Chagas' disease, caused by Trypanosoma cruzi infection, is one of the main causes of death due to heart failure in Latin American countries. Benznidazole, the chemotherapeutic agent most often used for the treatment of chagasic patients, is highly toxic and has limited efficacy, especially in the chronic phase of the disease. In the present study we used a mouse model of chronic Chagas' disease to investigate the effects of benznidazole treatment during the chronic phase on disease progression. The hearts of benznidazole-treated mice had decreased parasitism and myocarditis compared to the hearts of untreated chagasic mice. Both groups of Trypanosoma cruzi-infected mice had significant alterations in their electrocardiograms compared to those of the healthy mice. However, untreated mice had significantly higher cardiac conduction disturbances than benznidazole-treated mice, including intraventricular conduction disturbances, atrioventricular blocks, and extrasystoles. The levels of antibodies against T. cruzi antigens (epimastigote extract, P 2 ␤, and transsialidase) as well as antibodies against peptides of the second extracellular loops of ␤ 1 -adrenergic and M 2 -muscarinic cardiac receptors were also lower in the sera from benznidazole-treated mice than in the sera from untreated mice. These results demonstrate that treatment with benznidazole in the chronic phase of infection prevents the development of severe chronic cardiomyopathy, despite the lack of complete parasite eradication. In addition, our data highlight the role of parasite persistence in the development of chronic Chagas' disease and reinforce the importance of T. cruzi elimination in order to decrease or prevent the development of severe chagasic cardiomyopathy.

No abstract

Context Loss-of-function mutations of makorin RING finger protein 3 (MKRN3) are the most common monogenic cause of familial central precocious puberty (CPP). Objective To describe the clinical and hormonal features of a large cohort of patients with CPP due to MKRN3 mutations and compare the characteristics of different types of genetic defects. Methods Multiethnic cohort of 716 patients with familial or idiopathic CPP screened for MKRN3 mutations using Sanger sequencing. A group of 156 Brazilian girls with idiopathic CPP (ICPP) was used as control group. Results Seventy-one patients (45 girls and 26 boys from 36 families) had 18 different loss-of-function MKRN3 mutations. Eight mutations were classified as severe (70% of patients). Among the 71 patients, first pubertal signs occurred at 6.2 ± 1.2 years in girls and 7.1 ± 1.5 years in boys. Girls with MKRN3 mutations had a shorter delay between puberty onset and first evaluation and higher follicle-stimulating hormone levels than ICPP. Patients with severe MKRN3 mutations had a greater bone age advancement than patients with missense mutations (2.3 ± 1.6 vs 1.6 ± 1.4 years, P = .048), and had higher basal luteinizing hormone levels (2.2 ± 1.8 vs 1.1 ± 1.1 UI/L, P = .018) at the time of presentation. Computational protein modeling revealed that 60% of the missense mutations were predicted to cause protein destabilization. Conclusion Inherited premature activation of the reproductive axis caused by loss-of-function mutations of MKRN3 is clinically indistinct from ICPP. However, the type of genetic defect may affect bone age maturation and gonadotropin levels.

Background: Hypothalamic hamartoma (HH) represents the commonest cause of organic central precocious puberty (CPP). Follow-up of these patients in adulthood is scarce. Objective: To describe the anthropometric, metabolic, and reproductive parameters of patients with CPP due to HH before and after treatment with gonadotropin-releasing hormone analog (GnRHa). Methods: We performed a retrospective and cross-sectional study in a single tertiary center including 14 patients (7 females) with CPP due to HH. Results: The mean duration of GnRHa treatment was 7.7 ± 2.4 years in boys and 7.9 ± 2.1 years in girls. GnRHa treatment was interrupted at the mean chronological age (CA) of 12.1 ± 1.1 years in boys and 10.7 ± 0.5 years in girls. At the last visit, the mean CA of the male and female patients was 21.5 ± 3.2 and 24 ± 3.9 years, respectively. Eleven of the 14 patients reached normal final height (FH) (standard deviation score -0.6 ± 0.9 for males and -0.6 ± 0.5 for females), all of them within the target height (TH) range. The remaining 3 patients had predicted height within the TH range. The mean body mass index and the percentage of body fat mass was significantly higher in females, with a higher prevalence of metabolic disorders. All patients presented normal gonadal function in adulthood, and 3 males fathered a child. Conclusion: All patients with CPP due to HH reached normal FH or near-FH. A higher prevalence of overweight/obesity and hypercholesterolemia was observed in the female patients. Finally, no reproductive disorder was identified in both sexes, indicating that HH per se has no deleterious effect on the gonadotropic axis in adulthood.

OBJECTIVES:Unfavorable predicted adult height and psychosocial inadequacy represent parameters used to guide therapeutic intervention in girls with central precocious puberty. Gonadotropin-releasing hormone analog is the first-line treatment. The aim of this study was to compare two methods used to predict adult height and assess a validated tool for predicting the age at menarche in girls with central precocious puberty.METHODS:The predicted adult height of 48 girls with central precocious puberty was calculated at diagnosis using the Bayley-Pinneau method based on average and advanced bone age tables and compared with the predicted adult height calculated using a mathematical model. In addition, the age at spontaneous menarche was predicted using the new formulae. After Gonadotropin-releasing hormone analog treatment, the predicted adult height was calculated using only the Bayley-Pinneau tables.RESULTS:The achieved adult height was within the target height range in all treated girls with central precocious puberty. At diagnosis, the predicted adult height using the Bayley-Pinneau tables was lower than that using the mathematical model. After the Gonadotropin-releasing hormone analog treatment, the predicted adult height using the Bayley-Pinneau method with the average bone age tables was the closest to the achieved adult height. Using the formulae, the predicted age at spontaneous menarche was 10.1±0.5 yr. The Gonadotropin-releasing hormone analog treatment significantly postponed this event until 11.9±0.7 yr in these “idiopathic” central precocious puberty girls, highlighting the beneficial effect of this treatment.CONCLUSION:Both initial adult height prediction methods are limited and must be used with caution. The prediction of the age at spontaneous menarche represents an innovative tool that can help in clinical decisions regarding pubertal suppression.