Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens.
The objective of this work was to molecularly characterize 11 Cratylia argentea accessions, based on the ITS (ITS1/5.8S/ITS2) region sequencing, as well to establish its phylogenetic relationship with other legume species. The phylogenetic relationship of this species with other 15 legume ones was established using a gene sequence that codes the subunit 18S of the rRNA (rDNA 18S). DNA amplification of the ITS/5.8S region of these 11 accessions revealed an amplicon with around 650 bp. ITS/5.8S sequences were obtained from all accessions analysed, and then aligned with the region ITS/5.8S of Galactia striata legume. The size of ITS/5.8S region ranged from 565 to 615 bp. Average G + C contents in the ITS1 and ITS2 regions ranged between 46 and 47%. The multiple sequence alignment between the ITS sequences from C. argentea accessions and Galactia striata revealed the presence of deletions and insertions. C. argentea accessions formed a unique politomic clade. Cratylia argentea phylogenetic analysis demonstrated that this species is placed into the true Diocleinae Clade, and that Calopogonium and Pachyrhizus are not included in subtribe Diocleinae.
O objetivo deste trabalho foi realizar a caracterização molecular de 11 acessos de Cratylia argentea, com base no sequenciamento da região ITS (ITS1/5,8S/ITS2), bem como o estabelecimento de suas relações filogenéticas com outras leguminosas. As relações filogenéticas dessa espécie com outras 15 leguminosas foram estabelecidas com o uso de sequência do gene que codifica a subunidade 18S do rRNA (rDNA 18S). A amplificação do DNA da região ITS/5,8S dos 11 acessos revelou uma única banda de aproximadamente 650 pb. Sequências ITS/5,8S foram obtidas de todos os acessos analisados e depois alinhadas com a região ITS/5,8S da leguminosa Galactia striata. O tamanho das sequências ITS/5,8S dos acessos de C. argentea variou de 565 a 615 pb. Os conteúdos médios de G + C nas regiões ITS1 e ITS2 variaram entre 46 e 47%. O alinhamento múltiplo das seqüências ITS/5,8S dos acessos de C. argentea com Galactia striata revelou a presença de deleções e inserções. Os acessos de C. argentea constituíram um único clado politômico. A análise filogenética de C. argentea demonstrou que essa espécie está incluída no clado das Diocleinae verdadeiras e que os gêneros Calopogonium e Pachyrhizus estão fora desse clado.
Infection with both Human Immunodeficiency Virus (HIV) and Mycobacterium tuberculosis is currently the world's leading cause of death due to infectious agents. We evaluated factors related to the development of tuberculosis (TB) in HIV-infected patients who were being treated at an infectious diseases hospital in Fortaleza, Ceará, Brazil. From January 2004 to December 2005, we made an epidemiological study through the analysis of the medical records of 171 patients, who were diagnosed as having both HIV and tuberculosis. Among these co-infected patients, most (81%, p=0.0006) were male. Co-infection was more frequent (87.8%) among patients over 40 years of age and those with lower educational levels (less than eight years of schooling). Forty-one percent of the patients in the study had not had a smear culture test for acid-fast bacilli (AFB). CD4 cell counts were lower than 200 cells/µL in 71.9% of the patients, the mean being 169 cells/µL. This type of data is important for establishing strategies to improve the control of tuberculosis in HIV-infected patients.
This paper reports the overall effects of three lectins, extracted from Canavalia brasiliensis, Dioclea violacea, and D. grandiflora, on BALB/c mice popliteal draining lymph nodes. These lectins have presented high stimulatory capacity on lymph node T cells. Additionally, they were able to induce apoptosis and inflammation (frequently associated with high endothelial venule necrosis). The data presented here suggest that the Diocleinae lectins studied can stimulate in vivo T cell activation and apoptosis, as well as present important side effects.
ABSTRACT - The mobilization of seed proteins from Pisum arvense L. during germination in the absence of light was studied. The seeds were found to be completely consumed 22 days after germination and seedlings ceased growth after the 18th day. SDS-PAGE indicated that the main protein bands correspond to high molecular mass storage proteins which undergo proteolysis in the initial stages of germination and are not detected after the 7th day of germination. However, the corresponding lectin profiles were detected during the entire germination process, suggesting that these proteins are strongly resistant to seed proteolytic enzymes and should be important for seedling establishment. Furthermore, haemagglutinating activity in cotyledons was detected until 22 days after germination, indicating that the lectins remain active even in senescent cotyledons.
A mobilização das proteínas de sementes de Pisum arvense L. durante a germinação na ausência de luz foi estudada. As sementes foram completamente exauridas de suas reservas após 22 dias de germinação e as plântulas cresceram até o 18° dia de germinação. Experimentos de eletroforese em gel de poliacrilamida em presença de SDS indicaram que as principais bandas protéicas, correspondendo às proteínas de reserva de alta massa molecular, foram detectadas apenas até o 7° dia após a germinação. Entretanto, as bandas protéicas correspondentes às lectinas da semente puderam ser detectadas ao longo de todo o processo germinativo, sugerindo que essas proteínas são fortemente resistentes à ação das proteases da semente e devem, de alguma forma, ser importantes para o estabelecimento das plântulas. A atividade hemaglutinante nos cotilédones foi detectada até o 22° dia de germinação, indicando que as lectinas também permaneceram ativas quando os cotilédones estavam bastante exauridos de suas reservas.
The lectins, proteins which specifically recognize carbohydrate moieties, have been extensively studied in many biochemical and structural aspects in order to establish the molecular basis of this non-catalytic event. On the other hand, their clinical and agricultural potentials have been growing fast. Although lectins, mainly those from legume plants, had been investigated for biological properties, studies about the physiological functions of lectins are scarce in literature. Therefore, despite the accumulated data on lectins (as proteins), the role played by these signalizing molecules is poorly discussed. In the light of our accumulated results on legume lectins, specially those obtained from plants belonging to the Diocleinae sub-tribe and available data in literature, we discuss here the main hypothesis of their functions according to their carbohydrate/glycan-binding specificity.
As lectinas, proteinas que especificamente reconhecem estruturas que contém carboidratos, têm sido extensivamente estudadas em muitos aspectos bioquímicos e estruturais, objetivando estabelecer as bases moleculares deste evento não-catalítico. Por outro lado, os potenciais clínicos e agriculturais destas proteínas têm crescido rapidamente. Embora as lectinas, principalmente aquelas de legumes tenham sido bastante investigadas em suas propriedades biológicas, estudos sobre as funcões fisiológicas de lectinas são escassos na literatura. Além disto, a despeito da quantidade de dados acumulados sobre lectinas (como proteínas), o papel desempenhado por estas moléculas de sinalização é pobremente discutido. Valendo-se de nossos estudos sobre lectinas de leguminosas, principalmente da sub-tribo Diocleinae, e outros dados presentes na literatura, discutimos aqui, as principais hipóteses de suas funções com base na especificidade por carboidratos e glicanos complexos.