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3.
Curr Oncol ; 26(3): e346-e356, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31285679

RESUMO

Introduction: Total pancreatectomy for pancreatic ductal adenocarcinoma has historically been associated with substantial patient morbidity and mortality. Given advancements in perioperative and postoperative care, evaluation of the surgical treatment options for pancreatic adenocarcinoma should consider patient outcomes and long-term survival for total pancreatectomy compared with partial pancreatectomy. Methods: The U.S. National Cancer Database was queried for patients undergoing total pancreatectomy or partial pancreatectomy for pancreatic adenocarcinoma during 1998-2006. Demographics, tumour characteristics, operative outcomes, 30-day mortality, 30-day readmission, additional treatment, and Kaplan-Meier survival curves were compared. Results: The database query returned 807 patients who underwent total pancreatectomy and 5840 who underwent partial pancreatectomy. More patients who underwent total pancreatectomy than a partial pancreatectomy had a margin-negative resection (p < 0.0001). Mortality and readmission rates were similar in the two groups, as was long-term survival on Kaplan-Meier curves (p = 0.377). A statistically significant difference in the rate of surgery only (without additional treatment) was observed for patients in the total pancreatectomy group (p = 0.0003). Conclusions: Although total compared with partial pancreatectomy was associated with a higher rate of margin-negative resection, median survival was not significantly different for patients undergoing either procedure. Patients who underwent total pancreatectomy were significantly less likely to receive adjuvant therapy.


Assuntos
Adenocarcinoma/cirurgia , Pancreatectomia/métodos , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Bases de Dados Factuais , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Readmissão do Paciente , Estados Unidos
4.
Orthopade ; 42(8): 629-36, 2013 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-23912305

RESUMO

Until recently, metal-on-metal (MoM) hip implants were commonly used for joint replacement and resurfacings. Their use has rapidly declined following reports of Frühversagen and soft tissue disease caused by the release of metal debris from the prosthesis. Detection of these soft tissue lesions has proven difficult using conventional imaging techniques and blood metal ion tests. Current guidelines recommend the use of imaging modalities including metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI), computed tomography and ultrasound but provide little indication which is best. MARS significantly reduces the susceptibility artefact induced by the presence of metal objects, thereby producing diagnostic quality images that can be shared with other physicians and compared over time. The clinical interpretation of MRI findings of solid pseudotumours and severe muscle atrophy is straightforward: revision is usually recommended. However, the most common MRI findings are of a cystic pseudotumour and minor muscle wasting. In these cases decision-making is difficult and we currently use multi-disciplinary and multi-colleague based meetings to make decisions regarding patient management. This article presents a comparison of imaging modalities and an update on the interpretation of MARS MRI for the investigation of patients with MoM hip implants.The English full-text version of this article is available at Springer Link (under "Supplemental").


Assuntos
Doenças do Tecido Conjuntivo/etiologia , Doenças do Tecido Conjuntivo/patologia , Hipersensibilidade/etiologia , Hipersensibilidade/patologia , Prótese Articular/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Próteses Articulares Metal-Metal/efeitos adversos , Humanos
6.
Oncogene ; 27(25): 3596-604, 2008 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-18223692

RESUMO

Prostate cancer is one of the most prominent malignancies of elderly men in many Western countries including Europe and the United States with increasing trend worldwide. The growth of normal prostate as well as of prostate carcinoma cells depends on functional androgen receptor (AR) signaling. AR manifests the biological actions of androgens and its transcriptional activity is known to be influenced by signal transduction pathways. Here we show that Src, a nonreceptor tyrosine kinase, is overexpressed in androgen-independent prostate carcinoma C4-2 cells. Interestingly, the expression of Src was found to progressively increase (up to threefold) in transgenic adenocarcinoma of mouse prostate mice as a function of age and cancer progression. Blocking Src kinase function by a specific inhibitor, PP2, resulted in decreased AR transactivation function on two different reporters, mouse mammary tumor virus (MMTV) and prostate-specific antigen (PSA). Consistent with this, overexpression of a functional Src mutant also led to a dramatic decrease in AR transactivation potential in a hormone-dependent manner. Interference with Src function in C4-2 cells led to decreased recruitment of AR on the target gene PSA enhancer and also resulted in the abrogation of hormone-dependent PSA transcript induction. Src inhibition also led to a dramatic decrease in the cell invasion in addition to decreasing the cellular growth. We suggest that targeting Src kinase could be an effective strategy to inhibit prostate cancer growth and metastasis.


Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo , Androgênios/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Invasividade Neoplásica , Neoplasias da Próstata/metabolismo , Transcrição Gênica , Transgenes
7.
Oncogene ; 27(14): 2055-63, 2008 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-17998943

RESUMO

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L) is a promising candidate for cancer therapy, however, emergence of drug resistance limits its potential use. Here, we report for the first time that epigallocatechin-3-gallate (EGCG), the major polyphenolic constituent of green tea, sensitizes TRAIL-resistant LNCaP cells to TRAIL-mediated apoptosis through modulation of intrinsic and extrinsic apoptotic pathways. When combined with EGCG, Apo2L/TRAIL exhibited enhanced apoptotic activity in LNCaP cells characterized by three major molecular events. First, apoptosis induction was accompanied by the upregulation of poly(ADP-ribose) polymerase cleavage and modulation of pro- and antiapoptotic Bcl2 family of proteins. A synergistic inhibition of inhibitors of apoptosis with concomitant increase in caspase cleavage was observed. Second, pretreatment of cells with EGCG resulted in modulation of death-inducing signaling cascade complex involving DR4/TRAIL R1, Fas-associated death domain and FLICE-inhibitory protein proteins. Last, we observed a synergistic inhibition in the invasion and migration of LNCaP cells. This effect was observed to be mediated through inhibition in the protein expression of vascular endothelial growth factor, uPA and angiopoietin 1 and 2. Further, the activity and protein expression of MMP-2, -3 and -9 and upregulation of TIMP1 in cells treated with a combination of EGCG and TRAIL was observed. These data might have implications for developing new strategies aimed at eliminating prostate cancer cells resistant to TRAIL.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Camellia sinensis/química , Carcinoma/metabolismo , Catequina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias da Próstata/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/metabolismo , Carcinoma/irrigação sanguínea , Carcinoma/secundário , Catequina/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Masculino , Neovascularização Patológica/metabolismo , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/patologia
8.
J Appl Microbiol ; 98(1): 43-55, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15610416

RESUMO

AIMS: The aim of the present investigation was to determine the influence of Rhizoctonia solani and its pathogenicity factor on the production of nematicidal agent(s) by Pseudomonas fluorescens strain CHA0 and its GM derivatives in vitro and nematode biocontrol potential by bacterial inoculants in tomato. METHODS AND RESULTS: One (Rs7) of the nine R. solani isolates from infected tomato roots inhibited seedling emergence and caused root rot in tomato. Thin layer chromatography revealed that culture filtrates of two isolates (Rs3 and Rs7) produced brown spots at Rf-values closely similar to synthetic phenylacetic acid (PAA), a phytotoxic factor. Filtrates from isolate Rs7, amended with the growth medium of P. fluorescens, markedly repressed nematicidal activity and PhlA'-'LacZ reporter gene expression of the bacteria in vitro. On the contrary, isolate Rs4 enhanced nematicidal potential of a 2,4-diacetylphloroglucinol overproducing mutant, CHA0/pME3424, of P. fluorescens strain CHA0 in vitro. Therefore, R. solani isolates Rs4 and Rs7 were tested more rigorously for their potential to influence biocontrol effectiveness of the bacterial agents. Methanol extract of the culture filtrates of PAA-producing isolate Rs7 resulting from medium amended with phenylalanine enhanced fungal repression of the production of nematicidal agents by bacteria, while amendments with zinc or molybdenum eliminated such fungal repression, thereby restoring bacterial potential to cause nematode mortality in vitro. A pot experiment was carried out, 3-week-old tomato seedlings were infested with R. solani isolates Rs4 or Rs7 and/or inoculated with Meloidogyne incognita, the root-knot nematode. The infested soil was treated with aqueous cell suspensions (10(8) CFU) of P. fluorescens strain CHA0 or its GM derivatives or left untreated (as a control). Observations taken 45 days after nematode inoculation revealed that, irrespective of the bacterial treatments, galling intensity per gram of fresh tomato roots was markedly higher in soil amended with isolate Rs4 than in Rs7-amended soils. Soil amendments with R. solani and the bacterial antagonists resulted in substantial reductions of the number of galls per gram of root. These results are contradictory to those obtained under in vitro conditions where culture filtrates of PAA-positive Rs7 repressed the production of nematicidal compounds. Plants grown in Rs7-amended soils, with or without bacterial inoculants, had lesser shoot and root weights than plants grown in nonamended or Rs4-amended soils. Moreover, amendments with Rs7 substantially retarded root growth and produced necrotic lesions that reduced the number of entry sites for invasion and subsequent infection by nematodes. Populations of P. fluorescens in the tomato rhizosphere were markedly higher in Rs7-amended soils. CONCLUSIONS: PAA-producing virulent R. solani drastically affects the potential of P. fluorescens to cause death of M. incognita juveniles in vitro and influences bacterial effectiveness to suppress nematodes in tomato roots. SIGNIFICANCE AND IMPACT OF THE STUDY: As most agricultural soils are infested with root-infecting fungi, including R. solani, it is likely that some PAA-producing isolates of the fungus may also be isolated from such soils. The inhibitory effect of PAA-producing R. solani on the biosynthesis of nematicidal agent(s) critical in biocontrol may reduce or even eliminate the effectiveness of fluorescent pseudomonads against root-knot nematodes, both in nursery beds and in field conditions. Introduction of bacterial inoculants, for the control of any plant pathogen, should be avoided in soils infested with PAA-producing R. solani. Alternatively, the agents could be applied together with an appropriate quantity of fungicide or chemicals such as zinc to create an environment more favourable for bacterial biocontrol action.


Assuntos
Antinematódeos/metabolismo , Microbiologia de Alimentos , Controle de Pragas , Fenilacetatos/metabolismo , Rhizoctonia/metabolismo , Solanum lycopersicum/microbiologia , Animais , Depressão Química , Infecções por Nematoides/prevenção & controle , Organismos Geneticamente Modificados , Fenilacetatos/farmacologia , Infecções por Pseudomonas/microbiologia , Pseudomonas fluorescens/metabolismo , Tylenchoidea
9.
Lett Appl Microbiol ; 39(1): 74-83, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15189291

RESUMO

AIMS: The aim was to determine the influence of some Aspergillus species on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. METHODS AND RESULTS: Six species of Aspergillus, isolated from the rhizosphere of certain crops, produced a variety of secondary metabolites in vitro. Culture filtrate (CF) obtained from Ps. fluorescens strain CHA0 and its2,4-diacetylphloroglucinol overproducing mutant CHA0/pME3424 grown in King's B liquid medium caused significant mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with CF of A. niger enhanced nematicidal and beta-galactosidase activities of fluorescent pseudomonads while A. quadrilineatus repressed such activities. Methanol or ethyl acetate extracts of the CF of A. niger markedly optimized bacterial efficacy to cause nematode deaths while hexane extract of the fungus had no influence on the nematicidal activity of the bacterial strains. A. niger applied alone or in conjunction with the bacterial inoculants inhibited root-knot nematode galling in tomato. On the other hand, A. quadrilineatus used alone or together with CHA0 did not inhibit nematode galling but when used in combination with strain CHA0/pME3424 did reduce galling intensity. CONCLUSIONS: Aspergillus niger enhances the production of nematicidal compounds by Ps. fluorescensin vitro and improves biocontrol potential of the bacterial inoculants in tomato while A. quadrilineatus reduces bacterial performance to suppress root-knot nematodes. SIGNIFICANCE AND IMPACT OF THE STUDY: Rhizosphere harbours a variety of micro-organisms including bacteria, fungi and viruses. Aspergillus species are ubiquitous in most agricultural soils and generally produce a variety of secondary metabolites. Such metabolites synthesized by Aspergillus species may influence the production of nematicidal agents and subsequent biocontrol performance of the bacterial inoculants against plant-parasitic nematodes. This fact needs to be taken into consideration when using biocontrol strains in an agriculture system.


Assuntos
Aspergillus/crescimento & desenvolvimento , Doenças das Plantas/parasitologia , Pseudomonas fluorescens/crescimento & desenvolvimento , Solanum lycopersicum/parasitologia , Tylenchoidea/crescimento & desenvolvimento , Animais , Antibiose , Aspergillus/classificação , Aspergillus/metabolismo , Meios de Cultivo Condicionados/farmacologia , Controle Biológico de Vetores , Pseudomonas fluorescens/metabolismo
10.
Lett Appl Microbiol ; 38(3): 185-90, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14962038

RESUMO

AIMS: The aim of the present investigation was to determine the influence of nutrients on the nematicidal activity by Pseudomonas aeruginosa strain IE-6S+ and Ps. fluorescens strain CHA0 in vitro. METHODS AND RESULTS: Culture filtrate of IE-6S+ and CHA0 obtained from chemically defined medium caused mortality of Meloidogyne javanica juveniles in vitro and that growth medium amended with various C, N or inorganic phosphate (Pi) sources markedly influenced nematicidal activity of the two bacteria. Glycerol (C source), propionate (fatty acid precursor) and L-lysine (N source) enhanced nematicidal activity while glucose (C), L-valine (N) and Pi substantially repressed nematicidal activity of the two bacteria. CONCLUSION: Liquid culture amendments with various C, N or Pi sources modulate the biosynthesis of nematicidal agents to a different extent in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: Developing bacterial strains more responsive to certain environmental signals can be exploited for increased secondary metabolite production in pharmaceutical fermentations and offers new avenues to improve biocontrol.


Assuntos
Controle Biológico de Vetores/métodos , Pseudomonas aeruginosa/fisiologia , Pseudomonas fluorescens/fisiologia , Tylenchoidea/microbiologia , Aminoácidos/metabolismo , Animais , Metabolismo dos Carboidratos , Ácidos Carboxílicos/metabolismo , Meios de Cultura/química , Fosfatos/metabolismo , Pseudomonas aeruginosa/metabolismo , Pseudomonas fluorescens/metabolismo
11.
Lett Appl Microbiol ; 38(2): 169-75, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14746551

RESUMO

AIMS: To determine the influence of soil-borne fungus Trichoderma harzianum on the biocontrol performance of Pseudomonas fluorescens strain CHA0 and its 2,4-diacetylphloroglucinol (DAPG) overproducing derivative CHA0/pME3424 against Meloidogyne javanica. METHODS AND RESULTS: Amendment of the culture filtrate (CF) or methanol extract of the CF of a T. harzianum strain Th6 to P. fluorescens growth medium enhanced the production of nematicidal compound(s) by bacterial inoculants in vitro. In addition, bacteria overwhelmingly expressed phl'-'lacZ reporter gene when the medium was amended with CF of T. harzianum. Pseudomonas fluorescens and T. harzianum applied together in unsterilized sandy loam soil caused greater reduction in nematode population densities in tomato roots. CONCLUSIONS: Trichoderma harzianum improves root-knot nematode biocontrol by the antagonistic rhizobacterium P. fluorescens both in vitro and under glasshouse conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: The synergistic effect of T. harzianum on the production of nematicidal compound(s) critical in biocontrol may improve the efficacy of biocontrol bacteria against plant-parasitic nematodes. Considering the inconsistent performance of the biocontrol agents under field conditions, application of a mixture of compatible T. harzianum and P. fluorescens would more closely mimic the natural situation and might broaden the spectrum of biocontrol activity with enhanced efficacy and reliability of control.


Assuntos
Antinematódeos/metabolismo , Antinematódeos/farmacologia , Controle Biológico de Vetores/métodos , Pseudomonas fluorescens/metabolismo , Solanum lycopersicum/parasitologia , Trichoderma/fisiologia , Tylenchoidea/crescimento & desenvolvimento , Animais , Regulação Bacteriana da Expressão Gênica , Genes Reporter , Floroglucinol/análogos & derivados , Floroglucinol/metabolismo , Raízes de Plantas/parasitologia , Pseudomonas fluorescens/genética , Microbiologia do Solo , beta-Galactosidase/metabolismo
12.
J Appl Microbiol ; 95(5): 1039-48, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14633033

RESUMO

AIMS: To assess whether Pseudomonas fluorescens strain CHA0 and its genetically modified derivatives, CHA0/pME3424 (antibiotic over-producer) and CHA89 (antibiotic-deficient) could have an impact on the fungal community structure and composition in the rhizosphere of mungbean. METHODS AND RESULTS: Under glasshouse conditions, mungbean was grown repeatedly in the same soil, which was inoculated with CHA0, CHA0/pME3424, CHA89 or was left untreated. Treatments were applied to soil at the start of each 36-day mungbean growth cycle, and their effects on the diversity of the rhizosphere populations of culturable fungi were assessed at the end of the first, second and third cycles. The effects of CHA0 and CHA0/pME3424 did differ from the controls while CHA89 did not. Whereas all major fungal species were frequently isolated from both bacterized and nonbacterized rhizospheres, certain fungal species were exclusively promoted or specifically suppressed from Pseudomonas-treated soils. In general, fungal diversity and equitability tended to decrease with time while species richness slightly increased. Whilst a total of 29 fungal species were isolated from the mungbean rhizosphere, only eight species colonized the root tissues. CONCLUSIONS: Soil inoculation with Ps. fluorescens CHA0 or CHA0/pME3424 altered fungal community structure in mungbean rhizosphere but strain CHA89 failed to produce such effect. SIGNIFICANCE AND IMPACT OF THE STUDY: Pseudomonas fluorescens-mediated alteration in the composition and structure of fungal communities might have acute or lasting effects on ecosystem functioning. Furthermore, the study provides useful data pertinent to characterization of the fate of genetically modified inoculants (e.g. antibiotic-overproducing Pseudomonas strains) released into the environment.


Assuntos
Antibiose , Fabaceae/microbiologia , Fungos/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Pseudomonas fluorescens/patogenicidade , Contagem de Colônia Microbiana , Fungos/classificação , Fungos/isolamento & purificação , Engenharia Genética , Raízes de Plantas/microbiologia , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/crescimento & desenvolvimento , Microbiologia do Solo
13.
Lett Appl Microbiol ; 37(2): 109-14, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12859651

RESUMO

AIMS: The aim of the present investigation was to determine the influence of various Fusarium solani strains on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. METHODS AND RESULTS: Culture filtrates (CF) of P. fluorescens strain CHA0 and its diacetylphloroglucinol-overproducing derivative CHA0/pME3424 caused substantial mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with the growth medium of F. solani repressed the nematicidal activity of the bacteria. Methanol extract of F. solani CF resulting from Czapek's Dox liquid (CDL) medium without zinc amendment repressed the nematicidal activity of the bacteria while the CF obtained from CDL medium amended with zinc did not. Conidial suspension of F. solani strain Fs5 (repressor strain for the biosynthesis of nematicidal compounds in P. fluorescens) reduced biocontrol potential of the bacterial inoculants against M. javanica in tomato while strain Fs3 (non-repressor) did not. CONCLUSIONS: Fusarium solani strains with increased nematicidal activity repress the biosynthesis of nematicidal compounds by P. fluorescens strains in vitro and greatly alter its biocontrol efficacy against root-knot nematode under natural conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Fusarium solani strains are distributed worldwide and found in almost all the agricultural fields which suggest that some mycotoxin-producing strains will also be found in almost any soil sample taken. Besides the suppressive effect of these metabolite-producing strains on the production of nematicidal compound(s) critical in biocontrol, F. solani strains may also affect the performance of mycotoxin-sensitive biocontrol bacteria effective against plant-parasitic nematodes.


Assuntos
Antinematódeos/metabolismo , Fusarium/fisiologia , Controle Biológico de Vetores , Pseudomonas fluorescens/fisiologia , Animais , Técnicas In Vitro , Solanum lycopersicum/microbiologia , Solanum lycopersicum/parasitologia , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Microbiologia do Solo , Tylenchoidea/patogenicidade
14.
J Pak Med Assoc ; 53(4): 131-3, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12776894

RESUMO

OBJECTIVE: To compare improvement in hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and ferritin levels in children aged 5-10 years and women of reproductive age (15-45) supplemented with daily oral and once weekly with single and double dose of ferrous sulphate. METHOD: Twenty children received 200 mg ferrous sulfate daily and 20 received the same dose once weekly for two months. Ten women received 300 mg ferrous sulfate daily, 10 received the same dose once weekly while 10 received 600 mg of ferrous sulfate once weekly for one month. RESULTS: All parameters improved significantly in children who received 200 mg ferrous sulfate daily and weekly. Similarly, the parameters improved significantly in women who received 300 mg of ferrous sulfate daily and 600 mg of ferrous sulfate weekly. CONCLUSION: Weekly supplementation of iron is far better in controlling iron deficiency anemia due to cost effectiveness and better compliance.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/prevenção & controle , Compostos Ferrosos/administração & dosagem , Adolescente , Adulto , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Hemoglobinas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Estudos Prospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
16.
Lett Appl Microbiol ; 36(6): 392-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12753248

RESUMO

AIMS: To determine the influence of various trace minerals and carbon source on the biocontrol performance of Pseudomonas aeruginosa strain IE-6S+ and P. fluorescens strain CHA0 against Macrophomina phaseolina. METHODS AND RESULTS: In dual culture plate assay, P. aeruginosa IE-6S+ and P. fluorescens CHA0 inhibited radial growth of M. phaseolina producing zones of inhibition. Czapek's dox agar medium amended with both zinc and glucose remarkably improved antifungal activities of the bacterial inoculants. Under glasshouse conditions, soil amendment with zinc and/or glucose alone did not reduce M. phaseolina infection in tomato roots but did reduce significantly when used in combination with IE-6S+ or CHA0. Soil amendments with zinc and/or glucose increased fresh shoot weights but zinc amendment greatly reduced bacterial populations in the rhizosphere. CONCLUSIONS: Mineral and carbon amendments enhance the biocontrol performance of fluorescent pseudomonads against M. phaseolina. SIGNIFICANCE AND IMPACT OF THE STUDY: Identification of mineral and carbon amendments that favour biocontrol of certain bacterial strains may provide clues to soil factors or components of nutrient solutions in hydroponic culture that will improve the level and reliability of control.


Assuntos
Basidiomycota/crescimento & desenvolvimento , Carbono/metabolismo , Controle Biológico de Vetores , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas fluorescens/crescimento & desenvolvimento , Oligoelementos/metabolismo , Antibiose , Meios de Cultura , Glucose/metabolismo , Solanum lycopersicum/microbiologia , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , Zinco/metabolismo
17.
Lett Appl Microbiol ; 36(4): 239-44, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12641719

RESUMO

AIMS: To improve the efficacy of Pseudomonas fluorescens CHA0 and its genetically modified (GM) derivatives by adding ammonium molybdate to control Meloidogyne javanica, the root-knot nematode in mungbean. METHODS AND RESULTS: Culture filtrate of P. fluorescens CHA0 and its GM derivative (antibiotic overproducing strain CHA0/pME3424 and antibiotic-deficient CHA89) obtained from nutrient broth yeast extract medium amended with 1, 2 or 4 mm of ammonium molybdate (NH4-Mo) caused substantial mortality of M. javanica juveniles in vitro. Pseudomonas fluorescens CHA0 or CHA0/pME3424 applied in conjunction with NH4-Mo caused greater reduction of nematode penetration in mungbean roots compared with the bacterial application alone. Ammonium molybdate at 4 mg kg-1 of soil along with CHA0 also enhanced plant height while shoot weight remained unaffected. Either used alone or in conjunction with NH4-Mo, strain CHA89 did not reduce nematode invasion compared with the controls. Bacterial strains did not differ significantly in their colonization potential in the mungbean rhizosphere. Efficacy of the biocontrol bacteria to control root-knot nematode was accentuated when soil was treated with NH4-Mo and zinc (both at 1 mg kg-1 of soil). CONCLUSION: The addition of ammonium molybdate enhances the production of nematicidal compounds by P. fluorescensin vitro and improves bacterial efficacy against root-knot nematode under glasshouse conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Application of minerals such as ammonium molybdate is appealing because they are cheap and can easily be applied under field conditions to improve biocontrol potential of the bacterial inoculants. They also significantly reduce the amount of biocontrol inoculant biomass required to achieve root-knot disease control, with a consequent reduction in cost.


Assuntos
Molibdênio/farmacologia , Controle Biológico de Vetores , Pseudomonas fluorescens/efeitos dos fármacos , Pseudomonas fluorescens/fisiologia , Animais , Biomassa , Fabaceae/parasitologia , Doenças das Plantas/parasitologia , Pseudomonas fluorescens/genética , Tylenchoidea/patogenicidade
18.
Lett Appl Microbiol ; 35(3): 212-7, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12180943

RESUMO

AIMS: To assess the effects of various carbon and mineral sources on the nematicidal potential of biocontrol inoculants of Pseudomonas aeruginosa IE-6S+ and Ps. fluorescens CHA0 under laboratory and glasshouse conditions. METHODS AND RESULTS: Culture filtrates of strains IE-6S+ and CHA0, cultured in nutrient yeast extract broth, caused substantial mortality of the juveniles of Meloidogyne javanica. The nematicidal activities of the culture filtrates were altered after amendment with various carbon and mineral sources. Soil amendment with zinc alone or in combination with glycerol improved the biocontrol efficacy against root-knot nematode, promoted tomato plant growth and enhanced bacterial rhizosphere and endophytic colonization. CONCLUSIONS: Appropriate quantities of glycerol and zinc alone or in combination enhance the nematicidal activity of Ps. aeruginosa and Ps. fluorescens. Glucose reduces the activity of these bacteria against nematodes. SIGNIFICANCE AND IMPACT OF THE STUDY: Minerals and carbon sources are appealing because they are easy and economical to provide during liquid fermentation of inoculants or as fertilizer amendments to improve the biocontrol activity of indigenous and introduced bacteria.


Assuntos
Glicerol , Controle Biológico de Vetores , Pseudomonas/metabolismo , Solanum lycopersicum/parasitologia , Tylenchoidea/crescimento & desenvolvimento , Zinco , Animais , Anti-Helmínticos/metabolismo , Anti-Helmínticos/farmacologia , Meios de Cultura , Glicerol/metabolismo , Glicerol/farmacologia , Doenças das Plantas/parasitologia , Pseudomonas/crescimento & desenvolvimento , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismo , Pseudomonas fluorescens/crescimento & desenvolvimento , Pseudomonas fluorescens/metabolismo , Tylenchoidea/efeitos dos fármacos , Zinco/metabolismo , Zinco/farmacologia
19.
Phytother Res ; 15(6): 538-40, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11536387

RESUMO

The aqueous, methanol and chloroform extracts of Trigonella foenum-graecum caused significant (p < 0.05) mortality of Meloidogyne javanica larvae. The methanol soluble fraction eluted from pure distilled water showed the highest (>92%) nematicidal activity compared with the fractions eluted from pure methanol and different ratios of chloroform and methanol indicate that the nematicidal compound was polar in nature.


Assuntos
Antinematódeos/farmacologia , Extratos Vegetais/farmacologia , Trigonella/química , Tylenchoidea/efeitos dos fármacos , Animais , Doenças das Plantas
20.
J Nematol ; 9(1): 56-82, 1977 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19305572

RESUMO

The ultrastructure of the anterior body region of the free-living marine nematode Deontostoma calilornicum was studied by electron microscopy. The body wall consists of a nine-layered cuticle, a cellular hypodermis containing eight nerve bundles, and a well-developed coelomyarian somatic musculature. Nerves in the dorsal, lateral, ventral, and submedian hypodermal chords anterior to the nerve ring were observed with regularity. Structure of subventral somatic setae suggests a mechanoreceptive function. The esophagus is cellular and consists of three marginal cells alternating with an equal number of radial muscle cells, three esophageal glands, and three enteric nerves. The membranes of adjacent esophageal cells are sinuous. Apices of the triradiate lumen are connected with the outer wall of each marginal cell by bands of electron-dense nonmyofibrils, whereas two types of myofilaments run radially between the apophyses of the lumen and the outer walls of radial cells. Each myofibril, which forms hemidesmosomes at both ends, is interpreted to be the morphological equivalent of one sarcomere. Synaptic junctions between the processes of muscles, gland cells, and axons of the enteric nerves are described in detail.

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