Interatrial block can occur in the absence of left atrial enlargement: New experimental model

We present the surface electrocardiogram of an open-chest anesthetized healthy adult swine after direct application of ice at the transversus sinus of the pericardium where the Bachmann's region is located. Gradual and transient interatrial block (IAB) in the absence of structural atrial disease is described. This new experimental model demonstrated that IAB is an independent entity from left atrial enlargement.     

Cyane-carvone,a Synthetic Derivative of Carvone,Inhibits Inflammatory Response by Reducing Cytokine Production and Oxidative Stress and Shows Antinociceptive Effect in Mice

Cyane-carvone (CC) was studied to elucidate its anti-inflammatory, antinociceptive, and antioxidant effects in Mus musculus. Anti-inflammatory (bradykinin, histamine, prostaglandin E₂, serotonin, and carrageenan) and antinociceptive (acetic acid and formalin) models were utilized. Myeloperoxidase activity, interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α), and glutathione (GSH) levels were evaluated. Analysis of variance followed by Student-Newman-Keuls’ test was done. Results were compared with control groups (significantly when p?<?0.05). In bradykinin, histamine, prostaglandin E₂, and serotonin tests, 75 mg/kg CC decreased significantly paw edema (t?=?30, 60, 90, and/or 120 min). In carrageenan test, 50 and 75 mg/kg CC (t?=?3 h and t?=?4 h) and 25 mg/kg CC (t?=?4 h) decreased significantly paw edema. CC (75 mg/kg) inhibited significantly mieloperoxidase activity and decreased IL-1β and TNF-α, and all doses increased GSH levels. CC (75 mg/kg) decreased significantly the number of contortions of animals and time of licking (phase 2). CC showed anti-inflammatory, antinociceptive, and antioxidant effects in mice.     

Apical transportation associated with ProTaper? Universal F1, F2 and F3 instruments in curved canals prepared by undergraduate students

Objective

This study evaluated apical transportation associated with ProTaper^® Universal Fl, F2 and F3 rotary files in curved canais prepared by undergraduate students.

Material and Methods

Twenty mesial roots of mandibular molars with curvatures ranging between 25° and 35° were selected. Mesiobuccal canals were instrumented by twenty students with the ProTaper^® system (Dentsply-Maillefer, Ballaigues, Switzerland) according to the manufacturer''s instructions. Pre-fiaring was performed with Sl and SX files. A #15 K-file was inserted into the root canal up to the working length (WL), and an initial digital radiograph was taken in a buccolingual direction (baseline). Afterwards, the S1, S2, F1, F2, and F3 files were employed up to the WL. Other radiographies were taken in the same orientation of the baseline after the use of the Fl, F2, and F3 files, with each file inserted into the root canal. The radiographic images were overlapped, and the Image J software was used to measure the distance between the rotary files'' ends and the #15 K-file''s end, characterizing the apical transportation. Data were analyzed by Repeated Measure ANOVA and by the SNK post hoc test (P<0.05).

Results

It was verified that file size affected apical transportation significantly (P<0.001). The F3 file showed higher apical transportation than Fl and F2, while between these last files there was no difference.

Conclusion

The undergraduate students produced lower apical transportation in curved canals when they did not use the F3 rotary file.     

ADHESION OF AN ENDODONTIC SEALER TO DENTIN AND GUTTA-PERCHA: SHEAR AND PUSH-OUT BOND STRENGTH MEASUREMENTS AND SEM ANALYSIS

The use of an adequate method for evaluation of the adhesion of root canal filling materials provides more reliable results to allow comparison of the materials and substantiate their clinical choice. The aims of this study were to compare the shear bond strength (SBS) test and push-out test for evaluation of the adhesion of an epoxy-based endodontic sealer (AH Plus) to dentin and guttapercha, and to assess the failure modes on the debonded surfaces by means of scanning electron microscopy (SEM). Three groups were established (n=7): in group 1, root cylinders obtained from human canines were embedded in acrylic resin and had their canals prepared and filled with sealer; in group 2, longitudinal sections of dentin cylinders were embedded in resin with the canal surface smoothed and turned upwards; in group 3, gutta-percha cylinders were embedded in resin. Polyethylene tubes filled with sealer were positioned on the polished surface of the specimens (groups 2 and 3). The push-out test (group 1) and the SBS test (groups 2 and 3) were performed in an Instron universal testing machine running at crosshead speed of 1 mm/min. Means (±SD) in MPa were: G1 (8.8±1.13), G2 (5.9±1.05) and G3 (3.8±0.55). Statistical analysis by ANOVA and Student''s t-test (α=0.05) revealed statistically significant differences (p<0.01) among the groups. SEM analysis showed a predominance of adhesive and mixed failures of AH Plus sealer. The tested surface affected significantly the results with the sealer reaching higher bond strength to dentin than to guttapercha with the SBS test. The comparison of the employed methodologies showed that the SBS test produced significantly lower bond strength values than the push-out test, was skilful in determining the adhesion of AH Plus sealer to dentin and gutta-percha, and required specimens that could be easily prepared for SEM, presenting as a viable alternative for further experiments.     

Detection and evaluation of endocrine-disruption activity in water samples from Portuguese rivers

Water samples (n = 183) from Portuguese rivers were tested for the presence of endocrine disruptors using the recombinant yeast assay (RYA) combined with chemical identification of compounds having endocrine-disruption properties by liquid chromatography coupled to mass spectrometry. Ten selected locations were sampled monthly for a period of 20 months, from April 2001 to December 2002. More than 90% of samples showed either no detectable or low levels of estrogenicity (<0.1 ng/L of estradiol equivalents). The remaining samples (17 in total, 9.3%) showed estrogenicity values ranging from 0.1 to 1.7 ng/L of estradiol equivalents; only two samples showed values greater than 1 ng/L of estradiol equivalents. Most highly estrogenic samples (13 of 17 samples) originated in five sampling sites clustered in two zones near Porto and Lisbon. Chemical analysis detected alkylphenolic compounds (octyl- and nonylphenol plus nonylphenol ethoxylates) in all samples, albeit at concentrations less than 1 microg/L for each compound in 80% of samples. Total analyte concentration exceeded 10 microg/L in only 10 samples, with all but one of those originating from only two sampling sites. In these two locations, a good correlation was observed between the concentrations of octylphenol, nonylphenol, and to a lesser extent, bisphenol A in the samples and their estrogenicity values as calculated by RYA. We conclude that estrogenic activity can be explained by alkylphenol contamination in only these sites; for the remainder, we propose that pesticides and urban waste may be the main factors responsible for estrogenic contamination.     

Fate of gasoline oxygenates in conventional and multilevel wells of a contaminated groundwater table in Düsseldorf, Germany

In a gasoline-contaminated site in Düsseldorf, Germany a two-year monitoring program was carried out to determine the presence, behavior, and fate of 12 gasoline additives in a total of 96 samples from 14 groundwater wells. The origin of contamination was suspected to be a gasoline spill at a gas station. Target compounds were methyl-tert-butyl ether (MTBE), its main degradation products, tert-butyl alcohol (TBA) and tert-butyl formate (TBF); other gasoline additives, oxygenate dialkyl ethers: Ethyl-tert-butyl ether (ETBE), tert-amyl methyl ether (TAME) and diisopropyl ether (DIPE); aromatics: Benzene, toluene, ethylbenzene and xylenes (BTEX), and other compounds causing odor problems: Dicyclopentadiene and trichloroethylene. Purge and trap coupled with gas chromatography-mass spectrometry permitted detection of ng/L concentrations. Ninety of the 96 samples analyzed contained MTBE at levels varying between 0.01 to 645 microg/L. Five contaminated hot spots were identified with levels up to U.S. Environmental Protection Agency (U.S. EPA) drinking water advisory values (20-40 microg/L) and one of them doubling Danish suggested toxicity level of 350 microg/L at a depth of 11 m. No significant natural attenuation was found in MTBE degradation, although samples with high levels of MTBE contained 0.1 to 440 microg/L of TBA. These levels were attributed to its presence in the contamination source more than MTBE degradation. tert-Butyl alcohol was found to be recalcitrant in groundwater. In all cases, BTEX were at low concentrations or not detected, showing less persistence than MTBE. The monitoring of the contamination plume showed that the distribution of the MTBE and TBA in the aquifer formed a similar vertical concentration profile that was influenced by the groundwater flow direction.     

Mucosal immunization of sheep with a Maedi-Visna virus (MVV) env DNA vaccine protects against early MVV productive infection

Gene gun mucosal DNA immunization of sheep with a plasmid expressing the env gene of Maedi-Visna virus (MVV) was used to examine the protection against MVV infection in sheep from a naturally infected flock. For immunization, sheep were primed with a pcDNA plasmid (pcDNA-env) encoding the Env glycoproteins of MVV and boosted with combined pcDNA-env and pCR3.1-IFN-gamma plasmid inoculations. The pcDNA plasmid used in the control group contained the lacZ coding sequences instead of the env gene. Within a month post-challenge, the viral load in the vaccinated group was lower (p < or = 0.05) and virus was only detected transiently compared with the control group. Furthermore, 2 months later, neutralizing antibodies (NtAb) were detected in all the control animals and none of the vaccinated animals (p < or = 0.01). These results demonstrated a significant early protective effect of this immunization strategy against MVV infection that restricts the virus replication following challenge in the absence of NtAb production. This vaccine protective effect against MVV infection disappeared after two years post-challenge, when active replication of MVV challenge strain was observed. Protection conferred by the vaccine could not be explained by OLA DRB1 allele or genotype differences. Most of the individuals were DRB1 heterozygous and none was totally resistant to infection.     

Efficacy of ultrasound in removal of intraradicular posts using different techniques

The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied.     

Antinociceptive profile of 2-phenylselenenyl-1,8-cineole in mice

2-Phenylselenenyl-1,8-cineole (PSC) increased both the pentobarbital-induced sleeping time and the reaction time (up to 2 h) in the tail immersion method. PSC also caused dose-dependent inhibition of acetic acid induced writhing with maximum inhibition of 93.4% and was approximately 8.5-fold more potent than 1,8-cineole. These findings show that PSC presents sedative effect and significant antinociceptive activity.     

Health and functional status among elderly individuals living in nursing homes in Madrid

OBJECTIVES: Epidemiologic studies on probabilistic samples of the institutionalized elderly in Spain are very scarce. The aim of this study was to describe the health and functional status of a population of older people living in nursing homes. SUBJECTS AND METHOD: A cross-sectional epidemiologic study was carried out. A sample of 800 subjects living in 19 public and 26 private nursing homes in Madrid was obtained through a stratified cluster method. Residents, main caregivers, doctors and nurses were interviewed. Cognitive status, perceived health, depression, pain, functional capacity, chronic illnesses, pressure ulcers, urinary and fecal incontinence, drug consumption and hospitalizations were assessed. RESULTS: Seventy-five percent of the sample were women. The mean age was 83.4 (standard deviation, 7.3) years. Forty-four percent had some degree of cognitive impairment. Forty-six percent were independent or mildly dependent in basic activities of daily living. Fifty-five percent reported very good or good perceived health. Thirty percent had depressive symptoms. Thirty-one percent had experienced daily pain in the previous 7 days. Three percent had pressure ulcers. The most prevalent illnesses were hypertension (45%), osteoarthritis (34%), dementia (33%) and anxiety (27%). The prevalence of Alzheimer's disease was 14%. Fifty-three percent had urinary incontinence and 26% had fecal incontinence. Twenty-six percent had been transferred to an emergency unit in the previous year. CONCLUSIONS: The estimates of the main variables, such as cognitive impairment and functional status, were in general more favorable than those in other populations of nursing home residents in Europe and North America. This is partly explained by the greater proportion of persons with a low need for care in the nursing homes in Madrid.