The cardiovascular protective actions of estrogen are partially mediated by a direct effect on the vessel wall. Estrogen is active both on vascular smooth muscle and endothelial cells where functionally competent estrogen receptors have been identified. Estrogen administration promotes vasodilation in humans and in experimental animals, in part by stimulating prostacyclin and nitric oxide synthesis, as well as by decreasing the production of vasoconstrictor agents such as cyclooxygenase-derived products, reactive oxygen species, angiotensin II, and endothelin-1. In vitro, estrogen exerts a direct inhibitory effect on smooth muscle by activating potassium efflux and by inhibiting calcium influx. In addition, estrogen inhibits vascular smooth muscle cell proliferation. In vivo, 17ß-estradiol prevents neointimal thickening after balloon injury and also ameliorates the lesions occurring in atherosclerotic conditions. As is the case for other steroids, the effect of estrogen on the vessel wall has a rapid non-genomic component involving membrane phenomena, such as alteration of membrane ionic permeability and activation of membrane-bound enzymes, as well as the classical genomic effect involving estrogen receptor activation and gene expression.

PURPOSE: To evaluate the safety and efficacy of limbal relaxing incisions for the correction of corneal astigmatism during phacoemulsification. METHODS: Fifty eyes of 37 patients (mean age 66.5 years, range: 45 to 80 years) with cataract and coexisting topographic astigmatism were included in the study. Eyes were randomly divided into two groups: eyes that underwent cataract surgery with limbal relaxing incisions (cataract LRI group) and eyes that underwent cataract surgery only (control group). All limbal relaxing incisions were performed during phacoemulsification. Best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), and corneal topography were recorded preoperatively and 1, 3, and 6 months postoperatively. RESULTS: A statistically significant improvement in BSCVA was seen in the cataract LRI eyes from 0.9±0.7 preoperatively to 0.1±0.1 at l, 3, and 6 months postoperatively (P<.01). A statistically significant improvement in BSCVA was seen in control eyes from 0.8±0.6 before surgery to 0.2±0.2 at 1, 3, and 6 months after surgery (P<.01). No difference in postoperative BSCVA was noted between the groups. A statistically significant reduction in the mean topographic astigmatism was seen in the cataract LRI eyes from 1.93±0.58 diopters (D) preoperatively to 1.02±0.60 D 6 months postoperatively (P<.05). The control eyes did not show a statistically significant change in topographic astigmatism. CONCLUSIONS: Limbal relaxing incisions performed during phacoemulsification surgery appear to be a safe, effective, and stable procedure to reduce pre-existing corneal astigmatism. [J Refract Surg. 2007;23:499504.]

The tolerance of wheat to manganese was investigated in soil and solution culture. Although no critical toxicity concentration could be identified, growth was reduced when the ratio of magnesium to manganese in the shoots (Rp) fell below 20:1 (mgg 1/mgg-1). In soil, plant growth relative to unstressed plants (Y) could be described by the empirical equation:In solution culture the value of Rp was related to the ratio of the two ions in the nutrient solution (R~) according to the expression:In Rp : 0.42 + 0.48 In R~ The magnesium concentration in the nutrient solution for optimum growth at a given concentration of manganese was given by: ln[Mg] = 2.89 + 0.54 ln [Mn] Magnesium increased the tolerance of plants to high concentrations of manganese in shoot tissue and also increased the ability of the plant to discriminate against manganese ions in translocation of nutrients from roots to shoots.

The aims of this study were to isolate, identify and characterize culturable endophytic bacteria from chickpea (Cicer arietinum L.) roots grown in different soils. In addition, the effects of rhizobial inoculation, soil and stress on the functionality of those culturable endophytic bacterial communities were also investigated. Phylogenetic analysis based on partial 16S rRNA gene sequences revealed that the endophytic bacteria isolated in this work belong to the phyla Proteobacteria, Firmicutes and Actinobacteria, with Enterobacter and Pseudomonas being the most frequently observed genera. Production of indoleacetic acid and ammonia were the most widespread plant growth-promoting features, while antifungal activity was relatively rare among the isolates. Despite the fact that the majority of bacterial endophytes were salt- and Mn-tolerant, the isolates obtained from soil with Mn toxicity were generally more Mn-tolerant than those obtained from the same soil amended with dolomitic limestone. Several associations between an isolate’s genus and specific plant growth-promoting mechanisms were observed. The data suggest that soil strongly impacts the Mn tolerance of endophytic bacterial communities present in chickpea roots while rhizobial inoculation induces significant changes in terms of isolates’ plant growth-promoting abilities. In addition, this study also revealed chickpea-associated endophytic bacteria that could be exploited as sources with potential application in agriculture.

Background/Aims: β₂-adrenoceptor (β₂-AR) activation induces smooth muscle relaxation and endothelium-derived nitric oxide (NO) release. However, whether endogenous basal β₂-AR activity controls vascular redox status and NO bioavailability is unclear. Thus, we aimed to evaluate vascular reactivity in mice lacking functional β₂-AR (β₂KO), focusing on the role of NO and superoxide anion. Methods and Results: Isolated thoracic aortas from β₂KO and wild-type mice (WT) were studied. β₂KO aortas exhibited an enhanced contractile response to phenylephrine compared to WT. Endothelial removal and L-NAME incubation increased phenylephrine-induced contraction, abolishing the differences between β₂KO and WT mice. Basal NO availability was reduced in aortas from β₂KO mice. Incubation of β₂KO aortas with superoxide dismutase or NADPH inhibitor apocynin restored the enhanced contractile response to phenylephrine to WT levels. β₂KO aortas exhibited oxidative stress detected by enhanced dihydroethidium fluorescence, which was normalized by apocynin. Protein expression of eNOS was reduced, while p47^phox expression was enhanced in β₂KO aortas. Conclusions: The present results demonstrate for the first time that enhanced NADPH-derived superoxide anion production is associated with reduced NO bioavailability in aortas of β₂KO mice. This study extends the knowledge of the relevance of the endogenous activity of β₂-AR to the maintenance of the vascular physiology.

A B S T R A C TCambisols are the major Reference Soil Group in Portugal. The yield of annual crops in these soils is generally poor, and the situation is aggravated in wet winters. In the south of Portugal, manganese toxicity has been identified as the major cause of poor growth and leaching as the main reason for the negative effect of rainfall observed in Cambisols developed on granitic formations. Manganese toxicity also appears to be present in the Cambisols in other regions of Portugal. Manganese toxicity is cross-related to the magnesium concentration, either in the soil solution or in plant shoots. Therefore, soil amendment using dolomitic limestone is needed to overcome the problem. Current soil test methods are unable to predict the level of Mn toxicity. However, new approach using the extraction of soil solution is proposed, although further work is needed to fully implement the method.Keywords: leaching, magnesium, Mg/Mn ratio, Soil, soil amendment R E S U M OOs Cambissolos são o Grupo de Referência de Solos mais representativo em Portugal. As produções das culturas anuais são geralmente baixas e a situação agrava-se em anos de Inverno húmido. A toxicidade de manganês foi identificada como a principal causa das produções baixas e a lixiviação o principal efeito negativo dos Invernos húmidos nos Cambissolos derivados de granito no Sul de Portugal. A toxicidade de Mn está relacionada com um desequilíbrio com o magnésio, quer na solução do solo quer na concentração dos dois iões na parte aérea da planta. A solução do problema exige, assim, a aplicação de calcário dolomítico. Os actuais métodos de análise de solo não parecem capazes de prever a ocorrência da toxicidade de manganês. Uma nova abordagem utilizando a extracção da solução do solo é proposta. No entanto, a utilização desta abordagem exige investigação suplementar. A toxicidade de Mn pode não ser restrita aos Cambissolos do sul do país.Palavras-chave: lixiviação, magnésio, razão Mg/Mn, Solo, correcção do solo

Bacterial endophytes, a subset of a plant’s microbiota, can facilitate plant growth by a number of different mechanisms. The aims of this study were to assess the diversity and functionality of endophytic bacterial strains from internal root tissues of native legume species grown in two distinct sites in South of Portugal and to evaluate their ability to promote plant growth. Here, 122 endophytic bacterial isolates were obtained from 12 different native legume species. Most of these bacteria possess at least one of the plant growth-promoting features tested in vitro, with indole acetic acid production being the most common feature among the isolates followed by the production of siderophores and inorganic phosphate solubilization. The results of in planta experiments revealed that co-inoculation of chickpea plants with specific endophytic bacteria along with N2-fixing symbionts significantly improved the total biomass of chickpea plants, in particular when these plants were grown under saline conditions. Altogether, this study revealed that Mediterranean native legume species are a reservoir of plant growth-promoting bacteria, that are also tolerant to salinity and to toxic levels of Mn. Thus, these bacterial endophytes are well adapted to common constraints present in soils of this region which constitutes important factors to consider in the development of bacterial inoculants for stressful conditions in the Mediterranean region.

Objetivou-se com este estudo avaliar o efeito da época de corte sobre a composição bromatológica e digestibilidade in vitro de genótipos de cana-de-açúcar, comparar a composição bromatológica e digestibilidade in vitro das frações colmo e folhas, e estabelecer possíveis correlações entre composição química e digestibilidade in vitro da planta inteira de genótipos da cana-de-açúcar. Nove genótipos foram colhidos em maio e setembro de 2006. Em maio, somente a fração planta inteira foi analisada, em setembro foram separados em colmos, folhas ou planta inteira para determinação da composição bromatológica, sacarose (POL) e digestibilidade in vitro. Colmos apresentaram menor teor de fibra em detergente neutro (FDN) e lignina na MS, e maior digestibilidade in vitro da matéria seca (DIVMS) do que folhas. Em contrapartida, apresentaram menor digestibilidade in vitro da FDN (DIVFDN), maior teor de lignina na FDN e menor concentração de proteína bruta (PB). Houve redução no teor e digestibilidade da FDN com o avanço da maturidade, enquanto que DIVMS, POL e lignina aumentaram. A DIVMS se mostrou negativamente correlacionada com FDN e FDN/POL, porém não houve correlação entre DIVFDN e FDN ou FDN/POL. Conclui-se que o avanço da maturidade promoveu redução na DIVFDN e aumento na DIVMS, não existindo correlação genética entre acúmulo de açúcar e digestibilidade in vitro da fibra. Os dados deste artigo indicam não ser esperado que a seleção de genótipos com maior DIVFDN do colmo altere o teor de açúcar do mesmo.