Encapsulated Essential Oils as an Alternative to Insecticides in Funnel Traps.

Pheromone-lured funnel traps are widely used for pest monitoring and mass trapping in agricultural fields and stores. DDVP vapona (dichlorvos), the insecticide of choice as a killing agent inside traps, has been banned, and research on new products is being pursued. Essential oils (EO) could be an alternative if properly formulated. To test their potential, beads of encapsulated coriander and basil EO were tested in funnel traps in stores of almonds and pet foods during 2 mo. The number of adult moth (Plodia interpunctella (Hübner) and Ephestia kuehniella Zeller) dead captures was similar with either coriander or basil EO beads and with vapona tablets while there were more insects alive in the control. These preliminary results indicate a good potential for the development of such natural products as an alternative to synthetic insecticides to include them inside funnel traps.

Burnout prevalence and correlates amongst Colombian dental students: the STRESSCODE study.

INTRODUCTION: Accumulating evidence amongst dental students indicates an alarming prevalence of stress, which can precipitate the development of burnout--a state of mental or physical exhaustion and disengagement. Understanding individual and educational correlates of burnout is necessary for its prevention. The aims of this study were to determine the prevalence of burnout amongst a large sample of Colombian dental undergraduates and investigate its psychosocial and educational correlates. MATERIALS AND METHODS: Survey data collected from 5647 students participating in the Stress in Colombian Dental Education study were used for this analysis. Burnout was measured using the Maslach Burnout Inventory-Student Survey (MBI-SS). Covariates included participants' socio-demographic characteristics and perceived stress, as well as educational environment factors. Descriptive, bivariate and multivariate methods based on multilevel mixed-effects logistic regression modelling were used for data analysis. RESULTS: Seven per cent of the students surveyed met the criteria for burnout. The prevalence of burnout was higher amongst upper classes, older and married students, those who reported not having passed all required courses and not having dentistry as their first career choice, as well as students in public institutions and those with large class sizes. Moreover, students' perceived stress in the domains of workload and self-efficacy was significantly and positively associated with burnout. CONCLUSIONS: Both personal and educational environment characteristics were found to be associated with burnout. Irrespective of these factors, students' perceived stress with regard to workload and self-efficacy was a strong influence on burnout and its alleviation may be a promising avenue to prevent psychological morbidity.

Cleavage of the MLL gene by activators of apoptosis is independent of topoisomerase II activity.

Exposure to topoisomerase II inhibitors is linked to the generation of leukemia involving translocations of the MLL gene, normally restricted to an 8.3 kbp tract, the breakpoint cluster region (BCR). Using an in vitro assay, apoptotic activators, including radiation and anti-CD95 antibody, trigger site-specific cleavage adjacent to exon 12 within the MLL BCR and promote translocation of the MLL gene in cells that can survive. To explore the mechanism of cleavage and rearrangement in more detail, the entire MLL BCR was placed into the pREP4 episomal vector and transfected into human lymphoblastoid TK6 cells. Episomes containing either the MLL BCR, or deletion constructs of 367 bp or larger, were cleaved at the same position as genomic MLL after exposure to apoptotic stimuli. Further analysis of sequence motifs surrounding the cleaved region of MLL showed the presence of both a predicted nuclear matrix attachment sequence and a potential strong binding site for topoisomerase II, flanking the site of cleavage. Inactivation of topoisomerase II by the catalytic inhibitor merbarone did not inhibit MLL cleavage, suggesting that the initial cleavage step for MLL rearrangement is not mediated by topoisomerase II.

Apoptotic triggers initiate translocations within the MLL gene involving the nonhomologous end joining repair system.

Translocations involving the MLL gene at 11q23 are a frequent finding in therapy-related leukemia and are concentrated within a short, 8.3-kb tract of DNA, the breakpoint cluster region. In addition, a specific site adjacent to exon 12 within this region of MLL is cleaved in cells undergoing apoptosis. We show here, using human TK6 lymphoblastoid cells, that irradiation and the apoptotic trigger anti-CD95 antibody are each able to initiate translocations at the MLL exon 12 cleavage site. The translocation junctions produced contain regions of microhomology consistent with operation of the nonhomologous end joining (NHEJ) repair process. Participation of the NHEJ process is supported by the identification of the NHEJ component DNA-PKcs at the site of apoptotic cleavage. Suppression of DNA-PKcs function by the phosphatidylinositol 3-kinase inhibitor wortmannin compromises DNA end joining, increases site-specific cleavage within MLL, and eliminates MLL-restricted translocations. We propose that activation of apoptotic effector nucleases alone is sufficient to generate proleukemogenic translocations and raises the possibility that some of these may persist in cells that evade apoptotic execution and survive.

Antifungal activity of the essential oil of flowerheads of garland chrysanthemum (Chrysanthemum coronarium) against agricultural pathogens.

The antifungal activity of Chrysamthemum coronarium was evaluated against 12 agricultural pathogens. Flowerhead oil was active both in contact and headspace in vitro assays producing hyphal growth inhibition, although there was less activity on faster growing fungi. The main compounds identified in the oil were camphor (29.2%), alpha-pinene (14.8%), beta-pinene (9.5%) and lyratyl acetate (9.8%). The blue color of the oil was due to the presence of chamazulene (0.5%).

Development of formulations to improve the controlled-release of linalool to be applied as an insecticide.

In recent studies, insecticide activity of a monoterpene, linalool, has been demonstrated, finding, however, limitations in application because of its rapid volatilization. Potential effectiveness of microcapsules and effects of various types of matrices on its stability as controlled-release systems for the slow volatilization of linalool to be applied as insecticide were evaluated. To study controlled-release, linalool was entrapped into microcapsules, inclusion complexes, and beads, obtained by different methods, inverse gelation (IG1, IG2, IG3, IG4, and IG5), oil-emulsion-entrapment (OEE), interfacial coacervation (INCO), and chemical precipitation (Cyc5 and Cyc10). The encapsulation yield turned out to be different for each formulation, reaching the maximum retention for IG1 and OEE. In controlled-release, OEE followed by INCO presented a long time necessary for releasing as a result of the presence of glycerol or chitosan. These results pointed out remarkable differences in the release behavior of linalool depending on matrix composition and the method of encapsulation.

The utility of the Golgi-Cox method in the morphological characterization of the autonomic innervation in the rat heart.

The autonomic innervation in the heart is predominantly by postganglionic, parasympathetic, and sympathetic neurons, which are organized in a plexus of ganglions into the heart. The knowledge of the density, distribution, location, morphology, and intrinsic connection of this system that constitute the heart autonomic innervation is limited and controversial. Methods that provide clear information in this field are desirable. A widely used method to study the morphology of the nerve cells in the central nervous system (CNS) is used in this study to characterize the autonomic innervation in rat hearts. The method consisted of impregnation of the fresh whole heart of 12 adult male Wistar rats with the Golgi-Cox stain for 30 days, after which they were incubated in 30% sucrose solution for 2-3 days and then were sectioned (200 microm) with a vibratome. The tissues were mounted on gelatin-covered slides and analyzed by using the Sholl method under light microscopy adapted to a camera lucida. The results clearly show a distribution of the ganglion plexuses in the epicardium, myocardium, and endocardium, joined by an extensive network of nerve fibers in the four cardiac chambers. We also identified and characterized the morphology of an isolated cardiac nerve cell. As results similar to that in the CNS, the Golgi-Cox method is a simple, efficient, and an accessible tool to study the autonomic innervation in the rat heart and provides a good resolution of the morphology of the plexuses of the ganglions and nerve fibers.

Surviving apoptosis.

The concept that cells subjected to chromatin cleavage during apoptosis are destined to die is being challenged. The execution phase of apoptosis is characterized by the activation of effector caspases, such as caspase-3, that cleave key regulatory or structural proteins and in particular activate apoptotic nucleases such as the caspase activated deoxyribonuclease (CAD). It is apparent that caspases of this type may become active both through non-apoptotic processing and potentially within cells that exhibit apoptotic morphology but are subsequently able to survive. In such systems caspase suppressor molecules, the inhibitors of apoptotic proteins or IAP's, may rescue cells from apoptotic nuclease(s) attack initiated by transient caspase activation. The MLL gene is involved in leukemogenic translocations in ALL and AML and is a target of nuclease cleavage during apoptosis. Translocations initiated at the site of apoptotic nuclease attack within MLL have been identified and may offer a model, with clinical relevance, for DNA damage mediated by the apoptosis system in cells destined to survive. The specificity of apoptotic cleavage combined with the potential for recovery from the execution phase of apoptosis suggests a novel and pathogenic role for apoptosis in creating translocations with leukemogenic potential.

[Changes in the vasoconstrictor action of noradrenaline and in its receptor-binding kinetics induced by sex hormones]. / Cambios en la acción vasoconstrictora de la noradrenalina y en su cinética de unión a receptores, inducidos por hormonas sexuales.

The role of testosterone/17 B estradiol ratios (T/E), on the vasoconstrictor effect of norepinephrine (NE), were studied in strips of carotid arteries from dogs. T/E of 0.1 (T = 1 nM/E = 10 nM) shifted the concentration/effect (C-E) curve of NE to the right. T/E of 10 (T = 10 nM/E = 1 nM) deviated it to the left. T (1 nM and 10 nM) shifted the C-E curve of NE to the right; E = 1 nM did not modify it; E = 10 nM, shifted it to the left. In microsomal fraction of carotid arteries, adrenergic receptors were characterized with 3H-NE binding, and the role of T/E ratios also studied. Under the influence of T/E ratio of 10, the agonist affinity (Ka), was increased from 100 nM-1 to 128 nM-1, the receptors density (Bmax), increased from 78.3 nM to 148 nM. E (1 nM) reduced Ka to 88 nM-1, T did not change any of these parameters. In conclusion, T/E ratios of 10, as in male, may enhance the vasoconstrictor activity of NE, increasing Ka and Bmax of adrenergic receptors.

[Effect of acute myocardial ischemia on pulmonary venous flow pattern. Experimental study with transesophageal echocardiography]. / Efecto de la isquemia miocárdica aguda sobre el patrón del flujo venoso pulmonar. Estudio experimental con ecocardiografía transesofágica.

Pulmonary venous flow (PVF) has been analyzed by Doppler echocardiography in various cardiopathies, but up to now no studies of its behavior in acute myocardial ischemia have been reported. The purpose of this study is to describe the changes observed in the normal pattern of PVF with myocardial ischemia in an experimental model. Thoracotomy and pericardiectomy with exposure of the heart were performed on 19 mongrel dogs, weighing between 18 and 25 kg anesthetized with intravenous sodium pentobarbital. Pulmonary venous and mitral flows were analyzed by transesophageal echocardiography with pulsed Doppler and simultaneous recording of intracavitary pressures in left atrium (LA) and left ventricle (LV) before and after 30 minutes of partial occlusion of the middle portion of the anterior descending coronary artery distal to the first diagonal branch. The variables examined included maximal velocities and time-velocity integrals of antegrade systolic(s) and diastolic (D) PVF, mitral rapid filling flow (E) and left ventricular isovolumic relaxation time (LVIRT). The pressures directly measured were mean left atrial pressure (MLAP), systolic and diastolic pressures of the LV. Results included a decrease in peak velocities and time-velocity integrals of PVF (S and D) with myocardial ischemia, S velocity from 70.1 +/- 14.8 to 49.5 +/- 13.8 cm/sec (p < 0.001) and D from 41.4 +/- 16.5 to 29.5 +/- 11.4 cm/sec (p = 0.001), with an increase in LVIRT from 65.8 +/- 8.6 to 76.0 +/- 12.6 msec (p < 0.006) and elevation of the mean pressure of the LA from 4.3 +/- 1.0 to 6.4 +/- 1.5 mmHg (p < 0.001). This findings suggest that acute myocardial ischemia alters the normal pattern of PVF, producing a significant decrease in peak velocities and time-velocity integrals of antegrade systolic and diastolic flows as well as an increase in LVIRT and MLAP, which taken together may reflect altered diastolic function of the LV.