Characterization and distribution of Teredinidae assemblage in an estuary in Ceará, Brazil's Northeast

Teredinids are bivalves mollusks considered the most abundant of invertebrates group of marine wood borers performing an important role in the mangrove environment. This study aimed to characterize the Teredinidae species from the Acaraú River estuary in Ceará and analyse the relationship between the mangrove plant structure and the distribution of Teredinidae, according to gradients estuaries: vertical (flooding) and horizontal (salinity). The collection of mangrove logs with Teredinidae happened in three places within the estuary (inner, median, and upper); in each area, three transects were traced in which three plots were lined off, and a total of 40 logs were collected. Teredinidae species were found and identified: Nausitora fusticula; Neoteredo reynei; Teredo turnerae; Teredo cf. bartschi; Bankia bipennata; Bankia gouldi; Lirodus massa and Lyrodus cf. bipartitus. The Lyrodus cf. bipartitus, Bankia gouldi, and Teredo cf. bartschi species were registered for the first time in Ceará. The distribution and species richness of Teredinidae were directly related to the vertical gradient (flooding) and heterogeneity of the mangrove forest habitat. The data presented here are essential for comprehending the mechanisms responsible for the distribution patterns of the Teredinidae species in the mangrove, contributing to biodiversity conservation in Ceará coastal zones.

Coronary inflammation by computed tomography pericoronary fat attenuation in young male anabolic androgenic steroid users

Background

The illicit use of anabolic androgenic steroids (AAS) has been associated with diminished cholesterol efflux mediated by HDL, remarkable decrease in high-density lipoprotein (HDL) plasma concentration and subclinical coronary artery disease (CAD). Inflammation is the key to the atherogenic process associated with atherosclerotic plaque vulnerability. The pericoronary mean fat attenuation (pFAM) has emerged as a marker of coronary inflammation and can predict future cardiovascular events, which is measurable from standard coronary computed tomography angiography (CCTA). However, whether AAS abuse has a role in pFAM in young male AAS users is unknown.

Purpose

The aim of this study was to evaluate whether AAS abuse could leads to higher pFAM and premature coronary inflammation in young male AAS users.

Methods

Twenty strength-trained AAS users (AASU) age 29±5 yr, 20 age-matched strength-trained AAS nonusers (AASNU), and 10 sedentary controls (SC) were enrolled in this study. Coronary inflammation was assessed by pFAM-CCTA in the right coronary artery (RCA), left anterior descending artery (LDA) and left circumflex coronary artery (Cx).

Results

pFAM in the RCA was significantly higher in AASU compared with AASNU and SC (−64.59±9.45 vs. −79.21±6.67 vs. −80.97±7,91 Hounsfield Units (HU), respectively, p<0.001]. Also, the pFAM in the LAD was higher in AASU compared with AASNU and SC (−72.83±7.21 vs. −79.41±6.72 vs. −80.97±7.72 HU, p=0.006). However, no difference to pFAM in the Cx between AASU, AASNU and SC (−74.30±5.85 vs. −79.77±7.13 vs. −78.19±5.82 HU, respectively, p=0.069) was found.

Conclusion

This study indicates that AAS abuse may be associated with higher pFAM and premature coronary inflammation in the RCA and LAD. The higher pFAM may be linked to early development of CAD in young AAS users.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Fundação Zerbini

Carcass and meat quality of young Angus steers with different growth potential finished exclusively grass-fed or corn supplemented

Beef cattle production has a large variety of systems with different performance and technology levels. This study compared young Angus steers carcass and meat quality traits of high growth potential early-finished animals fed exclusively on pasture with low growth potential late-finished animals. Besides the grazed forage, the low growth potential group received corn grain at 0.8% of their body weight right after the slaughtering of the first group. Following weaning, the 20 steers grazed pastures composed of oat, ryegrass, and clovers. At winter's onset, animals were moved to native pastures improved with fescue and clovers. The supplemented period of late steers began when the first group of ten early-finished animals reached the requirements for slaughter. Supplementation ended when the animals got the slaughter requirements. The high growth potential steers showed a ribeye area (P < 0.0001) and a Longissimus muscle width highly significantly (P < 0.0001) superior to the low growth group. However, corn-supplemented animals showed better dressing percentage (P < 0.0001), subcutaneous fat thickness (P < 0.0001), marbling (P < 0.0001), and muscle (P = 0.0033) scores, but lower shear force (P = 0.0001). The finishing system did impact fat lightness (L*; P = 0.0234) at the slaughter time. Grass-fed animals showed higher red-green color parameter (a*) values than corn supplemented on fat at 24 h (P = 0.0439) but lower hue angle (P = 0.0418). The consumer panel showed better results for tenderness and general acceptability for supplemented animals beef compared to grass-fed. The supplementation resulted in a higher carcass standardization. It also provided higher PUFA: MUFA and n-6: n-3 ratios, and a higher amount of n-3. Supplemental corn grain did not have adverse effects upon the beneficial effects to human health of the grass-fed beef.

Lipid profile in a population with coronary artery disease in Madeira Island

Funding Acknowledgements

Type of funding sources: None.

Introduction

Coronary artery disease (CAD) remains a leading cause of morbidity and mortality worldwide. We know that plasma level of LDL cholesterol (LDL-C) is strongly associated with atherosclerosis, and its reduction with statins has led to a decrease in the incidence and complications of CAD. According to the 2019 ESC guidelines, in high-risk patient the aim is to achieve an absolute LDL-C treatment goal of &lt;55mg/dL. 2016 ESC guidelines purposed, in the same patients, a LDL-C level of &lt;70mg/dL.

Objective

To evaluate the degree of LDL-C control in coronary artery disease patients according to ESC guidelines.

Materials and Methods

Study analyses of 1687 patients selected from GENEMACOR study population, with at least one &gt; 75% coronary stenosis by angiography (median age 53.3 ± 3 years and 54.8% men).

LDL-C was determined by chemical methods and all patients were statin treated. The population was divided in four groups according to LDL-C levels: inferior to 55mg/dL, inferior to 70mg/dL, inferior to 115mg/dL and superior to 115mg/dL.

Results

LDL-C mean value was 108.7mg/dL, median 105.1mg/dL (P25 83.0 and P75 127.4mg/dL). 150 (8.9%) patients had LDL-C &lt; 55mg/dL vs 1537 (91.1%) with LDL-C ≥ 55 mg/dl. 275 (16.3%) patients had LDL-C &lt; 70 mg/dL vs 1412 (83.7%) with LDL-C ≥ 70 mg/dL.  1084 (64.3%%) patients had LDL &lt; 115 mg/dL vs 603 (35.7%) with LDL-C  ≥ 115 mg/dL.

Conclusion

In our population LDL-C control levels was low, with 91.1% patients with LDL-C ≥ 55mg/dL and 83.7% patients with LDL ≥ 70 mg/dL. It is interesting to note that most of our patients have LDL-C levels above the recommend by the newest and, surprisingly, the 2016 dyslipidemia guidelines. It is therefore important to implement a more intensive treatment strategy of dyslipidemia in coronary patients.

Homocysteine, a predictor of cardiovascular adverse events in coronary artery disease

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

GENEMACOR

Introduction

After the diagnosis of coronary artery disease (CAD), traditional risk factors such as diabetes mellitus, dyslipidemia, hypertension and smoking have been used to assess the risk of major cardiovascular adverse events (MACE). However, despite reduction of these factors, presence of MACE remains high. It is necessary to identify other causal risk factors for MACE in coronary patients and increased plasma Homocysteine (Hcy) level seems to be a likely candidate. However, the influence of Hcy levels in the prognosis of coronary patients presents a limited knowledge.

Objective

To evaluate the influence of high level of Hcy in MACE (defined as a composite endpoint of cardiovascular death, acute myocardial infarction, stroke, admission for heart failure and need to revascularization) of coronary artery patients.

Materials and Methods

Study analyses of 1687 patients selected from GENEMACOR study population, with at least one &gt; 75% coronary stenosis by angiography. That population was divided in three terciles according to the Hcy level and the population of the 2nd tercil (Hcy 11.1-13.6mmol/L) was excluded. The end population of 1118 patients was a median age of 53.1 ± 7.9 years and 77.6% were men. We compared patients in the 1st (Hcy &lt; 11.1mmol/L) and 3rd tercil (Hcy &gt; 13.6mmol/L) during a mean follow up of 5.0 ± 4.8 years.

Results

560 (50.1%) patients were included in the 1st tercil group (median age 51.6 ± 3 years, 72.0% men) and  558 (49.9%) patients were in the 3rd tercil group (median age 54.6 ± 3 years, 83.3% men). In our population, high levels of Hcy were associated with MACE (OR 1.43, 95% CI: 1.12-1.83, p 0.004).

Conclusion

 In our population a higher level of Hcy was associated with adverse prognosis and increased occurrence of MACE. Knowing that elevated homocysteine levels are associated with increased risk of MACE, in these patients is essential to have a more intensive therapeutic strategy.

P6196Lipoprotein (a) and cardiovascular risk: are women at increased risk?

Introduction

Coronary artery disease (CAD) is the leading cause of death worldwide, placing a major economic and resource burden on health and public health systems, so efforts are being made to accurately predict risk for major adverse cardiac events (MACE). The field of risk prediction and CAD prevention continues to evolve with the identification of novel risk factors and biomarkers, such as lipoprotein a [Lp)a]. Almost 20% of the population has elevated circulating levels of Lp(a), which is recognized as an independent risk factor for CAD, stroke, peripheral arterial disease, and aortic stenosis. Importantly, studies showed that this was particularly true for women.

Objective

To evaluate if the elevation of Lp(a) is associated with MACE in female, male or both.

Materials and methods

Case control study of 3050 subjects from the GENEMACOR study population. In female population (n=676): cases were 341 patients with at least one >75% coronary stenosis (median age 55.7±7.2) and 335 normal controls (median age 55.8±6) adjusted by age with cases. In male population (n=2374): 1278 patients with at least one >75% coronary stenosis (median age 52.7±8) and 1096 controls (median age 51.9±8) also adjusted by age. χ2 and T student tests were used to analyze the demographic, laboratorial, angiographic and anthropometric characteristics of the population. Lipoprotein (a) was determined by immunoturbidimetry. High Lp(a) level was considered if superior to 30 mg/dl. Logistic regression was used to evaluate Lp(a) as a risk factor for CAD in total, female and male populations.

Results

In female population 44.0% patients vs 21.2% controls (p<0.000) had Lp(a)>30mg/dl. In male population 39.4% patients vs 23.8% controls (p<0.000) had Lp(a)>30mg/dl. In total population Lp(a)>30mg/dl was a predictor for CAD (OR 2.24, 95% CI: 1.91–2.62, p<0.0001). Analyzing by gender, Lp(a)>30mg/dl was also a predictor for CAD either in male (OR 2.08, 95% CI: 1.74–2.5, p<0.0001) or female population (OR 2.92, 95% CI: 2.08–4.09, p<0.0001).

Conclusions

As opposed to other studies, in our population elevated Lp(a) levels (>30mg/dl) were associated with elevated CAD risk, in both men and women. We conclude that Lp(a) can be considered an independent risk factor for CAD disease in our population, and further strategies for Lp(a) reduction may indeed translate in improved outcomes in CAD disease.

P4132Decreased myocardial native T1 times and impaired myocardial contractility in young anabolic androgenic steroids users

Background

Anabolic androgenic steroids (AAS) have been associated with several injuries on the cardiovascular system. AAS abuse may have a direct toxic effect on the myocardium that could lead to cardiac function and structure alterations. Clinical and forensic cases have been reported myocardial fibrosis in AAS users. Myocardial fibrosis increases the risk of heart failure and sudden death. However, recent studies did not show evidence of focal myocardial fibrosis and diffuse myocardial fibrosis in AAS users using T1-mapping techniques. Thus, it remains unclear the association between AAS and cardiac structure alterations.

Purpose

The aim of this study was to evaluate cardiac structure by cardiovascular magnetic resonance (CMR) imaging with late-gadolinium enhancement (LGE), cardiac T1-mapping and extracellular volume measurements (ECV). Additionally, we also evaluated the cardiac contractility by CMR and echocardiography in young AAS users.

Methods

Twenty strength-trained AAS users (AASU) age 29±5 yr, 20 age-matched strength-trained AAS nonusers (AASNU), and 10 sedentary controls (SC) were enrolled. Cardiac structure was assessed by LGE, native T1-mapping and ECV. Cardiac contractility was evaluated as cardiac strain measured by CMR (feature tracking imaging technique) and echocardiography (speckle tracking technique).

Results

Global native T1 times [753 (683–870) vs 916 (815–1239) vs 1205 (825–1242) ms, respectively, p=0.03], and native T1 times at the left ventricle mid-ventricular slice [813 (695–1096) vs 922 (825–1095) vs 1140 (840–1322) ms, respectively, p=0.03] were lower in AASU compared with AASNU and SC. Mid-ventricular ECV was similar between AASU, AASNU and SC (22±6 vs 23±4 vs 24±4%, respectively, p=0.37). Focal myocardial fibrosis was found in 2 individuals (11%) of AASU. The mid anteroseptal and mid inferoseptal were the most affected segments. The total estimated mass of the LV mass was 1.25 g (0.65%). Three participants of SC showed focal myocardial fibrosis. The mid anterolateral, mid inferolateral and mid inferomedial were the most affected segments. The total estimated mass of the LV mass was 3.43 g (2.30%). In contrast, none of the AASNU had myocardial fibrosis. By CMR, AASU showed a lower medial radial strain (30±8 vs. 38±6%, p<0.01), medial circumferential strain (−17±3 vs −20±2%, p<0.01) and global longitudinal strain (−17±3 vs −20±3%, p<0.01) compared with AASNU. Echocardiography also demonstrated a lower 4CH longitudinal strain in AASU compared with AASNU (−15.5±3 vs −18.3±2%, p=0.03). Moreover, the AASU shower a higher left ventricle mass compared with AASNU and SC (185±20 vs 130±17 vs 112±14 g, respectively, p<0.01).

Conclusion

This study indicates that AAS abuse may be associated with decreased myocardial native T1 times, impaired myocardial contractility and focal myocardial fibrosis. These myocardial structural and functional alterations may be associated to unadapted cardiac hypertrophy in young AAS users.

Acknowledgement/Funding

Fundação de Amparo à Pesquisa do Estado de São Paulo [FAPESP], Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes).

In vitro inhibition of canine distemper virus by flavonoids and phenolic acids: implications of structural differences for antiviral design

Infection caused by canine distemper virus (CDV) is a highly contagious disease with high incidence and lethality in the canine population. Antiviral activity of flavonoids quercetin, morin, rutin and hesperidin, and phenolic cinnamic, trans-cinnamic and ferulic acids were evaluated in vitro against the CDV using the time of addition assay to determine which step of the viral replicative cycle was affected. All flavonoids displayed great viral inhibition when they were added at the times 0 (adsorption) and 1h (penetration) of the viral replicative cycle. Both quercetin and hesperidin presented antiviral activity at the time 2h (intracellular). In the other hand, cinnamic acid showed antiviral activity at the times 0 and 2h while trans-cinnamic acid showed antiviral effect at the times -1h (pre-treatment) and 0 h. Ferulic acid inhibited CDV replicative cycle at the times 0 and 1h. Our study revealed promising candidates to be considered in the treatment of CDV. Structural differences among compounds and correlation to their antiviral activity were also explored. Our analysis suggest that these compounds could be useful in order to design new antiviral drugs against CDV as well as other viruses of great meaning in veterinary medicine.

Dealing with the archetypes development process for a regional EHR system

OBJECTIVES

This paper aims to present the archetype modelling process used for the Health Department of Minas Gerais State, Brazil (SES/MG), to support building its regional EHR system, and the lessons learned during this process.

METHODS

This study was undertaken within the Minas Gerais project. The EHR system architecture was built assuming the reference model from the ISO 13606 norm. The whole archetype development process took about ten months, coordinated by a clinical team co-ordinated by three health professionals and one systems analyst from the SES/MG. They were supported by around 30 health professionals from the internal SES/MG areas, and 5 systems analysts from the PRODEMGE. Based on a bottom-up approach, the project team used technical interviews and brainstorming sessions to conduct the modelling process.

RESULTS

The main steps of the archetype modelling process were identified and described, and 20 archetypes were created.

LESSONS LEARNED

-The set of principles established during the selection of PCS elements helped the clinical team to keep the focus in their objectives;-The initial focus on the archetype structural organization aspects was important;-The data elements identified were subjected to a rigorous analysis aimed at determining the most suitable clinical domain;-Levelling the concepts to accommodate them within the hierarchical levels in the reference model was definitely no easy task, and the use of a mind mapping tool facilitated the modelling process;-Part of the difficulty experienced by the clinical team was related to a view focused on the original forms previously used;-The use of worksheets facilitated the modelling process by health professionals;-It was important to have a health professional that knew about the domain tables and health classifications from the Brazilian Federal Government as member in the clinical team.

CONCLUSION

The archetypes (referencing terminology, domain tables and term lists) provided a favorable condition for the use of a controlled vocabulary between the central repository and the EMR systems and, probably, will increase the chances of preserving the semantics from the knowledge domain. Finally, the reference model from the ISO 13606 norm, along with the archetypes, proved sufficient to meet the specificities for the creation of an EHR system for basic healthcare in a Brazilian state.

Screening of Jatropha curcas genotypes to anthracnose caused by Colletotrichum gloeosporioides

Anthracnose caused by Colletotrichum gloeosporioides is an important physic nut (Jatropha curcas) disease causing damages on leaves, stems and fruits and consequently a decrease in seed quantity and quality. Physic nut is a native plant of Central America that has gained international attention due to its potential as biodiesel crop. However despite its highest relevance, studies concerning the response of different Jatropha genotypes to infection with this disease are very limited. The main objective of this study is the evaluation of susceptibility of 38 Jatropha curcas genotypes from a worldwide germplasm collection to Colletotrichum gloeosporioides. A simple method using wounded detached leaves inoculated with a 5-mm mycelia plug was used. Observations (lesion diameter and % of infection) were made after 3 and 7 days under controlled conditions (25 degrees C and 85% RH). Results showed significantly differences (P < or = 0.001) in both percentage of infection and lesion diameter among the tested accessions. Two genotypes from Brazil and Cape Verde, presented no lesions after 7 days of treatment, while the others presented between 67 and 100% of infection. Lesion diameter showed an increase with time of incubation and proved to be a useful tool for evaluation of plant susceptibility.

Allele and genotype frequencies of metabolic genes in Native Americans from Argentina and Paraguay

Interethnic differences in the allele frequencies of CYP2D6, NAT2, GSTM1 and GSTT1 deletions have been documented for Caucasians, Asians, and Africans population. On the other hand, data on Amerindians are scanty and limited to a few populations from southern areas of South America. In this report we analyze the frequencies of 11 allele variants of CYP2D6 and 4 allele variants of NAT2 genes, and the frequency of GSTM1 and GSTT1 homozygous deleted genotypes in a sample of 90 donors representing 8 Native American populations from Argentina and Paraguay, identified as Amerindians on the basis of their geographic location, genealogical data, mitochondrial- and Y-chromosome DNA markers. For CYP2D6, 88.6% of the total allele frequency corresponded to *1, *2, *4 and *10 variants. Average frequencies for NAT2 *4, *5, *6 and *7 alleles were 51.2%, 25%, 6.1%, and 20.1%, respectively. GSTM1 deletion ranged from 20% to 66%, while GSTT1 deletion was present in four populations in less than 50%. We assume that CYP2D6 *2, *4, *10, *14; NAT2 *5, *7 alleles and GSTM1 and GSTT1 *0/*0 genotypes are founder variants brought to America by the first Asian settlers.

Resistance to white rust in pak choi and Chinese cabbage at the cotyledon stage

The biothrofic pathogen Albugo candida (Pers.) attacks all the cultivated Brassica species and several wild crucifers causing the disease known as white rust. The symptoms consist on the initial appearance of more or less conspicuous white sori on the plant leaves and stems, followed by severe distortions of the affected organs, especially flowers and siliqua. On delicate vegetable types of Brassica rapa L., like pak choi (B. rapa var. chinensis L.) and chinese cabbages (B. rapa var. pekinensis L.) even a slight white rust infection can render all the production unmarketable. Development of resistant cultivars is the best way to control the disease and to insure low pesticide spraying and residues in vegetables. The objective of this work were: i) the screening of a collection of B. rapa accessions from several seed banks for sources of resistance to white rust; and ii) the study of the inheritance of resistance in the most resistant accessions. Forty three accessions of B. rapa chinensis and 19 accessions of B. rapapekinensis were screened at the cotyledon stage following the methods of Santos and Dias (2004) with a Portuguese A. candida isolate Ac506 (Br) collected from turnip leaves. Four accessions of B. rapa chinensis presented more than 50% of resistant plants: the pak choi (BRA 117) was the most resistant accession with 85% of resistant plants, followed by pak choi (BRA227) with 73%, pai tsai 'Ex China 1' (B00083) with 60% and pak choi 'Ai Jiao Huang' (BRA 225) with 53%. On the opposite, B. rapa pekinensis accessions were all consider as susceptible presenting only 0-11% of resistant plants. The inheritance of resistance was studied in two crosses between pak choi BRA 117 and the rapid cycling B. rapa plant line CrGC 1.19. Selfed parents and F1 and F2 generations were produced, and screened at the cotyledon stage as previously described. Analysis of the results suggests that inheritance of resistance to Ac506 in pak choi BRA 117 is controlled by two nuclear genes with dominant recessive interaction.

Aureobasidium pullulansas a biocontrol agent of blue mold in "Rocha" pear

The blue mold of "Rocha" pear caused by Penicillium expansum is an important postharvest disease which is adequately controlled by application of synthetic fungicides. In recent years, strategies like biological control have been considered a desirable alternative to chemicals. Several studies have demonstrated the potential of the yeast-like fungus Aureobasidium pullulans for control of postharvest decay of pear. A Portuguese isolate of Aureobasidium pullulans was characterized and evaluated for its activity in reducing postharvest blue mold decay of "Rocha" pear caused by Penicillium expansum. Study of optimal conditions for antagonist growth was carried out in six different culture media. The effect of four maturity stages of fruits in the development of A. pullulans was also studied. Biocontrol studies were performed with two concentrations of the antagonist (3 x 10(8) and 4 x 10(9) CFU/ml). A. pullulans growth was significantly different (P < or = 0.001) according to the various media and time of incubation. Best results were obtained in Corn Meal Agar (CMA) and Potato Dextrose Agar (PDA) media which contains the higher concentration of glucose (20 mg/l). Medium resulted from fruits of the first harvest date presented lower colony diameter. Inoculation of A. pullulans at 3 x 10(8) and 4 x 10(9) CFU/ml reduced the incidence of the disease by 23 and 63%, and reduced the lesion diameter by 36 and 46%, respectively.

[HLA-B27 polymorphism and spondyloarthropathies]

The association of HLA-B27 with ankylosing spondylitis (AS), and other spondyloarthropathies (SpA), remains as one of the strongest between HLA molecules and human disease. Since it was reported, in 1973, it has been extensively studied in order to understand the underlying pathogenic mechanism. The objective of this article is to review the current knowledge on the structure and polymorphism of HLA-B27 molecule, as well as describe the main pathogenic hypotheses trying to explain its association with AS.

Isolation and characterisation of genomic and cDNA clones coding for a serine-, alanine-, and proline-rich protein of Trypanosoma cruzi

We report here the isolation and characterisation of genomic and cDNA clones encoding a Serine-, Alanine-, and Proline-rich protein (SAP) of Trypanosoma cruzi metacyclic trypomastigotes. The deduced peptides translated from these clones were characterised by a high content of residues of alanine, proline, serine, glycine, valine, and threonine distributed in several repeats: P(2-4), S(2-3), A(2-3), AS, SA, PA, AP, SP, PS, and TP. The repeats are partially homologous to the serine-, alanine-, and proline-containing motifs of Leishmania major and Leishmania mexicana proteophosphoglycans. Genes coding for SAP are part of a polymorphic family whose members are linked to members of gp85/sialidase and mucin-like gene families. This is consistent with the hypothesis that this genetic organisation could be a means by which T. cruzi co-ordinates the expression of major surface proteins.

Physical mapping of a 670-kb region of chromosomes XVI and XVII from the human protozoan parasite Trypanosoma cruzi encompassing the genes for two immunodominant antigens

As part of the Trypanosoma cruzi Genome Initiative, we have mapped a large portion of the chromosomal bands XVI (2.3 Mb) and XVII (2.6 Mb) containing the highly repetitive and immunodominant antigenic gene families h49 and jl8. Restriction mapping of the isolated chromosomal bands and hybridization with chromosome specific gene probes showed that genes h49 and jl8 are located in a pair of size-polymorphic homologous chromosomes. To construct the integrated map of the chromosomes harboring the h49 and jl8 loci, we used YAC, cosmid, and lambda phage overlapping clones, and long range restriction analysis using a variety of probes (i.e., known gene sequences, ESTs, polymorphic repetitive sequences, anonymous sequences, STSs generated from the YAC ends). The total length covered by the YAC contig was approximately 670 kb, and its map agreed and was complementary to the one obtained by long-range restriction fragment analysis. Average genetic marker spacing in a 105 kb region around h49 and jl8 genes was estimated to be 6.2 kb/marker. We have detected some polymorphism in the H49/JL8 antigens-encoding chromosomes, affecting also the coding regions. The physical map of this region, together with the isolation of specific chromosome markers, will contribute in the global effort to sequence the nuclear genome of this parasite.

Evaluation of recombinant antigens for serodiagnosis of Chagas' disease in South and Central America

The commercially available diagnostic tests for Chagas' disease employ whole extracts or semipurified fractions of Trypanosoma cruzi epimastigotes. Considerable variation in the reproducibility and reliability of these tests has been reported by different research laboratories, mainly due to cross-reactivity with other pathogens and standardization of the reagents. The use of recombinant antigens for the serodiagnosis of Chagas' disease is recommended to increase the sensitivity and specificity of serological tests. Expressed in Escherichia coli, as fusion products with glutathione S-transferase, six T. cruzi recombinant antigens (H49, JL7, A13, B13, JL8, and 1F8) were evaluated in an enzyme-linked immunosorbent assay for Chagas' disease. The study was carried out with a panel of 541 serum samples of chagasic and nonchagasic patients from nine countries of Latin America (Argentina, Bolivia, Brazil, Chile, Colombia, El Salvador, Guatemala, Honduras, and Venezuela). The optimal concentration of each recombinant antigen for coating of plates was determined with the help of 125I-labelled recombinant proteins. While the specificity of the epimastigote antigen was 84% because of false positives from leishmaniasis cases, for the recombinant antigens it varied from 96.2 to 99.6%. Recombinant antigens reacted with 79 to 100% of serum samples from chronic chagasic patients. In this way, it is proposed that a mixture of a few T. cruzi recombinant antigens should be employed in a diagnostic kit to minimize individual variation and promote high sensitivity in the diagnosis of Chagas' disease.

The Trypanosoma cruzi genome project: nuclear karyotype and gene mapping of clone CL Brener

By using improved pulsed field gel electrophoresis conditions, the molecular karyotype of the reference clone CL Brener selected for Trypanosoma cruzi genome project was established. A total of 20 uniform chromosomal bands ranging in size from 0.45 to 3.5 Megabase pairs (Mbp) were resolved in a single run. The weighted sum of the chromosomal bands was approximately 87 Mbp. Chromoblots were hybridized with 39 different homologous probes, 13 of which identified single chromosomes. Several markers showed linkage and four different linkage groups were identified, each comprising two markers. Densitometric analysis suggests that most of the chromosomal bands contain two or more chromosomes representing either homologous chromosomes and/or heterologous chromosomes with similar sizes.

Towards the physical map of the Trypanosoma cruzi nuclear genome: construction of YAC and BAC libraries of the reference clone T. cruzi CL-Brener

Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas disease.

Prevention of community-acquired and nosocomial pneumonia

Pneumonia is an important cause of morbidity and mortality in the United States. The provision of effective prophylaxis for pneumonia has become a major goal for both public health officials and individual physicians. Prophylaxis for community-acquired pneumonia is pathogen-specific and is directed toward the most common microorganisms that cause it. The 23-valent pneumococcal polysaccharide vaccine; the trivalent influenza vaccine; the Haemophilus b conjugate vaccine; and either trimethoprim-sulfamethoxazole, dapsone, or aerosolized pentamidine are recommended to prevent Streptococcus pneumoniae, influenza viruses, H. influenzae type b, and Pneumocystis carinii respectively. Except for the microorganisms listed above, the prevention of nosocomial pneumonia is not pathogen-specific. Rather, prevention of nosocomial pneumonia requires the use of infection control procedures, including patient and staff education; isolation of patients with highly contagious respiratory pathogens; vigorous hand washing; cleaning and sterilizaton of respiratory equipment; and use of sterile water in nebulizers and humidifiers. It also requires procedures to limit pooling and aspiration of secretions, such as positioning and rotation of the bed-bound patient; frequent suctioning of respiratory secretions using gloves and sterile suction catheters; and limiting enteral alimentation. Finally, selective decontamination of the digestive tract may be considered for intubated patients.

Organization and expression of the gene encoding an immunodominant repetitive antigen associated to the cytoskeleton of Trypanosoma cruzi

We have studied the genomic organization and expression of the gene encoding a high molecular mass (300 kDa) repetitive antigen associated with the cytoskeleton of Trypanosoma cruzi. Protease digestion of the native protein, restriction analysis of genomic DNA and sequencing of genomic and cDNA clones indicated that most of the protein is built up by tandemly arranged, nearly identical repeats of 68 amino acids. The gene size was estimated to be approx. 9.4 kb based on the sizes of the transcript and the native protein. The nucleotide sequence conservation among the repeats indicates that selective sequence homogenization, presumably through gene conversion, maintained the amino-acid sequence conservation. Two duplicated allelic forms of this gene were mapped in fragments of about 20 kb. In some strains an additional allele was located in a fragment of 9.4 kb. Our results suggest that this repetitive antigen is a structural protein which could be involved in the attachment of the flagellum to the cell body.

Detection of antibodies in sera from Chagas' disease patients using a Trypanosoma cruzi immunodominant recombinant antigen

A Trypanosoma cruzi DNA fragment encoding an immunodominant repetitive antigen (H49) was subcloned into a protein purification and expressed system. Purified H49 peptide reacted specifically in an enzyme-linked immunosorbent assay (ELISA) with sera from T. cruzi-infected patients, but not with sera from patients with other parasitic diseases such as leishmaniasis and T. rangeli-infection. The H49 recombinant ELISA was able to detect specific antibodies in 84% of chronic chagasic serum samples tested. One of the major advantage of the recombinant ELISA for serodiagnosis of chronic Chagas' disease resides in its high specificity (100%). Our data suggest that recombinant peptides could provide a practical basis for specific diagnosis tests for Chagas' disease.

[Chagas megaileum. Report of a case]

É apresentado um caso de megaíleo de natureza chagásica. O paciente, portador da Doença de Chagas, branco com 41 anos, apresentava história de 3 anos de episódios de eólicas abdominais, distensão e diarréia, que foram se tornando mais intensas e mais freqüentes. Fora das crises, apresentava-se assintomático. O diagnóstico de megaíleo foi estabelecido por meio do estudo radiológico contrastado do intestino delgado. O estudo histológico realizado em fragmento obtido à intervenção cirúrgica mostrou diminuição do número de células ganglionares dos plexos mientéricos.