RESUMO
Myelin associated glycoprotein (MAG) has growth promoting effect on mouse cerebellar neurons. In the present study, we examined which isoform of MAG has the effect. cDNA for L-MAG and S-MAG was stably transfected into BALB/c 3T3 cells, on which cerebellar neurons were cultured. The neurons were stained with antibody against microtubule-associated protein-2. Neurites of the neurons cultured on cells expressing L-MAG extended significantly further than those cultured on cells expressing S-MAG or on control cells. Therefore, intracellular domain of MAG may have the potential to affect MAG-neurite interaction.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Cerebelo/efeitos dos fármacos , Glicoproteína Associada a Mielina/metabolismo , Neuritos/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Contagem de Células , Diferenciação Celular/fisiologia , Tamanho Celular/genética , Células Cultivadas/citologia , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/metabolismo , Cerebelo/citologia , Cerebelo/crescimento & desenvolvimento , Expressão Gênica/fisiologia , Vetores Genéticos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Associadas aos Microtúbulos/metabolismo , Glicoproteína Associada a Mielina/genética , Neuritos/metabolismo , Neuritos/ultraestrutura , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína/fisiologia , TransfecçãoRESUMO
Although computed tomography (CT) and magnetic resonance imaging (MRI) can not measure the pulmonary arterial pressure, those can depict the morphological changes due to pulmonary hypertension, which are dilatation of main and central pulmonary artery, right ventricular hypertrophy and dilatation of right ventricle, right atrium, vena cava and coronary sinus. Right ventricular volume, mass and ejection fraction are calculated quantitatively by MRI using Simpson method. Thromboembolism can be detected by enhanced CT. Information about pulmonary blood flow and tricuspid regurgitation are given by MRI. Three dimensional MR angiography depicts the pulmonary artery as a whole. CT and MRI can detect pulmonary and congenital heart disease, the cause of pulmonary hypertension. CT and MRI are useful complementary method for evaluating pulmonary hypertension.
Assuntos
Hipertensão Pulmonar/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Doença Crônica , Humanos , Hipertensão Pulmonar/etiologia , Contração Miocárdica , Circulação Pulmonar , Embolia Pulmonar/complicações , Embolia Pulmonar/diagnóstico por imagem , Função Ventricular DireitaRESUMO
A 56-year-old man presented with an inferior myocardial infarction and a huge pseudoaneurysm below the inferior surface of the left ventricle, which had progressed from a small subepicardial aneurysm over a 6-month period. Transthoracic echocardiography, Doppler color flow images, radionuclide angiocardiography, magnetic resonance imaging and contrast ventriculography all revealed an abrupt disruption of the myocardium at the neck of the pseudoaneurysm, where the diameter of the orifice was smaller than the aneurysm itself, and abnormal blood flows from the left ventricle to the cavity through the orifice with an expansion of the cavity in systole and from the cavity to the left ventricle with the deflation of the cavity in diastole. Coronary angiography revealed 99% stenosis at the atrioventricular nodal branch of the right coronary artery. At surgery the pericardium was adherent to the aneurysmal wall and a 1.5-cm orifice between the aneurysm and the left ventricle was seen. Pathological examination revealed no myocardial elements in the aneurysmal wall. The orifice was closed and the postoperative course was uneventful. Over-intense physical activity as a construction worker was considered to be the cause of the large pseudoaneurysm developing from the subepicardial aneurysm. These findings indicate that a subepicardial aneurysm may progress to a larger pseudoaneurysm, which has a propensity to rupture, however, it can be surgically repaired.
Assuntos
Falso Aneurisma/etiologia , Aneurisma Cardíaco/diagnóstico , Disfunção Ventricular Esquerda/diagnóstico , Falso Aneurisma/diagnóstico , Aneurisma Roto/etiologia , Angiocardiografia , Angiografia Digital , Ecocardiografia Doppler em Cores/métodos , Aneurisma Cardíaco/complicações , Aneurisma Cardíaco/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Radiografia Torácica , Ruptura Espontânea/etiologia , Disfunção Ventricular Esquerda/etiologiaRESUMO
A report is presented of a liquefaction necrosis of mitral annular calcification in a patient with chronic renal failure and secondary hyperparathyroidism who had been managed by hemodialysis for 11 years. The mass was echogenic with an echo-lucent area inside, high density on computed tomography and low intensity on magnetic resonance imaging. The uptake of gallium-67 (67Ga)-citrate and the bone agent technetium-99m-methylene diphosphate (99mTc-MDP) was seen in the mass. These findings were compatible with liquefaction necrosis of the mitral annular calcification. After treatment with low calcium concentration hemodialysis, the size of the mass reduced with disappearance of the echo-lucent area on the echocardiography and there was no uptake of 67Ga-citrate or 99mTc-MDP. Liquefaction necrosis might be the early and reversible form of mitral annular calcification. When a tumorlike echogenic mass at the base of mitral leaflets is seen in patients with predisposing factors for mitral annular calcification, consider the possibility of this specific form of mitral annular calcification in order to avoid any unnecessary surgical intervention.
Assuntos
Calcinose , Cálcio , Falência Renal Crônica/complicações , Valva Mitral , Diálise Renal , Calcinose/diagnóstico , Calcinose/diagnóstico por imagem , Citratos , Ecocardiografia , Feminino , Gálio , Radioisótopos de Gálio , Doenças das Valvas Cardíacas/diagnóstico , Doenças das Valvas Cardíacas/diagnóstico por imagem , Humanos , Falência Renal Crônica/terapia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/patologia , Necrose , Compostos Radiofarmacêuticos , Diálise Renal/efeitos adversos , Medronato de Tecnécio Tc 99m , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios XRESUMO
The safety, findings and clinical usefulness of magnetic resonance (MR) imaging were assessed in patients with a prosthetic carbon valve in the mitral position. In vitro deflection, heating and image distortion due to the magnetic field of a 1.5 tesla MR machine were examined in three carbon valves (CarboMedics, St. Jude Medical and Björk-Shiley valves). In vivo MR imaging of the left ventricular horizontal long-axis, vertical long-axis and short-axis views was performed by electrocardiographically synchronized spin echo and field (gradient) echo techniques in eight patients with prosthetic mitral carbon valves, consisting of six CarboMedics valves, one St. Jude Medical valve and one Björk-Shiley valve. No deflection and significant heating was seen in all three valves in vitro. Although little image distortion was shown in the CarboMedics and St. Jude Medical valves, a small distortion toward the frequency encoded direction was seen in the Björk-Shiley valve but caused no difficulty in assessing the surrounding images. Four of the eight patients had normal sinus rhythm and the other four had atrial fibrillation. The prosthetic valves were depicted as signal voids in the images taken by both spin echo and field echo techniques in vivo. Clear structural information with little image distortion of the adjacent tissues of the prosthetic valves were obtained in all patients, although the image of the Björk-Shiley valve which contained stainless steel in the frame had a slightly stronger distortion than those of the CarboMedics and St. Jude Medical valves which contained titanium. The stainless wire suture material used to close the sternal incision was depicted as a signal void, and the areas of the signal loss were larger in the images taken by the field echo technique than those by the spin echo technique. The images taken by the spin echo technique in patients with atrial fibrillation had reduced quality due to the irregularity of repetition time. Cine MR imaging by the field echo technique showed physiological mitral regurgitant jets as signal loss within the flowing blood, which appeared as high signal intensity, bidirectionally in the bileaflet mechanical valve and unidirectionally in the monoleaflet mechanical valve. An abnormal cavity was seen behind the basal left ventricular myocardium in one patient with a CarboMedics valve. The wall of the abnormal cavity was disrupted abruptly and the rest of the wall consisted of pericardium and adjacent tissue in the image taken by the spin echo technique. The image taken by the field echo technique showed an abnormal jet flow from the basal part of the left ventricular cavity into the abnormal cavity, which was compatible with left ventricular pseudoaneurysm. Two-dimensional echocardiography and Doppler color flow mapping disclosed the abnormal cavity and the abnormal flow inside, but failed to show the connection between the left ventricle and the cavity due to reverberation of the ultrasound signal by the prosthetic valve. These findings suggest that MR imaging is a safe and promising method to assess the complications and valvular function in patients with a prosthetic carbon valve in the mitral position.
Assuntos
Próteses Valvulares Cardíacas , Imageamento por Ressonância Magnética/métodos , Valva Mitral/patologia , Idoso , Carbono , Feminino , Doenças das Valvas Cardíacas/diagnóstico , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The role of neurons on expression of myelin-associated glycoprotein (MAG) in oligodendrocytes and oligodendroglial differentiation was examined. Primary cultures of oligodendrocytes prepared from neonatal mouse brains were co-cultured with neuronal cells derived from embryonal carcinoma P19 cells. The levels of MAG mRNAs following this co-culture were determined by reverse transcription (RT)-PCR. In oligodendrocytes co-cultured in direct contact with P19-derived neurons, the levels of MAG mRNAs, particularly that of the L-type isoform, were markedly higher than those in cultures without any neuronal cells. On the other hand, when the P19-derived neurons were present, but not in direct contact, no significant induction of MAG expression was found, though oligodendrocytes appeared to mature morphologically. The L-MAG expression was also stimulated when just the neuronal cell membrane fraction was added, which implies that there might be some effecter(s) in the cell membrane which are possibly exerting a signal transduction for myelin formation. These results suggest that morphological differentiation and functional maturation of oligodendrocytes are due to independent factors. The former is caused by some humoral factor(s) liberated from neuronal cells, while the latter resulted from cellular contact with neuronal cells.
Assuntos
Córtex Cerebral/metabolismo , Glicoproteína Associada a Mielina/biossíntese , Neurônios/fisiologia , Oligodendroglia/fisiologia , Transcrição Gênica , Animais , Animais Recém-Nascidos , Comunicação Celular , Diferenciação Celular , Células Cultivadas , Córtex Cerebral/citologia , Técnicas de Cocultura , Camundongos , Camundongos Endogâmicos BALB C , Proteína Proteolipídica de Mielina/biossíntese , Neurônios/citologia , Oligodendroglia/citologia , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Teratoma , Células Tumorais CultivadasRESUMO
The mediastinal and cardiovascular anatomy is complex. We have developed a three-dimensional (3D) reconstruction system for the major mediastinal structures using magnetic resonance imaging data on a NeXT workstation. The program uses a combination of automatic and manual procedures to determine the contours of the cardiac structures. The geometric centers of the contours are connected by a 3D space curve, and the central axis of each cardiac structures is determined. The contours are projected on the perpendicular plane to the central axis and semiautomatically processed until the contours of one pixel are obtained. Then the surface rendering with transparency is performed. Compositing combines two images so that both appear in the composite, superimposed on each other. Demonstration of the various mediastinal lines and cardiovascular diseases by the composits of the partly transparent 3D images has promoted a better understanding of the complex mediastinal and cardiovascular anatomy and diseases.
Assuntos
Cardiopatias Congênitas/diagnóstico , Cardiopatias/diagnóstico , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Doenças do Mediastino/diagnóstico , Coração/anatomia & histologia , Humanos , Mediastino/anatomia & histologiaRESUMO
The usefulness of low-cost, three-dimensional (3D) images reconstructed from magnetic resonance (MR) imaging for investigating persistent left superior vena cava was assessed and compared to the diagnostic accuracy of chest radiography. MR imaging by the spin-echo technique and MR angiography were performed in 10 patients with this anomaly diagnosed previously by contrast echocardiography and radionuclide angiocardiography. Four patients had complicating cardiac anomalies, one with postoperative atrial septal defect, one with postoperative ventricular septal defect, one with atrial septal defect and partial anomalous pulmonary venous return, and one with aortic coarctation and patent ductus arteriosus. Multisectional and multiphasic MR images were used for the 3D-reconstruction of the cardiovascular and mediastinal structures with a NeXT workstation and a 3D-kit. The 3D-reconstructed MR imaging clearly showed the persistent left superior vena cava and the anatomical relationship with the other cardiovascular and mediastinal structures in all 10 patients. Vascular shadows were observed outside the upper left border of the aortic arch on the chest radiographs in seven patients, and the 3D-reconstructed MR images revealed these shadows to be compatible with superior caval vein. The ratios of the diameter between the left and right superior venae cavae with and without the left innominate vein were 0.63 +/- 0.14 (mean +/- SD) and 0.94 +/- 0.08, respectively. Three-dimensional reconstructed MR imaging is a useful method for recognizing persistent left superior vena cava and precise examination of the chest radiographs often allowed detection of the vascular shadows caused by this anomaly.
Assuntos
Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética/métodos , Radiografia Torácica , Síndrome da Veia Cava Superior/diagnóstico , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e EspecificidadeRESUMO
This study investigated the clinical significance of abnormally high signal intensity in the left ventricular myocardium on gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance (MR) imaging in patients with dilated cardiomyopathy. Gd-DTPA enhanced MR imaging, Tl-201 myocardial single photon emission computed tomography (SPECT), Tc-99m radionuclide angiocardiography, M-mode echocardiography, electrocardiography and chest radiography were performed in 18 patients with dilated cardiomyopathy. The left ventricle was divided into five areas, the anteroseptal, anterolateral, inferoseptal, posterolateral and apical areas. Five patients (group A) had 0-2 and 13 patients (group B) had 3-5 high signal intensity areas. High signal intensity areas were demonstrated in 19 of 90 areas (21%) before Gd-DTPA enhancement and 50 of 90 areas (56%) after enhancement. Fifteen of 34 areas (44%) with abnormal Tl-201 uptake showed high signal intensity before Gd-DTPA enhancement and 31 (91%) showed high signal intensity after enhancement. Fifteen areas without abnormal Tl-201 uptake also showed high signal intensity after enhancement. Left ventricular ejection fraction (LVEF) and percent fractional shortening (%FS) in group B were lower than those in group A. LVEF(r = 0.78) and %FS (r = 0.82) were significantly correlated with the number of high signal intensity areas. Systolic left ventricular dimension was larger in group B than that in group A, and a significant correlation (r = 0.62) between systolic left ventricular dimension and the number of high signal intensity areas was found. There was no significant difference in right ventricular ejection fraction, left ventricular peak filling rate, diastolic left ventricular dimension, left ventricular thickness, cardiothoracic ratio or SV1+RV5 or 6 between group A and B. There was no correlation of peak filling rate, diastolic left ventricular dimension, cardiothoracic ratio or SV1+RV5 or 6 with the number of high signal intensity areas. These results suggest that abnormal high signal intensity on Gd-DTPA enhanced MR imaging may reflect myocardial degeneration, necrosis or fibrosis, and the high signal intensity predicts the severity of left ventricular dysfunction in dilated cardiomyopathy.
Assuntos
Cardiomiopatia Dilatada/diagnóstico , Coração/diagnóstico por imagem , Compostos Organometálicos , Ácido Pentético/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiocardiografia , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Ecocardiografia , Eletrocardiografia , Feminino , Gadolínio DTPA , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Volume Sistólico , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
A soluble chimera protein consisting of the extracellular region of mouse myelin-associated glycoprotein (MAG) and the Fc region of human immunoglobulin G1, MAG-IgG, was prepared by transfecting an expression vector, BCMGSneo, containing the corresponding fused gene into mouse myeloma P3U1 cells. It was found that this MAG derivative promoted neurite growth of mouse cerebellar neurons in culture. In the presence of MAG-IgG the rates of neurite-bearing cells were significantly increased, and the neurites were distinctly lengthened. It was also observed that the anti-MAG monoclonal antibody inhibited this stimulation of neurite extension, supporting the specificity of the effect of MAG-IgG. These results suggest that soluble MAG derivative might act as a neurotrophic factor in the developing brain.
Assuntos
Cerebelo/citologia , Glicoproteína Associada a Mielina/farmacologia , Neurônios/efeitos dos fármacos , Animais , Anticorpos Monoclonais , Sequência de Bases , Encéfalo/citologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas/citologia , Células Cultivadas/efeitos dos fármacos , Imunoglobulina G/genética , Imunoglobulina G/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Glicoproteína Associada a Mielina/genética , Glicoproteína Associada a Mielina/imunologia , Fatores de Crescimento Neural/farmacologia , Neuritos/efeitos dos fármacos , Neurônios/citologia , Neurônios/ultraestrutura , Proteínas Recombinantes de Fusão/farmacologia , TransfecçãoRESUMO
The significance of abnormal high signal intensity observed in left ventricular myocardium by gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA) enhanced magnetic resonance (MR) imaging in hypertrophic cardiomyopathy (HCM) patients was assessed by comparison with T1-weighted MR imaging, thallium-201 (201Tl) myocardial scintigraphy, radionuclide angiocardiography, M-mode echocardiography, electrocardiography, and chest radiography. The 16 patients were divided into three groups: 8 patients (group I) with abnormal high signal intensity before and after Gd-DTPA enhancement, 4 (group II) with abnormal high signal intensity only after enhancement and 4 (group III) without abnormal high signal intensity. Thallium-201 myocardial single photon emission computed tomography (SPECT) showed 4 of the 8 patients in group I, 3 of the 4 patients in group II and only 1 of the 4 patients in group III had abnormalities of regional 201Tl uptake in the left ventricular myocardium. No significant difference in left ventricular ejection fraction (LVEF) was seen between groups I, II, and III (64 +/- 13%, 67 +/- 17% and 71 +/- 7%, respectively) although three patients of group I had LVEF of less than 55%. Left ventricular peak filling rates (PFR) of groups I and II were significantly lower than that of group III (1.90 +/- 0.44, 2.41 +/- 0.43 and 3.37 +/- 0.48 EDV/sec, respectively). Group I had larger end-diastolic left ventricular dimension (LVDd), significantly larger end-systolic left ventricular dimension (LVDs), and smaller % fractional shortening (%FS) than group III (49 +/- 4 vs 42 +/- 6 mm, 31 +/- 5 vs 22 +/- 4 mm, and 38 +/- 8 vs 49 +/- 4%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Cardiomiopatia Hipertrófica/diagnóstico , Gadolínio , Imageamento por Ressonância Magnética , Miocárdio/patologia , Compostos Organometálicos , Ácido Pentético/análogos & derivados , Adolescente , Adulto , Idoso , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/fisiopatologia , Ecocardiografia , Eletrocardiografia , Feminino , Gadolínio DTPA , Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular EsquerdaRESUMO
In vitro immune responses to Legionella pneumophila were investigated. When human peripheral blood lymphocytes (PBL) from healthy volunteers were stimulated with formalin-killed L. pneumophila for 7 days in vitro, strong proliferative responses were observed. The responding cells were shown to be a CD4 T cell subset. It was also found that the CD4 T cells secreted significant amounts of IFN-gamma into the PBL culture supernatant. The production of IFN-gamma and IL-4 by PBL was measured semiquantitatively by reverse transcriptase-assisted polymerase chain reaction (RT-PCR) methods. Formalin-killed or live L. pneumophila-stimulated PBL expressed the mRNA for IFN-gamma but not the mRNA for IL-4. The results suggest that the whole bacterium, as opposed to the supernatant, predominantly stimulates Th1 type helper T cells. The cloned T cells specific for L. pneumophila expressed the mRNA for IFN-gamma but not for IL-4. In contrast to formalin-killed or live L. pneumophila stimulation, when PBL were stimulated with the bacterial culture supernatant, the proliferating T cells produced the mRNA for IL-4 as well as for IFN-gamma. A significant correlation between the proliferative response to formalin-killed L. pneumophila and IFN-gamma release in culture was observed (r = 0.6932, P < 0.001) in PBL from 30 healthy volunteers. From these in vitro studies, it is suggested that the whole L. pneumophila bacterium and their soluble antigens stimulate T cells in a manner which results in a different pattern of cytokine production.
Assuntos
Interferon gama/metabolismo , Legionella pneumophila/imunologia , Linfócitos T/imunologia , Sequência de Bases , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Divisão Celular , Células Cultivadas , Humanos , Interleucina-4/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Linfócitos T/citologia , Linfócitos T/metabolismo , Células Th1/imunologiaRESUMO
The significance of exercise-induced S-T elevation in aVR was studied in 57 patients with recent anterior infarction and single-vessel disease. S-T elevation in aVR was found at peak exercise in 24 patients. Although the initial defect area was similar in the groups with and without S-T elevation in aVR, the redistribution area was larger in the former group (p < 0.01). When three electrocardiographic criteria were used in the multivariate analysis, S-T elevation in aVR was the significant variable related to redistribution in the anterior wall. Thus, S-T elevation in aVR may indicate ischemia of the anterior wall.
Assuntos
Eletrocardiografia , Exercício Físico , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Radioisótopos de Tálio , Adulto , Idoso , Angiografia Coronária , Eletrocardiografia/métodos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Valor Preditivo dos Testes , Ventriculografia com Radionuclídeos , Sensibilidade e EspecificidadeRESUMO
Prolonged survival of the patient with a single ventricle is rare. We report the case of a 57-year-old man who has type A3 of Van Praagh's classification of single ventricle with pulmonary hypertension without pulmonary stenosis. Favorable streaming, a large bulboventricular foramen, and intact atrioventricular valves may have contributed to his long-term survival.
Assuntos
Cardiopatias Congênitas/diagnóstico , Estenose da Valva Pulmonar , Ecocardiografia Transesofagiana , Eletrocardiografia , Cardiopatias Congênitas/mortalidade , Ventrículos do Coração/anormalidades , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/mortalidade , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , SobreviventesRESUMO
A 85-year-old woman consulted our hospital with general fatigue, palpitation and chest discomfort changing with different postures. Her electrocardiogram showed sinus tachycardia, atrial premature beats and left atrial overload. 53% cardiothoracic ratio, slightly protruding third arch of the cardiac silhouette and dilated pulmonary artery were seen on the chest X-ray. Two dimensional echocardiography revealed a mass in the left atrium although the quality of echocardiography was suboptimal due to her thoracic deformity. There was no uptake of T1-201 or Ga-67 by the mass. The four-chamber view of Tc-99m ECG-gated SPECT radionuclide angiocardiography showed a filling defect in the left atrium. The T1 weighted magnetic resonance imaging revealed a left atrial mass with relatively low signal intensity. After intravenous injection of Gadolinium-DTPA the signal intensity of the mass increased significantly and the contrast of the mass was improved. The size of the mass was 4 x 4 x 3 cm with a stalk connecting to the interatrial septum. These findings were compatible with left atrial myxoma. Gadolinium-DTPA magnetic resonance imaging is useful in diagnosing left atrial myxoma because it provides information on the size, anatomical location, relationship with other cardiovascular structures and even the characteristics of the mass.
Assuntos
Neoplasias Cardíacas/diagnóstico , Mixoma/diagnóstico , Compostos Organometálicos , Ácido Pentético/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Gadolínio DTPA , Átrios do Coração , Humanos , Imageamento por Ressonância MagnéticaRESUMO
The role of monoaminergic neural inputs to fluid regulatory systems in the median preoptic nucleus (MnPO) was investigated by examination of monoamine metabolism during reduction of systemic extracellular fluid volume in freely moving rats. Extracellular fluid volume was decreased iso-osmotically by subcutaneous polyethylene glycol (PEG), and extracellular noradrenaline (NA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were measured using intracerebral microdialysis techniques. PEG treatments significantly increased NA, DA and DOPAC release in the MnPO area. The results suggest that monoaminergic neural systems in the region of the MnPO are important in the control of extracellular fluid balance.