Giants of the Amazon: How does environmental variation drive the diversity patterns of large trees?

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class.

Annexin A1-FPR2/ALX Signaling Axis Regulates Acute Inflammation during Chikungunya Virus Infection.

Chikungunya (CHIKV) is an arthritogenic alphavirus that causes a self-limiting disease usually accompanied by joint pain and/or polyarthralgia with disabling characteristics. Immune responses developed during the acute phase of CHIKV infection determine the rate of disease progression and resolution. Annexin A1 (AnxA1) is involved in both initiating inflammation and preventing over-response, being essential for a balanced end of inflammation. In this study, we investigated the role of the AnxA1-FPR2/ALX pathway during CHIKV infection. Genetic deletion of AnxA1 or its receptor enhanced inflammatory responses driven by CHIKV. These knockout mice showed increased neutrophil accumulation and augmented tissue damage at the site of infection compared with control mice. Conversely, treatment of wild-type animals with the AnxA1 mimetic peptide (Ac2-26) reduced neutrophil accumulation, decreased local concentration of inflammatory mediators and diminished mechanical hypernociception and paw edema induced by CHIKV-infection. Alterations in viral load were mild both in genetic deletion or with treatment. Combined, our data suggest that the AnxA1-FPR2/ALX pathway is a potential therapeutic strategy to control CHIKV-induced acute inflammation and polyarthralgia.

Left ventricular pacing with a temporary pacemaker: Case report.

We report a case of temporary pacemaker lead malposition in the left ventricle crossing the interventricular septum (IVS). The majority of described cases occur due to a patent foramen ovale and are frequently incidental findings. A course across the IVS is rarely found and this complication with temporary leads is not even reported in the literature. This very rare location entails a risk of dangerous complications associated with left-to-right flow after lead removal. Echocardiography was an essential tool to diagnose the lead's course inside the heart and enabled secure removal of the lead with cardiac surgery backup.

In-depth characterization of a novel live-attenuated Mayaro virus vaccine candidate using an immunocompetent mouse model of Mayaro disease.

Mayaro virus (MAYV) is endemic in South American countries where it is responsible for sporadic outbreaks of acute febrile illness. The hallmark of MAYV infection is a highly debilitating and chronic arthralgia. Although MAYV emergence is a potential threat, there are no specific therapies or licensed vaccine. In this study, we developed a murine model of MAYV infection that emulates many of the most relevant clinical features of the infection in humans and tested a live-attenuated MAYV vaccine candidate (MAYV/IRES). Intraplantar inoculation of a WT strain of MAYV into immunocompetent mice induced persistent hypernociception, transient viral replication in target organs, systemic production of inflammatory cytokines, chemokines and specific humoral IgM and IgG responses. Inoculation of MAYV/IRES in BALB/c mice induced strong specific cellular and humoral responses. Moreover, MAYV/IRES vaccination of immunocompetent and interferon receptor-defective mice resulted in protection from disease induced by the virulent wt MAYV strain. Thus, this study describes a novel model of MAYV infection in immunocompetent mice and highlights the potential role of a live-attenuated MAYV vaccine candidate in host's protection from disease induced by a virulent MAYV strain.

Prediction of new onset of resting pulmonary arterial hypertension in systemic sclerosis.

BACKGROUND: Early detection of pulmonary arterial hypertension (PH) is crucial in systemic scleroderma. However, predictors of new onset of resting PH during follow-up (FUPH) have been poorly explored. AIM: To determine whether nailfold videocapillaroscopy (NVC) grade and exercise echocardiographic variables are predictors of FUPH. METHODS: We prospectively enrolled 40 patients with systemic sclerosis (age 54±13 years; 68% women). All patients underwent graded semisupine exercise echocardiography and NVC. Baseline resting PH and FUPH were defined as systolic pulmonary arterial pressure (sPAP)>35 mmHg, and exercise-induced PH (EIPH) as exercise sPAP>50 mmHg. RESULTS: Seventeen patients developed EIPH (43%). During follow-up (FU) (25±15 months), 11 patients without baseline PH developed FUPH (28%), all from the EIPH group. Patients with FUPH were significantly older (60±14 vs 50±12 years; P=0.04), had higher resting and exercise sPAP (30±4 vs 22±5 and 60±12 vs 40±11 mmHg, respectively; P<0.0001) and a higher exercise E/e' ratio (9.4±0.7 vs 5.8±0.4; P=0.0003) and presented more frequently NVC grade>2 (90% vs 35%; P=0.0009). After adjustment for age, resting sPAP, exercise sPAP and NVC grade>2 were associated with maximal resting sPAP during follow-up and FUPH (P<0.05). Patients with both EIPH and NVC grade>2 had a very high incidence of FUPH (82%), and both variables remained strongly associated with FUPH after adjustment for age (hazard ratio 11.6, 95% confidence interval 2.4-55.3; P=0.002). CONCLUSION: Exercise echocardiography and NVC can identify a subgroup of patients with systemic sclerosis who are at risk of developing FUPH.

Cardiovascular outcome in systemic sclerosis.

OBJECTIVES: Cardiovascular involvement is recognized as a poor prognostic factor in systemic sclerosis (SSc). The aim of this study was to evaluate the usefulness of nailfold video-capillaroscopy (NVC), brain natriuretic peptide (BNP) blood level and exercise echocardiography to predict the occurrence of cardiovascular events in SSc. METHODS: We prospectively enrolled 65 patients with SSc (age 54±14 years, 30% female) followed in CHU Sart-Tilman, Liège, Belgium. All patients underwent graded semi-supine exercise echocardiography. Both baseline resting pulmonary hypertension (PH) and PH during follow-up (FUPH) were defined as systolic pulmonary arterial pressure (sPAP)>35 mmHg, and exercise-induced PH (EIPH) as sPAP>50 mmHg during exercise. RESULTS: EIPH was present in 21 patients. During FU (27±18 months), 13 patients developed FUPH and 9 presented cardiovascular complications. Patients with cardiovascular events were significantly older (63±14 vs 52±13 years; P=0.03), presented more frequently NVC grade>2 (89 vs 43%; P=0.009), had higher resting and exercise sPAP (30±6 vs 24±6; P=0.007 and 57±13 vs 44±13 vs mmHg; P=0.01, respectively), and higher BNP blood level (112±106 vs 26±19 pg/ml; P=0.0001). After adjustment for age and gender, NVC grade>2 (ß=2.4±1.1; P=0.03), EIPH (ß=2.30±1.13; P=0.04), FUPH (ß=0.24±0.09; P=0.01 and ß=3.52±1.16; P=0.002, respectively;) and BNP (ß=0.08±0.04; P=0.02) were independent predictors of CV events. Beyond age, an incremental value of EIPH, BNP and NVC grade>2 was predictive of cardiovascular events (P<0.001). CONCLUSION: Cardiovascular complications are not rare in SSc (18%). NVC, BNP blood level assessment and exercise echocardiography could be useful tools to identify patients at risk of SSc.

Global longitudinal strain as a potential prognostic marker in patients with chronic heart failure and systolic dysfunction.

INTRODUCTION AND OBJECTIVE: The prognostic value of myocardium deformation measurements in chronic heart failure (CHF) is still poorly addressed. The purpose of this study was to evaluate the correlation of left ventricular (LV) global longitudinal strain (GLS) with clinical and prognostic indicators in patients with CHF and systolic dysfunction. METHODS: Ambulatory patients with CHF and LV ejection fraction (LVEF) <45% were studied by two-dimensional and Doppler transthoracic echocardiogram with assessment of GLS. An indication of prognostic status was obtained by the Seattle Heart Failure Model (SHFM) prognostic estimates for life expectancy. RESULTS: We included 54 CHF patients (mean age 55±12 years; 80% male). GLS was significantly correlated with NYHA functional class (r=0.41, p=0.002), BNP levels (r=0.47, p=0.001), LVEF (r=-0.69, p<0.001) and LV end-diastolic pressure, assessed by E/e' ratio (r=0.35, p<0.014) and left atrial maximal volume index (r=0.57, p<0.001). A significant correlation was found between GLS and SHFM prognostic estimates for life expectancy (r=-0.41, p=0.002). The multivariate logistic regression analysis showed that GLS independently predicted an estimated life expectancy <10 years (OR 2.614 [95% CI 1.010-6.763]). The corresponding area under the ROC curve was 0.802 (0.653-0.951) and the best obtained threshold was -9.5 (80% sensitivity, 65% specificity, p=0.003). CONCLUSIONS: GLS was strongly associated with a higher disease severity status and predicted a lower prognostic estimate for life expectancy.

Iron deficiency status irrespective of anemia: a predictor of unfavorable outcome in chronic heart failure patients.

OBJECTIVE: To assess the prognostic significance of iron deficiency (ID) in a chronic heart failure (CHF) outpatient population. METHODS AND RESULTS: We prospectively evaluated 127 patients with stable CHF and left ventricular ejection fraction ≤45%. Clinical and analytical data as well as information regarding the occurrence of the composite endpoint of overall mortality and nonfatal cardiovascular events were assessed. Among the 127 patients enrolled [81% men, median age: 62 years (25th-75th percentile: 53-68)], 46 (36%) patients had ID. Women, patients with higher plasma brain natriuretic peptide levels (>400 pg/ml) and with right ventricular systolic dysfunction presented ID more frequently (p < 0.05 for all). At 225 ± 139 days of follow-up, the composite endpoint occurred in 15 (12%) patients. It was more frequent in ID (24 vs. 5%, p = 0.001) and anemic patients (25 vs. 8%, p = 0.014). In a Cox regression analysis, ID was associated with a higher likelihood of composite endpoint occurrence (HR 5.00, 95% CI 1.59-15.78, p = 0.006). In a multivariable analysis adjusted for clinical variables, including the presence of anemia, ID remained a significant predictor of the composite endpoint (HR 5.38, 95% CI 1.54-18.87, p = 0.009). CONCLUSION: In a CHF outpatient population, ID carried a higher risk of unfavorable outcome, irrespectively of the presence of anemia.

The usefulness of the head-up tilt test in patients with suspected epilepsy.

PURPOSE: It is estimated that approximately 20-30% of patients diagnosed with epilepsy have been misdiagnosed, and neurocardiogenic syncope (NCS) might frequently be the real cause of transient loss of consciousness (TLOC) episodes. We assessed the role of the head-up tilt test (HUTT) in patients previously diagnosed with refractory epilepsy to evaluate the ability of this test to correctly diagnose patients with NCS. METHOD: We retrospectively analysed the clinical records of 107 consecutive patients with a previous diagnosis of refractory epilepsy that were taking antiepileptic drugs and who were referred for HUTT between January 2000 and December 2010. During the subsequent follow-up, we recorded the treatments performed and the recurrence of symptoms. RESULTS: Complete follow-up data were available for 94 (88%) patients, and the mean follow-up period was 80±36 months. The HUTT was positive in 54% of patients. Thirty-one (33%) patients were misdiagnosed with epilepsy, and 20 (21%) patients had a dual diagnosis of NCS and epilepsy. The recurrence of TLOC was reported in 55% of the patients, but it was significantly lower in the misdiagnosed group (42% versus 64%; P=0.039). CONCLUSION: NCS is an important cause of epilepsy misdiagnosis. The HUTT is often critical for making an accurate diagnosis and subsequently selecting the appropriate treatment for patients presenting with TLOC. The diagnostic overlap between epilepsy and NCS is not uncommon, suggesting that electroencephalographic monitoring during a HUTT may play an important role in diagnosing patients with recurrent, undiagnosed TLOC episodes.

Spirito-Maron echocardiographic score: a marker for morphological and physiological assessment of patients with hypertrophic cardiomyopathy.

AIMS: The heterogeneous distribution of hypertrophy in hypertrophic cardiomyopathy (HCM) limits the echocardiographic conventional measurements accuracy in the evaluation of left ventricular hypertrophy (LVH). The aim of this study was to assess the correlation of the echocardiographic Spirito-Maron score (SMS) with left ventricle (LV) mass quantification by cardiac magnetic resonance (CMR) and with LV diastolic function. METHODS AND RESULTS: Left ventricle diastolic function parameters, SMS, LV mass (American Society of Echocardiography formula), and maximal wall thickness (MWT) were evaluated by two-dimensional (2D) transthoracic echocardiography. The SMS was obtained by adding the MWT of 4 LV segments, at the mitral valve or papillary muscles short-axis views. Echocardiographic parameters of LVH, including SMS, were correlated with LV mass obtained by CMR and with E/e' ratio. We included 45 patients (60% male, mean age 48 ± 18 years), who underwent 2D echocardiography. Twenty-two of them performed a CMR study. A positive correlation was found between SMS and CMR LV mass (r = 0.80; P < 0.001), whereas MWT (r = 0.62; P = 0.002) and the 2D LV mass (r = 0.60; P = 0.011) presented a lower correlation with CMR LV mass. The SMS was significantly correlated with E/e' ratio (r = 0.60; P = 0.007), whereas a nonsignificant correlation was found with MWT (r = 0.41; P = 0.081) and 2D LV mass (r = 0.22; P = 0.400). CONCLUSION: Spirito-Maron score presents a highly positive correlation with CMR LV mass and with diastolic dysfunction severity in HCM patients. SMS is a reliable quantitative LVH measurement method and seems to provide more comprehensive morphological and physiological information than 2D echocardiographic conventional parameters used to estimate LVH.

Echocardiographic reference ranges for normal cardiac chamber size: results from the NORRE study.

AIMS: Availability of normative reference values for cardiac chamber quantitation is a prerequisite for accurate clinical application of echocardiography. In this study, we report normal reference ranges for cardiac chambers size obtained in a large group of healthy volunteers accounting for gender and age. Echocardiographic data were acquired using state-of-the-art cardiac ultrasound equipment following chamber quantitation protocols approved by the European Association of Cardiovascular Imaging. METHODS: A total of 734 (mean age: 45.8 ± 13.3 years) healthy volunteers (320 men and 414 women) were enrolled at 22 collaborating institutions of the Normal Reference Ranges for Echocardiography (NORRE) study. A comprehensive echocardiographic examination was performed on all subjects following pre-defined protocols. There were no gender differences in age or cholesterol levels. Compared with men, women had significantly smaller body surface areas, and lower blood pressure. Quality of echocardiographic data sets was good to excellent in the majority of patients. Upper and lower reference limits were higher in men than in women. The reference values varied with age. These age-related changes persisted for most parameters after normalization for the body surface area. CONCLUSION: The NORRE study provides useful two-dimensional echocardiographic reference ranges for cardiac chamber quantification. These data highlight the need for body size normalization that should be performed together with age-and gender-specific assessment for the most echocardiographic parameters.

Acute coronary syndrome in a patient with multifocal coronary vasospasm.

Vasospastic angina results from temporary spasm of one or more coronary segments. Although prognosis of patients presenting with coronary vasospasm appears to be generally good, multivessel coronary vasospasm may increase the risk of life-threatening cardiac events. We present a case of a 51-year-old man admitted to the emergency room due to severe retrosternal pain, who was documented with multifocal coronary vasospasm. .

Short-time variation in serum uric acid concentrations in post-myocardial infarction patients.

BACKGROUND: Studies on SUA temporal profile in relation to acute myocardial infarction (AMI) are controversial. The aim of this study was to evaluate the SUA level variations following myocardial infarction. METHODS: We studied 222 patients more than 18 years old diagnosed with AMI. SUA was measured at baseline and on day 2 to 4 and day 5 to 8 after AMI. Within and between person variability of SUA following an AMI was estimated using intraclass correlation coefficients (ICC). The change in SUA between each assessment point was analyzed by repeated measures one-way analysis of variance. To evaluated.SUA variation post-myocardial infarction and its predictors we used generalized linear mixed-effects models. RESULTS: The mean plasma concentration of SUA was lower at baseline (58.5 +/- 18.9 mg/L). The ICC across the three time points was 0.75 (95% CI 0.70 - 0.80). SUA levels increased 1.33 mg/L per day after AMI (2.3 mg/L/day in women and 1.0 mg/L/day in men). Normouricemic patients had a 1.6 fold increase risk to change to hyperuricemic status per day after AMI (OR = 1.60, 95% CI: 1.27 - 2.00). CONCLUSIONS: Serum uric acid concentration is relatively stable over an eight-day post-myocardial infarction period. However, even a small increase of SUA per day after AMI is associated with a high probability of changing the classification of hyperuricemic status.

[Metastatic tumor of the right ventricle: an unusual location of tumor involvement in laryngeal carcinoma]. / Tumor metastático do ventrículo direito: um local incomum de envolvimento tumoral de carcinoma laríngeo.

Secondary tumors are much more frequent than primary tumors, but cardiac metastasis of laryngeal carcinoma is uncommon. The authors report the case of a 71-year-old man, with a history of laryngeal carcinoma, admitted to the emergency room with symptoms of two weeks' evolution suggestive of respiratory infection. Due to lack of therapeutic response and progressive clinical deterioration, a transthoracic echocardiogram was performed which revealed a large infiltrating mass within the right ventricle, involving the apex, interventricular septum and free wall, not causing significant right ventricular outflow tract obstruction. Evaluation by computed tomography showed signs of widespread metastasis from the previously diagnosed laryngeal cancer.

[Hypocalcemia as a reversible cause of heart failure]. / Hipocalcemia como uma causa reversível de insuficiência cardíaca.

Calcium plays a key role in heart muscle contraction and relaxation. Hypocalcemic heart failure is a rare and potentially reversible disturbance, which reflects this intrinsic relationship. The authors present the case of a 35-year-old woman who developed acute heart failure during the early postoperative period following total thyroidectomy. The echocardiogram showed severe global left ventricular dysfunction. Laboratory tests showed severe hypocalcemia and new-onset hypoparathyroidism. Cardiac catheterization showed angiographically normal coronary arteries. After clinical, hemodynamic and metabolic stabilization, a repeat echocardiogram revealed recovery of left ventricular function. Subsequently, cardiac magnetic resonance imaging was performed, which also showed no alterations. The patient was discharged asymptomatic, medicated with calcium carbonate, calcitriol and levothyroxine. This case highlights the importance of considering hypocalcemia as a cause of reversible myocardial dysfunction.