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1.
World J Urol ; 40(1): 141-146, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34550425

RESUMO

PURPOSE: To assess the efficacy and safety of intravesical instillation of high molecular weight sodium hyaluronate (HMW-HA) for the treatment of radiation-induced cystitis. METHODS: This prospective cohort study was conducted in seven centers in France. Eligible patients with radiation-induced cystitis were recruited between April 2020 and March 2021. A sterile disposable 50 ml prefilled solution containing 0.16% (80 mg/50 mL) HMW-HA (INSTYLAN) was instilled weekly into the bladder. The treatment consisted of 6 sessions (V1 to V6). Outcomes were assessed 1 week (V7) and 4 weeks (V8) after the last session and were compared with baseline (V0). The primary endpoint was bladder pain, evaluated by a Questionnaire with 5 closed-ended response options. Secondary endpoints included changes from baseline for hematuria, urinary frequency, and the effect of urgencies on Quality of Life (QoL). Adverse events (AEs) were graded according to the CTCAE 3.0 classification. RESULTS: A total of 30 participants were enrolled. The Intent-to-Treat analysis showed a significant reduction in pelvic pain intensity (- 45.81%, p < 0.001), hematuria (- 26.87%, p = 0.008), total 24 h voids (- 23.92%, p < 0.001) and the effect of urgencies on QoL (- 33.92%, p < 0.001) at V7. The improvement for each outcome remained stable during the post-therapeutic period between V7 and V8. Bladder instillation therapy was well-tolerated: two treatment-related AEs (6.6%) were reported corresponding to two grade 1 hematuria. CONCLUSIONS: Intravesical instillation of HMW-HA appears to be effective in the treatment of radiation-induced cystitis. Further comparative studies with longer follow-up are needed to confirm our preliminary results.


Assuntos
Cistite/tratamento farmacológico , Ácido Hialurônico/administração & dosagem , Lesões por Radiação/tratamento farmacológico , Administração Intravesical , Idoso , Feminino , França , Humanos , Ácido Hialurônico/efeitos adversos , Masculino , Peso Molecular , Projetos Piloto , Estudos Prospectivos , Resultado do Tratamento
2.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34561304

RESUMO

Plant innate immunity is activated upon perception of invasion pattern molecules by plant cell-surface immune receptors. Several bacteria of the genera Pseudomonas and Burkholderia produce rhamnolipids (RLs) from l-rhamnose and (R)-3-hydroxyalkanoate precursors (HAAs). RL and HAA secretion is required to modulate bacterial surface motility, biofilm development, and thus successful colonization of hosts. Here, we show that the lipidic secretome from the opportunistic pathogen Pseudomonas aeruginosa, mainly comprising RLs and HAAs, stimulates Arabidopsis immunity. We demonstrate that HAAs are sensed by the bulb-type lectin receptor kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION/S-DOMAIN-1-29 (LORE/SD1-29), which also mediates medium-chain 3-hydroxy fatty acid (mc-3-OH-FA) perception, in the plant Arabidopsis thaliana HAA sensing induces canonical immune signaling and local resistance to plant pathogenic Pseudomonas infection. By contrast, RLs trigger an atypical immune response and resistance to Pseudomonas infection independent of LORE. Thus, the glycosyl moieties of RLs, although abolishing sensing by LORE, do not impair their ability to trigger plant defense. Moreover, our results show that the immune response triggered by RLs is affected by the sphingolipid composition of the plasma membrane. In conclusion, RLs and their precursors released by bacteria can both be perceived by plants but through distinct mechanisms.


Assuntos
Arabidopsis/imunologia , Arabidopsis/microbiologia , Glicolipídeos/metabolismo , Imunidade Vegetal/fisiologia , Pseudomonas syringae/patogenicidade , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/imunologia , Proteínas de Arabidopsis/metabolismo , Sinalização do Cálcio , Resistência à Doença/imunologia , Glicolipídeos/química , Interações Hospedeiro-Patógeno/fisiologia , Imunidade Inata , Fosforilação , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Pseudomonas syringae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Nicotiana/genética , Nicotiana/metabolismo
3.
Plant Dis ; 105(2): 384-391, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32734845

RESUMO

Allorhizobium vitis is the primary causal pathogen of grapevine crown gall disease. Because this endophytic bacterium can survive as a systemic latent (symptomless) infection in grapevine, detecting and monitoring its development in planta is of great importance. In plant bacteria studies, plate counting is routinely used as a simple and reliable method to evaluate the bacterial population level in planta. However, isolation techniques are time-consuming and present some disadvantages such as the risk of contamination and the need for fresh samples for research. In this study, we developed a DNA-based real-time PCR assay that can replace the classical method to monitor the development of Allorhizobium vitis in grapevine plantlets. Primers targeting Allorhizobium vitis chromosomic genes and the virulent tumor-inducing plasmid were validated. The proposed quantitative real-time PCR technique is highly reliable and reproducible to assess Allorhizobium vitis numeration at the earliest stage of infection until tumor development in grapevine plantlets. Moreover, this low-cost technique provides rapid and robust in planta quantification of the pathogen and is suitable for fundamental research to monitor bacterial development over time.


Assuntos
Vitis , Agrobacterium/genética , DNA , Reação em Cadeia da Polimerase em Tempo Real
4.
Int J Mol Sci ; 20(22)2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31744149

RESUMO

Phenolic compounds are implied in plant-microorganisms interaction and may be induced in response to plant growth-promoting rhizobacteria (PGPRs). Among PGPR, the beneficial bacterium Paraburkholderia phytofirmans PsJN was previously described to stimulate the growth of plants and to induce a better adaptation to both abiotic and biotic stresses. This study aimed to investigate the impact of PsJN on grapevine secondary metabolism. For this purpose, gene expression (qRT-PCR) and profiling of plant secondary metabolites (UHPLC-UV/DAD-MS QTOF) from both grapevine root and leaves were compared between non-bacterized and PsJN-bacterized grapevine plantlets. Our results showed that PsJN induced locally (roots) and systemically (leaves) an overexpression of PAL and STS and specifically in leaves the overexpression of all the genes implied in phenylpropanoid and flavonoid pathways. Moreover, the metabolomic approach revealed that relative amounts of 32 and 17 compounds in roots and leaves, respectively, were significantly modified by PsJN. Once identified to be accumulated in response to PsJN by the metabolomic approach, antifungal properties of purified molecules were validated in vitro for their antifungal effect on Botrytis cinerea spore germination. Taking together, our findings on the impact of PsJN on phenolic metabolism allowed us to identify a supplementary biocontrol mechanism developed by this PGPR to induce plant resistance against pathogens.


Assuntos
Burkholderiaceae/fisiologia , Polifenóis/metabolismo , Vitis/metabolismo , Aciltransferases/genética , Aciltransferases/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Botrytis/fisiologia , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Flavonoides/análise , Flavonoides/metabolismo , Flavonoides/farmacologia , Regulação da Expressão Gênica de Plantas , Espectrometria de Massas , Metaboloma , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Polifenóis/análise , Polifenóis/farmacologia , Análise de Componente Principal , Esporos Fúngicos/efeitos dos fármacos , Vitis/química , Vitis/crescimento & desenvolvimento
5.
Appl Environ Microbiol ; 85(11)2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902863

RESUMO

Members of the genus Burkholderia colonize diverse ecological niches. Among the plant-associated strains, Paraburkholderia phytofirmans PsJN is an endophyte with a broad host range. In a spatially structured environment (unshaken broth cultures), biofilm-constructing specialists of P. phytofirmans PsJN colonizing the air-liquid interface arose at high frequency. In addition to forming a robust biofilm in vitro and in planta on Arabidopsis roots, those mucoid phenotypic variants display a reduced swimming ability and modulate the expression of several microbe-associated molecular patterns (MAMPs), including exopolysaccharides (EPS), flagellin, and GroEL. Interestingly, the variants induce low PR1 and PDF1.2 expression compared to that of the parental strain, suggesting a possible evasion of plant host immunity. We further demonstrated that switching from the planktonic to the sessile form did not involve quorum-sensing genes but arose from spontaneous mutations in two genes belonging to an iron-sulfur cluster: hscA (encoding a cochaperone protein) and iscS (encoding a cysteine desulfurase). A mutational approach validated the implication of these two genes in the appearance of variants. We showed for the first time that in a heterogeneous environment, P. phytofirmans strain PsJN is able to rapidly diversify and coexpress a variant that outcompete the wild-type form in free-living and static conditions but not in plantaIMPORTANCEParaburkholderia phytofirmans strain PsJN is a well-studied plant-associated bacterium known to induce resistance against biotic and abiotic stresses. In this work, we described the spontaneous appearance of mucoid variants in PsJN from static cultures. We showed that the conversion from the wild-type (WT) form to variants (V) correlates with an overproduction of EPS, an enhanced ability to form biofilm in vitro and in planta, and a reduced swimming motility. Our results revealed also that these phenotypes are in part associated with spontaneous mutations in an iron-sulfur cluster. Overall, the data provided here allow a better understanding of the adaptive mechanisms likely developed by P. phytofirmans PsJN in a heterogeneous environment.


Assuntos
Biofilmes/crescimento & desenvolvimento , Burkholderiaceae/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Bactérias/genética , Burkholderiaceae/citologia , Burkholderiaceae/genética , Burkholderiaceae/crescimento & desenvolvimento , Liases de Carbono-Enxofre , Defensinas/metabolismo , Proteínas de Choque Térmico HSP70/genética , Mutação , Imunidade Vegetal , Raízes de Plantas/microbiologia , Percepção de Quorum/genética , Estresse Fisiológico , Sequenciamento Completo do Genoma
6.
Molecules ; 22(11)2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29120391

RESUMO

A new resveratrol dimer (1) called labruscol, has been purified by centrifugal partition chromatography of a crude ethyl acetate stilbene extract obtained from elicited grapevine cell suspensions of Vitis labrusca L. cultured in a 14-liter stirred bioreactor. One dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) analyses including ¹H, 13C, heteronuclear single-quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), and correlation spectroscopy (COSY) as well as high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) were used to characterize this compound and to unambiguously identify it as a new stilbene dimer, though its relative stereochemistry remained unsolved. Labruscol was recovered as a pure compound (>93%) in sufficient amounts (41 mg) to allow assessment of its biological activity (cell viability, cell invasion and apoptotic activity) on two different cell lines, including one human skin melanoma cancer cell line HT-144 and a healthy human dermal fibroblast (HDF) line. This compound induced almost 100% of cell viability inhibition in the cancer line at a dose of 100 µM within 72 h of treatment. However, at all tested concentrations and treatment times, resveratrol displayed an inhibition of the cancer line viability higher than that of labruscol in the presence of fetal bovine serum. Both compounds also showed differential activities on healthy and cancer cell lines. Finally, labruscol at a concentration of 1.2 µM was shown to reduce cell invasion by 40%, although no similar activity was observed with resveratrol. The cytotoxic activity of this newly-identified dimer is discussed.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Estilbenos/química , Estilbenos/farmacologia , Apoptose , Reatores Biológicos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dimerização , Humanos , Espectroscopia de Ressonância Magnética , Melanoma , Estrutura Molecular , Células Vegetais , Resveratrol , Neoplasias Cutâneas , Estilbenos/isolamento & purificação , Vitis , Melanoma Maligno Cutâneo
7.
Mol Plant Microbe Interact ; 30(12): 946-959, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28841114

RESUMO

Esca disease is one of the major grapevine trunk diseases in Europe and the etiology is complex, since several inhabiting fungi are identified to be associated with this disease. Among the foliar symptom expressions, the apoplectic form may be distinguished and characterized by sudden dieback of shoots, leaf drop, and shriveling of grape clusters in a few days that can ultimately induce the plant death. To further understand this drastic event, we conducted transcriptomic and metabolomic analyses to characterize responses of leaves during the period preceding symptom appearance (20 and 7 days before foliar symptom expression) and at the day of apoplexy expression. Transcriptomic and metabolomic analyses provide signatures for the apoplectic leaves and most changes concerning the metabolism of carbohydrates, amino acids, and phenylpropanoids. In deciphering glutathione-S-transferase (GST), its preferential location in phloem, correlated with the upregulation of GST genes and a decrease of the glutathione level, offers further support to the putative role of glutathione during apoplexy expression.


Assuntos
Doenças das Plantas/microbiologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Vitis/metabolismo , Vitis/microbiologia , Ciclotrons , Análise de Fourier , Fungos/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Estudos de Associação Genética , Glutationa/metabolismo , Hibridização In Situ , Espectrometria de Massas , Redes e Vias Metabólicas , Metaboloma/genética , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Vitis/genética
8.
Langmuir ; 33(38): 9979-9987, 2017 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-28749675

RESUMO

Natural and synthetic amphiphilic molecules including lipopeptides, lipopolysaccharides, and glycolipids are able to induce defense mechanisms in plants. In the present work, the perception of two synthetic C14 rhamnolipids, namely, Alk-RL and Ac-RL, differing only at the level of the lipid tail terminal group have been investigated using biological and biophysical approaches. We showed that Alk-RL induces a stronger early signaling response in tobacco cell suspensions than does Ac-RL. The interactions of both synthetic RLs with simplified biomimetic membranes were further analyzed using experimental and in silico approaches. Our results indicate that the interactions of Alk-RL and Ac-RL with lipids were different in terms of insertion and molecular responses and were dependent on the lipid composition of model membranes. A more favorable insertion of Alk-RL than Ac-RL into lipid membranes is observed. Alk-RL forms more stable molecular assemblies than Ac-RL with phospholipids and sterols. At the molecular level, the presence of sterols tends to increase the RLs' interaction with lipid bilayers, with a fluidizing effect on the alkyl chains. Taken together, our findings suggest that the perception of these synthetic RLs at the membrane level could be related to a lipid-driven process depending on the organization of the membrane and the orientation of the RLs within the membrane and is correlated with the induction of early signaling responses in tobacco cells.


Assuntos
Glicolipídeos/química , Biomimética , Membrana Celular , Bicamadas Lipídicas , Lipídeos de Membrana
9.
Molecules ; 22(3)2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-28300789

RESUMO

In the present study, resveratrol and various oligomeric derivatives were obtained from a 14 L bioreactor culture of elicited grapevine cell suspensions (Vitis labrusca L.). The crude ethyl acetate stilbene extract obtained from the culture medium was fractionated by centrifugal partition chromatography (CPC) using a gradient elution method and the major stilbenes contained in the fractions were subsequently identified by using a 13C-NMR-based dereplication procedure and further 2D NMR analyses including HSQC, HMBC, and COSY. Beside δ-viniferin (2), leachianol F (4) and G (4'), four stilbenes (resveratrol (1), ε-viniferin (5), pallidol (3) and a newly characterized dimer (6)) were recovered as pure compounds in sufficient amounts to allow assessment of their biological activity on the cell growth of three different cell lines, including two human skin malignant melanoma cancer cell lines (HT-144 and SKMEL-28) and a healthy human dermal fibroblast HDF line. Among the dimers obtained in this study, the newly characterized resveratrol dimer (6) has never been described in nature and its biological potential was evaluated here for the first time. ε-viniferin as well as dimer (6) showed IC50 values on the three tested cell lines lower than the ones exerted by resveratrol and pallidol. However, activities of the first two compounds were significantly decreased in the presence of fetal bovine serum although that of resveratrol and pallidol was not. The differential tumor activity exerted by resveratrol on healthy and cancer lines was also discussed.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Antineoplásicos Fitogênicos/farmacologia , Reatores Biológicos , Células Vegetais/metabolismo , Estilbenos/farmacologia , Vitis/citologia , Técnicas de Cultura Celular por Lotes , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Resveratrol , Estilbenos/química
10.
Phytopathology ; 106(6): 541-53, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26882851

RESUMO

Trunk diseases have become among the most important grapevine diseases worldwide. They are caused by fungal pathogens that attack the permanent woody structure of the vines and cause various symptoms in woody and annual organs. This study examined modifications of plant responses in green stem, cordon, and trunk of grapevines expressing Esca proper (E) or apoplexy (A) event, which are the most frequent grapevine trunk disease symptoms observed in Europe. Transcript expression of a set of plant defense- and stress-related genes was monitored by quantitative reverse-transcription polymerase chain reaction while plant phytoalexins and fungal metabolites were quantified by high-performance liquid chromatography-mass spectrometry in order to characterize the interaction between the grapevine and trunk disease agents. Expression of genes encoding enzymes of the phenylpropanoid pathway and trans-resveratrol content were altered in the three organs of diseased plants, especially in the young tissues of A plants. Pathogenesis-related proteins and the antioxidant system were severely modulated in A plants, which indicates a drastic stress effect. In the meantime, fungal polyketides 6-MSA, (R)-mellein, and (3R,4R)-4-hydroxymellein, were accumulated in A plants, which suggests their potential effect on plant metabolism during the appearance of foliar symptoms.


Assuntos
Fungos/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Doenças das Plantas/microbiologia , Vitis/metabolismo , Caules de Planta/microbiologia , Polifenóis/metabolismo , Sesquiterpenos/metabolismo , Estresse Fisiológico , Fitoalexinas
11.
Microbiol Mol Biol Rev ; 80(1): 1-43, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26609051

RESUMO

Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. Many Actinobacteria have a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture. Actinobacteria play diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species of Corynebacterium, Mycobacterium, Nocardia, Propionibacterium, and Tropheryma), soil inhabitants (e.g., Micromonospora and Streptomyces species), plant commensals (e.g., Frankia spp.), and gastrointestinal commensals (Bifidobacterium spp.). Actinobacteria also play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.


Assuntos
Actinobacteria/classificação , Actinobacteria/metabolismo , Produtos Biológicos/metabolismo , Filogenia , Actinobacteria/genética , Antibacterianos/biossíntese , Antibacterianos/química , Antifúngicos/química , Antifúngicos/metabolismo , Produtos Biológicos/química , Herbicidas/química , Herbicidas/metabolismo , Inseticidas/química , Inseticidas/metabolismo , Interações Microbianas , Pigmentos Biológicos/biossíntese , Pigmentos Biológicos/química , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo
12.
Am J Respir Crit Care Med ; 190(7): 733-7, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25166884

RESUMO

The largest ever Ebola virus disease outbreak is ravaging West Africa. The constellation of little public health infrastructure, low levels of health literacy, limited acute care and infection prevention and control resources, densely populated areas, and a highly transmissible and lethal viral infection have led to thousands of confirmed, probable, or suspected cases thus far. Ebola virus disease is characterized by a febrile severe illness with profound gastrointestinal manifestations and is complicated by intravascular volume depletion, shock, profound electrolyte abnormalities, and organ dysfunction. Despite no proven Ebola virus-specific medical therapies, the potential effect of supportive care is great for a condition with high baseline mortality and one usually occurring in resource-constrained settings. With more personnel, basic monitoring, and supportive treatment, many of the sickest patients with Ebola virus disease do not need to die. Ebola virus disease represents an illness ready for a paradigm shift in care delivery and outcomes, and the profession of critical care medicine can and should be instrumental in helping this happen.


Assuntos
Cuidados Críticos/métodos , Doença pelo Vírus Ebola/terapia , Assistência ao Paciente/métodos , África Ocidental/epidemiologia , Estado Terminal , Surtos de Doenças/estatística & dados numéricos , Doença pelo Vírus Ebola/epidemiologia , Humanos , Cuidados Paliativos/métodos
13.
Environ Sci Pollut Res Int ; 21(7): 4837-46, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23719689

RESUMO

Development and optimisation of alternative strategies to reduce the use of classic chemical inputs for protection against diseases in vineyard is becoming a necessity. Among these strategies, one of the most promising consists in the stimulation and/or potentiation of the grapevine defence responses by the means of elicitors. Elicitors are highly diverse molecules both in nature and origins. This review aims at providing an overview of the current knowledge on these molecules and will highlight their potential efficacy from the laboratory in controlled conditions to vineyards. Recent findings and concepts (especially on plant innate immunity) and the new terminology (microbe-associated molecular patterns, effectors, etc.) are also discussed in this context. Other objectives of this review are to highlight the difficulty of transferring elicitors use and results from the controlled conditions to the vineyard, to determine their practical and effective use in viticulture and to propose ideas for improving their efficacy in non-controlled conditions.


Assuntos
Imunidade Inata/efeitos dos fármacos , Controle de Pragas/métodos , Agricultura , Praguicidas/imunologia , Plantas/imunologia , Vitis , Vinho
14.
Int J Mol Sci ; 14(7): 14136-70, 2013 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-23880860

RESUMO

Phytoalexins are antimicrobial substances of low molecular weight produced by plants in response to infection or stress, which form part of their active defense mechanisms. Starting in the 1950's, research on phytoalexins has begun with biochemistry and bio-organic chemistry, resulting in the determination of their structure, their biological activity as well as mechanisms of their synthesis and their catabolism by microorganisms. Elucidation of the biosynthesis of numerous phytoalexins has permitted the use of molecular biology tools for the exploration of the genes encoding enzymes of their synthesis pathways and their regulators. Genetic manipulation of phytoalexins has been investigated to increase the disease resistance of plants. The first example of a disease resistance resulting from foreign phytoalexin expression in a novel plant has concerned a phytoalexin from grapevine which was transferred to tobacco. Transformations were then operated to investigate the potential of other phytoalexin biosynthetic genes to confer resistance to pathogens. Unexpectedly, engineering phytoalexins for disease resistance in plants seem to have been limited to exploiting only a few phytoalexin biosynthetic genes, especially those encoding stilbenes and some isoflavonoids. Research has rather focused on indirect approaches which allow modulation of the accumulation of phytoalexin employing transcriptional regulators or components of upstream regulatory pathways. Genetic approaches using gain- or less-of functions in phytoalexin engineering together with modulation of phytoalexin accumulation through molecular engineering of plant hormones and defense-related marker and elicitor genes have been reviewed.


Assuntos
Sesquiterpenos/metabolismo , Resistência à Doença/genética , Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Escopoletina/metabolismo , Sesquiterpenos/química , Nicotiana/metabolismo , Fatores de Transcrição/metabolismo , Fitoalexinas
15.
J Urol ; 186(6): 2293-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22014814

RESUMO

PURPOSE: We examined the incidence of asymptomatic and symptomatic lower extremity venous thromboembolism in patients who underwent urological surgery for cancer, and identified preoperative and operative risk factors predictive of the thromboembolism. MATERIALS AND METHODS: A cohort of 583 consecutive patients undergoing urological cancer surgery was prospectively assessed using complete lower limb ultrasound at postoperative day 7 from January 2005 to July 2009. In all patients heparin and mechanical thromboprophylaxis were prescribed until complete ambulation. Potential variables predictive of venous thrombosis were analyzed. RESULTS: Complete data were available in 538 patients (463 male and 75 female), of whom 177 underwent nephrectomy, 86 radical cystectomy and 275 radical prostatectomy. A total of 40 deep venous thrombosis cases were found (7.4%), most of which were asymptomatic (92%) and limited to deep calf veins (80%). Of those asymptomatic deep venous thrombosis cases 86% were limited to deep calf veins. In all, 12 pulmonary embolisms were diagnosed, of which 4 were lethal. On multivariate analysis history of venous thromboembolism (OR 5.16, p = 0.02) and radical cystectomy (OR 3.47, p = 0.002) were independently associated with venous thromboembolism. CONCLUSIONS: Lower extremity venous thromboembolism has a high rate of occurrence after urological surgery for cancer despite the recommended venous thromboembolism prophylaxis. Most cases are asymptomatic and limited to deep calf veins. Our results suggest that complete lower limb ultrasound should be performed early after radical cystectomy and in patients with a personal history of venous thromboembolism.


Assuntos
Cistectomia , Extremidade Inferior/irrigação sanguínea , Nefrectomia , Complicações Pós-Operatórias/epidemiologia , Prostatectomia , Tromboembolia Venosa/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/patologia , Estudos Prospectivos , Fatores de Risco , Neoplasias Urológicas/cirurgia , Tromboembolia Venosa/patologia
16.
Mol Plant Microbe Interact ; 24(9): 1061-73, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21649510

RESUMO

The oomycete Plasmopara viticola is responsible for downy mildew, a severe grapevine disease. In infected grapevine leaves, we have observed an abnormal starch accumulation at the end of the dark period, suggesting modifications in starch metabolism. Therefore, several complementary approaches, including transcriptomic analyses, measurements of enzyme activities, and sugar quantification, were performed in order to investigate and to understand the effects of P. viticola infection on leaf starch and-to a larger extent-carbohydrate metabolism. Our results indicate that starch accumulation is associated with an increase in ADP-glucose pyrophosphorylase (AGPase) activity and modifications in the starch degradation pathway, especially an increased α-amylase activity. Together with these alterations in starch metabolism, we have observed an accumulation of hexoses, an increase in invertase activity, and a reduction of photosynthesis, indicating a source-to-sink transition in infected leaf tissue. Additionally, we have measured an accumulation of the disaccharide trehalose correlated to an increased trehalase gene expression and enzyme activity. Altogether, these results highlight a dramatic alteration of carbohydrate metabolism correlated with later stages of P. viticola development in leaves.


Assuntos
Enzimas/metabolismo , Oomicetos/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Amido/metabolismo , Vitis/fisiologia , Metabolismo dos Carboidratos , Clorofila/metabolismo , Enzimas/genética , Regulação da Expressão Gênica de Plantas , Glucose-1-Fosfato Adenililtransferase/genética , Glucose-1-Fosfato Adenililtransferase/metabolismo , Hexoses/análise , Hexoses/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Oomicetos/patogenicidade , Fotossíntese/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Polissacarídeos/análise , Polissacarídeos/metabolismo , RNA de Plantas/genética , Amido/análise , Trealose/metabolismo , Vitis/enzimologia , Vitis/genética , Vitis/microbiologia , alfa-Amilases/genética , alfa-Amilases/metabolismo , beta-Amilase/genética , beta-Amilase/metabolismo
17.
Mol Biol Rep ; 38(5): 3327-37, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21104020

RESUMO

F-box proteins are key components of the ubiquitin (Ub)/26S proteasome pathway that mediates selective degradation of regulatory proteins involved in a wide variety of cellular processes affecting eukaryotic cells. In plants, F-box genes form one of the largest multigene superfamilies and control many important biological functions. Among the F-box genes characterized to date only few have been involved in the regulation of plant defense responses. Moreover, no F-box genes have been studied and characterized in grapevine. Using a differential display approach we isolated a F-box gene (BIG-24.1), which is up-regulated during Botrytis cinerea infection of grapevine leaves. BIG-24.1 encodes a polypeptide of 386 amino acids with a conserved F-box domain in the N-terminus region and a kelch domain. By investigating expression profiles of BIG-24.1, we show that the gene expression is strongly stimulated in B. cinerea infected berries and in grapevine cells challenged by MAMP rhamnolipids, a non-host bacterium and an endophytic rhizobacterium. The gene is also strongly induced by abiotic stresses including UV-C and wounding or by salicylic acid, methyl-jasmonate, ethylene and abscisic acid that are known to be involved in defense signalling pathways. In addition, sequence analysis of the BIG-24.1 promoter revealed the presence of several regulatory elements involved in the activation of plant defense responses.


Assuntos
Proteínas F-Box/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/microbiologia , Folhas de Planta/fisiologia , Estresse Fisiológico , Vitis/genética , Sequência de Aminoácidos , Botrytis/metabolismo , Botrytis/patogenicidade , Proteínas F-Box/metabolismo , Perfilação da Expressão Gênica , Dados de Sequência Molecular , Folhas de Planta/metabolismo , Regiões Promotoras Genéticas , Alinhamento de Sequência , Análise de Sequência de DNA , Regulação para Cima/efeitos dos fármacos , Vitis/anatomia & histologia , Vitis/metabolismo , Vitis/microbiologia
18.
Planta ; 219(1): 141-6, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-14963707

RESUMO

The regulation of developmental pathways in cultured microspores of tobacco ( Nicotiana tabacum L) and snapdragon ( Antirrhinum majus L) by medium pH is described for the first time. Unicellular tobacco and snapdragon microspores developed into normal, fertile pollen when cultured in media T1 and AT3 at pH 7.0 and 25 degrees C for 6 and 8 days, respectively. First, pollen mitosis was asymmetric and mature pollen grains were filled with starch granules and germinated upon transfer to a germination medium. However, when tobacco and snapdragon microspores were cultured in media T1 and AT3, respectively, at pH 8.0-8.5 for 4-6 days at 25 degrees C, the frequency of symmetric division increased significantly with the formation two nuclei of equal size, and the gametophytic pathway was blocked, as seen by the lack of starch accumulation and the inhibition of pollen germination. The transfer of these microspores to embryogenesis medium AT3 at pH 6.5 resulted in the formation of multicellular structures in both species and, in tobacco, in the formation of embryos and plants. In order to understand the possible mechanisms of the action of high pH, sucrose metabolism was analysed in isolated microspores of tobacco cultured at various pH values. Invertase (EC 3.2.1.26) activity in microspores was maximal at pH 5.0 and strongly decreased at higher pH, leading to a slow-down of sucrose cleavage. At the same time the incorporation of (14)C-labelled sucrose from the medium into microspores was drastically reduced at high pH. These data suggest that isolated microspores are not able to metabolise carbohydrates at high pH and thus undergo starvation stress, which was shown earlier to block the gametophytic pathway and trigger sporophytic development.


Assuntos
Antirrhinum/metabolismo , Meios de Cultura/metabolismo , Nicotiana/metabolismo , Antirrhinum/citologia , Antirrhinum/crescimento & desenvolvimento , Células Cultivadas , Concentração de Íons de Hidrogênio , Pólen/citologia , Sementes/citologia , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Nicotiana/citologia , Nicotiana/crescimento & desenvolvimento
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