Molecular Characterization of Tc964, A Novel Antigenic Protein from Trypanosoma cruzi

The Tc964 protein was initially identified by its presence in the interactome associated with the LYT1 mRNAs, which code for a virulence factor of Trypanosoma cruzi. Tc964 is annotated in the T. cruzi genome as a hypothetical protein. According to phylogenetic analysis, the protein is conserved in the different genera of the Trypanosomatidae family; however, recognizable orthologues were not identified in other groups of organisms. Therefore, as a first step, an in-depth molecular characterization of the Tc946 protein was carried out. Based on structural predictions and molecular dynamics studies, the Tc964 protein would belong to a particular class of GTPases. Subcellular fractionation analysis indicated that Tc964 is a nucleocytoplasmic protein. Additionally, the protein was expressed as a recombinant protein in order to analyze its antigenicity with sera from Chagas disease (CD) patients. Tc964 was found to be antigenic, and B-cell epitopes were mapped by the use of synthetic peptides. In parallel, the Leishmania major homologue (Lm964) was also expressed as recombinant protein and used for a preliminary evaluation of antigen cross-reactivity in CD patients. Interestingly, Tc964 was recognized by sera from Chronic CD (CCD) patients at different stages of disease severity, but no reactivity against this protein was observed when sera from Colombian patients with cutaneous leishmaniasis were analyzed. Therefore, Tc964 would be adequate for CD diagnosis in areas where both infections (CD and leishmaniasis) coexist, even though additional assays using larger collections of sera are needed in order to confirm its usefulness for differential serodiagnosis.

Fine-needle aspiration of six carotid body paragangliomas

We report six carotid body paragangliomas diagnosed by fine-needle aspiration (FNA) in five patients. A total of eight aspirations were performed. The cytologic findings are characteristic: hemorrhagic background, hypo- to hypercellular smears (depending on the skill of the aspirator) with cells having delicate, ill-defined, vacuolated cytoplasm, pleomorphic nuclei with distinct nucleoli, rare intranuclear cytoplasmic inclusions, and prominent rosette formation. No complications arose in any of the eight aspirations. FNA is a safe, accurate means of diagnosing carotid body paragangliomas. It can provide essential information for treatment planning and patient management.

Cuspal perforations caused by long suture ends in implanted bioprosthetic valves

A description is presented of the gross anatomic, histologic, and scanning electron microscopic features of cuspal abrasions, perforations, and tears caused by excessively long ends of braided sutures in bioprosthetic cardiac valves implanted in the mitral position in sheep. These lesions are produced as consequences of contact between the ends of the sutures and the inflow surfaces of the bioprosthetic cusps, leading to a process of surface erosion that progresses to actual perforation of the cusps. The perforation has the appearance of a crater, the wider end of which faces the inflow surface and the walls of which are formed by broken ends of collagen fibrils. Suture perforations can extend to form tears that involve the free edge of the cusp and result in hemodynamically important regurgitation. Therefore, care must be taken to avoid leaving excessively long suture ends during the implantation of bioprosthetic cardiac valves.

Effect of ibuprofen on the healing phase of experimental myocardial infarction in the rat

The healing phase of acute myocardial infarction (AMI) is initiated by proteolysis of necrotic myocardium, followed by infiltration of fibroblasts and deposition of collagen. To assess whether ibuprofen, a potent antiinflammatory agent, preserves existing collagen and enhances deposition of new collagen during infarct healing, biochemical and morphologic studies were made of experimentally induced myocardial infarcts in untreated rats and in rats treated with ibuprofen. All treated rats received 12.5 mg/kg of ibuprofen at 1, 6 and 18 hours after AMI. Group 1 rats underwent measurement of myocardial hydroxyproline (HP) content at 24 hours after AMI. Group 2 rats received ibuprofen, 12.5 mg/kg, twice a day for 2 additional days, with measurement of myocardial HP at 3 days (group 2a) or 21 days (group 2b) after AMI. Group 3 rats received ibuprofen, 12.5 mg/kg, twice a day for 6 additional days with measurement of HP content, or infarct size and degree of thinning at 21 days after AMI. Compared with untreated rats, ibuprofen-treated rats had significantly greater amounts of HP in the infarct at 24 hours (group 1, 8.9 +/- 2.2 nmol/mg dry weight vs untreated, 7.1 +/- 2.8 nmol/mg dry weight, p less than 0.04) and at 21 days (group 2b, 112 +/- 37 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.05, and group 3, 125 +/- 51 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.003). Substantial scar thinning was noted in all rats; no difference in scar thinning was noted between treated and untreated rats at 21 days after AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular lesions in collagen-vascular diseases

In this review, the cardiac lesions which develop in association with the various collagen-vascular diseases are described. In rheumatoid arthritis, the most frequent lesions are: fibrous obliterative pericarditis, with pericardial deposits of calcium, fibrin, cholesterol, and rheumatoid granulomas; granulomatous or nonspecific myocarditis; valvulitis, vasculitis, and amyloid deposits. In ankylosing spondylitis, the lesions involve mainly the valves (aortic and mitral valves) and the aorta. In systemic lupus erythematosus, the predominant cardiovascular lesions are: pericarditis, Libman-Sacks endocarditis, nonspecific myocarditis, vasculitis with fibrinoid necrosis, and acceleration of atherosclerosis. In scleroderma, the main cardiac lesion is fibrosis with only scanty inflammatory cells; pericarditis and nonbacterial thrombotic endocarditis also occur. In dermatomyositis/polymyositis, fibrous or fibrinous pericarditis can occur, as well as myocarditis with infiltrates of lymphocytes and plasma cells and with degeneration and necrosis of myocytes; valvulitis is uncommon except when the disease is related to mucinous adenocarcinoma. In polyarteritis nodosa, various stages of necrotizing vasculitis involve all layers of the arterial walls; foci of myocardial necrosis of various sizes can occur in association with these lesions; cardiac hypertrophy related to hypertension and pericarditis related to uremia, may also be found. In Wegener's granulomatosis, pericarditis, inflammatory infiltrates, necrotizing granulomas, and vasculitis have been observed in the heart.

Granulomatous inflammation of the heart

Morphologic characteristics of granulomatous inflammation in the heart and pericardium are discussed. In rheumatic fever, two types of myocardial lesion are present--a nonspecific myocarditis and a specific lesion characterized by granulomas known as Aschoff's nodules. The latter undergo a cycle of development and resolution; in their mature stage, they contain Aschoff's cells which are uni- or multinucleated histiocytes with a serrated nuclear chromatin bar. Ultrastructural studies do not suggest a relationship between these cells and cardiac or smooth muscle cells. In metabolic disorders, granulomas occur in Farber's disease (lipogranulomatosis), gout (in which tophi are associated with calcific deposits and with a foreign body cellular reaction), the various syndromes of oxalosis (in which oxalate deposits also lead to a foreign body reaction), and in chronic granulomatous disease of childhood. Foreign body giant-cells can also be found in association with calcification of necrotic myocytes and in the syndromes of "cholesterol pericarditis." Well-developed granulomas occur in sarcoidosis, giant cell myocarditis, as a reaction to foreign bodies and devices implanted within the cardiovascular system, and in certain diseased caused by infective agents (tuberculosis, fungal and parasitic disorders). Infiltration of the heart by nongranulomatous masses of histiocytes can occur in Whipple's disease, Niemann-Pick disease, the hyperlipoproteinemias, Gaucher's disease, and in proliferative disorders of the mononuclear phagocyte system (juvenile xanthogranuloma, Chester-Erdheim syndrome, and malignant histiocytosis).

Specificity of light and electron microscopic features of hypertrophic obstructive and nonobstructive cardiomyopathy. Qualitative, quantitative and etiologic aspects

A review is presented of the histologic and ultrastructural abnormalities found in the hearts of patients with hypertrophic cardiomyopathy. Evidence is presented to show that myocardial fiber disarray is found in hypertrophic cardiomyopathy as well as in other conditions; however, in the latter it seldom involves more than 5% of the myocytes in transverse sections of ventricular septum. A new theory of morphogenesis is proposed to account for the asymmetric cardiac hypertrophy that characterizes hypertrophic cardiomyopathy. This theory is summarized as follows: (1) hypercontractility is the underlying abnormality affecting cardiac myocytes; (2) this hypercontractility is present during embryonic development and constitutes the stimulus to the inappropriate increase in cardiac mass that takes place in hypertrophic cardiomyopathy; (3) during embryonic development this stimulus results in increased mitotic division (i.e. hyperplasia) rather than in increased size of individual myocytes (i.e. hypertrophy); (4) hyperplasia is preferentially increased in the ventricular septum (perhaps because of the mechanical forces exerted by left and right ventricular contraction on the ventricular septum), thus exaggerating the asymmetric growth that occurs normally in this area during prenatal development; (5) after birth, the septal asymmetry does not regress in patients with hypertrophic cardiomyopathy, as it does in normal individuals, because it is complicated by hyperplasia (i.e. increased numbers of myocytes are already present in the ventricular septum); (6) the prenatal phase of hyperplasia is followed by a postnatal phase of gradual, progressive hypertrophy in which myocytes enlarge, septal hypertrophy becomes exaggerated, and clinical symptoms eventually develop.