Multimodality imaging and systemic biomarkers in classical low-flow low-gradient aortic stenosis: key findings for cardiac remodeling evaluation

Background

Elevated levels of troponin I (hsTnT) and B-type natriuretic peptide (BNP) have been related with poor prognosis in patients with LFLG-AS. Biomarkers are less expensive, more practical and more accessible than imaging tests, so their use can be an alternative to imaging in the evaluation of patients with LFLG-AS.

Purpose

The aim of the present study is to assess multimodality imaging findings according to systemic biomarkers (i.e. hsTnT and BNP) in Low-Flow, Low-Gradient Aortic Stenosis (LFLG-AS) and reduced left ventricular ejection fraction (LVEF) patients.

Methods

Prospective study with LFLG-AS patients (LVEF <50%, aortic valve area ≤1,0 cm2 and mean gradient <40 mmHg) that underwent hsTNnT, BNP, cardiac magnetic resonance (CMR) with T1 mapping and 2 dimensional echocardiogram (2DEcho). All patients also underwent dobutamine stress echocardiogram to define aortic stenosis severity. Patients were divided into 3 groups according to BNP and hsTnT levels: Group 1: BNP and hsTnT levels below median (BNP <395 pg/ml and TnI-Ultra <0.042 ng/ml); Group 2: BNP or hsTnT higher than median; and Group 3: both hsTnT and BNP higher than median.

Results

49 patients with LFLG-AS were included (Group 1: 17 patients, Group 2: 14 patients and Group 3: 18 patients). Clinical characteristics (including risk scores) were not able to stratify these groups. Patients with elevation of both biomarkers had lower valvuloarterial impedance (P=0.03), lower LVEF (P=0.02), less moderate/severe mitral (P=0.01) and tricuspid regurgitation (P<0.01) by 2DEcho. CMR identified a progressive increase (from Group 1 to 3) of right and left chamber volumes; reduction in right and left ejection fraction and a marked increase in myocardial fibrosis assessed by extracellular volume (ECV) and indexed extracellular volume (iECV) (Figure 1).

Conclusion

Higher levels of BNP and hsTnT in LFLG-AS patients were associated with worse multi-modality imaging parameters and can be a surrogate of cardiac remodeling.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): No funding

Can the atrial septal defect size in newborn patient predict spontaneous closure?

Funding Acknowledgements

Type of funding sources: None.

onbehalf

Hospital Albert Eisntein"s pediatric echocardiogram team

Can atrial septal defect size in newborn predict spontaneous closure?

Introduction

Spontaneous closure of atrial septal defect (ASD) has been reported to occur in 33%-75% of patients. Factors that influence spontaneous closure are size of the ASD and age of the patients.

Purpose

We aimed to investigate if the diameter of ASD measured by echocardiogram in the newborn can anticipate clinical outcome and predict spontaneous closure.

Methods

We reviewed 1012 two-dimensional echocardiograms (2DE) performed in the first days of life of newborn at our hospital from January 2015 to December 2019 with ASD or patent foramen ovale (PFO) as initial diagnoses. The exclusion criteria were associated congenital heart disease, except ventricular septal defect and patent ductus arteriosus both without repercussion. 153 newborns with ASD or PFO in the first 2DE were included in this study. The individual data collected were age at the exam, birth weight, gestational age, height by birth, ASD diameter, total diameter of atrial septum and Septum/ASD ratio (Table 1). The results were expressed as mean ± SD, or percentage. Comparisons of continuous variables between groups of patients were performed using the Student T test. Statistical significance was determined by p <0,05. The newborn was grouped according to the observation or not of spontaneous closure.

Results

ASD or PFO was found in 153 newborns. 60 had PFO, spontaneous closure was reported in 38 (63%). 93 had ASD in the first 2DE, spontaneous closure was reported in 41 (44%). The mean age of diagnosis was 3,37 ±4,39 days of life. The diameter of the ASD in the first exam and the septum/ASD ratio were associated with spontaneous closure. There was no association between spontaneous closure of ASD and birth weight or gestational age in this studied group.

Conclusion

The ASD diameter obtained at the first 2DE in the first days of life was associated with spontaneous closure of the defect.

Table 1 Non-closure group (N = 52) Closure group (N= 41) P Age at the exam (days) 3,48 (±4,52) 3,2 (±4,27) 0,78 Birth weight (grams) 2459,85 (±1098,79) 2350,12 (±1247,70) 0,65 Gestational age (weeks) 34,88 (±5,17) 34,54 (±5,10) 0,75 Height by birth (cm) 44,46 (±6,81) 43,67 (±6,77) 0,57 ASD diameter (mm) 3,66 (± 2,66 (±0,57) <0,01 Septum diameter (mm) 18,74 (±3,9) 18,92(±4,51) 0,83 Septum/ ASD ratio 5,74 (±2,38) 7,28 (±1,96) <0,01 cm = centimeter, mm = millimeter, ASD = atrial septal defect. Unit: Mean and standard deviation.

P697 Left ventricular non compaction highlighted by three-dimensional and speckle tracking echocardiography

Introduction

Left ventricular non-compaction (LVNC) is a relatively new cardiomyopathy, first reported by Chin et al. in 1990. Since then, much has been learned about this entity, but until now, there are some limitations for the diagnosis of this disease. Cardiac Magnetic Resonance Imaging is considered the gold standard for the diagnosis of LVNC, but echocardiography remains the first line imaging modality due to its availability and cost efficacy.

Case report

In this case, we report a case of an asymptomatic 21 years old young male with no personal or familiar history of cardiomyopathies. Two dimensional echocardiography (2D Echo) evidenced increased left ventricular trabeculation in the apical segments of lateral and anterior walls and a non compacted myocardium/ (compacted + non compacted myocardium) ratio of 0,33, compatible with LVNC according to Chin´s criteria. 3D Echo provided more detailed LV morphology analysis and 3D Echo Color Doppler evidenced ventricular flow within the intraventricular recesses. Strain analysis by speckle tracking (STE) evidenced global longitudinal strain = - 17% (Normal values < -18%), probably related to an incipient systolic dysfunction not evidenced by the evaluation of left ventricular ejection fraction by 2D Echo.

Conclusions

This case illustrates new echocardiographic modalities for LVNC diagnosis. 3D Echo and STE are new technologies that may play an incremental role in the evaluation of LVNC but need further investigation and validation.

Abstract P697 Figure.

1102 Rare association of left ventricular non-compaction and hypertrophic cardiomyopathy

Background

LVNC and HCM are cardiomyopathies with distinct clinical presentation that may present common genetic mutations. Some studies suggest a common genetic basis between HCM and LVNC and the possibility of a phenotypic association of these two cardiomyopathies in the same patient.

Case report

A 39 year old man was referred to our hospital with syncope. His past medical history was unremarkable. His father died of sudden death, at age 49, without investigation of Left ventricular non compaction (LVNC) or Hypertrophic cardiomyopathy (HCM). Physical examination was unremarkable. Electrocardiogram showed sinus rhythm with left chambers overload and isolated ventricular extrasystoles. Transthoracic Echocardiogram (TTE) evidenced significant left ventricular (LV) hypertrophy predominantly in the apical region and inferolateral wall, in the absence of a significant intraventricular gradient at rest and after provocative maneuvers, with preserved LV function, suggesting non-obstructive HCM. Cardiac magnetic resonance imaging (CMRI) showed LV hypertrophy predominantly in the lateral wall, with a maximum thickness of 35 mm, no signs of left ventricular outflow tract (LVOT) obstruction and prominent apical trabeculation, compatible with the association of LVNC and HCM. A genetic test was performed on this patient with inconclusive results.

Conclusions

The association of diagnostic criteria in cardiac imaging tests (TTE and CMRI) compatible with LVNC and HCM in the same patient is uncommon. This patient shows an infrequent location of the most prominent hypertrophy in the inferolateral wall.This case highlights the importance of integrating cardiac imaging methods in the diagnosis of these two disctinct and rare cardiomyopathies.

Legend Figure 1: 2D TTE evidencing prominent hypertropfhy and intraventricular recesses at apical region and inferolateral wall (red arrows), abnormalities suggesting HCM and LVNC at LV apex (blue arrows) in Paraesternal Long Axis (A and B), Short Axis View (C to F), Apical 4 Chambers (G and H) and Apical 2 Chambers View (I and H). Speckle tracking analysis evidencing incipient LV systolic dysfunction by reduced global longitudinal strain (GLS:-8,9%) despite the preserved LVEF (K to N). CMR evidencing findings compatible with the association of LVNC (blue arrows) and HCM (red arrow) in 4 Chambers (O and P), 2 Chambers (Q and R) and Short Axis Views (S to V).

Abstract 1102 Figure 1

1186 Three-dimensional analysis of right ventricle strain in transplanted hearts and rejection: an ongoing prospective study

Background

The main obstacle for success after heart transplantation is graft rejection, since is mainly asymptomatic and diagnosed by endomyocardial biopsy (EMB). New echocardiographic technologies could bring benefits to that population if subtle changes in heart mechanics were related to an incipient state of rejection.

Purpose

To quantify echocardiographic parameters of right ventricle strain and volumes by a semi-automated offline software and to identify the presence of any relation between those findings and the histopathologic diagnose of rejection.

Methods

a prospective cohort of 35 postoperative heart transplant patients who were submitted to echocardiographic evaluation up to six hours after EMB, including two-dimensional chamber quantification of left ventricular (LV) volumes and ejection fraction; conventional and tissue Doppler measurements were used for flow and functional analysis. Offline assessment of the right ventricle (RV) was made by TOMTEC software, with the acquisition of RV volumes (EDV, ESV, SV) and ejection fraction, TAPSE, FAC and three-dimensional(3D) RV free wall and septal strain using speckle tracking. EMB results were classified as positive for cellular rejection if graded as 2R (two or more interstitial infiltrate spots and myocyte damage) and positive for humoral rejection if they show any response by immunofluorescence assay.

Results

We studied 35 patients, aged 50 ±11, 21 male (67%), totaling 58 examinations, and then we made two analysis of EMB: one in two groups regarding cellular rejection (53 negative and 5 positive) and other regarding humoral rejection (50 negative and 8 positive). RVEDV was higher in the cellular rejection group (112,5 ± 29,6 ml) compared to those with negative biopsy (86,8 ± 24,7 mL; p = 0,01). RV stroke volume showed a similar behavior (53,5 ± 22,3 mL vs. 34,5 ± 11,3 mL; p < 0,01). Regarding humoral rejection by immunofluorescence, patients who tested positive showed lower RVEDV (79,5 ± 10,5 mL vs. 90,57 ± 27,31 mL; p = 0,02) and RVESV (45,53 ± 6,33 mL vs. 53,87 ± 19,87 mL; p = 0,01). RV free wall strain was lower in the group with positive immunofluorescence (-18,35 ± 2,79% vs. -15,34 ± 5,35%; p = 0,01). Regarding 2D measurements , interventricular septal (11,5 ± 1,06 mm vs. 10,56 ± 1,38 mm; p = 0,02) and left ventricular posterior wall (10,75 ± 1,03 mm vs. 10,04 ± 1,1 mm; p = 0,05) were also thicker in the group with positive immunofluorescence for rejection.

Conclusion

Both cellular and humoral rejection after heart transplantation are associated to increased 3D RV volumes whereas a decrease in RV free wall strain is only observed in humoral rejection; in patients with positive immunofluorescence results a significant increase is seen for septal and posterior wall thickness.

P1396 Three-dimensional cardiac mechanics for prediction of events in Chagas disease

Introduction

Chagas disease (CD) is an endemic infectious disease that still remains a great economic burden. Three-dimensional speckle tracking (3D STE) may play a role in the evaluation of CD. We assessed the hypothesis that 3D STE may predict clinical events in patients with CD.

Methods

This was a convenience sample. Patients with any systemic disease were excluded. Eight hundred and eight patients with CD were evaluated but only seventy-two were included. Clinical, electrocardiographic and comprehensive conventional and 3D echocardiography were performed. Patients were followed up for thirty-six up to sixty months. Clinical events were defined as hospitalization for heart failure, ventricular arrhythmias and cardiovascular death.

Results

Seventy-two patients were enrolled in three groups: Group 1 (G1), patients with left ventricular ejection fraction (LVEF) < 0.35 (N = 22); Group 2 (G2), LVEF between 0.35 and 0.55 (N = 22); Group 3 (G3), normal LVEF (N = 28). Gender distribution, mean age, anthropometric variables and risk factors were similar between the groups. 2D STE feasibility was 99.5, 99 and 100% in G1, G2 and G3. 3D Longitudinal strain feasibility was 93, 89 e 88% in G1, G2 and G3. Interobserver and intraobserver variabilities (Blant-Altman) for longitudinal (2D and 3D GLS), circumferential (3D GCS), radial (3D GRS) and area strain (3D AS) are displayed in Table 1.

Hospitalization was related do indexed left atrium volume (p = 0,03) in G1. In G2, non-sustained ventricular tachycardia were related to 2D GLS values (p = 0,04); all clinical events were related do diastolic function (p = 0,30). In G1 and G2, hospitalization was related do indexed left atrium volume (p = 0,01); all clinical events were related do diastolic function (p = 0,004) and 3D LVEF (p = 0,02). 3D STE parameters were not related to clinical events.

Conclusions

In conclusion, 3D STE in patients with CD appears to be an accurate, reproducible and promising method but was not related to clinical events.

Table 1 INTEROBSERVER INTRAOBSERVER 2D GLS 0.96 ± 0.04 0.90 ± 0.08 3D GLS 0.92 ± 0.07 0.93 ± 0.10 3D GCS 0.88 ± 0.07 0.82 ± 0.15 3D AS 0.93 ± 0.05 0.90 ± 0.05 3D RS 0.85 ± 0.05 0.84 ± 0.11 Table 1. Interobserver and intraobserver variabilities for longitudinal (2D and 3D GLS), circumferential (3D GCS), radial (3D GRS) and area strain (3D AS).

P6483Predictors of contractile reserve on dobutamine stress echocardiography in patients with classical low-flow, low-gradient aortic stenosis

Background

There is a lack of information on factors that influence contractile reserve (CR) on dobutamine stress echocardiography (DSE) in patients with classical low-flow, low-gradient aortic stenosis (LFLG-AS).

Purpose

This study sought to evaluate the predictors of CR in patients with LFLG-AS.

Methods

Prospective study including 43 consecutive LFLG-AS patients (aortic valve area [AVA] ≤1.0 cm2, mean transaortic gradient <40 mmHg, left ventricular ejection fraction [LVEF] <50%) with true severe aortic stenosis. All patients underwent dobutamine stress echocardiography and T1-mapping cardiac magnetic resonance (CMR). CR was defined as an increase ≥20% in the left ventricular stroke volume at peak stress. Patients with pseudo-severe aortic stenosis were excluded.

Results

All of the patients in the study had degenerative aortic stenosis, with a median age of 67 [60–74] years, most of them being male (83.7%). A high prevalence of comorbidities was found, highlighted by diabetes (42%), hypertension (70%), atrial fibrillation (25%) and coronary artery disease (38%). Mean transaortic gradient was 25 [20–33] mmHg, AVA was 0.88 [0.68–0.95] cm2, LVEF was 35 [28–43]% and 32.6% had moderate/severe functional mitral regurgitation. CMR myocardium extracellular volume fraction (ECV) was 28.8 [26.3–33.0] %, indexed ECV was 35.4 [25.0–41.2] ml/m2, 32.6% had positive transmural delayed-enhancement images and 25.6% had positive mesocardial delayed-enhancement images. On DSE, 30 patients (69.7%) had CR and 13 patients (30.3%) had no CR. Global longitudinal strain was 10 [7–12] %, Δ indexed flow rate was 25 [3–38] ml/m2.seg and Δ mean gradient was 10 [3–16] mmHg. By multivariate analysis, moderate/severe functional mitral regurgitation (HR 0.122, 95% CI 0.020–0.759, p=0.024) and AVA (HR 0.606, 95% CI 0.396–0.925, p=0.020 [for each increase of 0.05 cm2]) were the only factors associated with CR. ECV, indexed ECV and positive transmural or mesocardial delayed-enhancement images were not associated with CR in the univariate analysis.

Conclusions

In our study, the absence of moderate/severe functional mitral regurgitation and AVA were predictors of CR on DSE in patients with LFLG-AS. As AVA was smaller in patients with CR, our finding contradicts the hypothesis that more severe aortic stenosis could also contribute to the lack of CR. Other possible factors that are surrogate of myocardium fibrosis, as ECV, indexed ECV and positive delayed-enhancement images, were not associated with the absence of CR.

Acknowledgement/Funding

FAPESP

P2515Cardiac rehabilitation in patients with refractory angina: preliminary results

Introduction

Refractory angina (RA) implies important impairment of quality of life. Cardiac rehabilitation (CR) is still not recommended by guidelines due to few evidence regarding its effects in this population. This study evaluated the impact of CR on physical performance and on angina/ischemia threshold.

Methods

36 RA patients undergoing optimal medical therapy were randomly assigned to a 12-week exercise based CR program or stablished clinical follow-up (CF). Clinical evaluation, exercise bicycle stress echocardiography (SE) and cardiopulmonary exercise testing (CP) were performed before and after the protocol. CR group performed in-hospital exercise sessions, and the aerobic training prescription was based on CP parameters or ischemia/ angina threshold. Each CR class was 60 min in duration (5min warm-up, 30min aerobic and 5min cooldown, 15min low load resistance training and 5min stretching). Bonferroni multiple comparison and t test were used in statistical analysis.

Results

Baseline characteristics didn't differ between groups. In RC group, 40% presented CCS 2, 25% CCS 3 and 35% CCS 4, while in CF group, 41%, 23.5% and 35.5%, respectively (p=0.5). There was no change in CCS between groups after intervention. CR group presented an increase in ischemic threshold in SE when compared to CF group (234.6±87.9s to 293.8±130.9 s vs. 200.9±78.6s to 203.7±93.7s, p=0.044), increase in angina threshold in SE (156.00±62.2s to 260.1±152.8s vs. 190.6±96.6s to 152.9±76, 7s, p=0.041) and increase in CP total duration (347.9±143.2s to 489.8±170.2s vs. 331.7±128.5s to 323.5±101.0s, p=0,016).

Baseline characteristics in both groups Variables CR group (n=19) CF group (n=17) p Male sex (%) 63.2 58.8 0.8 Age, years (mean ± SD) 61.2±8.7 62.9±8.8 0.6 LVEF, % (mean ± SD) 55.7±7.3 50.0±10.4 0.08 SBP, mmHg (mean ± SD) 125.6±18.0 122.6±14.5 0.6 DBP, mmHg (mean ± SD) 77.5±9.6 76.2±13,1 0.7 HR, bpm (mean ± SD) 60.5±6.2 60.6±7.1 0.9 BMI, kg/m2 (mean ± SD) 28.8±4.1 26.1±10.9 0.4 Fasting glucose, mg/dl (mean ± SD) 136.4±33.6 153.6±64.7 0.3 HBA1C, % (mean ± SD) 6.8±1.2 7.2±1.6 0.4 LDL-c, mg/dl (mean ± SD) 77.8±29.0 84.7±28.6 0.5

Results

CR seems to be an effective adjuvant treatment in RA, increasing ischemia and angina threshold, improving physical performance.

Acknowledgement/Funding

FAPESP

Identification of passion fruit (Passiflora edulis) chromosomes using BAC-FISH

Passiflora edulis, the yellow passion fruit, is the main crop from the Passiflora genus, which comprises 525 species with its diversity center in South America. Genetic maps and a BAC (bacterial artificial chromosome) genomic library are available, but the nine chromosome pairs of similar size and morphology (2n = 18) hamper chromosome identification, leading to different proposed karyotypes. Thus, the aim of this study was to establish chromosome-specific markers for the yellow passion fruit using single-copy and repetitive sequences as probes in fluorescent in situ hybridizations (FISH) to allow chromosome identification and future integration with whole genome data. Thirty-six BAC clones harboring genes and three retrotransposons (Ty1-copy, Ty3-gypsy, and LINE) were selected. Twelve BACs exhibited a dispersed pattern similar to that revealed by retroelements, and one exhibited subtelomeric distribution. Twelve clones showed unique signals in terminal or subterminal regions of the chromosomes, allowing their genes to be anchored to six chromosome pairs that can be identified with single-copy markers. The markers developed herein will provide an important tool for genomic and evolutionary studies in the Passiflora genus.

Activity of Antarctic fungi extracts against phytopathogenic bacteria

This study aims to obtain secondary metabolites extracts from filamentous fungi isolated from soil and marine sediments from Antarctic ecosystems and to assess its potential antibacterial activity on Xanthomonas euvesicatoria and Xanthomonas axonopodis pv. passiflorae (phytopathogenic bacteria causing diseases in pepper and tomato and passionfruit, respectively). Among the 66 crude intracellular and extracellular extracts obtained from fungi recovered from soil and 79 obtained from marine sediment samples, 25 showed the ability to prevent the growth of X. euvesicatoria in vitro and 28 showed the ability to prevent the growth of X. axonopodis pv. passiflorae in vitro. Intracellular and extracellular extracts from soil fungi inhibited around 97% of X. euvesicatoria and 98% of X. axonopodis pv. passiflorae at 2·1 mg ml^-1 . The average inhibition rates against X. euvesicatoria and X. axonopodis pv. passiflorae for intracellular and extracellular extracts from marine sediments fungi were around 96 and 97%, respectively, at 3·0 mg ml^-1 . Extracts containing secondary metabolites with antimicrobial activity against X. euvesicatoria and X. axonopodis pv. passiflorae were obtained, containing possible substitutes for the products currently used to control these phytopathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Micro-organisms from extreme ecosystems, such as the Antarctic ecosystem, need to survive in harsh conditions with low temperatures, low nutrients and high UV radiation. Micro-organisms adapt to these conditions evolving diverse biochemical and physiological adaptations essential for survival. All this makes these micro-organisms a rich source of novel natural products based on unique chemical scaffolds. Discovering novel bioactive compounds is essential because of the rise in antibiotic-resistant micro-organisms and the emergence of new infections. Fungi from Antarctic environments have been proven to produce bioactive secondary metabolites against various micro-organisms, but few studies have shown activity against Xanthomonas phytopathogens.

Identification of Stylosanthes guianensis varieties using molecular genetic analysis

BACKGROUND AND AIMS

The botanical classification of Stylosanthes guianensis is controversial, and few studies have used molecular markers to analyse this species. We used microsatellite markers to study the genetic diversity and population structure of S. guianensis and compare our results with the current infraspecific botanical classification.

METHODOLOGY

A representative sample from the S. guianensis Brazilian germplasm collection (150 accessions) was analysed using 20 microsatellite loci. A model-based Bayesian approach implemented in the software STRUCTURE was used to assign accessions into clusters. A dendrogram was constructed based on Roger's genetic distances.

PRINCIPAL RESULTS

The number of alleles per locus varied from 2 to 11, with an average of 4.7. The observed (H(O)) and expected (H(E)) heterozygosity values varied from 0 to 0.58 (mean of 0.18) and from 0.04 to 0.83 (mean of 0.55), respectively. Nine groups were assembled in STRUCTURE, and these groups were consistent with clusters inferred from the genetic distances and taxonomic varieties described for S. guianensis. The G(ST) among the nine groups was 0.46.

CONCLUSIONS

The low H(O) and the G(ST) values observed are in agreement with the outcrossing rate (26 %) estimated for this species. The data indicate a high genetic diversity among and within the botanical varieties and suggest that microsatellite-based information can be combined with classical taxonomy to elucidate infraspecific levels.

Report of a Large Brazilian Family With a Very Attenuated Form of Hunter Syndrome (MPS II)

Hunter syndrome, or Mucopolysaccharidosis type II (MPS II), is a rare X-linked recessive disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The phenotypic spectrum varies from severe to attenuated clinical forms. We report a large Brazilian family with 16 affected individuals exhibiting a very attenuated form of MPS II. Fourteen female carriers were also identified. Twelve affected male patients, whose ages ranged from 1 to 35 years, were examined. Molecular analysis showed a novel missense mutation (p.A77D) in the IDS gene, confirming the diagnosis. Nine of the family members presented some degree of heart damage, though only the proband became symptomatic and required heart transplantation. One 19-year-old adult and 1-year-old twin boys each had a normal echocardiogram. Short stature was found in two adults while macrocephaly was found in one; the remaining adults had anthropometric measures within normal range. All affected adults had normal cognitive development and were able to perform normal daily activities, except one who had mild learning disability. Two patients died due to natural causes beyond 70 years of age. The female carriers did not present any signs of disease. In this large family with a mild form of MPS II and variable degree of clinical manifestations, it is noteworthy that several affected individuals have remained asymptomatic even at advanced age and even without enzyme replacement therapy.

Genetic diversity and a PCR-based method for Xanthomonas axonopodis detection in passion fruit

Xanthomonas axonopodis pv. passiflorae causes bacterial spot in passion fruit. It attacks the purple and yellow passion fruit as well as the sweet passion fruit. The diversity of 87 isolates of pv. passiflorae collected from across 22 fruit orchards in Brazil was evaluated using molecular profiles and statistical procedures, including an unweighted pair-group method with arithmetical averages-based dendrogram, analysis of molecular variance (AMOVA), and an assigning test that provides information on genetic structure at the population level. Isolates from another eight pathovars were included in the molecular analyses and all were shown to have a distinct repetitive sequence-based polymerase chain reaction profile. Amplified fragment length polymorphism technique revealed considerable diversity among isolates of pv. passiflorae, and AMOVA showed that most of the variance (49.4%) was due to differences between localities. Cluster analysis revealed that most genotypic clusters were homogeneous and that variance was associated primarily with geographic origin. The disease adversely affects fruit production and may kill infected plants. A method for rapid diagnosis of the pathogen, even before the disease symptoms become evident, has value for producers. Here, a set of primers (Xapas) was designed by exploiting a single-nucleotide polymorphism between the sequences of the intergenic 16S-23S rRNA spacer region of the pathovars. Xapas was shown to effectively detect all pv. passiflorae isolates and is recommended for disease diagnosis in passion fruit orchards.

Impact of continuous positive airway pressure treatment on left atrial volume and function in patients with obstructive sleep apnoea assessed by real-time three-dimensional echocardiography

Background:

Obstructive sleep apnoea (OSA) has been reported as a predictor of left ventricle (LV) diastolic dysfunction and left atrium (LA) remodelling. The aim of this study is to evaluate the impact of OSA treatment with a continuous positive airway pressure device (CPAP) on the LA volume and function, as well as on the LV diastolic function.

Methods:

In total, 56 OSA patients were studied. All patients underwent real-time three-dimensional (RT3DE) and two-dimensional echocardiogram with tissue Doppler evaluation in order to estimate LA volumes, function and LV diastolic performance. A total of 30 patients with an apnoea-hypopnoea index greater than 20 were randomly selected to receive sham CPAP (n = 15) or effective CPAP (n = 15) for 24 weeks. They underwent echo examination on three different occasions: at baseline, after 12 weeks and 24 weeks of CPAP or sham CPAP.

Results:

In the effective CPAP group we observed the following changes from the baseline to the 24-week echo evaluation: (a) a reduction in the E/E′ ratio (10.3 (1.9) to 7.9 (1.3), p = 0.03); (b) an increase in the LA passive emptying fraction (28.8% (11.9%) to 46.8% (9.3%), p = 0.01); and (c) a reduction in the LA active emptying fraction (42.7% (11.5%) to 25.7 (15.7), p<0.01). In the sham group, there were no changes from the baseline to the 24-week echo. We found a positive correlation between 24 week/baseline LA active emptying volume and 24 week/baseline E/E′ ratios (r = 0.40, p<0.05) and a negative correlation between 24 week/baseline LA passive emptying volume and 24 week/baseline E/E′ ratios (r = −0.53, p<0.05). No significant changes were found on LA total emptying fraction.

Conclusion:

CPAP improved LV diastolic function and LA passive emptying, but not LA structural variables in OSA patients.

Trial registration number:

NCT00768807.

Resistance to Passion fruit woodiness virus in Transgenic Passionflower Expressing the Virus Coat Protein Gene

We report the use of the coat protein (CP) gene from Passion fruit woodiness virus (PWV) to produce resistant transgenic plants of yellow passion fruit. A full-length CP gene from a severe PWV isolate from the state of São Paulo, Brazil (PWV-SP) was cloned into pCAMBIA 2300 binary vector, which was further introduced into Agrobacterium tumefaciens strain EHA 105. Leaf disks were used as explants for transformation assays, e.g., 2,700 and 2,730 disks excised from plants from the Brazilian cultivars IAC-275 and IAC-277, respectively. In vitro selection was performed in kanamycin. After transferring to the elongation medium, 119 and 109 plantlets of IAC-275 and IAC-277, respectively, were recovered. Integration of the PWV CP gene was confirmed in seven of eight plants evaluated by Southern blot analysis, showing different numbers of insertional events for the CP gene. Three transgenic plants (T3, T4, and T7) expressed the expected transcript, but the 32 kDa PWV CP was detected by Western blot in only two plants (T3 and T4). The results of three successive mechanical inoculations against the transgenic plants using three PWV isolates showed that the primary transformant T2 of IAC-277 was immune to all isolates.

Repeated echocardiographic examinations of patients with suspected infective endocarditis

OBJECTIVE

To study the diagnostic contribution of repeated transthoracic (TTE) and transoesophageal echocardiography (TOE) among patients with suspected infective endocarditis.

METHODS

262 patients with 266 episodes of suspected infective endocarditis were referred for TTE and TOE over three years in a 423 bed university cardiology hospital. Patients were a mean (SD) of 47.6 (17.9) years old. 139 (52.3%) episodes occurred in men and 127 (47.7%) in women. The diagnostic information obtained from repeated TTE and TOE examinations was evaluated relative to the diagnosis of endocarditis.

RESULTS

TTE examinations were repeated in 192 (72.2%) and TOE examinations were repeated in 49 (18.4%) of 266 episodes. A mean of 2.4 TTE and 1.2 TOE examinations were performed for each episode of suspected endocarditis. The second and third TTEs added diagnostic information in 34 (26.7%) and the second and third TOEs added diagnostic information in 25 (19.7%) of 127 episodes with definite endocarditis. After the third TTE or TOE no additional diagnostic information was obtained.

CONCLUSIONS

The diagnostic contribution of repeated TTE or TOE for the diagnosis of endocarditis decreased as the number of repetitions increased. In this setting, the data do not substantiate more than three TTE or TOE examinations as an efficient strategy to increase the diagnostic yield for all but selected patients with suspected endocarditis.

Cryopreservation of Arachis species by vitrification of in vitro-grown shoot apices and genetic stability of recovered plants

A storage protocol at cryogenic temperature was established for shoot apices from in vitro plants of the cultivated groundnut (Arachis hypogaea) and wild Arachis species (A. retusa and A. burchellii) using a basic vitrification protocol with direct immersion in liquid nitrogen (LN). The effect of pre-treatments of donor-plants with ABA as well as of different supplements in the post-thaw culture medium was studied. After rapid warming at 40 C, the explants were cultured on MS medium devoid of growth regulators (MS0) or MS supplemented with 4.4(M benzylaminopurine (BAP) and 0.5(M naphthalene acetic acid (NAA) plus 5(M silver nitrate (AgNO3), 0.25% polyvinylpyrrolidone (PVP) or 0.2% activated charcoal. Non-frozen explants from the three species formed one shoot through meristematic amplification when cultured on MS0 medium. These explants also developed callus on MS supplemented with growth regulators (4.4(M BAP and 0.5(M NAA) alone or plus PVP or AgNO3. Callus formation was suppressed in the presence of activated charcoal. Post-thaw regeneration ocurred only through indirect organogenesis on media containing AgNO3 or PVP. Preculturing on medium supplemented with abscisic acid (ABA) improved regrowth rate in these media. Recovery failed to occur in the presence of activated charcoal. The genetic stability of shoots of A. burchellii originated from shoot apices was analyzed through Random Amplified Polymorphic DNA (RAPD) markers.