984 resultados para Intrapulmonary Tidal Volume Distribution
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Several studies suggest that hypothalamic cocaine- and amphetamine-regulated transcript (CART) may interact with the hypothalamic-pituitary-adrenal (HPA) axis in the control of neuroendocrine function and may also participate in cardiovascular regulation. Therefore, this study aimed to evaluate, in experimental models of isotonic (I-EVE) and hypertonic (H-EVE) extracellular volume expansion and water deprivation (WD), the activation of CART- and corticotrophin releasing factor (CRF)-immunoreactive neurons, as well as the relative expression of CART and CRF mRNAs in the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus. Both H-EVE (0.30M NaCl, 2mL/100g of body weight, in 1 minute) and 24 hours of WD significantly increased plasma sodium concentrations, producing, respectively, either an increase or a decrease in extracellular volume. I-EVE (0.15M NaCl, 2mL/100g of body weight, in 1 minute) evoked a significant increase in the circulating volume accompanied by unaltered plasma concentrations of sodium. CART-expressing neurons of both magnocellular and parvocellular hypothalamic divisions were activated to produce Fos in response to H-EVE but not in response to I-EVE. Furthermore, increased expression of CART mRNA was found in the PVN of H-EVE but not I-EVE rats. These data show for the first time that EVE not only activates hypothalamic CRF neurons but also increases CRF mRNA expression in the PVN. In contrast, WD increases the number of CART-immunoreactive neurons activated to produce Fos in the PVN and SON but does not change the number of neurons double labeled for Fos and CRF or expression of CRF mRNA in the PVN. These findings provided new insights into the participation of CART in diverse processes within the PVN and SON, including its possible involvement in activation of the HPA axis and cardiovascular regulation in response to changes in extracellular volume and osmolality. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
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Recent evidence has shown that the serotonergic mechanism of the lateral parabrachial nucleus (LPBN) participates in the regulation of renal and hormonal responses to isotonic blood volume expansion (BVE). We investigated the BVE-induced Fos activation along forebrain and hindbrain nuclei and particularly within the serotonergic clusters of the raphe system that directly project to the LPBN. We also examined whether there are changes in the concentration of serotonin (5HT) within the raphe nucleus in response to the same stimulus. With this purpose, we analyzed the cells doubly labeled for Fos and Fluorogold (FG) following BVE (NaCl 0.15 M, 2 ml/100 g b.w., 1 min) 7 days after FG injection into the LPBN. Compared with the control group, blood volume-expanded rats showed a significant greater number of Fos-FG double-labeled cells along the nucleus of the solitary tract, locus coeruleus, hypothalamic paraventricular nucleus, central extended amygdala complex, and dorsal raphe nucleus (DRN) cells. Our study also showed an increase in the number of serotonergic DRN neurons activated in response to isotonic BVE. We also observed decreased levels of 5HT and its metabolite 5-hydroxyindoleacetic acid (measured by high-pressure liquid chromatography) within the raphe nucleus 15 min after BVE. Given our previous evidence on the role of the serotonergic system in the LPBN after BVE, the present morphofunctional findings suggest the existence of a key pathway (DRN-LPBN) that may control BVE response through the modulation of 5HT release. (c) 2008 Wiley-Liss, Inc.
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Production and secretion of testosterone in Leydig cells are mainly controlled by the luteinizing hormone (LH). Biochemical evidences suggest that the activity of Cl(-) ions can modulate the steroidogenic process, but the specific ion channels involved are not known. Here, we extend the characterization of Cl(-) channels in mice Leydig cells (50-60 days old) by describing volume- activated Cl(-) currents (I(Cl,swell)). The amplitude of I(Cl,swell) is dependent on the osmotic gradient across the cell membrane, with an apparent EC(50) of similar to 75 mOsm. These currents display the typical biophysical signature of volume- activated anion channels (VRAC): dependence on intracellular ATP, outward rectification, inactivation at positive potentials, and selectivity sequence (I(-)>Cl(-)>F(-)). Staurosporine (200 nM) did not block the activation of I(Cl), swell. The block induced by 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB; 128 mu M), SITS (200 mu M), ATP (500 mu M), pyridoxalphosphate-6- azophenyl-2`,4`-disulfonate (PPADS; 100 mu M), and Suramin (10 mu M) were described by the permeant blocker model with apparent dissociation constant at 0 mV K(d)(0) and fractional distance of the binding site (delta) of 334 mu M and 47%, 880 mu M and 35%, 2,100 mu M and 49%, 188 mu M and 27%, and 66.5 mu M and 49%, respectively. These numbers were derived from the peak value of the currents. We conclude that ICl, swell in Leydig cells are activated independently of purinergic stimulation, that Suramin and PPADS block these currents by a direct interaction with VRAC and that ATP is able to permeate this channel.
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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.
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Objective To investigate whether standardization of the multiplanar view (SMV) when evaluating the uterus using three-dimensional ultrasonography (3D-US) improves intra-and interobserver reliability and agreement with regard to endometrial measurement. Methods Two-dimensional (2D) and 3D-US was used to measure endometrial thickness by two observers in 30 women undergoing assisted reproduction treatment. Endometrial volume was measured with Virtual Organ Computer-aided AnaLysis (VOCAL (TM)) in the longitudinal (A) and coronal (C) planes using an unmodified multiplanar view (UMV) and a standardized multiplanar view (SMV). Measurement reliability was evaluated by intraclass correlation coefficient (ICC) and agreement was examined using Bland-Altman plots with limits of agreement (LoA). The ease of outlining the endometrial-myometrial interface was compared between the A-and C-planes using subjective assessment. Results Endometrial volume measurements using the SMV and A-plane were more reliable (intra-and interobserver ICCs, 0.979 and 0.975, respectively) than were measurements of endometrial thickness using 2D-US (intra-and interobserver ICCs, 0.742 and 0.702, respectively) or 3D-US (intra-and interobserver ICCs, 0.890 and 0.784, respectively). The LoAs were narrower for SMV than for UMV. Reliability and agreement were not much different between the A- and C-planes. However the observers agreed that delineating the endometrial-myometrial interface using the A-plane was easier (first and second observer, 50.0 and 46.7%, respectively) or `comparable` (50 and 53.3%, respectively), but never more difficult than using the C-plane. Conclusions Endometrial volume measurements are more reliable than endometrial thickness measurements and are best performed using SMV and the A-plane. Copyright (C) 2011 ISUOG. Published by John Wiley & Sons, Ltd.
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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).
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Objective(s): We intend to verify if fetal volume and crown-rump length were different between singletons and twins in pregnancies aged from 7 to 10 weeks and to evaluate if fetal volume is more accurate to determine the gestational age than crown-rump length at this gestational age. Study design: From 52 days (7 weeks and 3 days) to 73 days (10 weeks and 3 days) weekly three-dimensional Ultrasonography was per-formed in 20 twin fetuses and 20 singletons. Crown-rump length and fetal volume using VOCAL were assessed in all examinations. The `true` gestational age was based on oocyte retrieval. Results: At the age of 52 days, the crown-rump length was 11.74 +/- 0.27 mm (mean +/- S.D.) and 11.48 +/- 0.22 mm (singletons and twins, respectively), while the fetal volume was 0.354 +/- 0.015 cm(3) and 0.324 +/- 0.012 cm(3). At the gestational age of 73 days, the crown-rump length was 36.19 +/- 0.90 mm and 35.87 +/- 0.54 mm and the fetal volume was 6.204 +/- 0.090 cm(3) and 6.083 +/- 0.081 cm(3). The total relative increase observed was much higher for fetal volume than for CRL: 1705 +/- 301% vs. 210 +/- 33% in singletons and 1827 +/- 305% vs. 214 +/- 25% in twins. The 95% limits of agreement (+/- 2.3 days vs. +/- 3.2 days, fetal volume vs. crown-rump length) and the intraclass correlation coefficients (0.989 vs. 0.978) between the ""true"" gestational age and that predicted by fetal volume were better than those predicted by crown-rump length. No significant difference was identified between singletons and twins for both fetal volume and crown-rump length. Conclusion(s): Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. Condensation: Fetal volume and crown-rump length were similar between singletons and twins. Fetal volume relative increase was higher and the predicted gestational age was better. (c) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The aim of this study was to compare the crown-rump length (CRL) and the fetal head and trunk (HT) volume between singletons and twins conceived after in vitro fertilization. Thirty pregnant patients submitted to embryo transfer were enrolled in this research. Ten conceived twins (20 dichorionic fetuses) while other 20 conceived singletons. The gestational age was calculated by adding 14 d to the number of days between the oocyte retrieval and the scheduled ultrasound. Three-dimensional ultrasound scans were performed weekly from 73 d (10 wk and 3 d) to 101 d (14 wk and 3 d) of gestational age. HT volume was assessed by VOCAL using 15 degrees step rotation on the manual mode. The measurement of CRL was performed by using the longitudinal plane of the fetus in the multiplanar view. The CRL and HT volume weekly relative increase were evaluated to compare the growth between singletons and twins. No significant difference was identified, in any analyzed week, when comparing the mean of CRL and HT volume between singletons and twins. Additionally, no significant difference between singletons and twins was noticed when comparing the weekly relative increase, both for CRL and HT volume. However, the weekly relative increase was significantly higher for HT volume than for CRL in every week studied for both singletons and twins. The total relative increase observed between 73 and 101 d was much higher for HT volume than for CRL: 679 +/- 39% versus 138 +/- 18% in singletons and 689 +/- 58% versus 139 +/- 21% in twins (HT volume and CRL, respectively), suggesting that HT volume could more accurately determine the gestational age.
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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.
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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.
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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.
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Chagas` disease and idiopathic achalasia patients have similar impairment of distal esophageal motility. In Chagas` disease, the contractions occurring in the distal esophageal body are similar after wet or dry swallows. Our aim in this investigation was to evaluate the effect of wet swallows and dry swallows on proximal esophageal contractions of patients with Chagas` disease and with idiopathic achalasia. We studied 49 patients with Chagas` disease, 25 patients with idiopathic achalasia, and 33 normal volunteers. We recorded by the manometric method with continuous water perfusion the pharyngeal contractions 1 cm above the upper esophageal sphincter and the proximal esophageal contractions 5 cm from the pharyngeal recording point. Each subject performed in duplicate swallows of 3-mL and 6-mL boluses of water and dry swallows. We measured the time between the onset of pharyngeal contractions and the onset of proximal esophageal contractions (pharyngeal-esophageal time [ PET]), and the amplitude, duration, and area under the curve (AUC) of proximal esophageal contractions. Patients with Chagas` disease and with achalasia had longer PET, lower esophageal proximal contraction amplitude, and lower AUC than controls (P <= 0.02). In Chagas` disease, wet swallows caused shorter PET, higher amplitude, and higher AUC than dry swallows (P <= 0.03). There was no difference between swallows of 3- or 6-mL boluses. There was no difference between patients with Chagas` disease and with idiopathic achalasia. We conclude that patients with Chagas` disease and with idiopathic achalasia have a delay in the proximal esophageal response and lower amplitude of the proximal esophageal contractions.
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The report was commissioned by the Department of Education, Science and Training to investigate the perceived efficacy of middle years programmes in all States and Territories in improving the quality of teaching, learning and student outcomes, especially in literacy and numeracy and for student members of particular target groups. These target groups included students from lower socio-economic communities, Aboriginal and Torres Strait Islander communities, students with a language background other than English, rural and remote students, and students struggling with the transition from middle/upper primary to the junior secondary years. The project involved large scale national and international literature reviews on Australian and international middle years approaches as well as an analysis of key literacy and numeracy teaching and learning strategies being used. In the report, there is emergent evidence of the relative efficacy of a combination of explicit state policy, dedicated funding and curriculum and professional development frameworks that are focused on the improvement of classroom pedagogy in the middle years. The programs that evidenced the greatest current and potential value for target group students tended to have developed in state policy environments that encouraged a structural rather than adjunct approach to middle years innovations. The authors conclude that in order to translate the gains made into sustainable improvement of educational results in literacy and numeracy for target groups, there is a need for a second generation of middle years theorising, research, development and practice.