RESUMO

METHODS: We analyzed the potential influence that associated risk factors (ARF), such as smoking, alcoholism, overweight, and hypertension, could have on the establishment of chronic chagasic cardiomyopathy (CC). The sample was comprised of 124 individuals, 69 males and 55 females (mean age +/- SD, 41 +/- 9.5 years), who were born in en demic areas of Northern Argentina and migrated further to Rosario City, an area where autochthonous cases of Chagas' disease have never been registered. Assessments included the following: clinical examination to discard previous cardiomyopathies; search for the presence of ARF according to standard criteria; specific serology; frontal chest X-ray, and 12-lead resting electrocardiogram (ECG). Subjects were classified on the basis of their serological status and presence of ARF into four groups: Tc+ARF+ T. cruzi-infected persons with ARF (n = 41); Tc-ARF+ seronegativity in presence of ARF (n = 27); Tc+ARF- individuals showing positive serology that lacked ARF (n = 27), and Tc-ARF- seronegative individuals having no ARF (n = 29). RESULTS: Except for a higher female/male ratio in groups presenting no ARF (p < 0.02), no statistical differences as to age, length of residence in endemicity areas (LR), and ARF distribution were recorded among groups. Forty-one persons presented abnormal ECG tracings, distributed thus: Tc+ARF+, 18/41; Tc-ARF+, 14/27, Tc+ARF-, 14/27, and Tc-ARF, 4/29 (p < 0.01, in relation to the latter group). Subjects from the Tc+ARF+, Tc-ARF+, and Tc+ARF- groups had 4.89-, 6.7-, and 6.7-fold increases, respectively, if having an abnormal ECG when compared with Tc-ARF- individuals. Comparisons on the frequency of abnormal ECG between seropositives carrying ARF or not yielded a non-significant odds ratio, be it estimated as crude, or after adjusting for sex, age, and LR in multivariate analysis. CONCLUSIONS: Presence of ARF was not associated with an increasing risk of cardiac affectation in chronically T. cruzi-infected persons, but resulted in chagasic-compatible ECG abnormalities in those seronegative individuals.

Assuntos

RESUMO

Heparinised blood samples were obtained from 20 patients with chronic plaque psoriasis and from 13 age-matched healthy controls. After preliminary titration, mononuclear cells separated over Ficoll-Tryoson were cultured for 5 days with 10 microg ml(-1) of 15 mycobacterial preparations, or with pokeweed mitogen and concanavalin A. Stimulation indices were determined for each reagent and means were determined for patients and controls. Results for patients showed a striking reduction of responsiveness to mycobacteria, apparently due to loss of responses to group i, common mycobacterial antigens, and no differences in responses to mitogens. These observations relate psoriasis to certain other diseases, notably mycobacterial infections, rheumatoid arthritis, Chagas' disease and human immunodeficiency virus infection. The observations may be relevant to the aetiology of psoriasis, and to potential immunotherapy for the disease.

Assuntos

RESUMO

To evaluate the status of the cellular immune response of patients with community acquired pneumonia (CAP), 8 CAP cases were studied for their in vitro T-cell responses to concanavalin A (Con A), tuberculin, and candidin, as well as levels of major T-cell populations in peripheral blood. Assessment on admission revealed that CAP patients had significantly decreased responses to both antigen and mitogen driven lymphocyte proliferation when compared to age and sex matched controls. Studies performed upon 1 week of antibiotic treatment made evident, in turn, that clinical improvement was accompanied by a reestablishment of the in vitro responses to tuberculin and candidin, whereas the lymphoproliferation induced by Con A remained decreased as in its first evaluation. Data from admission and day 7 of treatment showed no significant differences as to the levels of peripheral T-cell subsets when compared to those of healthy controls. Our results indicate that CAP coincides with reduced in vitro T-cell responses to antigen and mitogen stimulation.

Assuntos

RESUMO

The immune response is impaired in the silent stage of Chagas' disease. We used quadruple skin-testing with new tuberculins in 37 adults who were symptom-free but seropositive for Trypanosoma cruzi and in 37 matched seronegative controls. Whereas 19% of controls responded to common mycobacterial antigens, none of the Chagas' seropositive group responded to them (p < 0.006), demonstrating specificity in their unresponsiveness. The enhanced tuberculin reactivity after BCG vaccination in the control group was suppressed in seropositive subjects (p < 0.002). Selective loss of response to common mycobacterial antigens may have implications for the autoimmune pathology of Chagas' disease, and for susceptibility to tuberculosis, leprosy, and HIV disease.

Assuntos

RESUMO

To analyze whether electrocardiographic alterations (ECGA) in patients with antibodies to Trypanosoma cruzi showed a pattern of familial aggregation, a sample of 379 young adults (166 men and 213 women) distributed in sibships, were assessed for the presence of anti-T. cruzi antibodies, and subjected to a complete clinical examination and a standard resting electrocardiogram (ECG). Positive T. cruzi serology was detected in 165 individuals, 48 of them showing an abnormal ECG (overall prevalence 29%). One hundred and eleven seropositive individuals were distributed in 45 sibships, each of them constituted by more than one seropositive sib, with ECGA being present in 34 out of these patients. Seropositive subjects with ECGA were detected in 27 sibships. Since the index case within each sibship is counted exactly once, affected individuals selected at random as propositi were extracted to calculate the prevalence of ECGA among first degree relatives of probands. Abnormal ECGs were recorded in 7 out of 45 sibs yielding a prevalence that did not differ from estimations registered in the general population or seropositive sibs. Data from the present sample show no familial aggregation for the occurrence of ECGA in patients with T. cruzi. infection.

Assuntos

RESUMO

To ascertain whether maternal infection with Trypanosoma cruzi may influence the course of the parasitic infection in offspring, two groups of female 1 rats were mated with syngeneic sires. One group of females was infected with 10(6) trypomastigotes of T. cruzi three times at weekly intervals. All offspring were nursed by their mothers until weaning and then separated into two groups of young, one to be infected with the same dose of T. cruzi, and the other to remain uninfected. Infection of pregnant rats caused no aggravated disease but resulted in a self-controlled infection that did not cause any deaths or affect their reproductive capacity. The number of young delivered, litter size, fertility coefficient, and offspring weights at weaning were also unaffected by maternal infection; however, the survival coefficient decreased in comparison with values recorded in the offspring of uninfected mothers. The latter finding is likely due to neonatal transmission, since bloodstream forms of T. cruzi were observed in a few offspring of infected mothers. While infected offspring whose mothers had been inoculated with T. cruzi during pregnancy were not protected from acute infection, the occurrence of chronic focal myocarditis was less prevalent when compared with that recorded in chronically infected offspring born to uninfected mothers.

Assuntos

RESUMO

Concomitant immunity (IC) is usually defined as the capacity of any animal bearing a progressor tumor to inhibit a second challenge with the same tumor. In order to establish the contribution of the host to the origin of this phenomenon, IC was induced in two lines of rats with a different behavior when challenged with Sarcoma E 100 (SE 100), i.e., line IIMc: 90% take and 100% regression; line "m": 100% take and death. The rats received a second challenge on day 3 (Group II), 7 (III), and 14 (IV), as well as the control groups: II', III' and IV', respectively. The animals reinoculated on day 7 showed a decrease, both in percentage of takes (Fig. 1, III vs III') and tumor surface (Table 1, 2). Likewise, in rats IIMc, a lesser development of the first inoculum (Table 1, Ia vs I') was observed. The Winn assay (Table 3) confirmed the presence of immunocompetent spleen cells (CE) against SE 100 in IIMc rat spleens: namely, 1) immune rats (II), 2) unique tumor bearing rats (IV), 3) first progressor and second negative inoculum (V). In line "m" the percentage of takes was only smaller in the group inoculated conjointly with CE from immune rats (Table 3, VI vs VII). A mere 10% (3/30) of "m" rats were immunized against SE 100. Consequently, these results could attribute the IC, in IIMc rats, to immunological mechanisms, while in "m" it could be due to factor(s) released and/or induced by the first tumor, as proposed by Gorelik.

Assuntos

RESUMO

El fenómeno de inmunidad concomitante (IC) se define clásicamente como la capacidad que tiene un animal portador de un tumor progresor de inhibir el crecimiento de un segundo inóculo del mismo tumor. En dos líneas de ratas, que tienen distinto comportamiento al desafiarse con Sarcoma E 100 (SE 100), lnea IIMc: 90 por ciento de toma y 100 por ciento de regresión; línea "m": 100 por ciento de toma y muerte), se indujo IC a fin de establecer la participación del huésped en la generación de este fenómeno frente al mismo tumor. Las ratas recibieron el segundo desafío los días 3 ó 14, al igual que los respectivos grupos testigos. Los animales reinoculados el día 7 presentarón menor porcentagen de toma y menores superficies tumorales; además en las ratas IIMc se observó menor desarrollo del primer inóculo. El ensayo de Winn en ratas IIMc confirmó la presencia de células esplénicas (CE) comprometidas contra el SE 100 en los bazos de: ratas inmunes: portadoras de un solo tumor; de primer inóculo en crecimiento y segundo negativo en IC. En línea "m" el porcentagen de toma sólo fue menor en el grupo inoculado conjuntamente con el CE de ratas inmunes. Sólo un 10 por ciento (3/30) de ratas "m" pudieron inmunizarse contra el SE 100. Estos resultados perimitirían atribuir el fenômeno de IC, en ratas IIMc, a mecanismos inmunitários y en ratas "m", de acuerdo a lo postulado por Gorelik, a un factor o factores liberados y/o inducidos por el primer tumor. Se sugiere que prevalecería uno u otro mecanismo según las características biológicas del huésped

Assuntos

RESUMO

Concomitant immunity (IC) is usually defined as the capacity of any animal bearing a progressor tumor to inhibit a second challenge with the same tumor. In order to establish the contribution of the host to the origin of this phenomenon, IC was induced in two lines of rats with a different behavior when challenged with Sarcoma E 100 (SE 100), i.e., line IIMc: 90

take and 100

regression; line [quot ]m[quot ]: 100

take and death. The rats received a second challenge on day 3 (Group II), 7 (III), and 14 (IV), as well as the control groups: II, III and IV, respectively. The animals reinoculated on day 7 showed a decrease, both in percentage of takes (Fig. 1, III vs III) and tumor surface (Table 1, 2). Likewise, in rats IIMc, a lesser development of the first inoculum (Table 1, Ia vs I) was observed. The Winn assay (Table 3) confirmed the presence of immunocompetent spleen cells (CE) against SE 100 in IIMc rat spleens: namely, 1) immune rats (II), 2) unique tumor bearing rats (IV), 3) first progressor and second negative inoculum (V). In line [quot ]m[quot ] the percentage of takes was only smaller in the group inoculated conjointly with CE from immune rats (Table 3, VI vs VII). A mere 10

(3/30) of [quot ]m[quot ] rats were immunized against SE 100. Consequently, these results could attribute the IC, in IIMc rats, to immunological mechanisms, while in [quot ]m[quot ] it could be due to factor(s) released and/or induced by the first tumor, as proposed by Gorelik.

RESUMO

El fenómeno de inmunidad concomitante (IC) se define clásicamente como la capacidad que tiene un animal portador de un tumor progresor de inhibir el crecimiento de un segundo inóculo del mismo tumor. En dos líneas de ratas, que tienen distinto comportamiento al desafiarse con Sarcoma E 100 (SE 100), lnea IIMc: 90 por ciento de toma y 100 por ciento de regresión; línea "m": 100 por ciento de toma y muerte), se indujo IC a fin de establecer la participación del huésped en la generación de este fenómeno frente al mismo tumor. Las ratas recibieron el segundo desafío los días 3 ó 14, al igual que los respectivos grupos testigos. Los animales reinoculados el día 7 presentarón menor porcentagen de toma y menores superficies tumorales; además en las ratas IIMc se observó menor desarrollo del primer inóculo. El ensayo de Winn en ratas IIMc confirmó la presencia de células esplénicas (CE) comprometidas contra el SE 100 en los bazos de: ratas inmunes: portadoras de un solo tumor; de primer inóculo en crecimiento y segundo negativo en IC. En línea "m" el porcentagen de toma sólo fue menor en el grupo inoculado conjuntamente con el CE de ratas inmunes. Sólo un 10 por ciento (3/30) de ratas "m" pudieron inmunizarse contra el SE 100. Estos resultados perimitirían atribuir el fen¶meno de IC, en ratas IIMc, a mecanismos inmunitários y en ratas "m", de acuerdo a lo postulado por Gorelik, a un factor o factores liberados y/o inducidos por el primer tumor. Se sugiere que prevalecería uno u otro mecanismo según las características biológicas del huésped (AU)

Assuntos