Crescimento, defesas e herbivoria em folhas jovens de Qualea parviflora (Vochysiaceae) em três diferentes habitats de Cerrado

Insect herbivory is strongly influenced by the properties of their host leaves. Otherwise, such influence may be mediated by the environment in which the host plant is found. We examined three characteristics that may influence insect herbivory on young leaves of Qualea parviflora Mart. (Vochysiaceae), a widespread tree of the Brazilian Cerrado: leaf expansion rate, sclerophylly (leaf toughness), and tannin concentration during four consecutive months. Herbivory rates were measured on four marked intact leaves in five trees in three different physiognomies of the Cerrado biome: campo sujo (grassland), cerrado sensu stricto (savanna), and cerradão (woodland). Sclerophylly was higher in February while the highest concentration of tannins occurred in November but no variation in the rates of herbivory among months and physiognomies was found. A tendency of higher mean leaf growth rates was observed in the “cerradao” (1.03%) and “cerrado” (1.04%) in comparison with the campo sujo trees (0.86%). Higher sclerophylly and lower expansion rates and leaf size were observed in trees of the campo sujo. There was a tendency for higher herbivory rates in cerrado (10.5%), where the leaves showed lower concentration of tannins (1.5%) than in cerradão (2.1%). New leaves of Q. parviflora showed higher tannins concentration and lower damage than fully expanded leaves. Final leaf area explained 24% of the variation in total herbivory. Leaf size and associated nutritional factors exerted stronger influence on herbivory than defensive compounds on young leaves of Q. parviflora. Key words: Cerrado, leaf age, leaf growth, Neotropical savanna, plant defenses, sclerophylly.A herbivoria por insetos é fortemente influenciada pelas propriedades das folhas hospedeiras. No entanto, esta influência pode ser mediada por condições ambientais do habitat da planta. Neste estudo foram examinadas três características que podem influenciar a herbívora por insetos em folhas jovens de Qualea parvifl ora Mart. (Vochysiaceae), uma árvore comum do Cerrado brasileiro: taxa de expansão foliar, esclerofilia (rigidez foliar) e concentração de taninos. As taxas de herbívora foram medidas em quatro folhas intactas de cinco árvores em três diferentes fitofisionomias do bioma Cerrado: “campo sujo”, “cerrado sensu stricto” e “cerradão”. A esclerofilia foi maior em Fevereiro enquanto altas concentrações de taninos ocorreram em Novembro. No entanto, não foi observada variação nas taxas de herbívora entre os meses e entre fisionomias. Uma tendência em maiores taxas de crescimento foliar foi observada em árvores ocorrentes no “cerradão” (1,03%) e no “cerrado” (1,04%) em comparação com as ocorrentes no “campo sujo” (0,86%). Maiores valores de esclerofilia, baixas taxas de expansão foliar e menor tamanho foliar foram observadas no “campo sujo”. Houve uma tendência em altas taxas de herbívora no “cerrado” (10,5%), onde as folhas apresentaram concentrações de taninos mais baixas (1,5%) que no “cerradão” (2,1%). As folhas jovens de Q. parviflora apresentaram maiores concentrações de taninos e menor dano por herbívora que folhas maduras. A área foliar final explicou 24% da variação da herbívora total. O tamanho das folhas e fatores nutricionais associados exerceram influências mais fortes na herbívora que a concentração de compostos de defesa em folhas jovens de Q. parviflora. Palavras-chave: Cerrado, crescimento foliar, defesa de plantas, esclerofilia, idade foliar, savana neotropical

Cloud condensation nuclei from biomass burning during the Amazonian dry-to-wet transition season

Aircraft measurements of cloud condensation nuclei (CCN) during the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) were conducted over the Southwestern Amazon region in September-October 2002, to emphasize the dry-to-wet transition season. The CCN concentrations were measured for values within the range 0.1-1.0% of supersaturation. The CCN concentration inside the boundary layer revealed a general decreasing trend during the transition from the end of the dry season to the onset of the wet season. Clean and polluted areas showed large differences. The differences were not so strong at high levels in the troposphere and there was evidence supporting the semi-direct aerosol effect in suppressing convection through the evaporation of clouds by aerosol absorption. The measurements also showed a diurnal cycle following biomass burning activity. Although biomass burning was the most important source of CCN, it was seen as a source of relatively efficient CCN, since the increase was significant only at high supersaturations.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Financiadora de Estudos e Projetos (FINEP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Mycobacterium leprae virulence-associated peptides are indicators of exposure to M. leprae in Brazil, Ethiopia and Nepal

Silent transmission of Mycobacterium leprae, as evidenced by stable leprosy incidence rates in various countries, remains a health challenge despite the implementation of multidrug therapy worldwide. Therefore, the development of tools for the early diagnosis of M. leprae infection should be emphasised in leprosy research. As part of the continuing effort to identify antigens that have diagnostic potential, unique M. leprae peptides derived from predicted virulence-associated proteins (group IV.A) were identified using advanced genome pattern programs and bioinformatics. Based on human leukocyte antigen (HLA)-binding motifs, we selected 21 peptides that were predicted to be promiscuous HLA-class I T-cell epitopes and eight peptides that were predicted to be HLA-class II restricted T-cell epitopes for field-testing in Brazil, Ethiopia and Nepal. High levels of interferon (IFN)-γ were induced when peripheral blood mononuclear cells (PBMCs) from tuberculoid/borderline tuberculoid leprosy patients located in Brazil and Ethiopia were stimulated with the ML2055 p35 peptide. PBMCs that were isolated from healthy endemic controls living in areas with high leprosy prevalence (EChigh) in Ethiopia also responded to the ML2055 p35 peptide. The Brazilian EChigh group recognised the ML1358 p20 and ML1358 p24 peptides. None of the peptides were recognised by PBMCs from healthy controls living in non-endemic region. In Nepal, mixtures of these peptides induced the production of IFN-γ by the PBMCs of leprosy patients and EChigh. Therefore, the M. leprae virulence-associated peptides identified in this study may be useful for identifying exposure to M. leprae in population with differing HLA polymorphisms

Long-term safety and efficacy of eculizumab in generalized myasthenia gravis

Introduction: Eculizumab is effective and well tolerated in patients with antiacetylcholine receptor antibody-positive refractory generalized myasthenia gravis (gMG; REGAIN; NCT01997229). We report an interim analysis of an open-label extension of REGAIN, evaluating eculizumab's long-term safety and efficacy. Methods: Eculizumab (1,200 mg every 2 weeks for 22.7 months [median]) was administered to 117 patients. Results: The safety profile of eculizumab was consistent with REGAIN; no cases of meningococcal infection were reported during the interim analysis period. Myasthenia gravis exacerbation rate was reduced by 75% from the year before REGAIN (P < 0.0001). Improvements with eculizumab in activities of daily living, muscle strength, functional ability, and quality of life in REGAIN were maintained through 3 years; 56% of patients achieved minimal manifestations or pharmacological remission. Patients who had received placebo during REGAIN experienced rapid and sustained improvements during open-label eculizumab (P < 0.0001). Discussion: These findings provide evidence for the long-term safety and sustained efficacy of eculizumab for refractory gMG. Muscle Nerve 2019

Consistent improvement with eculizumab across muscle groups in myasthenia gravis

Objective: To assess whether eculizumab, a terminal complement inhibitor, improves patient- and physician-reported outcomes (evaluated using the myasthenia gravis activities of daily living profile and the quantitative myasthenia gravis scale, respectively) in patients with refractory anti-acetylcholine receptor antibody-positive generalized myasthenia gravis across four domains, representing ocular, bulbar, respiratory, and limb/gross motor muscle groups. Methods: Patients with refractory anti-acetylcholine receptor antibody-positive generalized myasthenia gravis were randomized 1:1 to receive either placebo or eculizumab during the REGAIN study (NCT01997229). Patients who completed REGAIN were eligible to continue into the open-label extension trial (NCT02301624) for up to 4 years. The four domain scores of each of the myasthenia gravis activities of daily living profile and the quantitative myasthenia gravis scale recorded throughout REGAIN and through 130 weeks of the open-label extension were analyzed. Results: Of the 125 patients who participated in REGAIN, 117 enrolled in the open-label extension; 61 had received placebo and 56 had received eculizumab during REGAIN. Patients experienced rapid improvements in total scores and all four domain scores of both the myasthenia gravis activities of daily living profile and the quantitative myasthenia gravis scale with eculizumab treatment. These improvements were sustained through 130 weeks of the open-label extension. Interpretation: Eculizumab treatment elicits rapid and sustained improvements in muscle strength across ocular, bulbar, respiratory, and limb/gross motor muscle groups and in associated daily activities in patients with refractory anti-acetylcholine receptor antibody-positive generalized myasthenia gravis

Eculizumab in refractory generalized myasthenia gravis previously treated with rituximab: subgroup analysis of REGAIN and its extension study

Introduction/Aims: Individuals with refractory generalized myasthenia gravis (gMG) who have a history of rituximab use and experience persistent symptoms represent a population with unmet treatment needs. The aim of this analysis was to evaluate the efficacy and safety of eculizumab in patients with refractory anti-acetylcholine receptor antibody-positive (AChR+) gMG previously treated with rituximab. Methods: This post hoc subgroup analysis of the phase 3 REGAIN study (NCT01997229) and its open-label extension (OLE; NCT02301624) compared baseline characteristics, safety, and response to eculizumab in participants who had previously received rituximab with those who had not. Rituximab use was not permitted within the 6 months before screening or during REGAIN/OLE. Results: Of 125 REGAIN participants, 14 had received rituximab previously (7 received placebo and 7 received eculizumab). In the previous-rituximab group, 57% had used at least four other immunosuppressants compared with 16% in the no-previous-rituximab group. Myasthenia Gravis Activities of Daily Living total scores from eculizumab baseline to week 130 of eculizumab treatment improved in both the previous-rituximab and no-previous-rituximab groups (least-squares mean −4.4, standard error of the mean [SEM] 1.0 [n = 9] and least-squares mean −4.6, SEM 0.3 [n = 67], respectively; difference = 0.2, 95% confidence interval −1.88 to 2.22). In addition, in both groups, most patients who were treated with eculizumab for 130 weeks achieved a Myasthenia Gravis Foundation of America post-intervention status of minimal manifestations (66.7% and 65.0%, respectively). The eculizumab safety profile was similar between groups and consistent with its established profile. Discussion: Eculizumab is an effective therapy for patients with refractory AChR+ gMG, irrespective of whether they had received rituximab treatment previously