Anti-inflammatory effects of propranolol in the temporomandibular joint of female rats and its contribution to antinociceptive action.

BACKGROUND: ß-Blockers reduce temporomandibular joint (TMJ) pain. We asked whether they also reduce TMJ inflammation and, if so, whether this anti-inflammatory effect contributes to its analgesic action. METHODS: We measured many parameters of the inflammatory response after co-administration of the ß-blocker propranolol with the inflammatory agent carrageenan in the TMJ of female rats. We also hypothesized that the activation of ß-adrenoceptors in the TMJ induces nociception mediated, at least in part, by the inflammatory response. To test this hypothesis, we examined the nociceptive response induced by the activation of the ß-adrenoceptors in the TMJ in female rats pretreated with thalidomide and fucoidan. RESULTS: We found that the co-administration of propranolol with carrageenan in the TMJ of female rats significantly reduced several parameters of the inflammatory response induced by carrageenan such as plasma extravasation, neutrophil migration and the release of the pro-inflammatory cytokines TNF-α, IL-1ß and CINC-1. Furthermore, the injection of the ß-adrenergic receptor agonist isoproterenol in the TMJ induced nociception that was significantly reduced by thalidomide, fucoidan and by the co-administration of propranolol but not of the α-adrenergic receptor antagonist phentolamine. CONCLUSIONS: Propranolol has anti-inflammatory effects that contribute to its antinociceptive action in the TMJ of females. SIGNIFICANCE: ß-Blockers have an anti-inflammatory effect on temporomandibular joint (TMJ) that contributes to its analgesic effect. The results of this work suggest that ß-blockers can be used to treat the painful conditions of TMJ, especially when they are associated with an inflammatory process.

Hydrogen sensing via anomalous optical absorption of palladium-based metamaterials.

A palladium (Pd)-based optical metamaterial has been designed, fabricated and characterized for its application in hydrogen sensing. The metamaterial can replace Pd thin films in optical transmission schemes for sensing with performances far superior to those of conventional sensors. This artificial material consists of a palladium-alumina metamaterial fabricated using inexpensive and industrial-friendly bottom-up techniques. During the exposure to hydrogen, the system exhibits anomalous optical absorption when compared to the well-known response of Pd thin films, this phenomenon being the key factor for the sensor sensitivity. The exposure to hydrogen produces a large variation in the light transmission through the metamembrane (more than 30% with 4% in volume hydrogen-nitrogen gas mixture at room temperature and atmospheric pressure), thus avoiding the need for sophisticated optical detection systems. An optical homogenization model is proposed to explain the metamaterial response. These results contribute to the development of reliable and low-cost hydrogen sensors with potential applications in the hydrogen economy and industrial processes to name a few, and also open the door to optically study the hydrogen diffusion processes in Pd nanostructures.

Unravelling the tunable exchange bias-like effect in magnetostatically-coupled two dimensional hybrid (hard/soft) composites.

Hybrid 2D hard-soft composites have been fabricated by combining soft (Co73Si27) and hard (NdCo5) magnetic materials with in-plane and out-of-plane magnetic anisotropies, respectively. They have been microstructured in a square lattice of CoSi anti-dots with NdCo dots within the holes. The magnetic properties of the dots allow us to introduce a magnetostatic stray field that can be controlled in direction and sense by their last saturating magnetic field. The magnetostatic interactions between dot and anti-dot layers induce a completely tunable exchange bias-like shift in the system's hysteresis loops. Two different regimes for this shift are present depending on the lattice parameter of the microstructures. For large parameters, dipolar magnetostatic decay is observed, while for the smaller one, the interaction between the adjacent anti-dot's characteristic closure domain structures enhances the exchange bias-like effect as clarified by micromagnetic simulations.

Automatized and desktop AC-susceptometer for the in situ and real time monitoring of magnetic nanoparticles' synthesis by coprecipitation.

The main purpose of this work was to design, develop, and construct a simple desktop AC susceptometer to monitor in situ and in real time the coprecipitation synthesis of magnetic nanoparticles. The design incorporates one pair of identical pick-up sensing coils and one pair of Helmholtz coils. The picked up signal is detected by a lock-in SR850 amplifier that measures the in- and out-of-phase signals. The apparatus also includes a stirrer with 45°-angle blades to promote the fast homogenization of the reaction mixture. Our susceptometer has been successfully used to monitor the coprecipitation reaction for the synthesis of iron oxide nanoparticles.

Influence of working length and apical preparation size on apical bacterial extrusion during reciprocating instrumentation.

AIM: To evaluate the influence of reciprocating single-file instrumentation with different working lengths (WL) and apical preparation sizes on apical bacterial extrusion. METHODOLOGY: Sixty-eight human single-rooted pre-molars were used. Conventional access cavities were prepared, and the root canals were contaminated with an Enterococcus faecalis suspension and incubated at 37°C for 30 days. Teeth were then divided into four groups of 15 specimens each (Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen). Positive and negative controls consisted of four infected and four uninfected pre-molars that were instrumented according to each experimental group. Bacteria extruded from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbiological samples were then incubated in a brain-heart agar medium for 24 h. The resulting bacterial titre, in colony-forming units (CFU) per mL, was determined, and these data were analysed using a Wilcoxon matched-pairs signed rank test and a Kruskal-Wallis H-test. The level of significance was set at α = 0.05. RESULTS: No growth was observed in the negative control group. All positive controls demonstrated bacterial growth after the experimental time interval. No significant difference was found in the number of CFU amongst all experimental groups (P = 0.95). CONCLUSIONS: This study showed that the WL and the apical preparation size did not have a significant effect on bacterial extrusion when performing reciprocating instrumentation.

Muscle hyperalgesia induced by peripheral P2X3 receptors is modulated by inflammatory mediators.

ATP, via activation of P2X3 receptors, has been highlighted as a key target in inflammatory hyperalgesia. Therefore, the aim of this study was to confirm whether the activation of P2X3 receptors in the gastrocnemius muscle of rats induces mechanical muscle hyperalgesia and, if so, to analyze the involvement of the classical inflammatory mediators (bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines and neutrophil migration) in this response. Intramuscular administration of the non-selective P2X3 receptor agonist α,ß-meATP in the gastrocnemius muscle of rats induced mechanical muscle hyperalgesia, which, in turn, was prevented by the selective P2X3 and P2X2/3 receptors antagonist A-317491, the selective bradykinin B1-receptor antagonist Des-Arg9-[Leu8]-BK (DALBK), the cyclooxygenase inhibitor indomethacin, the ß1- or ß2-adrenoceptor antagonist atenolol and ICI 118,551, respectively. Also, the nonspecific selectin inhibitor fucoidan. α,ß-meATP induced increases in the local concentration of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin 1ß (IL-1ß), which were reduced by bradykinin antagonist. Finally, α,ß-meATP also induced neutrophil migration. Together, these findings suggest that α,ß-meATP induced mechanical hyperalgesia in the gastrocnemius muscle of rats via activation of peripheral P2X3 receptors, which involves bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines release and neutrophil migration. It is also indicated that bradykinin is the key modulator of the mechanical muscle hyperalgesia induced by P2X3 receptors. Therefore, we suggest that P2X3 receptors are important targets to control muscle inflammatory pain.

Peripheral P2X7 receptor-induced mechanical hyperalgesia is mediated by bradykinin.

P2X7 receptors play an important role in inflammatory hyperalgesia, but the mechanisms involved in their hyperalgesic role are not completely understood. In this study, we hypothesized that P2X7 receptor activation induces mechanical hyperalgesia via the inflammatory mediators bradykinin, sympathomimetic amines, prostaglandin E2 (PGE2), and pro-inflammatory cytokines and via neutrophil migration in rats. We found that 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate triethylammonium salt (BzATP), the most potent P2X7 receptor agonist available, induced a dose-dependent mechanical hyperalgesia that was blocked by the P2X7 receptor-selective antagonist A-438079 but unaffected by the P2X1,3,2/3 receptor antagonist TNP-ATP. These findings confirm that, although BzATP also acts at both P2X1 and P2X3 receptors, BzATP-induced hyperalgesia was mediated only by P2X7 receptor activation. Co-administration of selective antagonists of bradykinin B1 (Des-Arg(8)-Leu(9)-BK (DALBK)) or B2 receptors (bradyzide), ß1 (atenolol) or ß2 adrenoceptors (ICI 118,551), or local pre-treatment with the cyclooxygenase inhibitor indomethacin or the nonspecific selectin inhibitor fucoidan each significantly reduced BzATP-induced mechanical hyperalgesia in the rat hind paw. BzATP also induced the release of the pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, IL-6 and cytokine-induced neutrophil chemoattractant-1 (CINC-1), an effect that was significantly reduced by A-438079. Co-administration of DALBK or bradyzide with BzATP significantly reduced BzATP-induced IL-1ß and CINC-1 release. These results indicate that peripheral P2X7 receptor activation induces mechanical hyperalgesia via inflammatory mediators, especially bradykinin, which may contribute to pro-inflammatory cytokine release. These pro-inflammatory cytokines in turn may mediate the contributions of PGE2, sympathomimetic amines and neutrophil migration to the mechanical hyperalgesia induced by local P2X7 receptor activation.

Investigation of complexity of the instruction manuals for electrical coffeepots.

BACKGROUND: Electrical coffeepots are commonly used in professional and residential environments. Their instruction manuals are related to issues that involve the user's safety and ability to operate the machine correctly. To provide the best product performance to the user, one must indicate or inform the correct usability, to turn the interaction easier. OBJECTIVE: This research proposes to investigate the instruction manuals of the electrical coffeepots. METHODS: Four coffee pot instruction manuals were analyzed in relation to the complexity through the heuristic evaluation. For that, eight experts of the Graphic Design were chosen to answer twenty four questions with the aim of analyzing: images; texts; layout development; information and warnings. RESULTS: This study shows the results of the 04 (four) items analyzed: a) images; b) texts; c) layout development; d) information and warnings, together with the suggestions of improvements for each manual. CONCLUSIONS: It is believed that the methodological procedures for the application of the heuristic evaluation have facilitated the diagnosis of fragilities and barriers that the users find during the interaction with electrical coffeepot manuals.

Correlations among magnetic, electrical and magneto-transport properties of NiFe nanohole arrays.

In this work, we use anodic aluminum oxide (AAO) templates to build NiFe magnetic nanohole arrays. We perform a thorough study of their magnetic, electrical and magneto-transport properties (including the resistance R(T), and magnetoresistance MR(T)), enabling us to infer the nanohole film morphology, and the evolution from granular to continuous film with increasing thickness. In fact, different physical behaviors were observed to occur in the thickness range of the study (2 nm < t < 100 nm). For t < 10 nm, an insulator-to-metallic crossover was visible in R(T), pointing to a granular film morphology, and thus being consistent with the presence of electron tunneling mechanisms in the magnetoresistance. Then, for 10 nm < t < 50 nm a metallic R(T) allied with a larger anisotropic magnetoresistance suggests the onset of morphological percolation of the granular film. Finally, for t > 50 nm, a metallic R(T) and only anisotropic magnetoresistance behavior were obtained, characteristic of a continuous thin film. Therefore, by combining simple low-cost bottom-up (templates) and top-down (sputtering deposition) techniques, we are able to obtain customized magnetic nanostructures with well-controlled physical properties, showing nanohole diameters smaller than 35 nm.

Tailoring the physical properties of thin nanohole arrays grown on flat anodic aluminum oxide templates.

The introduction of voids in a magnetic thin-film alters the stray field distribution and enables the tailoring of the corresponding physical properties. Here we present a detailed study on thin magnetic nanohole arrays (NhAs) grown on top of hexagonally-ordered anodic aluminum oxide (AAO) substrates. We address the effect of AAO topography on the corresponding electrical and magneto-transport properties. Optimization of the AAO topography led to NhAs with improved resistance and magnetoresistance responses, while retaining their most important feature of enhanced coercivity. This opens new pathways for the growth of more complex structures on AAO substrates, a crucial aspect for their technological viability.

Magnetic behavior of high density arrays of Co bars with strong magnetostatic coupling.

Magnetization reversal processes have been analyzed by Magnetic Force Microscopy in dense arrays of Co bars with well defined shape anisotropy and strong magnetostatic interactions. Two different geometries have been used: rectangular and rhombic so that the sign of dipolar interactions between adjacent chains of bars is changed from antiferromagnetic (rectangular array) to ferromagnetic (rhombic array), having a profound influence on the shape of a nucleus of inversion at the magnetization reversal.

Resonant tunneling through electronic trapping states in thin MgO magnetic junctions.

We report an inelastic electron tunneling spectroscopy study on MgO magnetic junctions with thin barriers (0.85-1.35 nm). Inelastic electron tunneling spectroscopy reveals resonant electronic trapping within the barrier for voltages V>0.15 V. These trapping features are associated with defects in the barrier crystalline structure, as confirmed by high-resolution transmission electron microscopy. Such defects are responsible for resonant tunneling due to energy levels that are formed in the barrier. A model was applied to determine the average location and energy level of the traps, indicating that they are mostly located in the middle of the MgO barrier, in accordance with the high-resolution transmission electron microscopy data and trap-assisted tunneling conductance theory. Evidence of the influence of trapping on the voltage dependence of tunnel magnetoresistance is shown.

Versatile, high sensitivity, and automatized angular dependent vectorial Kerr magnetometer for the analysis of nanostructured materials.

Magneto-optical Kerr effect (MOKE) magnetometry is an indispensable, reliable, and one of the most widely used techniques for the characterization of nanostructured magnetic materials. Information, such as the magnitude of coercive fields or anisotropy strengths, can be readily obtained from MOKE measurements. We present a description of our state-of-the-art vectorial MOKE magnetometer, being an extremely versatile, accurate, and sensitivity unit with a low cost and comparatively simple setup. The unit includes focusing lenses and an automatized stepper motor stage for angular dependent measurements. The performance of the magnetometer is demonstrated by hysteresis loops of Co thin films displaying uniaxial anisotropy induced on growth, MnIr/CoFe structures exhibiting the so called exchange bias effect, spin valves, and microfabricated flux guides produced by optical lithography.

Atividade antifúngica do extrato aquoso de Arctium minus (Hill) Bernh. (Asteraceae) sobre espécies orais de Candida / Antifungal activity of the aqueous extract from Arctium minus (Hill) Bernh. (Asteraceae) on oral Candida species

Este estudo teve como objetivo avaliar a atividade antifúngica do extrato aquoso de folhas de "bardana" [Arctium minus (Hill) Bernh.], por meio da determinação da Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) sobre diferentes espécies e linhagens do gênero Candida. Foram incluídas no trabalho as espécies de Candida albicans, C. tropicalis, C. glabrata, C. stellatoidea, C. dubliniensis e C. krusei. Utilizaram-se quatro linhagens de C. albicans e três de C.tropicalis, enquanto que para as demais espécies, apenas uma linhagem foi testada. Estas leveduras foram utilizadas no estudo devido à importância e frequência na cavidade bucal. As leveduras foram submetidas a tratamentos com concentrações do extrato aquoso que variaram de 0,09 a 25 mg mL-1. Os resultados indicaram que concentrações inferiores a 12,5 mg mL-1 não são suficientes para apresentar efeito fungistático ou fungicida. A concentração de 12,5 mg mL-1 apresentou efeito fungistático sobre a maioria das linhagens e espécies testadas (C. albicans 04A e ATCC44858; C. tropicalis 23600 e 23651; C. glabrata; C. stellatoideia; C. dubliniensis e C. krusei). Entretanto, efeito fungicida foi observado apenas sobre a espécie C. krusei (CFM=12,5 mg mL-1). Comportamento diferenciado foi observado entre diferentes linhagens de uma espécie (para C. albicans e C. tropicalis). Assim, a ação antifúngica do extrato aquoso de A. minus (Hill) Bernh. provavelmente está associada à variabilidade genética existente entre as diferentes linhagens de uma mesma espécie e das diferentes espécies, sendo que concentrações inferiores a 12,5 mg mL-1 não apresentaram efeito sobre as leveduras testadas. Com base na metodologia empregada e dentro das limitações deste estudo, conclui-se que o extrato aquoso de A. minus revelou efeito antifúngico, principalmente fungistático, contra espécies de Candida orais. Porém, novos estudos são necessários para avaliar o seu real potencial antifúngico dentro do meio bucal.

This study aimed to evaluate the antifungal activity of the aqueous extract from leaves of burdock [Arctium minus (Hill) Bernh.] by determining the Minimum Inhibitory Concentration (MIC) and the Minimum Fungicidal Concentration (MFC) on different species and strains of Candida genus. The species Candida albicans, C. tropicalis, C. glabrata, C. stellatoidea, C. dubliniensis, and C. Krusei were included in this study. Four C. albicans and three C. tropicalis strains were used, whereas only one strain of each remaining species was tested. Such yeasts were used in this study due to their importance and frequency in the oral cavity. The yeasts were subjected to treatments with aqueous extract concentrations that ranged from 0.09 to 25 mg mL-1. Concentrations lower than 12.5 mg mL-1 were not enough to present fungicidal or fungistatic effect. The concentration of 12.5 mg mL-1 had fungistatic effect on most tested strains and species (C. albicans 04A and ATCC44858; C. tropicalis 23600 and 23651; C. glabrata; C. stellatoideia; C. dubliniensis; and C. krusei). However, fungicidal effect was only observed on the species C. krusei (MFC=12.5 mg mL-1). A distinct performance was observed among different strains from the same species (for C. albicans and C. tropicalis). Thus, the antifungal action of A. minus (Hill) Bernh. aqueous extract is probably associated with the genetic variability present among the different strains of one same species and among different species; besides, concentrations lower than 12,5 mg mL-1 did not have an effect on the tested yeasts. The adopted methodology and considering the limitations of this study led to the conclusion that the aqueous extract of A. minus presented antifungal effect, mainly fungistatic, against oral Candida species. However, new studies are needed to evaluate its real antifungal potential inside the oral environment.

Influence of pinholes on MgO-tunnel junction barrier parameters obtained from current-voltage characteristics.

Magnetic tunnel junctions (MTJs) with thin barriers are already used as read sensors in recording media. However, the presence of pinholes across such few A thick barriers cannot be excluded and one needs to investigate their effect on the MTJ-transport properties. By applying large electrical currents we could change the electrical resistance of the studied MgO MTJs (due to pinhole-size variations), and study how pinholes influence the barrier parameters (thickness t and height phi) obtained by fitting current-voltage characteristics to Simmons' model. We found that, with decreasing resistance, the barrier thickness (height) decreases (increases). These results were well reproduced by a model of parallel-resistances, allowing us to estimate pinhole-free barrier parameters.

Synthesis of (Ca,Nd)TiO3 powders by complex polymerization, Rietveld refinement and optical properties.

Neodymium calcium titanate, (Ca(0.99)Nd(0.01))TiO(3) powders were synthesized by the complex polymerization method and heat treated at different temperatures for 2 h under air atmosphere. The structural evolution of these powders as a function of heat treatment temperature was analyzed by X-ray diffraction (XRD) and micro-Raman (MR) spectroscopy. The optical properties were investigated by Ultraviolet-visible (UV-vis) absorption spectroscopy and Photoluminescence (PL) measurements. XRD patterns, Rietveld refinement and MR spectra indicated that the powders heated treated at 750 degrees C for 2 h present an orthorhombic structure without secondary phases. UV-vis measurements suggested the presence of intermediary energy in disordered (Ca(0.99)Nd(0.01))TiO(3) powders. Broad and narrow bands were observed in the PL spectra of these powders when excited with 350 nm wavelength. The broad bands were associated to the structural defects and/or p-d electronic transitions while, the narrow bands were ascribed to f-f transitions arising from Nd(3+) ions.

[First autochthonous cases, caused by the Dengue-3 serotype in Federal District, Brazil]. / Apparition des premiers cas autochtones causes par le sérotype Dengue-3 dans le District fédéral, Brésil.

During the first four months of 2003, the survey laboratory of the Federal District (LACEN Laboratory of Virology), Brasília, Brazil, isolated ten strains of dengue virus serotype 3, five of them autochthonous, and the remaining ones from cases imported from Tocantins, Goias and Bahia States. The virus isolations were performed in C6/36 cell culture inoculated with total blood collected between the 1st and the 5th days after the onset of the symptoms. The age of the patients varied from 26 to 59 years old. The strains were typed as DEN-3 by indirect immunofluorescence assay using serotype-specific monoclonal antibodies. Viral RNAs were extracted from total blood using the trizol method. The nested RT-PCR method detected DNA products of 290 bp, confirming the serotype identifications. The introduction of DEN-3 in Brazil and especially in the Federal District represents a serious threat, since most people are susceptible to this serotype and many have already been infected by serotypes DEN-1 or DEN-2, thus increasing the risk of epidemic of more severe forms of the disease. The use of a fast and reliable method for continuous monitoring of the circulation of this serotype is of primary importance for the prevention and control of future epidemics.

Effect of direct fetal opioid analgesia on fetal hormonal and hemodynamic stress response to intrauterine needling.

BACKGROUND: Whether the fetus can experience pain remains controversial. During the last half of pregnancy, the neuroanatomic connections for nociception are in place, and the human fetus mounts sizable stress responses to physical insults. Analgesia has been recommended for intrauterine procedures or late termination, but without evidence that it works. The authors investigated whether fentanyl ablates the fetal stress response to needling using the model of delayed interval sampling during intrahepatic vein blood sampling and transfusion in alloimmunized fetuses undergoing intravascular transfusion between 20 and 35 weeks. METHODS: Intravenous fentanyl (10 microg/kg estimated fetal weight x 1.25 placental correction) was given once at intrahepatic vein transfusion in 16 fetuses, and changes (posttransfusion - pretransfusion) in beta endorphin, cortisol, and middle cerebral artery pulsatility index were compared with intrahepatic vein transfusions without fentanyl and with control transfusions at the placental cord insertion. RESULTS: Fentanyl reduced the beta endorphin (mean difference in changes, -70.3 pg/ml; 95% confidence interval, -121 to -19.2; P = 0.02) and middle cerebral artery pulsatility index response (mean difference, 0.65; 95% confidence interval, 0.26-1.04; P = 0.03), but not the cortisol response (mean difference, -10.9 ng/ml, 95% confidence interval, -24.7 to 2.9; P = 0.11) in fetuses who had paired intrahepatic vein transfusions with and without fentanyl. Comparison with control fetuses transfused without fentanyl indicated that the beta endorphin and cerebral Doppler response to intrahepatic vein transfusion with fentanyl approached that of nonstressful placental cord transfusions. CONCLUSIONS: The authors conclude that intravenous fentanyl attenuates the fetal stress response to intrahepatic vein needling.

Fetal hypothalamic-pituitary-adrenal stress responses to invasive procedures are independent of maternal responses.

Paired fetal and maternal samples were obtained, at fetal blood sampling and intrauterine transfusion, to study hypothalamic-pituitary-adrenal stress responses. This confirmed that the fetus mounts an hypothalamic-pituitary-adrenal stress response to transfusion via the intrahepatic vein, which involves piercing the fetal trunk, but not to transfusion via the placental cord insertion [mean cortisol response via intrahepatic vein delta = 52.6 nmol/L, 95% CI (25.3-79.9), P = 0.001; mean beta-endorphin response delta =106 pg/mL, 95% CI (45.3-167), P = 0.002]. Baseline maternal fetal ratios were 13 [95% CI (10.7-15.2)] for cortisol and 0.8 [95% CI (0.5-1.0)] for beta-endorphin. The novel findings were: 1) that the fetal responses were independent of those of the mother, which did not change during transfusion at either site; 2) that there was a correlation between baseline fetal and maternal cortisol levels (r = 0.58, n = 51, P < 0.0001) but not between baseline fetal and maternal ss-endorphin levels, suggesting cortisol transfer across the placenta, rather than joint control by placental CRH; and 3) that fetal beta-endorphin responses were apparent from 18 weeks gestation and independent of gestational age, whereas fetal cortisol responses were apparent from 20 weeks gestation and were dependent on gestational age (y = -91.4 + 5.08x, r = 0.51; n = 16; P = 0.04; CI for slope, 0.16-10.0), consistent with the maturation of the fetal pituitary before the fetal adrenal.

First isolation of dengue 1 virus from Aedes aegypti in Federal District, Brazil.

Dengue is present in the Federal District since 1991 and virological studies of the vector began in 1998. Two strains of DEN1 were isolated from 9 pools of female Aedes aegypti (78 mosq.), collected in April in Gama county, where the Breteau index was 5.4, and 32 autochtonous human cases were notified.