Long-term follow-up of a patient since the acute phase of Chagas disease (South American trypanosomiasis): further treatment and cure of the infection

ABSTRACTA woman had been followed since 1957 for acute phase Chagas disease. Parasitological and serological tests were positive, and treatment included benznidazole in 1974. Following treatment, parasitological test results were negative and conventional serology remained positive until 1994, with subsequent discordant results (1995-1997). The results became consistently negative since 1999. She had an indeterminate chronic form until 1974. Only two minor and transitory nonspecific alterations on electrocardiogram were noted, with the last nine records normal until June 2014. This case confirms the possibility of curing chronic disease and suggests the benefit of specific treatments for preventing long-term morbidity.

Activity of natural killer cells during HIV-1 infection in Brazilian patients

Natural killer cells are increasingly being considered an important component of innate resistance to viruses, but their role in HIV infection is controversial. Some investigators have found that natural killer cells do not confer a protective effect during the progression of HIV disease, whereas others have shown that natural killer cells may be protective and retard the progression of the disease, either through their lytic activity or by a chemokine-related suppression of HIV replication. In this study, we analyzed functional alterations in the activity of natural killer cells during HIV-1 infection using a natural killer cells activity assay with K562 cells as targets. RESULTS: Our results show that the activity of natural killer cells decreases only in the advanced phase of HIV infection and when high (40:1) effector cell-target cell ratios were used. The depression at this stage of the disease may be related to increased levels of some viral factors, such as gp120 or gag, that interfere with the binding capacity of natural killer cells, or to the decreased production of natural killer cells -activity-stimulating cytokines, such as IFN-a and IL-12, by monocytes, a subset of cells that are also affected in the late stage of HIV infection. The data suggest that decreased natural killer cells cell activity may contribute to the severe impairment of the immune system of patients in the late stages of HIV infection.

Analysis of the Prevalence of Ventricular Late Potentials in the Late Phase of Myocardial Infarction Based on the Site of Infarction

OBJECTIVE: The initial site of myocardial infarction (MI) may influence the prevalence of ventricular late potentials (VLP), high-frequency signals, due to the time course of ventricular activation. The prevalence of VLP in a period of more than 2 years after acute MI was assessed focusing on the initially injured wall . METHODS: The prevalence of VLP in a late phase after MI (median of 924 days) in anterior/antero-septal and inferior/infero-dorsal wall lesion was analyzed using signal-averaged electrocardiogram in time domain. The diagnostic performance of the filters employed for analysis on was tested at high-pass cut-off frequencies of 25 Hz, 40 Hz and 80 Hz. RESULTS: The duration of the ventricular activation and its terminal portion were larger in inferior than anterior infarction, at high-pass cut-off frequencies of 40 Hz and 80 Hz. In patients with ventricular tachycardia, these differences were more remarked. The prevalence of ventricular late potentials was three times greater in inferior than anterior infarction. CONCLUSION: Late after myocardial infarction, the prevalence and the duration of ventricular late potentials are greater in lesions of inferior/infero-dorsal than anterior/antero-septal wall confirming their temporal process, reflecting their high-frequency content.

Assessment of Autonomic Function by Phase Rectification of RRInterval Histogram Analysis in Chagas Disease

Background:In chronic Chagas disease (ChD), impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC) and parasympathetic, deceleration phase (DC) influences on cardiac autonomic modulation.Objective:This study investigated heart rate variability (HRV) as a function of RR-interval to assess autonomic function in healthy and ChD subjects.Methods:Control (n = 20) and ChD (n = 20) groups were studied. All underwent 60-min head-up tilt table test under ECG recording. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 600–1100 ms. In each class, mean RR-intervals (MNN) and root-mean-squared difference (RMSNN) of consecutive normal RR-intervals that suited a particular class were calculated. Average of all RMSNN values in each class was analyzed as function of MNN, in the whole series (RMSNNT), and in AC (RMSNNAC) and DC (RMSNNDC) phases. Slopes of linear regression lines were compared between groups using Student t-test. Correlation coefficients were tested before comparisons. RMSNN was log-transformed. (α < 0.05).Results:Correlation coefficient was significant in all regressions (p < 0.05). In the control group, RMSNNT, RMSNNAC, and RMSNNDCsignificantly increased linearly with MNN (p < 0.05). In ChD, only RMSNNAC showed significant increase as a function of MNN, whereas RMSNNT and RMSNNDC did not.Conclusion:HRV increases in proportion with the RR-interval in healthy subjects. This behavior is lost in ChD, particularly in the DC phase, indicating cardiac vagal incompetence.

Assessment of Galectin-3 Polymorphism in Subjects with Chronic Chagas Disease

AbstractBackground:Galectin-3, a β-galactoside binding lectin, has been described as a mediator of cardiac fibrosis in experimental studies and as a risk factor associated with cardiovascular events in subjects with heart failure. Previous studies have evaluated the genetic susceptibility to Chagas disease in humans, including the polymorphisms of cytokine genes, demonstrating correlations between the genetic polymorphism and cardiomyopathy development in the chronic phase. However, the relationship between the galectin-3 single nucleotide polymorphism (SNP) and phenotypic variations in Chagas disease has not been evaluated.Objective:The present study aimed to determine whether genetic polymorphisms of galectin-3 may predispose to the development of cardiac forms of Chagas disease.Methods:Fifty-five subjects with Chagas disease were enrolled in this observational study. Real-time polymerase chain reaction (PCR) was used for genotyping the variants rs4644 and rs4652 of the galectin-3 gene.Results:For the SNP rs4644, the relative risk for the cardiac form was not associated with the genotypes AA (OR = 0.79, p = 0.759), AC (OR = 4.38, p = 0.058), or CC (OR = 0.39, p = 0.127). Similarly, for the SNP rs4652, no association was found between the genotypes AA (OR = 0.64, p = 0.571), AC (OR = 2.85, p = 0.105), or CC (OR = 0.49, p = 0.227) and the cardiac form of the disease.Conclusion:Our results showed no association between the different genotypes for both SNPs of the galectin-3 gene and the cardiac form of Chagas disease. (Arq Bras Cardiol. 2015; [online].ahead print, PP.0-0)

Effects of intraspecific competition and food deprivation on the immature phase of Ascia monuste orseis (Lepidoptera, Pieridae)

The effect of intraspecific competition for food on larvae and of food deprivation for 24 h on 2nd and 4th instars of Ascia monuste orseis (Godart, 1819) was investigated. Intraspecific competition for food during the immature phase leads to long pupation time, high larval mortality, reduced adult weight, and reduced number of eggs per female. In food deprivation experiments, the major differences in A. monuste orseis performance were long pupation time in the group that was deprived during the 2nd instar; and a negative effect on reproduction in the group that was deprived during the 4th instar, with reduced adult weight. Both food deprived periods tested are critical, and deprivation during the 2nd instar seems to have an effect as drastic as during the 4th instar because it directly affects larvae survival. Immatures can resist food deprivation for 24 h during the 2nd and 4th instars (low mortality), have a compensatory behaviour (high ingestion and biomass gain) during the 5th instar, and do not demonstrate cannibalistic behaviour during food deprivation.

Studies on the relationship between lectin binding carbohydrates and different strains of Leishmania from the New World

The culture forms of L. mexicana pifanoi (LRC L-90), L. mexicana mexicana (LRC L-94, M-379); L. braziliensis braziliensis (LRC L-77, L-1, M-2903, H-LSS) and L. mexicana amazonensis (H-JMMO, M-JOF, H-21, H-PLL,M-1696) were tested with the following lectins: Canavalia ensiformis, Ricinus communis-120, Axinella polypoides, Phaseolus vulgaris, Evonymus europaeus, lotus tetragonolobus, Dolichos biflorus, Aaptos papillata II, Laburnum alpinum, Ulex europaeus, Arachis hypogaea and Soja hispida. All examined strains of Leishmania were agglutinated by C. ensiformis, R. communis-120 and A. popypoides. No agglutination reactions were observed with P. vulgaris, D.biflorus, A. papillata II, E. europaeus and L. tetragonolobus. Only L. m. pifanoi and the L. m. amazonensis strains H-JMMO and MJOF showed agglutination reactions with S. hispida, U. europaeus, L. alpinum and A. hypogaea, while L. m. mexicana (LRC L-94; M-379) strains, L. b. braziliensis H. LSS, LRC L-77; L-1; M-2903 and the L. m. amazonensis strains, H-PLL, H-21, M-1696 showed no agglutination reactions with these four lectins.

A simple method for assessing the binding of concanavalin A to mononuclear cell surfaces: no interference of visceral leishmaniasis serum on this binding

We report a simple method for evaluating the binding of concanavalin A (ConA) to human peripheral blood mononuclear cells (PBMC). The binding is evidenced by an immunoenzymic assay using peroxidase-conjugated immunoglobulins of a rabbit anti-ConA serum. Using the method we show that sera from patients with American leishmaniasis do not interfere with binding of ConA to PBMC.

Analysis of toxoplasma gondii proteins after Triton X-114 solubilization and hidropholic chromotograhy

The distribution of the surface proteins of toxoplasma gondii radiodinated were studied using the phase separation technique and ability of binding in the phenyl-Sepharose column. Eight polypeptides with Mr 22 to 180 distributed exclusively in the detergent rich-phase, while six polypeptides with mol. wt. 15,000 to 76,000 distributed exclusively in the detergent poor-phase. Twopolypeptides with 15,000 and 70,000 distributed on both phase. All the polypeptides present in the detergent rich-phase binding in the phenyl-Sepharose column, and can be isolated in two peak according with their relative hydrophobicities.two polypeptides hydrophobic with Mr 60 and 66 recognized by human serum were isolated by the association of the two technique. Our result showed that the surface proteins of t. gondii present different degrees of hydrophobicity and that the use of hydrophobic interaction chromatography after Triton X-114 extraction may be an important isolation method of membrane proteins.

Experimental chagas' disease in rhesus monkeys. I. Clinical parasitological, hematological and anatomo-pathological studies in the acute and indeterminate phase of the disease

Rhesus monkeys (macaca mulatta) were infected subcutaneously with 1.0 x 10**4 to 1.5 x 10**4 metacyclic trypomastigotes of Trypanosoma cruzi (Colombian strain). Parasitological and immunological parameters were evaluated in these animals for periods of 1 month to over 3 years. a chagona was observed between the 3 rd and the 13th day after infection (a.i) and patent parasitaemia between the 13th and 59th day a.i.. Thereafter, parasites were demonstrated only by haemoculture and/or xenodiagnosis. Circulating specifc IgM and IgC antibodies were observed as early as in the 2nd week a. i. IgG levels persisted until the end of the expriment, but IgM antibodies were detectable nine months a. i. Haematological alterations comprised leucocytosis and lymphocytosis. Eletrocardiographic alterations were minor and transient, similar to those observe in non-lethal human acute Chagas' myocarditis. Myocarditis and myositis, characterized by multiple foci of lympho-histiocyte inflammatory infiltrate, were present in monkeys sacrificed on the 41 th, 70th and 76 th day but not in the animal sacrificed 3 years and 3 months a. i.. The results suggest that Chagas' disease in rhesus monkeys reproduces the acute and indeterminate phases of human Chagas' disease.