Posibilidades de reproducción de Schinus johnstonii (Anacardiaceae), una especie nativa del Monte argentino

Schinus johnstonii F. A. Barkley (Anacardiaceae) es un arbusto nativo de la ProvinciaFitogeográfica del Monte, donde representa un importante componente del pastizal natural. Su tolerancia a la sequía, junto a la presencia de una floración abundante,la convierten en una buena opción para proyectos paisajísticos y de restauración de ambientes degradados y deforestados. Para tales fines es necesario contar con informaciónacerca de sus posibilidades de reproducción. Los objetivos de este trabajo fueron determinar los requerimientos básicos para la germinación de sus semillas(reproducción sexual), en condiciones de laboratorio, la viabilidad de las mismas y analizar la supervivencia de estacas (reproducción vegetativa), en condiciones controladasy bajo distintos tratamientos. Las semillas recolectadas se sometieron a seis tratamientos pre-germinativos: exocarpo intacto (control), remoción de exocarpo(desnudas), semillas desnudas con escarificación mecánica, semillas desnudas con escarificación química, semillas desnudas en remojo y semillas desnudas con exposicióna humo. Sólo se observó germinación en semillas sin exocarpo. Las semillas desnudas germinaron a partir de los 10 días, con un valor máximo del 38%, sinencontrarse diferencias entre los tratamientos. Se observó, además, una importanteproporción de semillas no viables o vacías (30-40%). El estudio de reproducciónvegetativa, con estacas recolectadas durante los estadios fenológicos vegetativo yreproductivo, con y sin hormona de enraizamiento, dio como resultado un porcentajebajo de rebrote (20%), sin diferencias entre tratamientos. Según los resultados,las semillas de S. johnstonii presentarían dormición física impuesta por la cubierta(superada por remoción del exocarpo). La reproducción de este arbusto no seríarecomendable por medio de estacas, aunque se sugiere realizar más estudios.Schinus johnstonii F. A. Barkley (Anacardiaceae) is a native shrub to the Monte Phytogeographic Province, where it represents an important component of rangelands. Its tolerance to drought and abundant flowering, render it a good option for landscaping and land restoration projects on degraded and deforested areas. For such purposes, information about its reproductive possibilities is needed. The objectives of this work were to determine the basic requirements for seed germination (sexual reproduction) under laboratory conditions, viability and to analyze the survival of cuttings (vegetative reproduction), under controlled conditions and different treatments. The collected seeds were subjected to six pre-germination treatments: intact exocarp (control), exocarp removal (bare), bare seeds with mechanical scarification, bare seeds with chemical scarification, bare seeds with soaking and bare seeds with exposure to smoke. Germination was only observed in seeds without exocarp. Bare seeds germinated after 10 days, with a maximum value of 38%, with no differences between treatments. In addition, a significant proportion of non-viable or empty seeds (30-40%) was observed. The vegetative reproductive study, with cuttings collected during the vegetative and reproductive phenological stages, with and without rooting hormone, resulted in a low percentage of regrowth (20%), with no differences between treatments. According to these results, seeds of S. johnstonii would present physical dormancy imposed by the seed coat (overcome by the removal of the exocarp). The reproduction of this shrub by cuttings is not recommended, although further studies are suggested

Microenvironmental regulation of the IL-23R/IL-23 axis overrides chronic lymphocytic leukemia indolence

Although the progression of chronic lymphocytic leukemia (CLL) requires the cooperation of the microenvironment, the exact cellular and molecular mechanisms involved are still unclear. We investigated the interleukin (IL)-23 receptor (IL-23R)/IL-23 axis and found that circulating cells from early-stage CLL patients with shorter time-to-treatment, but not of those with a more benign course, expressed a defective form of the IL-23R complex lacking the IL-12R beta 1 chain. However, cells from both patient groups expressed the complete IL-23R complex in tissue infiltrates and could be induced to express the IL-12R. 1 chain when cocultured with activated T cells or CD40L(+) cells. CLL cells activated in vitro in this context produced IL-23, a finding that, together with the presence of IL-23 in CLL lymphoid tissues, suggests the existence of an autocrine/paracrine loop inducing CLL cell proliferation. Interference with the IL-23R/IL-23 axis using an anti-IL-23p19 antibody proved effective in controlling disease onset and expansion in xenografted mice, suggesting potential therapeutic strategies

BAFF Mediates Splenic B Cell Response and Antibody Production in Experimental Chagas Disease

Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Central and South America. It affects 20 million people and about 100 million people are at risk of infection in endemic areas. Some cases have been identified in non-endemic countries as a consequence of blood transfusion and organ transplantation. Chagas disease presents three stages of infection. The acute phase appears one to two weeks after infection and includes fever, swelling around the bite site, enlarged lymph glands and spleen, and fatigue. This stage is characterized by circulating parasites and many immunological disturbances including a massive B cell response. In general, the acute episode self-resolves in about 2 months and is followed by a clinically silent indeterminate phase characterized by absence of circulating parasites. In about one-third of the cases, the indeterminate phase evolves into a chronic phase with clinically defined cardiac or digestive disturbances. Current knowledge suggests that the persistence of parasites coupled with an unbalanced immune response sustain inflammatory response in the chronic stage. We believe that an effective treatment for chronic Chagas disease should combine antiparasitic drugs with immunomodulators aimed at reducing inflammation and autoreactive response. Our findings enlighten a new role of BAFF-BAFF-R signaling in parasite infection that partially controls polyclonal B cell response but not parasitespecific class-switched primary effectors B cells