[18F]-Sodium fluoride uptake in Takayasu arteritis.

BACKGROUND: While 18F-fluorodeoxyglucose and 18F-sodium fluoride with positron emission tomography relate with inflammation and calcification, their role in the assessment of patients with Takayasu arteritis has not yet been studied. METHODS: We present 5 patients with suspected active metabolic disease who underwent PET with 18F-fluorodeoxyglucose and 18F-sodium fluoride in order to explore the locations and correlations of 18F-fluorodeoxyglucose and 18F-sodium fluoride uptakes. Diagnosis of metabolic active disease was based on 18F-fluorodeoxyglucose uptake. RESULTS: We studied 3 female patients and 2 male patients. Median age was 29 years (min: 19 max: 63). In areas with atherosclerotic plaques, we found a negative correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = -0.78) (P = .001). Meanwhile, in areas with only metabolic active disease, we found a positive correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = 0.94) (P = .019). CONCLUSIONS: In Takayasu arteritis, 18F-sodium fluoride uptake can document different stages of metabolic disease, even in the absence of active metabolic disease or symptoms.

Serotypes, virulence markers and cell invasion ability of Shiga toxin-producing Escherichia coli strains isolated from healthy dairy cattle.

AIM: The occurrence of virulence markers, serotypes and invasive ability were investigated in Shiga toxin-producing Escherichia coli (STEC) isolated from faecal samples of healthy dairy cattle at Rio de Janeiro State, Brazil. METHODS AND RESULTS: From 1562 stx-positive faecal samples, 105 STEC strains were isolated by immuno-magnetic separation (IMS) or plating onto MacConkey agar (MC) followed by colony hybridisation. Fifty (47·6%) strains belonged to nine serotypes (O8:H19, O22:H8, O22:H16, O74:H42, O113:H21, O141:H21, O157:H7, O171:H2 and ONT:H21). The prevalent serotypes were O157:H7 (12·4%), O113:H21 (6·7%) and O8:H19 (5·7%). Virulence genes were identified by polymerase chain reaction (PCR). E-hlyA (77·1%) was the more prevalent virulence marker, followed by espP (64·8%), saa (39%), eae (24·8%) and astA (21·9%). All O157:H7 strains carried the γ (gamma) variant of the locus of enterocyte effacement (LEE) genes and the stx2c gene, while the stx1/stx2 genotype prevailed among the eae-negative strains. None of the eae-positive STEC produced the localized adherence (LA) phenotype in HEp-2 or Caco-2 cells. However, intimate attachment (judged by the fluorescent actin staining test) was detected in some eae-positive strains, both in HEp-2 (23·1%) and in Caco-2 cells (11·5%). Most strains (87·5%) showed 'peripheral association' (PA) adherence phenotype to undifferentiated Caco-2 cells. Twenty-five (92·6%) of 27 strains invaded Caco-2 cells. The highest average value of invasion (9·6%) was observed among the eae-negative bovine strains from serotypes described in human disease. CONCLUSION: Healthy dairy cattle is a reservoir of STEC carrying virulence genes and properties associated with human disease. SIGNIFICANCE AND IMPACT OF THE STUDY: Although reports of human disease associated with STEC are scarce in Brazil, the colonization of the animal reservoir by potentially pathogenic strains offers a significant risk to our population.

Tropical land-cover change alters biogeochemical inputs to ecosystems in a Mexican montane landscape.

In tropical regions, the effects of land-cover change on nutrient and pollutant inputs to ecosystems remain poorly documented and may be pronounced, especially in montane areas exposed to elevated atmospheric deposition. We examined atmospheric deposition and canopy interactions of sulfate-sulfur (SO4(2-)-S), chloride (Cl-), and nitrate-nitrogen (NO(3-)-N) in three extensive tropical montane land-cover types: clearings, forest, and coffee agroforest. Bulk and fog deposition to clearings was measured as well as throughfall (water that falls through plant canopies) ion fluxes in seven forest and five coffee sites. Sampling was conducted from 2005 to 2008 across two regions in the Sierra Madre Oriental, Veracruz, Mexico. Annual throughfall fluxes to forest and coffee sites ranged over 6-27 kg SO4(2-)-S/ha, 12-69 kg Cl-/ha, and 2-6 kg NO(3-)-N/ha. Sulfate-S in forest and coffee throughfall was higher or similar to bulk S deposition measured in clearings. Throughfall Cl- inputs, however, were consistently higher than Cl- amounts deposited to cleared areas, with net Cl- fluxes enhanced in evergreen coffee relative to semi-deciduous forest plots. Compared to bulk nitrate-N deposition, forest and coffee canopies retained 1-4 kg NO(3-)-N/ha annually, reducing NO(3-)-N inputs to soils. Overall, throughfall fluxes were similar to values reported for Neotropical sites influenced by anthropogenic emissions, while bulk S and N deposition were nine- and eightfold greater, respectively, than background wet deposition rates for remote tropical areas. Our results demonstrate that land-cover type significantly alters the magnitude and spatial distribution of atmospheric inputs to tropical ecosystems, primarily through canopy-induced changes in fog and dry deposition. However, we found that land cover interacts with topography and climate in significant ways to produce spatially heterogeneous patterns of anion fluxes, and that these factors can converge to create deposition hotspots. For land managers, this finding suggests that there is potential to identify species and ecosystems at risk of excess and increasing deposition in montane watersheds undergoing rapid transformation. Our data further indicate that montane ecosystems are vulnerable to air pollution impacts in this and similar tropical regions downwind of urban, industrial, and agricultural emission sources.

Genetic relatedness of a non-motile variant O157 enteropathogenic Escherichia coli (EPEC) strain and E. coli strains belonging to pathogenic related groups.

The study was undertaken to determine the clonal relationship and the genetic diversity among Escherichia coli isolates by comparing a non-motile O157 variant with three O157:H7 EHEC isolates and one O55:H7 enteropathogenic E. coli (EPEC) strain. E. coli strains were characterized by sorbitol phenotype, multilocus enzyme electrophoresis, pulsed-field gel electrophoresis, random amplification polymorphic DNA, and the presence of specific virulence genes (stx, E-hly and LEE genes). Sorbitol fermentation was observed in O157:H- (strain 116I), O55:H7 and O157:H7 (strain GC148) serotypes. stx1 or stx2 and E-hly genes were only detected among O157:H7 isolates. LEE typing revealed specific allele distribution: eaegamma, tirgamma, espAgamma, espBgamma associated with EPEC O55:H7 and EHEC O157:H7 strains (B1/1 and EDL 933), eaealpha, tiralpha, espAalpha, espBalpha related to the 116I O157:H- strain and the GC148 strain presented non-typable LEE sequences. Multilocus enzyme profiles revealed two main clusters associated with specific LEE pathotypes. E. coli strains were discriminated by random amplification of polymorphic DNA-polymerase chain reaction and pulsed-field gel electrophoresis methodologies. The molecular approaches used in this study allowed the determination of the genetic relatedness among E. coli strains as well as the detection of lineage specific group markers.

Stability study of a constant-volume thin film flow.

We study the stability of a constant volume of fluid spreading down an incline. In contrast to the commonly considered flow characterized by constant fluid flux, in the present problem the base flow is time dependent. We present a method to carry out consistently linear stability analysis, based on simultaneously solving the time evolution of the base flow and of the perturbations. The analysis is performed numerically by using a finite-difference method supplemented with an integral method developed here. The computations show that, after a short transient stage, imposed perturbations travel with the same velocity as the leading contact line. The spectral analysis of the modes evolution shows that their growth rates are, in general, time dependent. The wavelength of maximum amplitude, lambda_{max} , decreases with time until it reaches an asymptotic value which is in good agreement with experimental results. We also explore the dependence of lambda_{max} on the cross sectional fluid area A , and on the inclination angle alpha of the substrate. For considered small A 's, corresponding to small Bond numbers, we find that the dependence of lambda_{max} on A is in good agreement with experimental data. This dependence differs significantly from the one observed for the films characterized by much larger A 's and Bond numbers. We also predict the dependence of lambda_{max} on the inclination angle alpha .

[Anesthesia for electroconvulsive therapy: clinical experience]. / Anestesia en terapia electroconvulsiva. Experiencia clínica.

OBJECTIVE: To assess the utility of propofol and succinylcholine in obtaining optimal convulsions and assuring patient safety during electroconvulsive therapy. PATIENTS AND METHODS: This was a prospective observational study of patients undergoing electroconvulsive therapy under general anesthesia with propofol and succinylcholine. We recorded patient characteristics, doses of propofol and succinylcholine, electroencephalographically-recorded duration of convulsions, and complications. Descriptive statistics were compiled and the data were subjected to analysis of correlations, comparison with the Student t test for independent samples, the Mann-Whitney U test, and analysis of variance. RESULTS: We studied 108 patients, 62% women and 38% men, 80% classified as ASA 1 and 20% as ASA 2. The patients underwent 844 sessions of electroconvulsive therapy; their mean (SD) age was 39.95 (18.09) years. The doses of propofol and succinylcholine were 1.34 (0.32) mgxkg(-1) and 1.35 (0.26) mgxkg(-1), respectively. The mean recorded duration of the first convulsion (29.87 [22.42] seconds) was negatively correlated with age (r = -0.12) and unrelated to propofol dose (r = 0.06) or body weight (r = 0.02). Male and schizophrenic patients had longer-lasting convulsions (P < .01). Cardiovascular complications occurred in 2.4% and psychomotor agitation in 1.4%; there were no respiratory complications, musculoskeletal injuries, nausea, or vomiting. CONCLUSIONS: Electroconvulsive therapy can be safely applied in an operating room or similar space undergeneral anesthesia and with a neuromuscular blockade in order to prevent psychological or musculoskeletal trauma. Propofol did not affect the convulsions at the dosages administered.

Spreading of a micrometric fluid strip down a plane under controlled initial conditions.

We experimentally study the spreading of a small volume of silicon oil down a vertical plane with small Bond number. The initial condition is characterized by a horizontal long fluid strip with cross sectional area A and width w(0). We find that the experiments are characterized by a unique nondimensional parameter, R proportional w4(0)/(a2A), where a is the capillary length. An empirical criterium to estimate the onset of the contact line instability is established. The later rivulet formation at the contact line leads to a pattern which is characterized by a dominant wavelength. We find that this wavelength is approximately proportional to R(-1/4).

Spreading of a thin two-dimensional strip of fluid on a vertical plane: experiments and modeling.

We study the thin-film flow of a constant volume of silicon oil (polydymethilsiloxane) spreading down a vertical glass plate. The initial condition is generated from a horizontal fluid filament of typical diameter 0.4 mm. Two optical diagnostic methods are used: One based on an anamorphic system, and the other on the Schlieren method. The first one allows for a detailed characterization of the early stable stage of the spreading which is used to estimate the thickness of the precursor film needed to model the flow. The second one captures the bidimensional pattern of the transversal film instability. We use these techniques to determine the film thickness profiles, and the evolution of the moving contact line, including its shape and Fourier spectra. The numerical simulations of the stable stage of spreading are in good quantitative agreement with the experimental results. We develop a model based on linear stability theory that predicts the evolution of the modes present in the linear stage of the instability.

Constituents of Coriaria ruscifolia fruits.

Corianin (1) and ellagic acid 3,3'-dimethylether (2) were obtained from the methanol extract of powdered fruits of Coriaria ruscifolia. Biological screening of both compounds and of the methanol extract revealed slight antibacterial activity and cytotoxicity.

Triterpene trimers from Maytenus scutioides: cycloaddition compounds?

Two novel trimers, triscutins A and B (1 and 2), based on pristimerin triterpene units, were isolated and characterized from Maytenus scutioides. Their structures were determined on the basis of spectroscopic evidence, including 1H-13C heteronuclear correlation (HMQC), long-range correlation with inverse detection (HMBC), and ROESY NMR experiments; and their absolute configurations, by means of CD studies. Compounds 1 and 2 were assayed for antimicrobial and cytotoxic activities, and their possible biosynthetic route is proposed.

New phenolic and quinone-methide triterpenes from Maytenus amazonica.

The new nortriterpene methylene quinones amazoquinone (1) and (7S, 8S)-7-hydroxy-7,8-dihydro-tingenone (2), and the new norphenolic triterpenes 7,8-dihydro-6-oxo-tingenol (3), 23-nor-6-oxo-tingenol (4), and 23-oxo-iso-tingenone (5) were isolated from Maytenus amazonica. Their structures were elucidated by spectroscopic methods. Compounds 1, 2, 3, and 5 showed low antitumor activity against four cancer cell lines.

Xanthine oxidase inhibitory activity of some Panamanian plants from Celastraceae and Lamiaceae.

Thirty four crude extracts of Panamanian plants, from nine species of Celastraceae and Lamiaceae, were assayed for xanthine oxidase (XO) inhibitory activity. The enzymatic activity was estimated by measuring the increase in absorbance at 290 nm due to uric acid formation. Eighty five percent of the crude extracts were found to possess XO inhibitory activity at 50 micrograms/ml and all the extracts of the species from Lamiaceae were active even at 1 micrograms/ml. The ethanol extracts of Hyptis obtusiflora Presl ex Benth. (Lamiaceae) and H. lantanaefolia Poit. (Lamiaceae) exhibited the highest activity with an inhibition of approximately 40% at 1 micrograms/ml.

New sesquiterpenes fromMaytenus species (Celastraceae). Taxonomic and chemotaxonomic considerations concerning chileanMaytenus.

Three new dihydro-ß-agarofuran sesquiterpenes from two species ofMaytenus were isolated and their structures were elucidated by means of(1)H and(13)C NMR studies. The differences and similarities noted in the chemical content of the dihydro-ß-agarofuran sesquiterpenes from the fourMaytenus species from Chile are in line with the taxonomic characterization of these species; their geographical distribution is also given.