680 research outputs found
Jasmonic acid methyl ester induces xylogenesis and modulates auxin-induced xylary cell identity with NO Involvement
In Arabidopsis basal hypocotyls of dark-grown seedlings, xylary cells may form from the pericycle as an alternative to adventitious roots. Several hormones may induce xylogenesis, as Jasmonic acid (JA), as well as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) auxins, which also affect xylary identity. Studies with the ethylene (ET)-perception mutant ein3eil1 and the ET-precursor 1-aminocyclopropane-1-carboxylic acid (ACC), also demonstrate ET involvement in IBA-induced ectopic metaxylem. Moreover, nitric oxide (NO), produced after IBA/IAA-treatments, may affect JA signalling and interact positively/negatively with ET. To date, NO-involvement in ET/JA-mediated xylogenesis has never been investigated. To study this, and unravel JA-effects on xylary identity, xylogenesis was investigated in hypocotyls of seedlings treated with JA methyl-ester (JAMe) with/without ACC, IBA, IAA. Wild-type (wt) and ein3eil1 responses to hormonal treatments were compared, and the NO signal was quantified and its role evaluated by using NO-donors/scavengers. Ectopic-protoxylem increased in the wt only after treatment with JAMe(10 μM), whereas in ein3eil1 with any JAMe concentration. NO was detected in cells leading to either xylogenesis or adventitious rooting, and increased after treatment with JAMe(10 μM) combined or not with IBA(10 μM). Xylary identity changed when JAMe was applied with each auxin. Altogether, the results show that xylogenesis is induced by JA and NO positively regulates this process. In addition, NO also negatively interacts with ET-signalling and modulates auxin-induced xylary identity
Developing an agro-climatic zoning model to determine potential growing areas for Camelina sativa in Argentina
The purpose of this paper was the development of an agro-climatic zoning model to determine potential growing areas for Camelina sativa in Argentina. Camelina (Camelina sativa L.) is a promising and sustainable alternative energy crop that belongs to the Brassicaceae (mustard) family. Camelina sativa oil contains around 40% fatty acids, of which only a small percentage are saturated. Camelina sativa derived biokerosene used in aviation has shown 84% reduction in greenhouse gas emissions during its life cycle, compared to petroleum kerosene. It has the potential of becoming the renewable fuel of choice for air navigation in the future. Agro-climatology is a valuable tool in the identification of agro-climates with favorable conditions for the introduction of new crops. Agro-climatic zoning permits identifying areas with different potential yields, as per their environmental conditions. It was necessary to evaluate the requirements, limits and bio-meteorological tolerance and conditions for these species, taking into account the climatological characteristics of native areas and regions for their successful cultivation around the world. In order to define this crop's agroclimatic aptitude in Argentina, climatic data was analyzed from meteorological stations, corresponding to the period 1981-2010. Finally, Camelina's potential growing areas were obtained with 5 differentiated suitability classes. Based on international bibliography, the authors outlined an agro-climatic zoning model to determine potential growing areas in Argentina for Camelina sativa. This model may be applied to any part of the world, using the agroclimatic limits presented in this paper. This is an innovative work, made by the implementation of a Geographic Information System that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database.Fil: Falasca, Silvia Liliana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miranda del Fresno, Ma. Carolina. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Waldman, C.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; Argentin
A novel and selective PDK1 inhibitor reduces breast cancer cell invasion and tumour growth
Effectiveness of antihypertensive therapy in HIV-positive patients: evaluation to 144 weeks
Hypertension is more prevalent among HIV-infected subjects than in the general population, contributing to increased cardiovascular risk in HIV+ patients. The angiotensin II receptor blocker telmisartan is also a partial peroxisome proliferator activated receptor (PPAR)-γ agonist, with documented effects on improving hypertension, lipid metabolism and renal function. Therefore telmisartan was found to be the first choice for treatment of HIV+ hypertensive patients. Aim of this study was to evaluate the durability on 144 weeks of treatment with telmisartan in HIV+ patients. 13 HIV+ Caucasian male patients treated with combined antiretroviral therapy (cART) and discovered to be naïve hypertensive, were given 80 mg telmisartan daily. Systolic (SBP) and diastolic (DBP) blood pressure, viro-immunological, lipid and metabolic parameters, including triglycerides, cholesterol, insulin resistance (HOMA-IR), inflammatory markers, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), indexes of renal function and cardiovascular risk, microalbuminuria, cystatin C, were measured at baseline (T0), and after 24 (T24), 48 (T48), 72 (T72), 96 (T96), 120 (T120) and 144 (T144) weeks. Treatment with telmisartan decreased SBP and DBP levels during the 144 weeks of observation. We also observed improved HDL-cholesterol, HOMA-IR, microalbuminuria and cystatin C at the end of study. Triglycerides and total cholesterol significantly decreased and HDL-cholesterol significantly increased. Total cholesterol/HDL cholesterol ratio improved significantly. Throughout in the course of the trial our patients showed a significant improvement of the percentage of CD4+ and CD8+. Eventually in all 144 weeks of therapy with telmisartan 80 mg/day have not observed adverse events or dropouts. Telmisartan was effective in improving hypertension, lipid metabolism and renal function in 144 weeks of evaluation. It determines the improvement of cystatin C and microalbuminuria, markers of renal function and cardiovascular risk. Telmisartan doesn't interfere with cART, not interfering with the recovery of immunological HIV patients. Telmisartan has confirmed durability and effectiveness, excellent tolerability and an high persistance with a good blood pressure control. Therefore telmisartan reveals the first choice in the treatment of hypertension in HIV+ because of significant morbidity in this group of patients
Effects of dual renin-angiotensin system blockade on proteinuria in a hypertensive black African HIV infected patient
Kidney diseases manifesting as proteinuria or elevated creatinine are increasingly prevalent complications of HIV infection. We report the effects of dual renin-angiotensin system blockade on proteinuria in a hypertensive black African HIV-infected patient
A Small Molecule Inhibitor of PDK1/PLC gamma 1 Interaction Blocks Breast and Melanoma Cancer Cell Invasion
Strong evidence suggests that phospholipase Cγ1 (PLCγ1) is a suitable target to counteract tumourigenesis and metastasis dissemination. We recently identified a novel signalling pathway required for PLCγ1 activation which involves formation of a protein complex with 3-phosphoinositide-dependent protein kinase 1 (PDK1). In an effort to define novel strategies to inhibit PLCγ1-dependent signals we tested here whether a newly identified and highly specific PDK1 inhibitor, 2-O-benzyl-myo-inositol 1,3,4,5,6-pentakisphosphate (2-O-Bn-InsP5), could affect PDK1/PLCγ1 interaction and impair PLCγ1-dependent cellular functions in cancer cells. Here, we demonstrate that 2-O-Bn-InsP5 interacts specifically with the pleckstrin homology domain of PDK1 and impairs formation of a PDK1/PLCγ1 complex. 2-O-Bn-InsP5 is able to inhibit the epidermal growth factor-induced PLCγ1 phosphorylation and activity, ultimately resulting in impaired cancer cell migration and invasion. Importantly, we report that 2-O-Bn-InsP5 inhibits cancer cell dissemination in zebrafish xenotransplants. This work demonstrates that the PDK1/PLCγ1 complex is a potential therapeutic target to prevent metastasis and it identifies 2-O-Bn-InsP5 as a leading compound for development of anti-metastatic drugs
Jasmonate promotes auxin-induced adventitious rooting in dark-grown Arabidopsis thaliana seedlings and stem thin cell layers by a cross-talk with ethylene signalling and a modulation of xylogenesis
Background: Adventitious roots (ARs) are often necessary for plant survival, and essential for successful micropropagation. In Arabidopsis thaliana dark-grown seedlings AR-formation occurs from the hypocotyl and is enhanced by application of indole-3-butyric acid (IBA) combined with kinetin (Kin). The same IBA + Kin-treatment induces AR-formation in thin cell layers (TCLs). Auxin is the main inducer of AR-formation and xylogenesis in numerous species and experimental systems. Xylogenesis is competitive to AR-formation in Arabidopsis hypocotyls and TCLs. Jasmonates (JAs) negatively affect AR-formation in de-etiolated Arabidopsis seedlings, but positively affect both AR-formation and xylogenesis in tobacco dark-grown IBA + Kin TCLs. In Arabidopsis the interplay between JAs and auxin in AR-formation vs xylogenesis needs investigation. In de-etiolated Arabidopsis seedlings, the Auxin Response Factors ARF6 and ARF8 positively regulate AR-formation and ARF17 negatively affects the process, but their role in xylogenesis is unknown. The cross-talk between auxin and ethylene (ET) is also important for AR-formation and xylogenesis, occurring through EIN3/EIL1 signalling pathway. EIN3/EIL1 is the direct link for JA and ET-signalling. The research investigated JA role on AR-formation and xylogenesis in Arabidopsis dark-grown seedlings and TCLs, and the relationship with ET and auxin. The JA-donor methyl-jasmonate (MeJA), and/or the ET precursor 1-aminocyclopropane-1-carboxylic acid were applied, and the response of mutants in JA-synthesis and -signalling, and ET-signalling investigated. Endogenous levels of auxin, JA and JA-related compounds, and ARF6, ARF8 and ARF17 expression were monitored. Results: MeJA, at 0.01 μM, enhances AR-formation, when combined with IBA + Kin, and the response of the early-JA-biosynthesis mutant dde2–2 and the JA-signalling mutant coi1–16 confirmed this result. JA levels early change during TCL-culture, and JA/JA-Ile is immunolocalized in AR-tips and xylogenic cells. The high AR-response of the late JA-biosynthesis mutant opr3 suggests a positive action also of 12-oxophytodienoic acid on AR-formation. The crosstalk between JA and ET-signalling by EIN3/EIL1 is critical for AR-formation, and involves a competitive modulation of xylogenesis. Xylogenesis is enhanced by a MeJA concentration repressing AR-formation, and is positively related to ARF17 expression. Conclusions: The JA concentration-dependent role on AR-formation and xylogenesis, and the interaction with ET opens the way to applications in the micropropagation of recalcitrant species
Ethylene and auxin interaction in the control of adventitious rooting in Arabidopsis thaliana
Adventitious roots (ARs) are post-embryonic roots essential for plant survival and propagation. Indole-3-acetic acid (IAA) is the auxin that controls AR formation; however, its precursor indole-3-butyric acid (IBA) is known to enhance it. Ethylene affects many auxin-dependent processes by affecting IAA synthesis, transport and/or signaling, but its role in AR formation has not been elucidated. This research investigated the role of ethylene in AR formation in dark-grown Arabidopsis thaliana seedlings, and its interaction with IAA/IBA. A number of mutants/transgenic lines were exposed to various treatments, and mRNA in situ hybridizations were carried out and hormones were quantified In the wild-type, the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) at 0.1 μM enhanced AR formation when combined with IBA (10 μM), but reduced it when applied alone; this effect did not occur in the ein3eil1 ethylene-insensitive mutant. ACC inhibited the expression of the IAA-biosynthetic genes WEI2, WEI7, and YUC6, but enhanced IBA-to-IAA conversion, as shown by the response of the ech2ibr10 mutant and an increase in the endogenous levels of IAA. The ethylene effect was independent of auxin-signaling by TIR1-AFB2 and IBA-efflux by ABCG carriers, but it was dependent on IAA-influx by AUX1/LAX3. Taken together, the results demonstrate that a crosstalk involving ethylene signaling, IAA-influx, and IBA-to-IAA conversion exists between ethylene and IAA in the control of AR formation
Cadmium and arsenic affect quiescent centre formation and maintenance in Arabidopsis thaliana post-embryonic roots disrupting auxin biosynthesis and transport
The research was focussed on the effects of cadmium (Cd) and arsenic (As), alone or combined, on Arabidopsis post-embryonic roots, with attention to quiescent centre formation and development in relation to auxin homeostasis. To the aim, morphological and histochemical analyses were carried out on seedlings, exposed or not to Cd and/or As, of wild type, and transgenic lines useful for monitoring quiescent centre identity, auxin localization and cellular influx and efflux. Moreover, auxin levels and expression of the YUC6 auxin biosynthetic gene were monitored in Cd and/or As exposed wild type seedlings. Results showed that Cd and Cd plus As increased the lateral and adventitious root density, whereas As alone reduced it. In the lateral and adventitious root apices Cd and/or As negatively affected quiescent centre identity and auxin localization, changed auxin levels, expression of YUC6, and of PIN1 and LAX3, auxin efflux and influx carriers, respectively. The alteration in auxin homeostasis was different for the two pollutants, explaining their contrasting response on the post-embryonic roots
Early detection of pleuro-pulmonary tuberculosis by bedside lung ultrasound: A case report and review of literature
We present a case in which lung ultrasound (LUS) was relevant to reach an early diagnosis of lung tuberculosis and to manage the patient in the right setting. Moreover, ultrasound allowed to detect and treat massive pleural effusion through an ultrasound-guided thoracentesis
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