Inhibitory network interactions shape the auditory processing of natural communication signals in the songbird auditory forebrain

The role of GABA in the central processing of complex auditory signals is not fully understood. We have studied the involvement of GABA(A)-mediated inhibition in the processing of birdsong, a learned vocal communication signal requiring intact hearing for its development and maintenance. We focused on caudomedial nidopallium (NCM), an area analogous to parts of the mammalian auditory cortex with selective responses to birdsong. We present evidence that GABA(A)-mediated inhibition plays a pronounced role in NCM`s auditory processing of birdsong. Using immunocytochemistry, we show that approximately half of NCM`s neurons are GABAergic. Whole cell patch-clamp recordings in a slice preparation demonstrate that, at rest, spontaneously active GABAergic synapses inhibit excitatory inputs onto NCM neurons via GABA(A) receptors. Multi-electrode electrophysiological recordings in awake birds show that local blockade of GABA(A)-mediated inhibition in NCM markedly affects the temporal pattern of song-evoked responses in NCM without modifications in frequency tuning. Surprisingly, this blockade increases the phasic and largely suppresses the tonic response component, reflecting dynamic relationships of inhibitory networks that could include disinhibition. Thus processing of learned natural communication sounds in songbirds, and possibly other vocal learners, may depend on complex interactions of inhibitory networks.

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.

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.

Anandamide prior to sensitization increases cell-mediated immunity in mice

The endocannabinoid system has become a topic of great interest in pharmacology due to its remarkable distribution in mammal organisms and capacity to play a modulatory role on several physiological systems, including modulation of immunity. Many studies have shown that administration of cannabinoids causes inhibitory effects on immune cells, including decreased proliferation and antigen-presenting cell (APC) costimulatory activity. In contrast, other groups have shown that some cannabinoids might present stimulatory actions on macrophage activity and T cell activation. Therefore, we aimed to investigate whether a treatment in vivo with a low dose of anandamide (0.1 mg/kg) immediately prior to sensitization would have an immunosuppressive or immunostimulatory effect on cell-mediated immunity (Th1 response) in mice. We report here that anandamide, prior to sensitization, was able to increase the Th1 response to ovalbumin in vivo and ex vivo. Anandamide increased delayed type hypersensitivity (DTH), splenocyte proliferation, and IFN-gamma production in a co-culture of adherent and non-adherent splenocytes. Moreover, anandamide prior to sensitization increased both the expression of DC co-stimulatory molecules (CD80/CD86) and IL-12/IL23 (p40) production ex vivo. We have also assessed direct effects of anandamide in the IFN-gamma/IL-4 balance of ConA-stimulated splenocytes in vitro. Anandamide at nanomolar concentrations increased the production of IFN-gamma, while such production decreased at micromolar range. Thus, anandamide induced both the increment of DC activation and IFN-gamma production, which are likely the mechanisms involved in the increase of Th1 response reported here. (C) 2010 Elsevier B.V. All rights reserved.

Network structures of Bis-GMA/TEGDMA resins differ in DC, shrinkage-strain, hardness and optical properties as a function of reducing agent

Objectives. To evaluate the influence of different tertiary amines on degree of conversion (DC), shrinkage-strain, shrinkage-strain rate, Knoop microhardness, and color and transmittance stabilities of experimental resins containing BisGMA/TEGDMA (3: 1 wt), 0.25wt% camphorquinone, 1wt% amine (DMAEMA, CEMA, DMPT, DEPT or DABE). Different light-curing protocols were also evaluated. Methods. DC was evaluated with FTIR-ATR and shrinkage-strain with the bonded-disk method. Shrinkage-strain-rate data were obtained from numerical differentiation of shrinkage-strain data with respect to time. Color stability and transmittance were evaluated after different periods of artificial aging, according to ISO 7491: 2000. Results were evaluated with ANOVA, Tukey, and Dunnett`s T3 tests (alpha = 0.05). Results. Studied properties were influenced by amines. DC and shrinkage-strain were maximum at the sequence: CQ < DEPT < DMPT <= CEMA approximate to DABE < DMAEMA. Both DC and shrinkage were also influenced by the curing protocol, with positive correlations between DC and shrinkage-strain and DC and shrinkage-strain rate. Materials generally decreased in L* and increased in b*. The strong exception was the resin containing DMAEMA that did not show dark and yellow shifts. Color varied in the sequence: DMAEMA < DEPT < DMPT < CEMA < DABE. Transmittance varied in the sequence: DEPT approximate to DABE < DABE approximate to DMPT approximate to CEMA < DMPT approximate to CEMA approximate to DMAEMA, being more evident at the wavelength of 400 nm. No correlations between DC and optical properties were observed. Significance. The resin containing DMAEMA showed higher DC, shrinkage-strain, shrinkage-strain rate, and microhardness, in addition to better optical properties. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Estimating Income Inequality in China Using Grouped Data and the Generalized Beta Distribution

There are two main types of data sources of income distributions in China: household survey data and grouped data. Household survey data are typically available for isolated years and individual provinces. In comparison, aggregate or grouped data are typically available more frequently and usually have national coverage. In principle, grouped data allow investigation of the change of inequality over longer, continuous periods of time, and the identification of patterns of inequality across broader regions. Nevertheless, a major limitation of grouped data is that only mean (average) income and income shares of quintile or decile groups of the population are reported. Directly using grouped data reported in this format is equivalent to assuming that all individuals in a quintile or decile group have the same income. This potentially distorts the estimate of inequality within each region. The aim of this paper is to apply an improved econometric method designed to use grouped data to study income inequality in China. A generalized beta distribution is employed to model income inequality in China at various levels and periods of time. The generalized beta distribution is more general and flexible than the lognormal distribution that has been used in past research, and also relaxes the assumption of a uniform distribution of income within quintile and decile groups of populations. The paper studies the nature and extent of inequality in rural and urban China over the period 1978 to 2002. Income inequality in the whole of China is then modeled using a mixture of province-specific distributions. The estimated results are used to study the trends in national inequality, and to discuss the empirical findings in the light of economic reforms, regional policies, and globalization of the Chinese economy.