RÉSUMÉ
The theory of heat conduction paths has been widely recognized and widely studied in the research about the thermal conductivity of thermal conductive polymer composites at present. Encapsulating polymer pellets with thermally conductive fillers and processing them into thermally conductive polymer composites is a simple and effective method for constructing heat conduction paths. It is meaningful to investigate the related heat conduction mechanism of this method. Otherwise, this approach can significantly preserve the performance of the polymer substrate, making it highly valuable for practical material applications. In this work, polyethylene-octene elastomer (POE) pellets were encapsulated with thermal conductive fillers by physical absorption. Subsequently, the composite films containing heat conduction paths were fabricated using the encapsulated POE pellets through a heating press. Alumina (Al2O3), boron nitride (BN), and alumina/boron nitride hybrid (Al2O3/BN) fillers were used to prepare Al2O3@POE, BN@POE, and BN/Al2O3@POE composite films to investigate the influence of filler shapes on heat conduction path construction. The influence of the constitute and density of heat conduction paths on the thermal conductivity of composite films was analyzed by infrared thermal imaging, finite element analysis, and thermal resistance theory in detail. Owing to the reserved good adhesion and flexibility of the POE substrate, the composite films could be directly used as thermal interface materials for chip cooling, which presented a good heat dissipation effect. Furthermore, a series of integrated composite materials were prepared by the combination of encapsulated pellets with various functional films (copper foil, aluminum foil, and graphite sheet) through a one-pot heating press, exhibiting a good electromagnetic shielding effect. The performance of the composites and the corresponding preparation method demonstrate the strong significance of this research for practical applications.
RÉSUMÉ
BACKGROUND: Acute pulmonary embolism and severe renal bleeding are two lethal postoperative complications, but there has been no report that involves both of them after mini-percutaneous nephrolithotomy. CASE PRESENTATION: A 62-year-old woman was admitted to our hospital with extremely severe hydronephrosis and multiple right renal calculi. After thorough examination, she received prone-position mini-percutaneous nephrolithotomy under spinal anaesthesia. Three days postoperatively, the patient complained of chest pain and dyspnea. Computed tomography pulmonary angiogram (CTPA) showed multiple embolisms in the left pulmonary artery and its branches. Symptoms were relieved after anticoagulant and thrombolysis therapy. On the 6th postoperative day, the patient developed shortness of breath, computed tomography angiography (CTA) showed massive hemorrhage in the right kidney, diffused contrast medium in the middle and lower part of the right kidney was seen during digital substraction angiography (DSA). Superselective right renal artery embolization (SRAE) was then applied using coil to occlude the responsible artery. The patient generally recovered under conscientious care and was approved to be discharged 26 days postoperatively. CONCLUSIONS: This is the first case that involved both acute pulmonary embolism and severe post thrombolysis renal bleeding. The importance of D-dimer in the prediction and early detection of pulmonary embolism should be noted. For post thrombolysis renal bleeding, SRAE is considered as a reliable treatment.
Sujet(s)
Néphrolithotomie percutanée , Néphrostomie percutanée , Embolie pulmonaire , Femelle , Hémorragie/étiologie , Humains , Rein , Adulte d'âge moyen , Néphrolithotomie percutanée/effets indésirables , Néphrostomie percutanée/effets indésirables , Embolie pulmonaire/complications , Embolie pulmonaire/thérapie , Artère rénale , Traitement thrombolytique/effets indésirablesRÉSUMÉ
BACKGROUND: Lingual nerve injury (LNI) is a rare complication following the use of laryngeal mask airway (LMA). The occurrence of this unexpected complication causes uncomfortable symptoms in patients and worsens their quality of life. We present an unusual case of LNI caused by the use of an LMA in percutaneous nephrolithotomy (PCNL). CASE SUMMARY: A 49-year-old man presented to our hospital with a 3-year history of intermittent left lower back pain. Abdominal computed tomography showed a 25 mm × 20 mm stone in the left renal pelvis. PCNL surgery using LMA was performed to remove the renal stone. The patient reported numbness on the tip of his tongue after the operation, but there were no signs of swelling or trauma. The patient was diagnosed with LNI after other possible causes were ruled out. The symptom of numbness eventually improved after conservative medical therapy for 1 wk. The patient completely recovered 3 wk after surgery. CONCLUSION: This is the first case report describing LNI with the use of LMA in PCNL. In our case, an inappropriate LMA size, intraoperative movement, and a specific surgical position might be potential causes of this rare complication.
RÉSUMÉ
Rice false smut, caused by the fungal pathogen Villosiclava virens, is one of the most important rice diseases in the world. Previous studies reported that the pathogen has less number of cell wall-degraded genes and attacks dominantly rice stamen filaments and extends intercellularly. To reveal why the fungus infects plant stamen filaments, inoculation test on barley was carried out with the similar protocol to rice. The experimental results showed that the fungus could penetrate quickly into barley stamen filaments and extends both intracellularly and intercellularly, usually resulting in severe damage of the stamen filament tissues. It also attacked young barley lodicules and grew intercellularly by chance. The light microscopic observations found that the epidermal and cortex cells in barley stamen filaments arranged loosely with very thick cell walls and large cell gaps. Cellulose microfibrils in barley stamen filament cell walls arranged very sparsely so that the cell walls looked like transparent. The cell walls were very soft and flexible, and often folded. However, V. virens extended dominantly in the noncellulose regions and seemed never to degrade microfibrils in barley and rice cell walls. This suggested that the unique structures of rice and barley stamen filaments should be fit for their function of elongation in anthesis, and also endow with the susceptibility to the fungus, V. virens.
Sujet(s)
Paroi cellulaire/ultrastructure , Fleurs , Hordeum , Hypocreales/ultrastructure , Oryza , Fleurs/microbiologie , Fleurs/ultrastructure , Hordeum/microbiologie , Hordeum/ultrastructure , Microscopie , Microscopie électronique à transmission , Oryza/microbiologie , Oryza/ultrastructure , Maladies des plantes/microbiologieRÉSUMÉ
The filamentous fungus Magnaporthe oryzae is the causal agent of rice blast disease. Here we show that glycogen metabolic genes play an important role in plant infection by M. oryzae. Targeted deletion of AGL1 and GPH1, which encode amyloglucosidase and glycogen phosphorylase, respectively, prevented mobilisation of glycogen stores during appressorium development and caused a significant reduction in the ability of M. oryzae to cause rice blast disease. By contrast, targeted mutation of GSN1, which encodes glycogen synthase, significantly reduced the synthesis of intracellular glycogen, but had no effect on fungal pathogenicity. We found that loss of AGL1 and GPH1 led to a reduction in expression of TPS1 and TPS3, which encode components of the trehalose-6-phosphate synthase complex, that acts as a genetic switch in M. oryzae. Tps1 responds to glucose-6-phosphate levels and the balance of NADP/NADPH to regulate virulence-associated gene expression, in association with Nmr transcriptional inhibitors. We show that deletion of the NMR3 transcriptional inhibitor gene partially restores virulence to a Δagl1Δgph1 mutant, suggesting that glycogen metabolic genes are necessary for operation of the NADPH-dependent genetic switch in M. oryzae.
Sujet(s)
Protéines fongiques/métabolisme , Glucosyltransferases/métabolisme , Glycogène/métabolisme , Magnaporthe/enzymologie , Oryza/microbiologie , Protéines fongiques/génétique , Délétion de gène , Glucosyltransferases/génétique , Glycogène/génétique , Magnaporthe/génétique , NADP/génétique , NADP/métabolismeRÉSUMÉ
Sclerotinia sclerotiorum is a filamentous fungal pathogen that can infect many economically important crops and vegetables. Alternative oxidase is the terminal oxidase of the alternative respiratory pathway in fungal mitochondria. The function of alternative oxidase was investigated in the regulation of sensitivity of S. sclerotiorum to two commercial fungicides, azoxystrobin and procymidone which have different fungitoxic mechanisms. Two isolates of S. sclerotiorum were sensitive to both fungicides. Application of salicylhydroxamic acid, a specific inhibitor of alternative oxidase, significantly increased the values of effective concentration causing 50% mycelial growth inhibition (EC50) of azoxystrobin to both S. sclerotiorum isolates, whereas notably decreased the EC50 values of procymidone. In mycelial respiration assay azoxystrobin displayed immediate inhibitory effect on cytochrome pathway capacity, but had no immediate effect on alternative pathway capacity. In contrast, procymidone showed no immediate impact on capacities of both cytochrome and alternative pathways in the mycelia. However, alternative oxidase encoding gene (aox) transcript and protein levels, alternative respiration pathway capacity of the mycelia were obviously increased by pre-treatment for 24 h with both azoxystrobin and procymidone. These results indicate that alternative oxidase was involved in the regulation of sensitivity of S. sclerotiorum to the fungicides azoxystrobin and procymidone, and that both fungicides could affect aox gene expression and the alternative respiration pathway capacity development in mycelia of this fungal pathogen.
Sujet(s)
Ascomycota/effets des médicaments et des substances chimiques , Ascomycota/enzymologie , Composés bicycliques pontés/pharmacologie , Fongicides industriels/pharmacologie , Méthacrylates/pharmacologie , Protéines mitochondriales/métabolisme , Oxidoreductases/métabolisme , Protéines végétales/métabolisme , Pyrimidines/pharmacologie , StrobilurinesRÉSUMÉ
We investigated the use of a high-voltage electrostatic system to immobilize bacterial cells or enzyme extract in alginate microcapsules for removing nonylphenol (NP) from wastewater sludge. With applied potential increased from 0 to 12kV, the gel bead diameter decreased from 950 to 250 µm. The amount of bacterial cells or enzyme extract immobilized in alginate microcapsules was greater than that in suspension, for improved tolerance to environmental loadings. Removal of NP at 2.0-20.0 mg L(-1) was greater with extract- than cell-containing microcapsules. The percentage of toxic chemicals (2.0 mg L(-1)) removed with alginate microcapsules, in descending order of magnitude, was bisphenol-F>bisphenol-A>NP>oxytetracycline>chlortetracycline>tetracycline>dibromodiphenyl ethers>tetrabromobisphenol-A>decabromodiphenyl ether.
Sujet(s)
Bacillus/cytologie , Enzymes immobilisées/métabolisme , Phénols/isolement et purification , Phénols/métabolisme , Pseudomonas/cytologie , Eaux d'égout/composition chimique , Électricité statique , Alginates/composition chimique , Bacillus/métabolisme , Dépollution biologique de l'environnement , Bioréacteurs/microbiologie , Capsules , Cellules immobilisées/métabolisme , Enzymes immobilisées/composition chimique , Pleurotus/enzymologie , Pseudomonas/métabolisme , Polluants chimiques de l'eau/isolement et purification , Polluants chimiques de l'eau/métabolismeRÉSUMÉ
Sclerotinia sclerotiorum is a cosmopolitan, filamentous, fungal pathogen that can cause serious disease in many kinds of crops. Alternative oxidase is the terminal oxidase of the alternative mitochondrial respiratory pathway in fungi and higher plants. We report the presence of this alternative pathway respiration and demonstrate its expression in two isolates of S. sclerotiorum under unstressed, normal culture conditions. Application of salicylhydroxamic acid, a specific inhibitor of alternative oxidase, severely inhibited the mycelial growth of S. sclerotiorum both on potato dextrose agar plates and in liquid culture media. Inhibition of alternative oxidase could influence the growth pattern of S. sclerotiorum, as salicylhydroxamic acid treatment induced obvious aerial mycelia growing on potato dextrose agar plates. Under the treatment with salicylhydroxamic acid, S. sclerotiorum formed sclerotia much more slowly than the control. Treatment with hydrogen peroxide in millimolar concentrations greatly decreased the growth rate of mycelia and delayed the formation of sclerotia in both tested S. sclerotiorum isolates. As well, this treatment obviously increased their alternative pathway respiration and the levels of both mRNA and protein of the alternative oxidase. These results indicate that alternative oxidase is involved in the regulation of growth, development, and resistance to oxidative stress of S. sclerotiorum.
Sujet(s)
Ascomycota/enzymologie , Ascomycota/physiologie , Protéines mitochondriales/métabolisme , Stress oxydatif , Oxidoreductases/métabolisme , Protéines végétales/métabolisme , Stress physiologique , Ascomycota/effets des médicaments et des substances chimiques , Ascomycota/croissance et développement , Milieux de culture/composition chimique , Antienzymes/métabolisme , Peroxyde d'hydrogène/toxicité , Hyphae/effets des médicaments et des substances chimiques , Hyphae/croissance et développement , Oxydants/toxicité , Salicylamides/métabolismeRÉSUMÉ
A novel organocatalytic asymmetric cyclopropanation of ß,γ-unsaturated α-ketoesters with stabilized sulfur ylides using C(2)-symmetric urea as a hydrogen-bond catalyst has been described. This reaction allows an efficient access to 1,2,3-trisubstituted cyclopropane derivatives in moderate to good yields with up to 16:1 dr and 90:10 er under mild reaction conditions. The mechanism study proved that the high stereoinduction originated from the cooperative effect of the hydrogen-bond catalyst.
Sujet(s)
Cyclopropanes/composition chimique , Cétones/composition chimique , Soufre/composition chimique , Urée/composition chimique , Catalyse , Cristallographie aux rayons X , Cyclisation , Esters , Spectroscopie par résonance magnétique , Structure moléculaire , StéréoisomérieRÉSUMÉ
The Magnaporthe oryzae genome contains two homologous CYP51 genes, MoCYP51A and MoCYP51B, that putatively encode sterol 14α-demethylase enzymes. Targeted gene deletion mutants of MoCYP51A were morphologically indistinguishable from the isogenic wild type M. oryzae strain Guy11 in vegetative culture, but were impaired in both conidiation and virulence. Deletion of MoCYP51B did not result in any obvious phenotypic changes compared with Guy11. The Δmocyp51A mutants were also highly sensitive to sterol demethylation inhibitor (DMI) fungicides, while Δmocyp51B mutants were unchanged in their sensitivity to these fungicides. Expression of both MoCYP51A and MoCYP51B was significantly induced by exposure to DMI fungicides. Analysis of intracellular localization of MoCyp51A showed that MoCyp51A was mainly localized to the cytoplasm of hyphae and conidia. Taken together, our results indicate that MoCYP51A is required for efficient conidiogenesis, full virulence and for mediating DMI sensitivity by the rice blast fungus.
Sujet(s)
Inhibiteurs de la 14-alpha déméthylase/métabolisme , Antifongiques/métabolisme , Magnaporthe/enzymologie , Oryza/microbiologie , Maladies des plantes/microbiologie , Spores fongiques/croissance et développement , Sterol 14-demethylase/métabolisme , Cytoplasme/enzymologie , Délétion de gène , Hyphae/enzymologie , Isoenzymes/génétique , Isoenzymes/métabolisme , Magnaporthe/effets des médicaments et des substances chimiques , Magnaporthe/pathogénicité , Magnaporthe/physiologie , Tests de sensibilité microbienne , Spores fongiques/enzymologie , Sterol 14-demethylase/génétique , VirulenceRÉSUMÉ
An insertional mutagenesis screen was used to investigate the biology of plant infection by the devastating rice blast pathogen, Magnaporthe oryzae. Here, we report the identification of a new mutant, LY-130, which is defective in multiple steps during infection-related morphogenesis and pathogenicity. Analysis of the mutation confirmed an insertion into gene MoRIC8, which encodes a 480-amino-acid protein that is a putative homologue of the Ric8 regulator of GTP-binding protein (G-protein) signaling, previously described in animals. Targeted gene deletion mutants of MoRIC8 were nonpathogenic and impaired in cellular differentiation associated with sporulation, sexual development, and plant infection. MoRic8 physically interacts with the Galpha subunit MagB in yeast two-hybrid assays and appears to act upstream of the cyclic AMP response pathway that is necessary for appressorium morphogenesis. Taken together, our results indicate that MoRic8 may act as a novel regulator of the G-protein signaling during infection-related development of rice blast fungus M. oryzae.
Sujet(s)
Protéines fongiques/métabolisme , Protéines G/métabolisme , Magnaporthe/métabolisme , Transduction du signal , Séquence d'acides aminés , AMP cyclique/métabolisme , Cytosol/métabolisme , Protéines fongiques/classification , Protéines fongiques/génétique , Protéines G/génétique , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme , Hordeum/microbiologie , Magnaporthe/génétique , Magnaporthe/pathogénicité , Microscopie de fluorescence , Données de séquences moléculaires , Mutation , Mycelium/génétique , Mycelium/croissance et développement , Mycelium/métabolisme , Oryza/microbiologie , Phylogenèse , Maladies des plantes/microbiologie , Liaison aux protéines , Similitude de séquences d'acides aminés , Techniques de double hybride , Virulence/génétiqueRÉSUMÉ
OBJECTIVE: To evaluate the clinical efficacy of treatment on the cases of severe hallux valgus by the first metatarsal basal osteotomy combined with Chevron-Gerbert operation. METHODS: From June 2004 to August 2008, 37 cases of severe hallux valgus (66 feet) underwent first metatarsal basal osteotomy combined with Chevron-Gerbert operation. There were 5 males (10 feet) and 21 females (38 feet), aged 21 - 76 years (mean 58 years). For all patients with follow-up, radiographic measurements of frontal and lateral position of foot were taken to measure the hallux valgus angle (HVA), the IMA (intermetatarsal angle) and the proximal articular set angle (PASA) preoperatively, postoperatively and in follow-up respectively. The measuring results were compared among the preoperative, the 6-week postoperative and the final follow-up. At the same time the patients were evaluated with the AOFAS Maryland score. RESULTS: Of the original 37 patients, 26 patients (48 feet) were followed up. The mean durations of follow-up was 2.3 years (range from 1 to 4 years). At final follow-up, HVA corrected 25.6° ± 3.8°, IMA corrected 8.6° ± 2.4°, and PASA corrected 4.7° ± 4.2°. According to AOFAS rating system, 91.7% patients were rated as excellent or good with excellent in 15 patients (28 feet), good in 8 patients (16 feet), and fair in 3 patients (4 feet). CONCLUSIONS: First metatarsal basal osteotomy combined with Chevron-Gerbert operation has good efficacy to the patients with severe hallux valgus. However there are disadvantages such as complexity relatively for multi-stage osteotomy and internal fixation.
Sujet(s)
Hallux valgus/chirurgie , Os du métatarse/chirurgie , Ostéotomie/méthodes , Adulte , Sujet âgé , Femelle , Études de suivi , Humains , Mâle , Adulte d'âge moyen , Résultat thérapeutique , Jeune adulteRÉSUMÉ
OBJECTIVE: To analyse the vola stress change after operation of wrop-around flap for thumb reconstruction,to know the influence of vola pressure change after operation of wrop-around flap. METHODS: From 1996 to 2004, 23 patients after the operation of wrop-around flap for thumb reconstruction were measured the entire footprint, the vola stress of single foot and double feet on static state and walking status. There were 16 males and 7 females,with a mean age of 23.7 years (17 to 42 years). The time from operation to measuring was 1.6 to 6 years (meana 3.8 years). The results of measuring were analyzed. RESULTS: Whether static footprint analysis or dynamic mechanical analysis, the plantar pressure distribution of donated foot were obviously different with those of the opposite site. The weight bearing of heel and the fourth and fifth metatarsal heads were nearly consistent with normal foot. But the former feet were obviously different. The weight bearing of the first metatarsal head was obviously lower than normal foot. And the weight bearing of the second and third metatarsal heads were obviously higher than normal foot. CONCLUSION: The operation of wrop-around flap for thumb reconstruction has advantage of the cosmesis and function of the reconstructed thumbs nearly consistent with normal thumbs. But the operation influences the postoperative foot pressure.
Sujet(s)
/méthodes , Contrainte mécanique , Lambeaux chirurgicaux , Orteils/chirurgie , Adolescent , Adulte , Femelle , Humains , Mâle , Posture , Orteils/anatomopathologie , Orteils/physiopathologie , Mise en charge , Jeune adulteRÉSUMÉ
Trehalose fulfils a wide variety of functions in cells, acting as a stress protectant, storage carbohydrate and compatible solute. Recent evidence, however, indicates that trehalose metabolism may exert important regulatory roles in the development of multicellular eukaryotes. Here, we show that in the plant pathogenic fungus Magnaporthe grisea trehalose-6-phosphate (T6P) synthase (Tps1) is responsible for regulating the pentose phosphate pathway, intracellular levels of NADPH and fungal virulence. Tps1 integrates glucose-6-phosphate (G6P) metabolism with nitrogen source utilisation, and thereby regulates the activity of nitrate reductase. Activity of Tps1 requires an associated regulator protein Tps3, which is also necessary for pathogenicity. Tps1 controls expression of the nitrogen metabolite repressor gene, NMR1, and is required for expression of virulence-associated genes. Functional analysis of Tps1 indicates that its regulatory functions are associated with binding of G6P, but independent of Tps1 catalytic activity. Taken together, these results demonstrate that Tps1 is a central regulator for integration of carbon and nitrogen metabolism, and plays a pivotal role in the establishment of plant disease.
Sujet(s)
Champignons/métabolisme , Glucosyltransferases/physiologie , Azote/métabolisme , Voie des pentoses phosphates , Champignons/génétique , Champignons/pathogénicité , Gènes fongiques , NADP/métabolisme , VirulenceRÉSUMÉ
One of the first responses of plants to microbial attack is the production of extracellular superoxide surrounding infection sites. Here, we report that Magnaporthe grisea, the causal agent of rice blast disease, undergoes an oxidative burst of its own during plant infection, which is associated with its development of specialized infection structures called appressoria. Scavenging of these oxygen radicals significantly delayed the development of appressoria and altered their morphology. We targeted two superoxide-generating NADPH oxidase-encoding genes, Nox1 and Nox2, and demonstrated genetically, that each is independently required for pathogenicity of M. grisea. Deltanox1 and Deltanox2 mutants are incapable of causing plant disease because of an inability to bring about appressorium-mediated cuticle penetration. The initiation of rice blast disease therefore requires production of superoxide by the invading pathogen.
Sujet(s)
Magnaporthe/enzymologie , NADPH oxidase/métabolisme , Oryza/microbiologie , Maladies des plantes/microbiologie , Espèces réactives de l'oxygène/métabolisme , Magnaporthe/génétique , Magnaporthe/métabolisme , Magnaporthe/pathogénicité , NADPH oxidase/génétique , NADPH oxidase/physiologie , Superoxydes/métabolismeRÉSUMÉ
The rice blast fungus Magnaporthe grisea infects plants by means of specialized infection structures known as appressoria. Turgor generated in the appressorium provides the invasive force that allows the fungus to breach the leaf cuticle with a narrow-penetration hypha gaining entry to the underlying epidermal cell. Appressorium maturation in M. grisea involves mass transfer of lipid bodies to the developing appressorium, coupled to autophagic cell death in the conidium and rapid lipolysis at the onset of appressorial turgor generation. Here, we report identification of the principal components of lipid metabolism in M. grisea based on genome sequence analysis. We show that deletion of any of the eight putative intracellular triacylglycerol lipase-encoding genes from the fungus is insufficient to prevent plant infection, highlighting the complexity and redundancy associated with appressorial lipolysis. In contrast, we demonstrate that a peroxisomally located multifunctional, fatty acid beta-oxidation enzyme is critical to appressorium physiology, and blocking peroxisomal biogenesis prevents plant infection. Taken together, our results indicate that, although triacylglycerol breakdown in the appressorium involves the concerted action of several lipases, fatty acid metabolism and consequent generation of acetyl CoA are necessary for M. grisea to complete its prepenetration phase of development and enter the host plant.
Sujet(s)
Acides gras/métabolisme , Métabolisme lipidique/physiologie , Magnaporthe/métabolisme , Péroxysomes/métabolisme , Plantes/microbiologie , Paroi cellulaire/métabolisme , Paroi cellulaire/ultrastructure , Protéines fongiques/génétique , Protéines fongiques/métabolisme , Régulation de l'expression des gènes fongiques , Génome fongique , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme , Triacylglycerol lipase/génétique , Triacylglycerol lipase/métabolisme , Magnaporthe/génétique , Magnaporthe/croissance et développement , Microscopie électronique , Microscopie de fluorescence , Mutation , Oignons/microbiologie , Oryza/microbiologie , Oxydoréduction , Péroxysomes/enzymologie , Maladies des plantes/microbiologieRÉSUMÉ
Magnaporthe grisea, the causal agent of rice blast disease, invades plant tissue due to the action of specialized infection structures called appressoria, which are used to breach the leaf cuticle and allow development of intracellular, infectious hyphae. In this report we demonstrate that peroxisomal carnitine acetyl transferase (CAT) activity is necessary for appressorium function, and in particular, for the elaboration of primary penetration hyphae. The major CAT activity in M. grisea is encoded by the PTH2 gene, which shows elevated expression in response to acetate and lipid, and is regulated by the cyclic AMP response pathway. Furthermore, a Pth2-GFP fusion protein colocalizes with a peroxisomal marker protein. Targeted deletion of PTH2, generated mutants that were completely non-pathogenic, lacked CAT activity and were unable to utilize a range of lipid substrates. The impairment of appressorium function in Deltapth2 was associated with a delay in lipid reserve mobilization from germ tubes into developing infection cells, and abnormal chitin distribution in infection structures. Addition of glucose to Deltapth2 mutants partially restored the ability to cause rice blast disease and lipid reserve mobilization. Taken together, our findings provide evidence that Pth2 plays a role in the generation of acetyl CoA pools necessary for appressorium function and rapid elaboration of penetration hyphae during host infection.
Sujet(s)
Carnitine O-acetyltransferase/métabolisme , Protéines fongiques/métabolisme , Hyphae/croissance et développement , Magnaporthe/enzymologie , Carnitine O-acetyltransferase/génétique , Chitine/métabolisme , Protéines fongiques/génétique , Régulation de l'expression des gènes au cours du développement/génétique , Régulation de l'expression des gènes fongiques/génétique , Glucose/pharmacologie , Protéines à fluorescence verte/génétique , Protéines à fluorescence verte/métabolisme , Hordeum/cytologie , Hordeum/microbiologie , Hyphae/métabolisme , Hyphae/ultrastructure , Lipides/analyse , Magnaporthe/effets des médicaments et des substances chimiques , Magnaporthe/croissance et développement , Microscopie électronique à transmission , Mutation , Oryza/cytologie , Oryza/microbiologie , Péroxysomes/enzymologie , Maladies des plantes/microbiologie , Feuilles de plante/cytologie , Feuilles de plante/microbiologie , Délétion de séquence , Facteurs tempsRÉSUMÉ
OBJECTIVES: To observe the cavernosal nerve dysfunction of diabetic Sprague Dawley rats. METHODS: Thirty-five Sprague-Dawley rats were divided randomly into diabetes model group(n = 25) and normal group(n = 10). Diabetes model was established by administration of streptozotocin (63 mg/kg) in single intraperitoneal dosing. Giving single wave stimulus, corpus cavernosal nerve was measured for its latent period of reaction and myopotential. RESULTS: Compared with other groups, diabetic rats had longer reflection latent period(P < 0.01) and higher corpus cavernosum smooth muscle myopotential (P < 0.01). CONCLUSIONS: The results indicate that corpus cavernosal nerve dysfunction may play an important role in the erectile dysfunction of diabetic rats.
Sujet(s)
Diabète expérimental/physiopathologie , Pénis/innervation , Animaux , Diabète expérimental/complications , Dysfonctionnement érectile/étiologie , Potentiels évoqués , Mâle , Monoxyde d'azote/physiologie , Rats , Rat Sprague-Dawley , StreptozocineRÉSUMÉ
We describe the isolation and characterization of ICL1 from the rice blast fungus Magnaporthe grisea, a gene that encodes isocitrate lyase, one of the principal enzymes of the glyoxylate cycle. ICL1 shows elevated expression during development of infection structures and cuticle penetration, and a targeted gene replacement showed that the gene is required for full virulence by M. grisea. In particular, we found that the prepenetration stage of development, before entry into plant tissue, is affected by loss of the glyoxylate cycle. There is a delay in germination, infection-related development and cuticle penetration in Delta icl1 mutants. Recent reports have shown the importance of the glyoxylate cycle in the virulence of the human pathogenic fungus Candida albicans and the bacterial pathogen Mycobacterium tuberculosis. Our results indicate that the glyoxylate cycle is also important in this plant pathogenic fungus, demonstrating the widespread utility of the pathway in microbial pathogenesis.