Secretory structures in leaves and flowers of two dragon’s blood croton (Euphorbiaceae): New evidence and interpretations

Premise of research. Previous studies of secretory structures in species of the Neotropical dragon’s blood Croton (section Cyclostigma) show inconsistencies in their classification. An accurate assessment of the identity and homology of such structures is essential for taxonomic and evolutionary studies. Methodology. Field-collected leaves, stipules, and flowers at different developmental stages were sampled. The material was subjected to standard anatomical study by light microscopy and SEM, and secretions were evaluated by histochemical analyses. Pivotal results. Leaves and flowers of Croton echinocarpus and Croton urucurana present five secretory structures (idioblasts, laticifers, colleters, extrafloral nectaries, and floral nectaries) with high similarity between the two species. Idioblasts secrete compounds of a mixed nature; laticifers are branched and nonarticulated; and colleters and nectaries present hydrophilic secretion. The leaf marginal glands previously described as extrafloral nectaries are actually colleters of the standard type. We found colleters in staminate and pistillate flowers. The histochemical tests detected proteins in the secretions of all structures. Conclusions. The classes of secondary metabolites detected support the biological activities of secretion described in the literature. The correct identification of colleters in flowers establishes a new register of these structures in flowers of this genus. We show that an approach integrating anatomic structure, histochemistry, and period of secretion activity allows for a more accurate classification and homology assessment of secretory elements in this genus, which is exceptionally rich in this type of structures.A grant from the CAPES foundation through the PDSE (99999.009518/2014–02) supported A. C. Feio during her stage at the Real Jardín Botánico-CSIC (Madrid). R. M. S. A. Meira was supported by CNPq (research grant 477867/2013–8). Additional support was provided by FAPEMIGand the “Centro de Ciências Ambientais Floresta Escola” (SECTES/UNESCO/ HidroEX/FAPEMIG). R. Riina was supported by a Visiting Scholar Fellowship to Brazil funded by FAPEMIG (CRA-BPV- 00043–14) and a CNPq research grant (477867/2013–8).Peer Reviewe

Four New Species of Dragon's Blood Croton (Euphorbiaceae) from South America

We are grateful to the staff of the abovementioned herbaria for allowing us to examine specimens from their collections. Christine Niezgoda (F) and Alfredo F. Fuentes (LPB) kindly sent us specimen images. We are grateful to Otavio M. L. da Silva for assistance with the QGIS software. ACF was supported by a CNPq research grant and the Programa de Capacitaç~ao Institucional (MPEG/ MCTIC). MIOR was supported by a mobilization scholarship from the National Fund for Scientific Development, Technological and Technological Innovation-FONDECYT, CONCYTEC (Lima, Peru), for a two-month internship at the RJB-CSIC in 2017. RR received support from the Synthesys Programme (GBTAF-2834). Three reviewers and the editors provided valuable comments and suggestions to improve earlier versions of this manuscript.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy

A new species of dragon's blood Croton (Euphorbiaceae) from South America with singular inflorescences

Croton amentiformis, a new species of Euphorbiaceae from western South America, is described and illustrated. Morphological evidence and data from leaf anatomy indicate that the new species belongs to the dragon’s blood group (Croton section Cyclostigma). The dense and congested inflorescence is unusual within the genus. This singular dragon’s blood species is dedicated to the Florence Tropical Herbarium (FT) on the occasion of its 100th Anniversary celebrated in 2014.Peer Reviewe

Coronary plaque rupture in patients with myocardial infarction after noncardiac surgery: Frequent and dangerous

textabstractPurpose: The pathophysiology of acute coronary syndromes (ACS) after noncardiac surgery is not established yet. Thrombosis over a vulnerable plaque or decreased oxygen supply secondary to anemia or hypotension may be involved. The purpose of this study was to investigate the pathophysiology of ACS complicating noncardiac surgery. Methods: Clinical and angiographic data were prospectively recorded into a database for 120 consecutive patients that had an ACS after noncardiac surgery (PACS), for 120 patients with spontaneous ACS (SACS), and 240 patients with stable coronary artery disease (CAD). Coronary lesions with obstructions greater than 50% were classified based on two criteria: Ambrose's classification and complex morphology. The presence of Ambrose's type II or complex lesions were compared between the three groups. Results: We analyzed 1470 lesions in 480 patients. In PACS group, 45% of patients had Ambrose's type II lesions vs. 56.7% in SACS group and 16.4% in stable CAD group (P< 0.001). Both PACS and SACS patients had more complex lesions than patients in stable CAD group (56.7% vs. 79.2% vs. 31.8%, respectively; P< 0.001). Overall, the independent predictors of plaque rupture were being in the group PACS (P< 0.001, OR 2.86; CI, 1.82-4.52 for complex lesions and P< 0.001, OR 3.43; CI, 2.1-5.6 for Ambrose's type II lesions) or SACS (P< 0.001, OR 8.71; CI, 5.15-14.73 for complex lesions and P< 0.001, OR 5.99; CI, 3.66-9.81 for Ambrose's type II lesions). Conclusions: Nearly 50% of patients with perioperative ACS have evidence of coronary plaque rupture, characterizing a type 1 myocardial infarction