

A laboratory analysis of gutta-percha-filled area obtained using Thermafil, System B and lateral condensation.

AIM: To determine the percentage of gutta-percha-filled area (PGFA) in the apical third of root canals when filled with either Thermafil, System B or lateral condensation. METHODOLOGY: Sixty extracted human maxillary central incisor teeth were root filled as following: G1: lateral condensation (n = 20), G2: System B (n = 20) and G3: Thermafil system (n = 20). A horizontal section was cut 2 and 4 mm from the apical foramen of each tooth. The samples were prepared for microscopic analysis and photomicrographs of each apical surface were taken at a magnification of 50x. Through digital image analysis, the cross-sectional area of the canal and the gutta-percha was measured. The PGFA was calculated. The PGFA data obtained in the three groups were analysed using a nonparametric Friedman and Wilcoxon signed-rank tests. RESULTS: Significant differences in PGFA were found between the Thermafil System (G3) and both System B (G2) and lateral condensation (G1) (P < 0.01). The greatest PGFA occurred in the Thermafil group. No significant statistical difference was found between System B and lateral condensation (P > 0.05). CONCLUSIONS: The coated carrier gutta-percha system Thermafil produced significantly higher PGFAs than lateral condensation and System B techniques.

Assessment of different gutta-percha brands during the filling of simulated lateral canals.

AIM: To compare the ability of five different commercially available gutta-percha points to fill simulated lateral canals when subjected to warm vertical compaction. METHODOLOGY: Fifty clear plastic teeth with a lateral canal in each third of the root were used. All teeth were filled using warm vertical compaction. Backfilling was completed with a sealer and the same gutta-percha point used during the apical condensation. After this, they were horizontally sectioned using a diamond disc adapted to a low-speed saw. The resulting sections were embedded in epoxy resin. The extent of gutta-percha and sealer filling were measured in each lateral canal using an IMAGE-PRO 4.0 software system. The voids in each canal were measured using the same system. Data were ranked and analysed using the Kruskal-Wallis statistical test. RESULTS: The mean percentage of the three lateral canals filled with gutta-percha and sealer were respectively: Konne (68.23% and 24.50%), Analytic (67.90% and 25.28%), Obtura (63.80% and 29.60%), Tanari (49.42% and 45.86%) and Dentsply (44.60% and 47.05%). There was significantly (P < 0.05) more gutta-percha in the lateral canal filled with Analytic, Obtura and Konne points than with Tanari and Dentsply points. CONCLUSIONS: The brand of gutta-percha cone had an influence on the length of filling within lateral canals. This may be a reflection of the chemical formulation of the gutta-percha points.

Recovery of Enterococcus faecalis after single- or multiple-visit root canal treatments carried out in infected teeth ex vivo.

AIM: To assess the presence of Enterococcus faecalis after root canal treatment in single or multiple visits in an ex vivo model. METHODOLOGY: Forty-five premolar teeth were infected ex vivo with E. faecalis for 60 days. The canals were then prepared using a crowndown technique with System GT and Gates-Glidden burs and irrigated with 2% chlorhexidine gel. The specimens were divided into five groups (G1, G2, G3, G4 and G5) according to the time elapsed between chemical-mechanical preparation and root canal filling, the irrigant solution used and the use or nonuse of a calcium hydroxide intra-canal medicament. The teeth were then root-filled and incubated for 60 days at 37 degrees C. Dentine chips were removed from the canal walls with sequential sterile round burs at low speed. The samples obtained with each bur were immediately collected in separate test tubes containing Brain-Heart Infusion broth. These samples were placed onto agar plates and colony forming units were counted after 24 h at 37 degrees C. Data were ranked and analysed using the Kruskal-Wallis statistical test. RESULTS: Enterococcus faecalis was recovered from 20% (three of 15 specimens) of G1 (chlorhexidine irrigation and immediate root filling in a single visit), 25% (four of 15 specimens) of G2 (chlorhexidine irrigation and filling after 14 days use of a calcium hydroxide dressing in multiple visits), 40% (two of five specimens) of G3 (chlorhexidine irrigation and filling after 7 days), 60% (three of five specimens) of G4 (saline irrigation and filling after 7 days) and from 100% (five of five specimens) of G5 (saline irrigation and immediate filling without sealer). CONCLUSIONS: Neither single- nor multiple-visit root canal treatment ex vivo, eliminated E. faecalis completely from dentinal tubules. Up to 60 days after root filling, E. faecalis remained viable inside dentinal tubules. When no sealer was used, E. faecalis presented a higher growth rate.

Cytotoxicity of MTA and Portland cement on human ECV 304 endothelial cells.

AIM: To evaluate the cytotoxic effects of two brands of mineral trioxide aggregate (MTA) (Pro-Root MTA and MTA Angelus) and Portland cement (PC) on the human ECV 304 endothelial cell line. METHODOLOGY: Endothelial ECV 304 cells were incubated at 37 degrees C in an atmosphere of 95% air, 5% carbon dioxide and 100% humidity for 7 days and grown in F12 medium supplemented with 10% fetal bovine serum with 50 microg mL(-1) of gentamicin sulphate. Effects of the materials on mitochondrial functions were measured by a colorimetric assay. At each experimental time interval (24, 48 and 72 h), a dimethyl-thiazol-diphenyl tetrazolium bromid assay was conducted to measure cell viability. All assays were repeated three times to ensure reproducibility. Results were expressed as average absorbance (A(570/nm)) +/- SD and the data were analysed statistically by one-way analysis of variance and the Bonferroni post-test. A P-value < 0.05 was considered statistically significant. RESULTS: No statistically significant difference was shown between any of the experimental materials (P > 0.05). CONCLUSIONS: The two brands of MTA analysed, as well as the PC, initially showed a similar elevated cytotoxic effect that decreased gradually with time allowing the cell culture to become reestablished.

Utilization of temperature distribution in expiratory speaking flow as a new parameter for speech production analysis.

A new instrument with potential use for speech production analysis is utilized in this study to measure the temperature and velocity of the expiratory speaking flow outside the oral cavity. From a physical point of view, the temperature patterns of individuals with healthy voices are expected to be different from individuals with breathy voices, since their air flow patterns are different: during breathy speech production, the glottis does not close completely, and the leakage of warm air through the glottis increases the extent of the hotter-than-ambient temperature field outside the oral cavity. The instrument is a pipe through which the tested individual breathes out while producing a sustained vowel. A tap water heat exchanger keeps the pipe wall at a temperature level considerably lower than the body temperature. The temperature gradient along the pipe centreline is measured and related to the average air velocity at the oral cavity. The measurements were performed in 30 male and 30 female subjects without vocal complaints. The objective of this initial investigation was to evaluate the possibility of establishing patterns of normality for the temperature distribution outside the oral cavity in expiratory speaking flow. In the experiments, all the temperature measurements increased as the expiratory air flow of the individual increased during speech production, therefore the instrument results agree with the physical behavior predicted by fluid mechanics and heat transfer principles. The collected data allowed for the construction of charts with two distinct normalized temperature distributions outside the oral cavity, for male and female individuals, respectively. These charts have the potential for future utilization in a follow-up study for comparison with similar measurements obtained with individuals with vocal fold pathologies, aiming to eventually produce a reliable new instrument for early detection of vocal problems through a non-invasive procedure.

Chemical and X-ray analyses of five brands of dental gutta-percha cone.

AIM: To determine the chemical composition of five commercially available nonstandardized gutta-percha points. METHODOLOGY: The organic fraction (gutta-percha polymer and wax/resin) of nonstandardized gutta-percha points (Dentsply, Tanari, Konne, Obtura Spartan and Analytic Endodontics) was separated from the inorganic fraction (ZnO and BaSO4) by dissolution in chloroform. Gutta-percha polymer was precipitated with acetone. Zinc oxide was partially separated from barium sulphate by reaction with HCl. Energy-dispersive X-ray microanalysis and X-ray diffraction were employed to identify the chemical elements and compounds (barium sulphate and zinc oxide). The barium sulphate content was calculated by percentage of sulphur from elemental microanalysis. All analyses were repeated three times. RESULTS: The means and standard deviations of the percentage by weight of gutta-percha in the points were: Dentsply (14.5 +/- 0.70%), Tanari (15.6 +/- 0.66%), Obtura (17.7 +/- 0.35%), Konne (18.9 +/- 0.32%) and Analytic (20.4 +/- 0.40%). The mean and SD of the zinc oxide content were: Dentsply (84.3 +/- 0.50%), Tanari (82.0 +/- 0.72%), Obtura (69.5 +/- 0.21%), Konne (78.0 +/- 0.05%) and Analytic (66.5 +/- 0.50%). CONCLUSIONS: The method was appropriate to quantify gutta-percha and resin/wax components of gutta-percha points, but not barium sulphate and zinc oxide. An alternative procedure to determine barium sulphate and zinc oxide contents has been proposed based on elemental microanalysis of sulphur. Some brands of gutta-percha did not contain barium sulphate.

[Use of botulinum toxin in the treatment of laryngeal dystonia (spasmodic dysphonia): preliminary study of twelve patients]. / O uso da toxina botulínica no tratamento da distonia laríngea (disfonia espasmódica): estudo preliminar com doze pacientes.

Laryngeal dystonia (spasmodic dysphonia) is a movement disorder characterized by involuntary contractions of laryngeal muscles involved with vocalization. The introduction of botulinum toxin in the treatment of laryngeal dystonia had a major clinical impact due to the striking improvement of symptoms. We report the preliminary results of therapeutical use of botulinum toxin in the treatment of twelve patients with laryngeal dystonia. After an extensive clinical evaluation, the patients underwent a videostroboscopic exam for diagnostic confirmation. Botulinum toxin was injected in the cricothyreoid membrane, directed towards the thyreoaritenoid muscle, with the aid of eletromyography needles. Most of patients who underwent botulinum toxin injection had a significant improvement of their symptoms (83%), with effects lasting for four months in average and without important side effects.

Fratura radicular horizontal: relato de caso / Root horizontal fracture: case related

Embora situaçöes de traumatismo dental com fratura radicular possam parecer de difícil soluçäo, na maioria dos casos o tratamento consiste apenas na reduçäo da fratura e sua contençäo. Apresentamos a conduta clínica adotada em caso de fratura radicular horizontal, onde tratou-se apenas o segmento coronário, sem intervençäo no segmento apical

[The influence of mail service on the incidence of absentees in a children health care center (author's transl)]. / A influência do correio na incidência de faltosos em um serviço de puericultura.

The authors have made a research on the influence of mailing letters on keeping up the returns in an ambulatory of health care service. The purpose of the paper was to seek a way to improve the return rate, which is usually low, and brings up difficulties to structure adequately a staff. One hundred children who had failed to come to their last appointment were studied and divided in two groups: 50 children to whose responsible were sent letters setting up a new appointment were included in group I; group II served as a control group. Out of the 97 absentees, 36 children (37.1%) returned. Their return was spontaneous in 22 cases (22.7%)--12 children of group I and 10 of group II. 14 mothers returned on the date set up by mail. Out of the 47 mailed letters, 20 (42.5%) were sent back by the post office. The authors have concluded that mailing letters was an effective method to decrease the number of children who miss their follow-up in ambulatory of health care service.