Label-retaining cells in the rat pancreas: location and differentiation potential in vitro.

Islets of Langerhans are micro-organs scattered throughout the pancreas that contain insulin-producing cells, called beta-cells. Although new light has been recently shed on beta-cell development, information on the phenotype and location of beta-stem cells remains scarce. Here, we provide evidence that beta-stem cells are slow-cycling cells located within and around the islets of Langerhans.

Endomyocardial fibrosis in infancy.

The patient was a 4-month-old infant, who underwent persistent ductus arteriosus interruption with titanium clips at the age of 13 days and, since the age of 2 months, had crises of hypoxia and hypertonicity. After clinical investigation, the presence of pulmonary hypertension was confirmed and left ventricular inflow tract obstruction was suspected. The patient underwent surgical treatment at the age of 4 months, during which right and left ventricular endocardial fibrosis was identified.

Morphology of the internal elastic lamina in arteries from pulmonary hypertensive patients: a confocal laser microscopy study.

The development and progression of pulmonary hypertension lesions involve continuous remodeling of the arterial wall, including the extracellular matrix components. The integrity of the internal elastic lamina may represent a barrier to cell migration and formation of intimal proliferative lesions. Some patients with congenital cardiac shunts develop precocious intimal occlusive lesions,whereas others evolve with isolated medial hypertrophy.

Ventricular expression of atrial natriuretic peptide in chronic chagasic cardiomyopathy is not induced by myocarditis.

Background: The ventricles of the normal heart are virtually devoid of atrial natriuretic peptide (ANP). Although ANP occurs in ventricles submitted to elevated wall stress, it is not clear whether ANP expression is affected by myocarditis. We investigated the immunohistochemical expression of ANP in chronic chagasic cardiomyopathy, an inflammatory cardiomyopathy caused by infection with the protozoan Trypanosoma cruzi.

Reversible pulmonary trunk banding. II. An experimental model for rapid pulmonary ventricular hypertrophy.

Objective: An experimental model with a reversible pulmonary trunk banding device was developed with the aim of inducing rapid ventricular hypertrophy. The device consists of an insufflatable cuff connected to a self-sealing button.

Methods: The right ventricles of 7 young goats (average weight, 8.

Comparison between adventitial and intimal inflammation of ruptured and nonruptured atherosclerotic plaques in human coronary arteries.

Objective: To verify the possible role of adventitial inflammation in atherosclerotic plaque vulnerability and coronary artery remodelling.

Methods: We compared the mean numbers of lymphocytes in the adventitia and in the plaque of ruptured thrombosed and stable equi-stenotic coronary segments of 34 patients who died due to acute myocardial infarction. We also analysed adventitial microvessels, adventitial fibrosis and the external elastic membrane.

A possible role for complement in the pathogenesis of chronic chagasic cardiomyopathy.

The membrane attack complex (MAC) of complement participates in several inflammatory and proliferative processes by releasing pro-inflammatory cytokines and growth factors from target cells. Chronic Chagasic cardiomyopathy (CCH) is a parasitic dilated cardiopathy, characterized by severe fibrosis and inflammation, which differs from idiopathic dilated cardiomyopathy (DCM). Trypanosoma cruzi, the pathogenic organism of CCH, is a strong complement activator and can also induce alternative pathway activation by mammalian cells.

Uhl's anomaly. Differential diagnosis and indication for cardiac transplantation in an infant.

We report the case of an 8-month-old female infant with Uhl's anomaly, who underwent successful cardiac transplantation. The clinical findings, complementary laboratory tests, anatomic findings, and differential diagnosis of the anomaly are discussed.

Double-outlet right ventricle with nonrelated ventricular septal defect: surgical results using the multiple patches technique.

Objective: Introduce a new surgical technique for biventricular correction of double-outlet right ventricle with noncommitted ventricular septal defect.

Methods: From April 1987 to February 1996, 15 patients with double-outlet right ventricle with noncommitted ventricular septal defect were operated on using a new technique for biventricular repair with multiple bovine pericardial patches to create a tunnel between the left ventricle and the aorta. Ages ranged from two months to 13 years (mean age 4.

[Growth factors in the myocardium of patients with chronic chagasic cardiomyopathy].

In this work we quantified various growth factors in the myocardium of 19 patients with chronic chagasic cardiomyopathy and heart failure, through the immunoperoxidase technique. We looked for T. cruzi antigens, growth factors (GM-CSF, TGF-beta1, PDGF-A and PDGF-B) and inflammatory cells (CD4+, CD8+, CD20+ and CD68+).

Cardiac rhabdomyomas exhibit a fetal pattern of atrial natriuretic peptide immunoreactivity.

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).

Systematic mapping of hearts from chronic chagasic patients: the association between the occurrence of histopathological lesions and Trypanosoma cruzi antigens.

To investigate the role played by Trypanosoma cruzi in the pathogenesis of chronic chagasic cardiopathy, the myocardiums of 12 hearts from individuals who had this condition were mapped in detail. Attempts were made to associate the histopathological lesions observed with the presence of parasitic antigens in the affected tissue. Samples from 26 regions of each heart were submitted to histological analysis and immunostained for the presence of T.

Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques.

This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas. We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction. These patients had typical symptoms of acute ischemic syndrome.

Great amount of C.pneumoniae in ruptured plaque vessel segments at autopsy. A comparative study with stable plaques.

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.

Reversible pulmonary trunk banding with a balloon catheter: assessment of rapid pulmonary ventricular hypertrophy.

Objective: We sought to assess the rapid hypertrophy of the right ventricle of young goats submitted to progressive pressure load by a balloon catheter.

Methods: The hearts of 6 young goats were assessed by means of echocardiography and cell morphology during and after right ventricular hypertrophy had been produced by a balloon catheter. Myocardial samples of the right ventricular outflow tract were harvested for microscopic studies.

Common arterial trunk associated with atrioventricular septal defect.

Described are the clinical, cross-sectional echocardiographic, electrocardiographic and angiographic findings, together with the results at autopsy, in a 5-month old infant with a common arterial trunk associated with an atrioventricular septal defect. As far as is known, this is only the 13th such case to be reported in the literature. A particularly unusual feature of this case was an intact atrial component of the atrioventricular septal defect.

Papillary fibroelastoma of the mitral valve 12 years after mitral valve commissurotomy.

A 63 year-old woman who had had mitral valve commissurotomy 12 years earlier was seen because of rheumatic mitral stenosis and left brachial paresis due to cerebral embolism. On clinical evaluation, a diastolic rumble was heard over the mitral area, and the echocardiogram revealed a mass attached to the mitral subvalvular apparatus. The patient was operated on, and both the surgical and histologic findings depicted papillary fibroelastoma.

[Absence of right atrioventricular connection. Morphological and clinical presentation when the dominant ventricle is morphologically right].

Absent right atrioventricular connection, with the left atrium connected to a dominant left-sided morphologically right ventricle is a rare situation. We report five cases with these anatomical features, with emphasis on the morphological and clinical aspects. Although this combination of lesions is very uncommon, the sequential segmental analysis can easily provide an accurate description of the anomaly.

Distribution of hyaluronan and dermatan/chondroitin sulfate proteoglycans in human aortic dissection.

Aortic dissections (AD) are characterized by the separation of the artery into two sheets, possibly due to fragility of the vessel wall. A mucoid histological pattern, imparted to the tissues mainly by hyaluronan and proteoglycans, can be seen in "cysts" and, in chronic cases, in a band of repair tissue. We studied the localization of hyaluronan, versican, decorin and biglycan in situ in aortas of 21 patients with recent AD, 8 with chronic AD and in 15 control cases.