63 resultados para Bouguer Anomaly
Resumo:
Background: Cardiac development is a complex and multifactorial biological process. Heterozygous mutations in the transcription factor NKX2.5 are between the first evidence of a genetic cause for congenital heart defects in human beings. In this study, we evaluated the presence and frequency of mutations in the NKX2.5 gene on 159 unrelated patients with a diverse range of non-syndromic congenital heart defects (conotruncal anomalies, septal defects, left-sided lesions, right-sided lesions, patent ductus arteriosus and Ebstein`s anomaly). Methods: The coding region of the NKX2.5 locus was amplified by polymerase chain reaction and mutational analysis was performed using denaturing high performance liquid chromatography (DHPLC) and DNA sequencing. Results: We identified two distinct mutations in the NKX2.5 coding region among the 159 (1.26%) individuals evaluated. An Arg25Cys mutation was identified in a patient with Tetralogy of Fallot. The second mutation found was an Ala42Pro in a patient with Ebstein`s anomaly. Conclusions: The association of NKX2.5 mutations is present in a small percentage of patients with non-syndromic congenital heart defects and may explain only a few cases of the disease. Screening strategies considering the identification of germ-line molecular defects in congenital heart disease are still unwarranted and should consider other genes besides NKX2.5. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Congenital anomalies of the inferior vena cava (IVC) call represent a difficult for abdominal surgeries, and the radiologist must be aware even of the less common of these anatomical variations. Preaortic iliac venous confluence, also known as marsupial vena cava, is a rare congenital anomaly of the development of the IVC in which the IVC or the left common iliac vein is located anterior to the aortic bifurcation or the right common iliac artery. We report 4 cases of marsupial vena cava detected on multidetector computed tomography examinations in asymptomatic patients and discuss that this congenital anomaly can be recognized more frequently with the use of this new technique based on thinner images.
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Annular pancreas is a rare congenital anomaly, which is only surgically treated in symptomatic cases. Surgical treatment consists of bypassing the duodenal transit by gastrojejunal or duodenal-jejunal anastomosis. In the absolute majority of published cases, laparotomy is the most widely used access technique. The aim of this article is to report a case of an annular pancreas and describe the technical steps involved in carrying out a laparoscopic duodenal-jejunal anastomosis, for correction of the duodenal obstruction. The patient`s recovery was uneventful; she was discharged on the fourth postoperative day and remained asymptomatic for the 2-year, outpatient follow-up period. Laparoscopic duodenal-jejunal bypass is shown to be feasible and safe, and produce less surgical trauma, when carried out by an experienced surgeon who is duly trained and familiar with the laparoscopic technique.
Resumo:
Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.
Resumo:
The Down syndrome (DS) immune phenotype is characterized by thymus hypotrophy, higher propensity to organ-specific autoimmune disorders, and higher susceptibility to infections, among other features. Considering that AIRE (autoimmune regulator) is located on 21q22.3, we analyzed protein and gene expression in surgically removed thymuses from 14 DS patients with congenital heart defects, who were compared with 42 age-matched controls with heart anomaly as an isolated malformation. Immunohistochemistry revealed 70.48 +/- 49.59 AIRE-positive cells/mm(2) in DS versus 154.70 +/- 61.16 AIRE-positive cells/mm(2) in controls (p < 0.0001), and quantitative PCR as well as DNA microarray data confirmed those results. The number of FOXP3-positive cells/mm(2) was equivalent in both groups. Thymus transcriptome analysis showed 407 genes significantly hypoexpressed in DS, most of which were related, according to network transcriptional analysis (FunNet), to cell division and to immunity. Immune response-related genes included those involved in 1) Ag processing and presentation (HLA-DQB1, HLA-DRB3, CD1A, CD1B, CD1C, ERAP) and 2) thymic T cell differentiation (IL2RG, RAG2, CD3D, CD3E, PRDX2, CDK6) and selection (SH2D1A, CD74). It is noteworthy that relevant AIRE-partner genes, such as TOP2A, LAMNB1, and NUP93, were found hypoexpressed in DNA microarrays and quantitative real-time PCR analyses. These findings on global thymic hypofunction in DS revealed molecular mechanisms underlying DS immune phenotype and strongly suggest that DS immune abnormalities are present since early development, rather than being a consequence of precocious aging, as widely hypothesized. Thus, DS should be considered as a non-monogenic primary immunodeficiency. The Journal of Immunology, 2011, 187: 3422-3430.
Resumo:
Tetralogy of Fallot (TOF), the most common severe congenital heart malformation, occurs sporadically, without other anomaly, and from unknown cause in 70% of cases. Through a genome-wide survey of 114 subjects with TOF and their unaffected parents, we identified 11 de novo copy number variants (CNVs) that were absent or extremely rare (<0.1%) in 2,265 controls. We then examined a second, independent TOF cohort (n = 398) for additional CNVs at these loci. We identified CNVs at chromosome 1q21.1 in 1% (5/512, P = 0.0002, OR = 22.3) of nonsyndromic sporadic TOF cases. We also identified recurrent CNVs at 3p25.1, 7p21.3 and 22q11.2. CNVs in a single subject with TOF occurred at six loci, two that encode known (NOTCH1, JAG1) disease-associated genes. Our findings predict that at least 10% (4.5-15.5%, 95% confidence interval) of sporadic nonsyndromic TOF cases result from de novo CNVs and suggest that mutations within these loci might be etiologic in other cases of TOF.
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Absence of the horizontal segment of the left portal vein (PV) or absence of bifurcation of the portal vein (ABPV) is extremely rare anomaly. The aim of this study was to study the extra-hepatic PV demonstrating the importance of its careful assessment for the purpose of split-liver transplantation. Human cadaver livers (n = 60) were obtained from routine autopsies. The cutting plane of the liver consisted of a longitudinal section made immediately on the left of the supra-hepatic inferior vena cava through the gallbladder bed preserving the arterial, portal and biliary branches in order to obtain two viable grafts (right lobe-segments V, VI, VII, and VIII and left lobe-segments II, III, and IV) as defined by the main portal scissure. The PV was dissected out and recorded for application of the liver splitting. The PV trunk has been divided into right and left branch in 50 (83.3%) cases. A trifurcation of the PV was found in 9 (15.2%) cases, 3 (5%) was a right anterior segmental PV arising from the left PV and 6 (10%) a right posterior segmental PV arising from the main PV. ABPV occurred in 1 (1.6%) case. Absence of bifurcation of the portal vein is a rare anatomic variation, the surgeon must be cautious and aware of the existence of this exceptional PV anomaly either pre or intra-operatively for the purpose of hepatectomies or even split-liver transplantation.
Resumo:
Purpose: To describe a patient with Tessier cleft number 5 and 9 and review the literature on the ocular impairment and management of this extremely rare anomaly. Methods: Interventional case report and literature review. Results: The literature review showed that the present patient is the second case with clefts 5/9. The ophthalmic consequences of this rare association are virtually unreported. Our case demonstrates that the presence of cleft number 9 adds a cicatricial component on the upper eyelid that severely impairs the dynamics of this lid. The corneal status of the patient was successfully managed with simultaneous upper eyelid lengthening and facial reconstruction. Conclusion: In order to avoid corneal perforation, simultaneous upper and lower eyelid reconstruction is mandatory in cases of cleft 5/9. The affected patients should be continuously followed in order to prevent amblyopia.
Resumo:
A 22-year-old woman was examined for a complaint of bilateral progressive enophthalmos that had begun after the cerebrospinal fluid shunting procedure 9 years ago. Photographs and CT scans taken before surgery proved that the position of her eyes was normal before surgery. The enophthalmos was so severe that it induced a poor eyelid-globe apposition with trichiasis and superficial keratopathy. CT of the orbits showed that both orbital roofs were arched and displaced toward the anterior cranial fossa. The placement of porous polyethylene sheets on the orbital roofs through a coronal approach corrected the eye position. A literature review indicated that cerebrospinal shuntings are plagued by a variety of complications including bone changes and craniosynostosis. We believe that enophthalmos associated with cerebrospinal fluid shunting results from a rare acquired bony orbital anomaly.
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Microwave techniques were applied to the study of dielectric properties of phosphate glasses on the basis of contributions from permanent and induced dipolar polarization of local structural units interacting with the electrical component of the electromagnetic radiation. The dielectric constant of the selected glass system (100-x)(50P(2)O(5)center dot 25Li(2)O center dot 25Na(2)O)center dot xFe(2)O(3), where 0 <= x <= 21 is in mol%, was measured using a microwave setup assembled to measure the phase shift of the standing wave pattern produced by the insertion of the sample. It is shown that the Fe2+ ions contribute effectively to the dielectric constant, as expected from the interactions of the dipoles of the local charge compensation pairs with the microwave radiation. However, there is the possibility of occurrence of some ions Fe3+, in general, at low iron content, which reinforces the glass structure and, therefore, decreases the dielectric constant. There is a gradual conversion from Fe3+ to Fe2+ as the iron ions increases. This is possibly the reason of the anomaly in the dielectric constant values observed in the results. These assumptions can be checked by results of electronic paramagnetic resonance (EPR) and optical absorption (OA). The dielectric constant of the glasses studied in this work was found to increase with the temperature in the range of 25-330 degrees C. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
We present the case of a 54-year-old female with a previous history of lung fibrosis secondary to methotrexate used for rheumatoid arthritis who was referred to cardiology evaluation due to precordial pain. Echocardiography showed biatrial enlargement with an enlarged coronary sinus and tubular image posterior to the heart. On the coronary angiogram, the right coronary artery was enlarged, and a distal fistula was identified. The patient underwent a contrast enhanced cardiac computed tomography which demonstrated an aneurysmatic right coronary artery with a distal fistula to the right atrium and coronary sinus. As the chest pain did not recur and there was a high risk of the intervention to correct coronary fistula, the patient remained on conservative treatment.
Resumo:
The impact of the inter-El Nio (EN) variability on the moisture availability over Southeastern South America (SESA) is investigated. Also, an automatic tracking scheme was used to analyze the extratropical cyclones properties (system density - SD and central pressure - CP) in this region. During the austral summer period from 1977-2000, the differences for the upper-level wave train anomaly composites seem to determine the rainfall composite differences. In fact, the positive rainfall anomalies over most of the SESA domain during the strong EN events are explained by an upper-level cyclonic center over the tropics and an anticyclonic center over the eastern subtropical area. This pattern seems to contribute to upward vertical motion at 500 hPa and reinforcement of the meridional moisture transport from the equatorial Atlantic Ocean and western Amazon basin to the SESA region. These features may contribute to the positive SD and negative CP anomalies explaining part of the positive rainfall anomalies found there. On the other hand, negative rainfall anomalies are located in the northern part of SESA for the weak EN years when compared to those for the strong events. Also, positive anomalies are found in the southern part, albeit less intense. It was associated with the weakening of the meridional moisture transport from the tropics to the SESA that seems have to contributed with smaller SD and CP anomalies over the most part of subtropics, when compared to the strong EN years.
Resumo:
This work presents an analysis of a lowermost stratospheric air intrusion event over the coast of Brazil, which may have been responsible for a secondary surface cyclogenesis over the southwestern Atlantic Ocean. The surface cyclone initiated at 0600 UTC 17 April 1999 in a cold air mass in the rear of a cold front after a primary cyclone developed over the same region. The analysis of the secondary cyclone revealed the presence of lowermost stratospheric air intrusion characterized by anomalous potential vorticity (PV), dry air, and high concentration of ozone in atmospheric column. The system developed on the eastern side of an upper level core of PV anomaly, which induced a cyclonic wind circulation at lower levels and favored the onset of the secondary cyclone. In midlevels (500 hPa), the cutoff low development contributed to reduce the propagation speed of the wave pattern. This feature seemed to (1) allow the low-level cold/dry air to heat/moisten associated with sensible and latent fluxes transferred from the ocean to the atmosphere, which intensified a baroclinic zone parallel to the coast, and (2) contribute to the long duration of the system. The present analysis indicates that this secondary cyclone development could be the result of the coupling between the PV anomaly in the upper levels and low-level air-sea interaction.
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Intraseasonal and interannual variability of extreme wet and dry anomalies over southeastern Brazil and the western subtropical South Atlantic Ocean are investigated. Precipitation data are obtained from the Global Precipitation Climatology Project (GPCP) in pentads during 23 austral summers (December-February 1979/80-2001/02). Extreme wet (dry) events are defined according to 75th (25th) percentiles of precipitation anomaly distributions observed in two time scales: intraseasonal and interannual. The agreement between the 25th and 75th percentiles of the GPCP precipitation and gridded precipitation obtained from stations in Brazil is also examined. Variations of extreme wet and dry anomalies on interannual time scales are investigated along with variations of sea surface temperature (SST) and circulation anomalies. The South Atlantic SST dipole seems related to interannual variations of extreme precipitation events over southeastern Brazil. It is shown that extreme wet and dry events in the continental portion of the South Atlantic convergence zone (SACZ) are decoupled from extremes over the oceanic portion of the SACZ and there is no coherent dipole of extreme precipitation regimes between tropics and subtropics on interannual time scales. On intraseasonal time scales, the occurrence of extreme dry and wet events depends on the propagation phase of extratropical wave trains and consequent intensification (weakening) of 200-hPa zonal winds. Extreme wet and dry events over southeastern Brazil and subtropical Atlantic are in phase on intraseasonal time scales. Extreme wet events over southeastern Brazil and subtropical Atlantic are observed in association with low-level northerly winds above the 75th percentile of the seasonal climatology over central-eastern South America. Extreme wet events on intraseasonal time scales over southeastern Brazil are more frequent during seasons not classified as extreme wet or dry on interannual time scales.
Resumo:
We present models for the upper-mantle velocity structure beneath SE and Central Brazil using independent tomographic inversions of P- and S-wave relative arrival-time residuals (including core phases) from teleseismic earthquakes. The events were recorded by a total of 92 stations deployed through different projects, institutions and time periods during the years 1992-2004. Our results show correlations with the main tectonic structures and reveal new anomalies not yet observed in previous works. All interpretations are based on robust anomalies, which appear in the different inversions for P-and S-waves. The resolution is variable through our study volume and has been analyzed through different theoretical test inversions. High-velocity anomalies are observed in the western portion of the Sao Francisco Craton, supporting the hypothesis that this Craton was part of a major Neoproterozoic plate (San Franciscan Plate). Low-velocity anomalies beneath the Tocantins Province (mainly fold belts between the Amazon and Sao Francisco Cratons) are interpreted as due to lithospheric thinning, which is consistent with the good correlation between intraplate seismicity and low-velocity anomalies in this region. Our results show that the basement of the Parana Basin is formed by several blocks, separated by suture zones, according to model of Milani & Ramos. The slab of the Nazca Plate can be observed as a high-velocity anomaly beneath the Parana Basin, between the depths of 700 and 1200 km. Further, we confirm the low-velocity anomaly in the NE area of the Parana Basin which has been interpreted by VanDecar et al. as a fossil conduct of the Tristan da Cunha Plume related to the Parana flood basalt eruptions during the opening of the South Atlantic.