The use of social simulation modelling to understand adherence to diabetic retinopathy screening programs

The success of screening programs depends to a large extent on the adherence of the target population, so it is therefore of fundamental importance to develop computer simulation models that make it possible to understand the factors that correlate with this adherence, as well as to identify population groups with low adherence to define public health strategies that promote behavioral change. Our aim is to demonstrate that it is possible to simulate screening adherence behavior using computer simulations. Three versions of an agent-based model are presented using different methods to determine the agent's individual decision to adhere to screening: (a) logistic regression; (b) fuzzy logic components and (c) a combination of the previous. All versions were based on real data from 271,867 calls for diabetic retinopathy screening. The results obtained are statistically very close to the real ones, which allows us to conclude that despite having a high degree of abstraction from the real data, the simulations are very valid and useful as a tool to support decisions in health planning, while evaluating multiple scenarios and accounting for emergent behavior.

P4797Genetic testing in 101 consecutive lone atrial fibrillation patients is able to identify a subgroup with increased severity

Introduction

Atrial fibrillation (AF) is the most common arrhythmia and the cause of 15% of all strokes and up to 6% of medical admissions. It is estimated that currently about 2.0 million Brazilians, and 30 million individuals worldwide, are affected by the disease. It is a complex and multifactorial disease, and the mechanisms are still not well understood. Between 10–20% of AF patients do not have any known predisposing factors, a condition once called “lone AF”. The role of genetic testing still remains controversial in this clinical scenario.

Purpose

The aim of this study was to identify the occurrence of pathogenic genetic variants in patients with atrial fibrillation without known risk factors.

Methods

In a tertiary hospital, 101 young patients with apparent “lone AF” were screened with genetic testing by NGS using a custom genetic panel with 159 channelopathy and cardiomyopathy related genes. Variants found were classified according to the American College of Genetic and Genomic (ACMG) criteria. Subjects were evaluated with clinical and familial history, electrocardiogram, 24 hours Holter monitoring, echocardiogram, cardiac MRI and treatment response. Multivariate analyses were performed by logistic linear regression model.

Results

During an inclusion period of 4 years, 101 consecutive patients, with mean age of 38.6 years old, were classified as “lone AF” (78% male); 76% presented paroxysmal AF and 24% persistent/permanent AF. Family history of early sudden death (bellow 60 years old) was reported in 37% of cases (78% below 50 years old); 10% had family members with pacemakers; and 44% reported having family members with early AF onset. Genetic testing demonstrated that 14/101 (13.8%) of patients presented genetic variants classified as pathogenic or likely pathogenic (P/LP) according to ACMG criteria. The genes most frequently affected were LMNA (3/101), ANK2 (3/101) and truncating variants in TTN (3/101). Two variables were significantly associated with harboring a pathogenic mutation: family history of sudden death (OR: 5.58; 1,19–26,12 CI; p=0.029) and pacemaker reported in the family history (OR: 6.83; 1.11–42.04 CI; p=0.038).

Conclusion

Our data showed that approximately 15% of “lone AF” patients are carriers of known pathogenic mutations in genes associated with inherithed cardiomyopathy. In addition, we show that being a carrier is potentially associated with a more severe phenotype. These findings suggest that genetic testing in “lone AF” patients may be able to identify a subgroup with a more severe phenotype are for whom a different management strategy might be indicated.

Acknowledgement/Funding

National Council for Scientific and Technological Development (CNPq)

Productive performance, bone characteristics, and intestinal morphology of laying hens fed diets formulated with L-glutamic acid

This study was conducted to evaluate the effects of L-glutamic acid (Glu) on the productive performance, eggshell quality, bone characteristics, and morphologic parameters of laying hens. Two hundred and forty 53-wk-old Hy-Line W36 laying hens were randomly allocated into 5 treatments, 6 replicates, and 8 birds each. The experimental period was 16 wk. The treatments consisted of a Basal diet (Glu calculated at 2.68%) and 4 L-glutamic acid inclusion levels: 2.88, 3.08, 3.28, and 3.48%. Glu inclusion levels in the hens diet had an increasing linear effect (P < 0.05) on eggshell Ca concentration and bone (tibiotarsus) strength index, and a decreasing linear effect (P < 0.05) on the Seedor index. Serum biochemistry results for total and ionic Ca, inorganic P, and alkaline phosphatase were affected by blood collection time (04:00 Pm, 03:00 Am, and 12:00 Pm) but not by the treatments. Jejunum morphometric variables were not influenced by the treatments except for crypt depth, which demonstrated a quadratic effect (P < 0.05). However, proliferating cell nuclear antigen qualitative immunohistochemical analysis of the jejunum showed more positive nuclei in the villus with the addition of Glu. Both with the basal diet and the lowest Glu inclusion treatment, positive nuclei were observed in the crypts and at the base of the villus, while in the treatments with higher Glu levels, positive cells were common all along the villus mucosa, including its extremity. In conclusion, diets formulated with increased levels of Glu had beneficial effects on eggshell Ca concentration, tibiotarsus structure, and proliferative activity of the jejunum of 69-wk-old laying hens. Therefore, dietary L-glutamic acid can be considered an alternative additive to improve bone characteristics in the productive phase of laying hens.

Genetic characterization of a Juquitiba-like viral lineage in Oligoryzomys nigripes in Rio de Janeiro, Brazil

Hantaviruses, family Bunyaviridae, are rodent-borne RNA viruses that have caused cases of hantavirus cardiopulmonary syndrome (HCPS) in various regions of the Americas. There are five hantaviral lineages associated with HCPS in Brazil: Juquitiba virus (JUQV), Araraquara virus (ARAV), Laguna Negra-like virus (LNV), Castelo dos Sonhos virus (CASV), and Anajatuba virus (ANAJV). Three additional hantaviruses have been described in rodents alone: Rio Mearim virus, Jaborá virus, and a hantavirus lineage related to Seoul virus. This study describes the genetic detection and characterization of a Juquitiba-like hantavirus in Oligoryzomys nigripes, or the black-footed pygmy rice rat, in the Serra dos Orgãos National Park, Rio de Janeiro State, where so far no cases of HCPS have been reported.

[Cultural effect on postoperative pain]

The objective of this study was to describe the influence of culture on 12 surgical patients. The data was collected by interviews and the analysis was based on the framework of the qualitative methodology. The results showed four categories of influence: the type of pain, the expectancy by pain, the meaning of the pain and the pain management. The meaning apprehended is suffering and was verbalized by metaphors. The study considers the importance of the cultural comprehension about pain by the nurse.

Anti-allergic properties of the natural PAF antagonist yangambin

In this study we examined the ability of the furofuran lignan yangambin to influence the local and systemic responses induced by antigen or PAF in actively sensitized or normal rats. Given intraperitoneally 1 h before stimulation, yangambin inhibited the pleural neutrophil and eosinophil infiltration evoked by the i.pl. injection of PAF or antigen into normal or 14 daysensitized rats whereas plasma exudation evoked by both stimuli was unaffected. The pleural neutrophil influx (6 h) after LTB4 stimulation was also significantly inhibited by yangambin. We also evidenced that the hemoconcentration, thrombocytopenia, and leucocytosis noted after i.v. PAF were all attenuated by yangambin. In actively sensitized rats, pretreatment with yangambin failed to modify the antigen-induced hemoconcentration and leucocytosis, but dose-dependently abrogated the thrombocytopenia noted 1 h post-stimulation. In vitro, the anaphylactic contraction of longitudinal jejunal segments to antigen challenge was significantly inhibited by yangambin (10(-5)-10(-4) M). Likewise, the contraction of jejunal segments from normal rats to PAF was markedly blocked by yangambin under conditions where the response to 5-hydroxytryptamine (5-HT) was not altered. In conclusion, our results show that antigen- and PAF-induced pleural neutrophil and eosinophil accumulation, but not exudation, is sensitive to treatment with yangambin. In addition, yangambin also suppressed the pleural neutrophil infiltration triggered by LTB4 as well as the blood thrombocytopenia and intestinal anaphylaxis elicited by antigen in rats. Thus, our findings indicate that yangambin shows an antagonistic action on receptors other than those of PAF, i.e., LTB4, and strongly suggest that it may be a useful drug in the treatment of some allergic inflammatory responses.

Chagas' disease reactivation after heart transplantation: efficacy of allopurinol treatment

BACKGROUND

Chagas' disease is a parasitic infection that provokes a severe form of dilated cardiomyopathy. In the initial experience with heart transplantation with Chagas' disease, a high rate of acute reactivation has been reported. Although benzinidazole and nifurtimox are effective in the treatment of reactivation or of the acute phase of the disease they are associated with important adverse effects. Allopurinol has substantial activity against Trypanosoma cruzi in vitro, in the experimental laboratory and in chronic human Chagas' disease; however, there is no information regarding its action in Chagas' reactivation after heart transplantation.

METHODS AND RESULTS

We describe two patients with Chagas' disease who underwent heart transplantation. The first one had asthenia, anorexia, and several painful subcutaneous nodules in the legs after transplantation; biopsy showed an inflammatory infiltrate with intracytoplasmatic nests of Trypanosoma cruzi, confirmed by immunohistochemical stains with monoclonal antibodies specific to parasitic antigens. Allopurinol (600 mg/day) produced complete regression of the symptoms and the nodules with a negative control biopsy within 2 weeks. Treatment was maintained for 2 months. Mild leukopenia developed which improved after azathioprine reduction, and no further side-effects were noted. The second patient had sudden heart failure months after transplantation; endomyocardial biopsy showed myocardial fibers infested with Trypanosoma, and a concomitantly performed right heart catheterization showed a low cardiac index and highfilling pressures. The patient received allopurinol at a daily dose of 900 mg and conventional treatment for heart failure. Echocardiogram showed improved wall motion and decreased left ventricular dimensions, and control biopsy showed no inflammatory activity; cardiac index and filling pressures normalized. Treatment was maintained for 2 months without side effects. The two patients have not had recurrences and were in New York Heart Association functional class I 12 and 3 months, respectively, after discontinuation of allopurinol.

CONCLUSIONS

Allopurinol seems to be safe and effective in treating Chagas' disease reactivation after heart transplantation. A larger number of case studies seems to be necessary to properly evaluate its role in the treatment of Chagas' disease reactivation.