Induced tolerance to abiotic and biotic stresses of broccoli and Arabidopsis after treatment with elicitor molecules.

The plant hormones salicylic acid (SA) and jasmonic acid (JA) regulate defense mechanisms capable of overcoming different plant stress conditions and constitute distinct but interconnected signaling pathways. Interestingly, several other molecules are reported to trigger stress-specific defense responses to biotic and abiotic stresses. In this study, we investigated the effect of 14 elicitors against diverse but pivotal types of abiotic (drought) and biotic (the chewing insect Ascia monuste, the hemibiotrophic bacterium Pseudomonas syringae DC 3000 and the necrotrophic fungus Alternaria alternata) stresses on broccoli and Arabidopsis. Among the main findings, broccoli pre-treated with SA and chitosan showed the highest drought stress recovery in a dose-dependent manner. Several molecules led to increased drought tolerance over a period of three weeks. The enhanced drought tolerance after triggering the SA pathway was associated with stomata control. Moreover, methyl jasmonate (MeJA) reduced A. monuste insect development and plant damage, but unexpectedly, other elicitors increased both parameters. GUS reporter assays indicated expression of the SA-dependent PR1 gene in plants treated with nine elicitors, whereas the JA-dependent LOX2 gene was only expressed upon MeJA treatment. Overall, elicitors capable of tackling drought and biotrophic pathogens mainly triggered the SA pathway, but adversely also induced systemic susceptibility to chewing insects. These findings provide directions for potential future in-depth characterization and utilization of elicitors and induced resistance in plant protection.

Splenectomy and ligation of the left gastric vein in schistosomiasis mansoni: the effect on esophageal variceal pressure measured by a non-invasive technique.

The treatment of choice, in the Northeast of Brazil, of patients with a history of upper GI bleeding from ruptured esophageal varices (EV) and with hepatosplenomegaly secondary to schistosomiasis (HSS), is splenectomy and left gastric vein ligation (SLGL). However, the effect of this procedure on the EV pressure, the parameter that best correlates to re-bleeding risk, has not yet been evaluated. With the introduction of a minimally invasive technique to measure the EV pressure, it has become possible to assess the effect of this surgery without an increased risk to the patient. SLGL was performed in twenty two patients with a history of HSS and upper GI Bleeding secondary to esophageal varices. The non-invasive endoscopic pneumatic balloon was used to measure the EV pressure before surgery and the results were then compared with measurements made between five and eight days post-operatively. The pre-operative EV pressure ranged from 20.0 mmHg to 28.7 mmHg (mean 24.35 +/- 2.36 mmHg), with no correlation between the pressure and the calibre of the varices. In the post-operative period, a significant decrease in EV pressure was observed, ranging from 14.6 mmHg to 21.5 mmHg (mean 17.29 +/- 1.75 mmHg, p < 0.001). These results support the use of SLGL in patients with HSS and a history of variceal bleeding. The operation results in, at least for the short term and in the majority of cases, a reduction in the EV pressure, and therefore a reduced risk of repeating upper GI Bleeding.

Esplenectomia e ligadura da veia gástrica esquerda na esquistossomose mansônica: efeito sobre a pressão das varizes de esôfago aferida por técnica não-invasiva / The role of splenectomy and ligature of the left gastric vein on the esophageal variceal pressure measured by a non-invasive technique in mansonic shistosomotic patients

Em ambos os hospitais universitários de Pernambuco, o tratamento de escolha para portadores de esquistossomose hepatoesplênica (EHE) com antecedente de hemorragia digestiva alta (HDA) por rotura de varizes de esôfago (VE) é a esplenectomia associada à ligadura da veia gástrica esquerda (ELGE); porém, o impacto desta cirurgia sobre a pressão das VE, provavelmente, o parâmetro que melhor se correlaciona com o risco de recidiva hemorrágica, ainda não foi estudado. Com a introdução, em nosso meio, de técnica não-invasiva de medição da pressão das VE, isto tounou-se possível, com mínimos riscos, tornando-se o objetivo do presente estudo. A ELGE foi empregada em vinte portadores de EHE com antecedentes de HDA. A pressão das VE foi medida através do método endoscópico não-invasivo do balão pneumático, antes da cirurgia, e estes valores comparados com novas medições realizadas cinco a oito dias após. A pressão nas VE no pré-operatório variou entre 20,0 e 28,7mmHg (média de 24,35ñ2,36mmHg). Não houve correlação da pressão com o calibre das VE. No pós-operatório (PO), observou-se uma queda significante na pressão das VE, que variou entre 14,6 e 21,5mmHg (média 17,29ñ1,75mmHg,p<0,00l). Os resultados do presente trabalho confirmam as idéias que fundamentam a indicação da ELGE em portadores de EHE com antecedente de HDA. Esta cirurgia determina, pelo menos a curto prazo e na ampla maioria dos casos, uma redução na pressão das VE reduzindo o risco de recidiva de HDA