Involvement of median raphe nucleus 5-HT1A receptors in the regulation of generalized anxiety-related defensive behaviours in rats

Changes in 5-HT1A receptor-mediated neurotransmission at the level of the median raphe nucleus (MRN) are reported to affect the expression of defensive responses that are associated with generalized anxiety disorder (e.g. inhibitory avoidance) but not with panic (e.g. escape). The objective of this study was to further explore the involvement of MRN 5-HT1A receptors in the regulation of generalized anxiety-related behaviours. Results of experiment 1 showed that intra-MRN injection of the 5-HT1A/7 receptor agonist 8-OH-DPAT (0.6 nmol) in male Wistar rats impaired the acquisition of inhibitory avoidance, without interfering with the performance of escape in the elevated T-maze test of anxiety. Pre-treatment with the 5-HT1A receptor antagonist WAY-100635 (0.18 nmol) fully blocked this anxiolytic-like effect. As revealed by experiment 2, intra-MRN injection of 8-OH-DPAT (0.6, 3 or 15 nmol) also caused anxiolytic effect in rats submitted to the light-dark transition test, another animal model that has been associated with generalized anxiety. In the same test, intra-MRN injection of WAY-100635 (0.18, 0.37 or 0.74 nmol) caused the opposite effect. Overall, the current findings support the view that MRN 5-HT neurons, through the regulation of 5-HT1A somatodendritic autoreceptors, are implicated in the regulation of generalized anxiety-associated behaviours. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Involvement of the lateral habenula in the regulation of generalized anxiety- and panic-related defensive responses in rats

Recently obtained evidence points to the involvement of the lateral habenular nuclei (LHb) in the mediation of coping defensive responses to threatening/stressful stimuli. Nevertheless, the role of this brain area in the regulation of defensive responses that have been associated with specific subtypes of anxiety disorders recognized in clinical settings is presently unknown. To address this question, we investigated the effects of either electrolytic lesions or chemical stimulation of the LHb on the defensive behaviors generated in rats by the elevated T-maze. This experimental model allows the measurement, in a same rat, of two defensive behaviors, inhibitory avoidance and escape, that have been related in terms of psychopathology to generalized anxiety and panic disorders, respectively. Bilateral electrolytic lesions of the LHb (1 mA, 10 s) impaired inhibitory avoidance acquisition and facilitated escape performance. On the other hand, chemical stimulation of the LHb by bilateral microinjection of kainic acid (30-60 pmol/0.2 mu L) had the opposite effect, i.e., facilitated inhibitory avoidance and impaired escape. The present results indicate that the LHb exerts an opposed regulatory control on generalized anxiety- and panic-related defensive responses in rats. (c) 2008 Elsevier Inc. All rights reserved.

Distribution of Hemoglobin Phenotypes in Four Different Districts of Porto Velho, Rondonia, Brazil

Hemoglobin profile studies have been carried out in four samples from different districts of Porto Velho (Rondonia State) in the western Amazonian region of Brazil: Candelaria, Bate Estaca, Hemeron (at the State Blood Bank), and Sao Carlos. Samples from 337 unrelated individuals were collected during medical and paramedical team visits by professionals from the Instituto de Pesquisa em Patologia Tropical and the Centro de Pesquisa em Patologias Tropicais (both research institutes in tropical diseases). The aim of this study is to assess the frequency of alleles in the hemoglobin system, mainly alleles HB*A, *S, and *E. The overall phenotype frequencies were FIB A,S = 0.025, HB A,E = 0.006, and HB A,A = 0.969. Samples from the blood bank subjects and samples from the homogeneous areas of Silo Carlos and Candelaria plus Bate Estaca have a chi-square of heterogeneity of 6.383 (p = 0.041) and 8.406 (p = 0.015), respectively. The allele frequencies (HB*A = 0.984, HB*S = 0.012, and HB*E = 0.003) do not significantly differ from frequencies found in other Brazilian regions.

Distribution of fentanyl in the placental intervillous space and in the different maternal and fetal compartments in term pregnant women

Fentanyl is used in obstetrical practice to promote analgesia and anesthesia during labor and in cesarean delivery, with rapid and short-term effects. To determine fentanyl concentrations in maternal plasma, in the placental intervillous space, and in the umbilical artery and vein in term pregnant women. Ten healthy pregnant women underwent epidural anesthesia with fentanyl plus bupivacaine and lidocaine, and fentanyl concentrations were determined in the various maternal and fetal compartments, including the placental intervillous space, which has not been previously studied in the literature. The ratios of fentanyl concentrations in the various maternal and fetal compartments revealed an 86% rate of placental fentanyl transfer. The highest fentanyl concentrations were detected in the placental intervillous space, being 2.19 times higher than in maternal plasma, 2.8 times higher than in the umbilical vein and 3.6 times higher than in the umbilical artery, with no significant differences between the umbilical vein and artery, demonstrating that there was no drug uptake by fetal tissues nor metabolism of the drug by the fetus despite the high rates of placental transfer. The present study demonstrated that the placental intervillous space acted as a site of fentanyl deposit, a fact that may be explained by two hypotheses: (1) the blood collected from the placental intervillous space is arterial and, according to some investigators, the arterial plasma concentrations of the drugs administered to patients undergoing epidural anesthesia are higher than the venous concentrations, and (2) a possible role of P-glycoprotein (P-gp).

Distribution of Bupivacaine Enantiomers and Lidocaine and Its Metabolite in the Placental Intervillous Space and in the Different Maternal and Fetal Compartments in Term Pregnant Women

The aim of this study is to determine the concentrations of lidocaine and its metabolite, monoethylglycine xylidide (MEGX), and of the enantiomers of bupivacaine in maternal and fetal compartments. Ten healthy pregnant women were submitted to epidural anesthesia. Drug concentrations were determined in the maternal vein, fetal umbilical artery and vein, and the placental intervillous space. The highest concentrations of the bupivacaine enantiomers lidocaine and of lidocaine and of its MEGX metabolite were detected in maternal plasma and in the placental intervillous space. The placental transfer was 33% for the (+)-(R)-bupivacaine enantiomer and 31% for the (-)-(S)-bupivacaine enantiomer. For lidocaine and its MEGX metabolite, respective placental transfers were 60% and 43%. Lidocaine concentration in the fetal umbilical vein was 1.46 times higher than in the fetal umbilical artery. The highest concentrations of lidocaine and its metabolite and of the enantiomers of bupivacaine were detected in the placental intervillous space. The higher lidocaine concentrations in the fetal umbilical vein than in the fetal umbilical artery suggest that there was tissue uptake of the drug or drug metabolization by the fetus.

Temporal distribution of trauma deaths: Quality of trauma care in a developing country

Background: Examination of the epidemiology and timing of trauma deaths has been deemed a useful method to evaluate the quality of trauma care. Objective: The purpose of this study was to evaluate the quality of trauma care in a regional trauma system and in a university hospital in Brazil by comparing the timing of deaths in the studied prehospital and in-hospital settings to those published for trauma systems in other areas. Methods: We analyzed the National Health Minister`s System of Deaths Information for the prehospital mortality and we retrospectively collected the demographics, timelines, and trauma severity scores of all in-hospital patients who died after admission through the Emergency Unit of Hospital das Clinicas de Ribeirao Preto between 2000 and 2001. Results. During the study period, there were 787 trauma fatalities in the city: 448 (56.9%) died in the prehospital setting and 339 (43.1%) died after being admitted to a medical facility. In 2 years, 238 trauma deaths occurred in the studied hospital, and we found a complete clinical set of data for 224 of these patients. The majority of deaths in the prehospital setting were caused by penetrating injuries (66.7%), whereas in-hospital mortality was mainly because of blunt traumas (59.1%). The largest number of in-hospital deaths occurred beyond 72 hours of stay (107 patients-47%). Conclusions: The region studied showed some deficiencies in prehospital and in-hospitals settings, in particular in the critical care and short-term follow-up of trauma patients when compared with the literature. Particularly, the late mortality may be related to training and human resources deficiency. Based on the timeline of trauma deaths, we can suggest that the studied region needs improvements in the prehospital trauma system and in hospital critical care.

Asymmetric page split generalized index search trees for formal concept analysis

Formal Concept Analysis is an unsupervised machine learning technique that has successfully been applied to document organisation by considering documents as objects and keywords as attributes. The basic algorithms of Formal Concept Analysis then allow an intelligent information retrieval system to cluster documents according to keyword views. This paper investigates the scalability of this idea. In particular we present the results of applying spatial data structures to large datasets in formal concept analysis. Our experiments are motivated by the application of the Formal Concept Analysis idea of a virtual filesystem [11,17,15]. In particular the libferris [1] Semantic File System. This paper presents customizations to an RD-Tree Generalized Index Search Tree based index structure to better support the application of Formal Concept Analysis to large data sources.

Reference distribution of the bioelectrical impedance vector in healthy term newborns

Bioelectrical impedance vector analysis (BIVA) is a new method that is used for the routine monitoring of the variation in body fluids and nutritional status with assumptions regarding body composition values. The aim of the present study was to determine bivariate tolerance intervals of the whole-body impedance vector and to describe phase angle (PA) values for healthy term newborns aged 7-28 d. This descriptive cross-sectional study was conducted on healthy term neonates born at a low-risk public maternity. General and anthropometric neonatal data and bioelectrical impedance data (800 mu A-50 kHz) were obtained. Bivariate vector analysis was conducted with the resistance-reactance (RXc) graph method. The BIVA software was used to construct the graphs. The study was conducted on 109 neonates (52.3% females) who were born at term, adequate for gestational age, exclusively breast-fed and aged 13 (SD 3.6) d. We constructed one standard, reference, RXc-score graph and RXc-tolerance ellipses (50, 75 and 95 %) that can be used with any analyser. Mean PA was 3.14 (SD 0.43)degrees (3.12 (SD 0.39)degrees for males and 3.17 (SD 0.48)degrees for females). Considering the overlapping of ellipses of males and females with the general distribution, a graph for newborns aged 7-28 d with the same reference tolerance ellipse was defined for boys and girls. The results differ from those reported in the literature probably, in part, due to the ethnic differences in body composition. BIVA and PA permit an assessment without the need to know body weight and the prediction error of conventional impedance formulas.

Sensitivity and uncertainty analyses for burden of disease and risk factor estimates

Epidemiological studies report confidence or uncertainty intervals around their estimates. Estimates of the burden of diseases and risk factors are subject to a broader range of uncertainty because of the combination of multiple data sources and value choices. Sensitivity analysis can be used to examine the effects of social values that have been incorporated into the design of the disability–adjusted life year (DALY). Age weight, where a year of healthy life lived at one age is valued differently from at another age, is the most controversial value built into the DALY. The discount rate, which addresses the difference in value of current versus future health benefits, also has been criticized. The distribution of the global disease burden and rankings of various conditions are largely insensitive to alternate assumptions about the discount rate and age weighting. The major effects of discounting and age weighting are to enhance the importance of neuropsychiatric conditions and sexually transmitted infections. The Global Burden of Disease study also has been criticized for estimating mortality and disease burden for regions using incomplete and uncertain data. Including uncertain results, with uncertainty quantified to the extent possible, is preferable, however, to leaving blank cells in tables intended to provide policy makers with an overall assessment of burden of disease. No estimate is generally interpreted as no problem. Greater investment in getting the descriptive epidemiology of diseases and injuries correct in poor countries will do vastly more to reduce uncertainty in disease burden assessments than a philosophical debate about the appropriateness of social value

Prevalence of Neospora caninum antibodies in cattle from Santarem, Para, Brazil

Prevalence of anti-Neospora caninum antibodies was measured in serum samples randomly collected from dairy (40 cows from four farms) and beef cattle (120 animals from 12 farms) from the municipality of Santarem, Para State, Brazil, calculated by using the Win Episcope 2.0 statistical program. The presence of anti-N. caninum antibodies was determined by indirect immunofluorescence-antibody test with a cut-off value of 1: 100. We found that 13 farms (81.25%) showed infection rates above 10%, which indicates widespread distribution of M caninum in the region. The frequency per animal was 19%. No difference was observed between the prevalence values in dairy and beef animals or between farms, which was probably due to the small number of dairy farms examined. The results confirm, for the first time, the presence of anti-N. caninum antibodies in cattle from Para State and the necessity to further investigate the epidemiology of M caninum in the Amazon region. (c) 2007 Elsevier Ltd. All rights reserved.

Genetic analysis of ticks belonging to the Rhipicephalus sanguineus group in Latin America

Phylogenetic analyses based on mitochondrial 16S rDNA sequences were generated from Rhipicephalus sanguineus group specimens collected in 29 localities among 9 Latin-American countries, plus ticks collected in South Africa, Spain, and Italy. Sequences from Latin America generated six different haplotypes (A, B, C, D, E, and F). Phylogenetic analyses generated trees that segregated our tick sequences into two distinct clades: one is represented by haplotypes A-C, and South African R. sanguineus and Rhipicephalus turanicus ticks; the second clade is represented by haplotypes D-F, and European R. sanguineus and R. turanicus ticks. When haplotypes A-Fare plotted in the Latin America map according to their geographical coordinates, it is clearly seen that haplotypes D-F are restricted to the southern portion of this continent, whereas haplotypes A-C are distributed in areas between northern Mexico and Brazil (except for the extreme south of this last country, where haplotype E was present). Hence, our phylogenetic analyses separated New World specimens of R. sanguineus into two distinct clades, one represented by tropical and subtropical populations (haplotypes A-C), here designated as the `tropical` species. On the other hand, haplotypes D-F are here designated as the `temperate` species because of their distribution in the southern portion of South America. Until recently, it was assumed that the R. sanguineus group was represented by a single species in the New World, namely R. sanguineus. While the present results coupled with recent studies support the presence of at least two species under the taxon R. sanguineus in the New World, they also show that even in the Old World, the taxon R. sanguineus might be represented by more than one species, since our phylogenetic analysis segregated European and South African R. sanguineus ticks into two distinct clades. The same can be applied for Spanish and South African R. turanicus. (C) 2010 Elsevier B.V. All rights reserved.