RESUMO
Rhabdomyomas are the most common heart tumors seen in infancy. However, whether they represent hamartomas or true neoplasms derived from cardiomyocytes is still controversial. The fetal pattern of atrial natriuretic peptide (ANP) expression (predominant in the atrial and ventricular subendocardium) becomes altered during the early postnatal period to that typical of the adult (all atrial cardiomyocytes and some cells in the ventricular impulse-conducting system). To better comprehend the nature and origin of cardiac rhabdomyomas, we investigated the immunohistochemical expression of ANP in seven surgically excised ventricular specimens and two necropsy cases of multiple, atrial, and ventricular rhabdomyomas in children aged 1 to 34 days. Immunogold labeling for ANP at the ultrastructural level was also performed on three ventricular tumors. Although all atrial tumors were immunoreactive for ANP, these usually showed a variable number of faintly positive cardiomyocytes, contrasting with the diffuse and intense immunoreactivity of the surrounding atrial myocardium. ANP was detected in the ventricular tumors of five (56%) of the nine cases. The positive ventricular tumor cells predominated in the subendocardium and areas with prominent fibrous tissue, usually around blood vessels. Immunoelectron microscopy of the ventricular tumors demonstrated rare, positive cytoplasmic granules surrounded by membranes, usually located near the nuclei. We conclude that cardiac rhabdomyomas exhibit a fetal pattern of ANP immunoreactivity, which suggests delayed maturation of the tumoral cardiomyocytes, reinforcing the notion that cardiac rhabdomyomas are fetal hamartomas.
Assuntos
Fator Natriurético Atrial/metabolismo , Neoplasias Cardíacas/metabolismo , Rabdomioma/metabolismo , Fator Natriurético Atrial/ultraestrutura , Feminino , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/cirurgia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Masculino , Microscopia Imunoeletrônica , Rabdomioma/patologia , Rabdomioma/cirurgiaRESUMO
A possible relationship between C.pneumoniae (CP) infection, atherosclerosis and acute myocardial infarction is a debated matter. Now we performed the search of CP in histological segments of fatal ruptured plaques and of stable plaques by histochemistry (Macchiavello stain), immunohistochemistry and in situ hybridization techniques. Electron microscopy and confocal laser microscopy techniques were used in two additional cases. The semi-quantification of CP + cells (0-4+) and quantification of lymphocytes demonstrated greater amount of CP + cells and more inflammation in the adventitia of vulnerable plaque vessel segments than of stable ones, larger amount of CP + cells in adventitia than in the plaque and high frequency of CP + cells in all groups studied. This preliminary study strongly suggests a direct pathogenetic involvement of adventitial CP in the rupture of the atheromatous plaque, development of acute myocardial infarction and also in the development of atherosclerosis.
Assuntos
Infecções por Chlamydia/complicações , Chlamydophila pneumoniae/isolamento & purificação , Doença da Artéria Coronariana/microbiologia , Humanos , Infarto do Miocárdio/microbiologia , Estudos Retrospectivos , RupturaRESUMO
OBJECTIVE: To analyse the morphological aspects of the extracellular matrix and microcirculation to clarify whether chronic Chagas' cardiopathy (CCC) is an accurate model to study the pathogenesis of idiopathic dilated cardiomyopathy (IDCM). DESIGN: Thick histological myocardial sections were prepared to analyse collagen, and microcirculation was examined during confocal laser and light microscopy. SETTING: The specimens were prepared at the pathology service of the Heart Institute of São Paulo, Brazil. PATIENTS: Nine control hearts, eight IDCM hearts, and 10 CCC hearts were studied after necropsy. MAIN OUTCOME MEASURES: The number of collagen struts per 100x field, the area of fibrosis (%), and the diameters of arterioles and capillaries were measured in each heart to establish outcome. RESULTS: A smaller number (mean (SD)) of collagen struts was seen in the hearts in the IDCM group (9.1 (4.1)) than in the control (22.4 (3.2)) (p < 0.05) or CCC (15.7 (7.4)) (p > 0.05) groups. Fibrosis was greater in the CCC hearts (13.8 (10.5)%) than in the IDCM hearts (5.9 (6.6)%) (p > 0.05). Major increases in arteriole (65.4 (9.9) microm) and capillary (9.9 (1.7) microm) diameters were seen in the CCC hearts but not in the IDCM hearts (arteriole diameter 40.3 (7.9) microm; capillary diameter 7.9 (1.3) microm). CONCLUSIONS: Hearts demonstrating CCC and IDCM present different extracellular and microvessel alterations. This suggests that distinct pathogenic mechanisms are responsible for each condition and that CCC is not an effective model to study IDCM.
Assuntos
Cardiomiopatia Dilatada/patologia , Cardiomiopatia Chagásica/patologia , Vasos Coronários/patologia , Adolescente , Adulto , Idoso , Arteríolas/patologia , Capilares/patologia , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Chagásica/metabolismo , Criança , Colágeno/análise , Matriz Extracelular/patologia , Feminino , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-IdadeRESUMO
PURPOSE: To determine the value of the quantitative analysis of lung biopsies from patients with congenital cardiac defects. METHODS: Fourty nine biopsies were examined, from patients: 43 patients increased pulmonary blood flow, 3 with pulmonary atresia and large systemic-to-pulmonary collateral vessels, and 3 with decreased pulmonary flow. The degree of lesion was determined as in Heath-Edwards and of Rabinovitch and col. RESULTS: The Heath and Edwards grade was determined in 41 cases; I in nine; II in 23; III in eight; IV in one; 3 biopsies showed evidence of reduced pulmonary flow and 5 had no signs of vascular disease. The Down patients (7) presented a greater proportion of severe lesions. Quantitative evaluation was obtained in 35 biopsies: 11 had grade B and 24 had grade C. Wall atrophy and dilatation of intraacinar arteries were detected in 7 cases, what suggested the existence of obstructive lesions in proximal vessels, even if not sampled. Medical thickness greater than 2 times the normal were observed in pre-acinar arteries from 14 biopsies. CONCLUSION: The morphometric approach allowed us to detect severe lesions which the qualitative analysis alone would not indicate adequately. In the patients presenting decreased pulmonary flow, morphometry made possible to assess if the degree of arterial wall hypertrophy was compatible with a surgery of atrio-pulmonary anastomosis.
Assuntos
Cardiopatias Congênitas/complicações , Hipertensão Pulmonar/etiologia , Pulmão/patologia , Artéria Pulmonar/patologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Hipertensão Pulmonar/patologia , Lactente , Masculino , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
1. Fragments of dog hearts submitted to 1, 6, 10, 24 and 48 h of autolysis at 20 degrees C were studied with freeze-fracture and thin-section techniques under the transmission electron microscope. 2. The freeze-fracture replicas revealed maximal reduction in the mean number and clustering of intramembrane particles at 6 h post mortem, indicating irreversible cellular damage. However, signs of lethal damage (intramitochondrial amorphous dense bodies) were not observed in thin sections of the same material. 3. The present study indicates that signs of irreversible damage similar to that occurring in in vivo ischemic alterations can be detected earlier by the freeze-fracture technique than by the thin-section technique.
Assuntos
Técnica de Fratura por Congelamento/métodos , Microtomia/métodos , Infarto do Miocárdio/patologia , Miocárdio/ultraestrutura , Animais , Cães , Feminino , MasculinoRESUMO
Fragments of dog hearts submitted to 1,6,10,24 and 48 h of autolysis at 20-C were studied with freeze-fracture and thin-section techniques under the transmission electron microscope. The freeze-fracture replicas revealed maximal reduction in the mean number and clustering of intramembrane particles at 6 h post mortem, indicating irreversible cellular damage. However, sings of lethal damage (intramitochondrial amorphous dense bodies) were not observed in thin sections of the same material. The present study indicates that signs of irreversible damage similar to that occuring in in vivo ischemic alterations can be detected earlier by the freeze-fracture technique than by the thin-section technique