scholarly journals Evolution of subpatent parasitaemia in Trypanosoma cruzi chronically infected mice with the help of a cyclophosphamide amplification transfer assay

1991 ◽  
Vol 33 (6) ◽  
pp. 509-514 ◽  
Author(s):  
José M. Alvarez ◽  
Ayumi Oshima ◽  
Veronica Mozer ◽  
Liliane Guimarães ◽  
Hércules Menezes

We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transferred with one Y strain parasite and in 20% of animals transferred with one CL strain parasite). Using acute phase bloodforms, the assay proved to be more sensitive than conventional subinoculation when dealing with the CL, but not the Y strain of the parasite. With the help of this parasite detection tool, we have studied during a one year period, the evolution of subpatent parasitaemias in a group of mice which survived through chemotherapy from lethal acute phase of T. cruzi infection. Cyclophosphamide transfer assay revealed occult parasitaemias in 100% of the chronic animals, nevertheless, continuous and discontinuous patterns of positivity were observed.

2019 ◽  
Vol 26 (36) ◽  
pp. 6519-6543 ◽  
Author(s):  
Adriana Egui ◽  
Paola Lasso ◽  
Elena Pérez-Antón ◽  
M. Carmen Thomas ◽  
Manuel Carlos López

Chagas disease courses with different clinical phases and has a variable clinical presentation and progression. The acute infection phase mostly exhibits a non-specific symptomatology. In the absence of treatment, the acute phase is followed by a chronic phase, which is initially asymptomatic. This chronic asymptomatic phase of the disease is characterized by a fragile balance between the host’s immune response and the parasite replication. The loss of this balance is crucial for the progression of the sickness. The virulence and tropism of the T. cruzi infecting strain together to the inflammation processes in the cardiac tissue are the main factors for the establishment and severity of the cardiomyopathy. The efficacy of treatment in chronic Chagas disease patients is controversial. However, several studies carried out in chronic patients demonstrated that antiparasitic treatment reduces parasite load in the bloodstream and leads to an improvement in the immune response against the Trypanosoma cruzi parasite. The present review is mainly focused on the cellular patterns associated to the clinical status and the evolution of the disease in chronic patients, as well as the effectiveness of the treatment related to T. cruzi infection control. Therefore, an emphasis is placed on the dynamics of specific-antigens T cell subpopulations, their memory and activation phenotypes, their functionality and their contribution to pathogenesis or disease control, as well as their association with risk of congenital transmission of the parasite.


1986 ◽  
Vol 19 (3) ◽  
pp. 161-164 ◽  
Author(s):  
Frederico G.C. Abath ◽  
Yara M. Gomes ◽  
Eridan M. Coutinho ◽  
Silvia M.L. Montenegro ◽  
Maria E.B. Melo ◽  
...  

In this experiment, the effect of betamethasone administered in the early post- acute infection of mice by Trypanosoma cruzi was studied. This drug was administered during 30 days after the 42nd day of infection in a dose of 0.15 mg/day. The betamethasone treatment did not cause fresh outbreaks of parasitemia and the histopathological findings in the chronic phase were not different from those in the control group. The higher cumulative mortality after treatment in the experimental group was due to superimposed bacterial infections. Outbred albino mice infected with low numbers ofY strain Trypanosoma cruzi trypomastigotes were not suitable models for Chagas' disease, since after 7 months of observation only mild histological lesions developed in all the animais. Prolonged betamethasone treatment of mice infected with low numbers o/Trypanosoma cruzi of the Y strain, during the post-acute phase did not aggravate the course of infection.


2003 ◽  
Vol 36 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Sonia S. Francolino ◽  
Antonio Fernandez Antunes ◽  
Rodolfo Talice ◽  
Rachel Rosa ◽  
Joel Selanikio ◽  
...  

A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment) could also be due to the advanced age of the patient.


1993 ◽  
Vol 26 (1) ◽  
pp. 25-33 ◽  
Author(s):  
E.C. Oliveira ◽  
M.M.A. Stefani ◽  
A.O. Luquetti ◽  
E.F. Vêncio ◽  
M.A.R. Moreira ◽  
...  

A new Trypanosoma cruzi stock isolated from a patient in the chronic phase of Chagas' disease with the digestive and cardiac fortn of the disease was characterized by experimental infection in isogenic, susceptible, A/Sn strain mice. Parasitemia curves showed up to 1.7x10(6) parasites/ml and no mortality was observed up to 300 days post infection. Specific IgM was found in mice in the acute phase up to 40 days and also in the chronic phase. IgG antibodies yvere detected in the acute and chronic phase. Histopathology examination demonstrated myotropism to the digestive tract muscle layers and to the heart.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucia Rangel-Gamboa ◽  
Lirio López-García ◽  
Francisco Moreno-Sánchez ◽  
Irma Hoyo-Ulloa ◽  
María Elisa Vega-Mémije ◽  
...  

Abstract Background Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi and is transmitted by triatomine insects. Clinical manifestations vary according to the phase of the disease. Cutaneous manifestations are usually observed in the acute phase (chagoma and Romaña’s sign) or after reactivation of the chronic phase by immunosuppression; however, a disseminated infection in the acute phase without immunosuppression has not been reported for CD. Here, we report an unusual case of disseminated cutaneous infection during the acute phase of CD in a Mexican woman. Methods Evaluation of the patient included a complete clinical history, a physical exam, and an exhaustive evaluation by laboratory tests, including ELISA, Western blot and PCR. Results Skin biopsies of a 50-year-old female revealed intracellular parasites affecting the lower extremities with lymphangitic spread in both legs. The PCR tests evaluated biopsy samples obtained from the lesions and blood samples, which showed a positive diagnosis for T. cruzi. Partial sequencing of the small subunit ribosomal DNA correlated with the genetic variant DTU II; however, serological tests were negative. Conclusions We present a case of CD with disseminated skin lesions that was detected by PCR and showed negative serological results. In Mexico, an endemic CD area, there are no records of this type of manifestation, which demonstrates the ability of the parasite to initiate and maintain infections in atypical tissues.


Parasitology ◽  
1991 ◽  
Vol 102 (3) ◽  
pp. 379-385 ◽  
Author(s):  
M. S. Leguizamon ◽  
O. E. Campetella ◽  
M. B. Reyes ◽  
C. F. Ibañez ◽  
M. A. Basombrio ◽  
...  

Several recombinantTrypanosoma cruziproteins previously isolated were used as antigens to analyse antibody specificities present in sera from human infections. Some parasite proteins such as SAPA (Shed Acute Phase Antigen) are antigenic early after infection. Others, like antigens 1 and 30, are antigenic mainly during the chronic phase of the infection. To understand why different proteins are antigenic at different periods of infection, specificities of antibodies present in the sera of infected mice were compared with the antigens expressed by parasites collected directly from blood. Parasites collected during the acute parasitaemia peak expressed not only antigen SAPA, but also antigens 1 and 30. However, only antibodies against SAPA were frequently observed during the early period and also in the chronic phase of murine infection. Long-lasting antibodies against SAPA were detected regardless of the mouse and parasite strains used. Furthermore, all 8 recombinant clones detected in aT. cruziexpression library with pooled sera from acutely infected mice were homologous to the SAPA gene. These results show that even though parasites from the acute parasitaemia peak in mice may express simultaneously several proteins known to be antigenic, only antibodies against SAPA were consistently detected.


2012 ◽  
Vol 68 (2) ◽  
pp. 424-437 ◽  
Author(s):  
D. E. Perez-Mazliah ◽  
M. G. Alvarez ◽  
G. Cooley ◽  
B. E. Lococo ◽  
G. Bertocchi ◽  
...  

2020 ◽  
Vol 11 (Vol.11, no.3) ◽  
pp. 344-349
Author(s):  
Gabriel GUSETU ◽  
Angelo BULBOACĂ ◽  
Monica Alina MAGER ◽  
Gabriel CISMARU ◽  
Alexandra Ina BULBOACĂ ◽  
...  

Patients with cervical spinal cord injury have a high incidence of cardiac arrhythmias, especially in the first 14 to 30 days after traumatic event (acute phase). Electrophysiological abnormalities described in the acute phase are most often bradycardia, which is spontaneous or triggered by various stimuli. In the chronic phase, varied arrhythmias are described, but ventricular arrhythmias as a result of autonomic dysregulation in chronic SCI are rare and isolated. We present the case of a patient with a C5-C6 incomplete spinal cord injury (ASIA-B grade) in which symptomatic ventricular arrhythmia is described one year after the traumatic event.


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