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Human chronic chagasic cardiopathy: participation of parasite antigens, subsets of lymphocytes, cytokines and microvascular abnormalities
Higuchi, Maria de Lourdes;
Memórias do Instituto Oswaldo Cruz , 1999, DOI: 10.1590/S0074-02761999000700044
Abstract: this article tries to demonstrate by new pathological findings (with the use of immunohistochemical technique and confocal laser microscopy) that chronic chagasic cardiomyopathy is a result of multiple factors involving myocarditis, immunodepression, severe fibrosis and microvessels dilatation and that all of these alterations are probably directly related with the presence of trypanosoma cruzi parasites in the host associated with inadequate immunological response of the host.
Human chronic chagasic cardiopathy: participation of parasite antigens, subsets of lymphocytes, cytokines and microvascular abnormalities  [cached]
Higuchi Maria de Lourdes
Memórias do Instituto Oswaldo Cruz , 1999,
Abstract: This article tries to demonstrate by new pathological findings (with the use of immunohistochemical technique and confocal laser microscopy) that chronic chagasic cardiomyopathy is a result of multiple factors involving myocarditis, immunodepression, severe fibrosis and microvessels dilatation and that all of these alterations are probably directly related with the presence of Trypanosoma cruzi parasites in the host associated with inadequate immunological response of the host.
Cardiovascular function in elderly patients with chronic chagasic cardiopathy
Rocha, Manoel Otávio Costa;Correia, Paulo César;Barros, Márcio Vinícius L.;Torres, Rosália Moraes;Ribeiro, Ant?nio Luiz P.;Teixeira, Mauro Martins;
Revista da Sociedade Brasileira de Medicina Tropical , 2003, DOI: 10.1590/S0037-86822003000500001
Abstract: the objective of this work was to verify the degree and type of heart damage of elderly chagasic patients seen at an outpatient referral center and to compare them with the changes found in young chagasic patients with a similar degree of heart damage. elderly and young patients without advanced cardiopathy presented good functional behavior. elderly patients with advanced cardiopathy had more ventricular premature beats (vpb) in 24 h and less functional capacity in the exercise test than young patients of the same subgroup. there was a higher occurrence of effort-induced vpb and a lower prevalence of severe forms in elderly men, suggesting that chagas' disease may have a worse evolution in males. the association of cardiac damage characteristic of aging with the secondary damage due to chagas' disease could explain the greater functional damage found in elderly chagasic patients. thus, it appears that the physiopathological components of chagas' disease do have an influence on the clinical course of cardiopathy in the elderly population.
Cardiovascular function in elderly patients with chronic chagasic cardiopathy
Rocha Manoel Otávio Costa,Correia Paulo César,Barros Márcio Vinícius L.,Torres Rosália Moraes
Revista da Sociedade Brasileira de Medicina Tropical , 2003,
Abstract: The objective of this work was to verify the degree and type of heart damage of elderly chagasic patients seen at an outpatient referral center and to compare them with the changes found in young chagasic patients with a similar degree of heart damage. Elderly and young patients without advanced cardiopathy presented good functional behavior. Elderly patients with advanced cardiopathy had more ventricular premature beats (VPB) in 24 h and less functional capacity in the exercise test than young patients of the same subgroup. There was a higher occurrence of effort-induced VPB and a lower prevalence of severe forms in elderly men, suggesting that Chagas' disease may have a worse evolution in males. The association of cardiac damage characteristic of aging with the secondary damage due to Chagas' disease could explain the greater functional damage found in elderly chagasic patients. Thus, it appears that the physiopathological components of Chagas' disease do have an influence on the clinical course of cardiopathy in the elderly population.
Trypanosoma cruzi isolates from Mexican and Guatemalan acute and chronic chagasic cardiopathy patients belong to Trypanosoma cruzi I
Ruíz-Sánchez, Rosario;León, María Paula de;Matta, Vivian;Reyes, Pedro A;López, R;Jay, David;Monteón, Victor M;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000300012
Abstract: trypanosoma cruzi is classified into two major groups named t. cruzi i and t. cruzi ii. in the present work we analyzed 16 stocks isolated from human cases and four isolated from triatomines from diverse geographical origins (mexico and guatemala). from human cases four were acute cases, six indeterminates, and six from chronic chagasic cardiophatic patients with diagnosis of dilated cardiomyopathy established based on the left-ventricular end systolic dimension and cardiothoracic ratio on chest x-radiography and impaired contracting ventricle and different degree conduction/rhythm aberrations. dna samples were analyzed based on mini-exon (me) polymorphism, using a pool of three oligonucleotide for the amplification of specific intergenic region of t. cruzi me gene. all the mexican and guatemalan isolates regardless their host or vector origin generated a 350 bp amplification product. in conclusion t. cruzi i is dominant in mexico and guatemala even in acute and chronic chagasic cardiopathy patients. to our knowledge, this is the first study describing predominance of t. cruzi i in human infection for north and central america.
Immunodominance: a new hypothesis to explain parasite escape and host/parasite equilibrium leading to the chronic phase of Chagas' disease?
Rodrigues, M.M.;Alencar, B.C.G. de;Claser, C.;Tzelepis, F.;
Brazilian Journal of Medical and Biological Research , 2009, DOI: 10.1590/S0100-879X2008005000054
Abstract: intense immune responses are observed during human or experimental infection with the digenetic protozoan parasite trypanosoma cruzi. the reasons why such immune responses are unable to completely eliminate the parasites are unknown. the survival of the parasite leads to a parasite-host equilibrium found during the chronic phase of chagasic infection in most individuals. parasite persistence is recognized as the most likely cause of the chagasic chronic pathologies. therefore, a key question in chagas' disease is to understand how this equilibrium is established and maintained for a long period. understanding the basis for this equilibrium may lead to new approaches to interventions that could help millions of individuals at risk for infection or who are already infected with t. cruzi. here, we propose that the phenomenon of immunodominance may be significant in terms of regulating the host-parasite equilibrium observed in chagas' disease. t. cruzi infection restricts the repertoire of specific t cells generating, in some cases, an intense immunodominant phenotype and in others causing a dramatic interference in the response to distinct epitopes. this immune response is sufficiently strong to maintain the host alive during the acute phase carrying them to the chronic phase where transmission usually occurs. at the same time, immunodominance interferes with the development of a higher and broader immune response that could be able to completely eliminate the parasite. based on this, we discuss how we can interfere with or take advantage of immunodominance in order to provide an immunotherapeutic alternative for chagasic individuals.
Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?
Higuchi, Maria de Lourdes;Kawakami, Joyce;Ikegami, Renata;Clementino, Maysa Beatriz Mandetta;Kawamoto, Flavio M;Reis, Marcia M;Bocchi, Edimar;
Memórias do Instituto Oswaldo Cruz , 2009, DOI: 10.1590/S0074-02762009000900026
Abstract: chronic cardiopathy (cc) in chagas disease is a fibrotic myocarditis with c5b-9 complement deposition. mycoplasma and chlamydia may interfere with the complement response. proteolytic enzymes and archaeal genes that have been described in trypanosoma cruzi may increase its virulence. here we tested the hypothesis that different ratios of mycoplasma, chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. materials and methods: eight indeterminate form (if) and 20 cc chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and pcr techniques for detection of mycoplasma pneumoniae (mp), chlamydia pneumoniae(cp), c5b-9 and archaeal-like bodies. results: mp and cp-dna were always present at lower levels in cc than in if (p < 0.001) and were correlated with each other only in cc. electron microscopy revealed mycoplasma, chlamydia and two types of archaeal-like bodies. one had electron dense lipid content (edl) and was mainly present in if. the other had electron lucent content (elc) and was mainly present in cc. in this group, elc correlated negatively with the other microbes and edl and positively with c5b-9. the cc group was positive for archaea and t. cruzi dna. in conclusion, different amounts of mycoplasma, chlamydia and archaeal organisms may be implicated in complement activation and may have a role in chagas disease outcome.
Malaria parasite interactions with the human host  [cached]
Pouniotis D,Proudfoot O,Minigo G,Hanley J
Journal of Postgraduate Medicine , 2004,
Abstract: The interaction between the malaria parasite and the human host involves a number of interactions that result in the parasite evading the human immune system. Since the stages of the malaria lifecycle are complex, this allows the use of various immune evasion strategies by the malaria parasite and has major implications in the development of a vaccine for malaria endemic areas. The present review highlights key host:parasite interactions. Plasmodia puts selection pressure on human gene frequencies, and studies into host genetic factors such as the Duffy blood group and sickle cell anaemia offer insight into the host- parasite relationship. In addition, parasite interactions with the different effector arms of the immune system can result in altered peptide ligand (APL) antagonism which alters the immune response from a pro- to an anti-inflammatory T cell response. Recent insights into the interaction between professional antigen presenting cells, dendritic cells (DCs), and malaria parasites is discussed in detail.
Host Sexual Dimorphism and Parasite Adaptation  [PDF]
David Duneau,Dieter Ebert
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1001271
Abstract: In species with separate sexes, parasite prevalence and disease expression is often different between males and females. This effect has mainly been attributed to sex differences in host traits, such as immune response. Here, we make the case for how properties of the parasites themselves can also matter. Specifically, we suggest that differences between host sexes in many different traits, such as morphology and hormone levels, can impose selection on parasites. This selection can eventually lead to parasite adaptations specific to the host sex more commonly encountered, or to differential expression of parasite traits depending on which host sex they find themselves in. Parasites adapted to the sex of the host in this way can contribute to differences between males and females in disease prevalence and expression. Considering those possibilities can help shed light on host–parasite interactions, and impact epidemiological and medical science.
Host Sexual Dimorphism and Parasite Adaptation  [PDF]
David Duneau ,Dieter Ebert
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1001271
Abstract: In species with separate sexes, parasite prevalence and disease expression is often different between males and females. This effect has mainly been attributed to sex differences in host traits, such as immune response. Here, we make the case for how properties of the parasites themselves can also matter. Specifically, we suggest that differences between host sexes in many different traits, such as morphology and hormone levels, can impose selection on parasites. This selection can eventually lead to parasite adaptations specific to the host sex more commonly encountered, or to differential expression of parasite traits depending on which host sex they find themselves in. Parasites adapted to the sex of the host in this way can contribute to differences between males and females in disease prevalence and expression. Considering those possibilities can help shed light on host–parasite interactions, and impact epidemiological and medical science.
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