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1.
Ann Surg Oncol ; 28(9): 5341-5348, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34109511

RESUMO

PURPOSE: This study was designed to assess the relationship between nerve-sparing (NS) status, positive surgical margin (PSM) location, and biochemical recurrence (BCR) based on a multicenter, radical prostatectomy (RP) database. METHODS: We retrospectively reviewed data from 726 patients who underwent RP without any neoadjuvant or adjuvant treatment between 2010 and 2014. We statistically assessed the impact of NS sides on PSM location and BCR. RESULTS: PSM rates were 21.9% in the 726 patients studied, 13.2% in patients with ≤pT2, and 46.8% in patients with ≥pT3. Regarding PSM locations, the anterior-apex (AA) was the most common site for PSM (43.3%). After adjusting for confounding factors, bilateral nerve sparing (BNS) had a significantly higher odds ratio of PSM than the absence of NS did (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.85-4.99). In the UNS RP in patients with ≤pT2, non-AA PSM on the non-NS side was significantly higher than that on the NS side (92.9% vs. 45.5%, p = 0.009). In all patients, 5.8% experienced BCR during a median follow-up of 43.5 months. PSM was significantly associated with BCR-free survival in patients with ≤pT2 (p = 0.013), but not in patients with ≥pT3 (p = 0.185). Non-AA PSM at the non-NS side was an independent risk factor for BCR (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.12-5.85), whereas AA PSMs, including NS/non-NS sides and non-AA PSM at the NS side, were not associated with BCR-free survival. CONCLUSIONS: Avoidance of non-AA PSM on the non-NS side may be rather important for maintaining BCR-free survival after RP.


Assuntos
Margens de Excisão , Neoplasias da Próstata , Humanos , Masculino , Recidiva Local de Neoplasia , Antígeno Prostático Específico , Prostatectomia , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos
2.
BMC Cancer ; 20(1): 302, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32293349

RESUMO

BACKGROUND: Although docetaxel-based chemohormonal therapy (CHT) is one of the standard treatments for castration-resistant prostate cancer (CRPC), pertinent biomarkers and precise mechanisms involved in the resistance for CHT for CRPC remain unknown. We investigated the relationship between chemohormonal resistance and the expression of steroid receptors and Hippo pathway proteins using a docetaxel-resistant prostate cancer (PCa) cell line and human PCa tissues in patients who underwent surgery with and without neoadjuvant therapy. METHODS: A docetaxel-resistant subline (22Rv1-DR) was generated to assess Hippo pathway protein expression and the effect of YAP1 inhibition on cellular characteristics. A tissue microarray with 203 cores from 70 high-risk localized PCa tissues was performed to assess steroid receptor and Hippo pathway protein expressions. RESULTS: Nuclear YAP (nYAP) expression was higher in 22RV-1-DR than in parental 22Rv-1 and YAP1 knockdown suppressed cell proliferation of 22Rv1-DR. Steroid receptor and Hippo pathway protein expressions varied among three different neoadjuvant groups, and nYAP1 expression was the highest in the CHT group. The patients with high nYAP in residual cancer after neoadjuvant CHT had a significantly higher biochemical recurrence (BCR) rate than those with low nYAP1. On multivariate analysis, the high nYAP1 was an independent prognostic factor for BCR. CONCLUSIONS: nYAP expression is a potential biomarker in high-risk patients treated with docetaxel-based CHT. Steroid receptors and Hippo pathway proteins may play a role in the chemohormonal resistance in advanced PCa.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Docetaxel/uso terapêutico , Neoplasia Residual/metabolismo , Neoplasias da Próstata/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal/genética , Linhagem Celular Tumoral , Núcleo Celular , Proliferação de Células , Técnicas de Silenciamento de Genes , Humanos , Masculino , Terapia Neoadjuvante , Neoplasia Residual/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Análise de Sobrevida , Análise Serial de Tecidos , Fatores de Transcrição/genética , Proteínas de Sinalização YAP
3.
Hinyokika Kiyo ; 62(12): 651-655, 2016 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-28103660

RESUMO

A 58-year-old male with alcoholic liver cirrhosis and a 58-year-old male with diabetes mellitus presented with high fever and urinary retention. Prostatic abscess was diagnosed by a computed tomography scan, which showed fluid collection in the prostate in both patients. Despite systematic antibiotic therapies, urinary retention persisted even after fever diminished. They underwent prostatic abscess drainage by transurethral resection (TUR). Urinary retention was released, and the recurrence of prostatic abscess has not been observed after TUR.


Assuntos
Abscesso/cirurgia , Doenças Prostáticas/cirurgia , Retenção Urinária/etiologia , Abscesso/complicações , Abscesso/diagnóstico por imagem , Drenagem , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Prostáticas/complicações , Doenças Prostáticas/diagnóstico por imagem , Doenças Prostáticas/patologia , Tomografia Computadorizada por Raios X
4.
Phytopathology ; 103(6): 623-32, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23324047

RESUMO

Leveillula taurica is an obligate fungal pathogen that causes powdery mildew disease on a broad range of plants, including important crops such as pepper, tomato, eggplant, onion, cotton, and so on. The early stage of this disease is difficult to diagnose and the disease can easily spread unobserved; for example, in pepper and tomato production fields and greenhouses. The objective of this study was to develop a detection and quantification method of L. taurica biomass in pepper leaves with special regard to the early stages of infection. We monitored the development of the disease to time the infection process on the leaf surface as well as inside the pepper leaves. The initial and final steps of the infection taking place on the leaf surface were consecutively observed using a dissecting microscope and a scanning electron microscope. The development of the intercellular mycelium in the mesophyll was followed by light and transmission electron microscopy. A pair of L. taurica-specific primers was designed based on the internal transcribed spacer sequence of L. taurica and used in real-time polymerase chain reaction (PCR) assay to quantify the fungal DNA during infection. The specificity of this assay was confirmed by testing the primer pair with DNA from host plants and also from another powdery mildew species, Oidium neolycopersici, infecting tomato. A standard curve was obtained for absolute quantification of L. taurica biomass. In addition, we tested a relative quantification method by using a plant gene as reference and the obtained results were compared with the visual disease index scoring. The real-time PCR assay for L. taurica provides a valuable tool for detection and quantification of this pathogen in breeding activities as well in plant-microbe interaction studies.


Assuntos
Ascomicetos/isolamento & purificação , Capsicum/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Ascomicetos/fisiologia , DNA Fúngico , Microscopia Eletrônica de Transmissão , Folhas de Planta/ultraestrutura , Reação em Cadeia da Polimerase em Tempo Real
5.
Mol Plant Microbe Interact ; 25(3): 372-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22074347

RESUMO

Hypersensitive response (HR) of plant cells to the attack of pathogens induces resistance to subsequent attacks by a broad spectrum of pathogens, leading to acquired resistance. In this study, we characterized the localized acquired resistance (LAR) in the epidermal cells of tomato. First, we report the discovery of a new isolate of tomato powdery mildew occurring in Japan, KTP-02, which has a different virulence spectrum compared with the previously-characterized isolate, KTP-01. Using these two isolates, we investigated LAR phenomenon in the epidermal cells of tomato plants carrying the Ol-4 resistance gene. Ol-4 encodes a nucleotide-binding site leucine-rich repeat protein that triggers HR in the epidermal cells in response to KTP-01 but not KTP-02. We mounted a single conidium of KTP-01 on a single tomato epidermal cell and then monitored the progress of HR in that cell by live microscopy. Once HR occurred in that cell, we mounted a single conidium of KTP-02 on cells adjacent to or at one-cell distance from the first challenged cells, in different time points. With a digital microscope, we consecutively tracked the progress of HR (i.e., induction of LAR) in those cells. Results showed that, in tomato plants carrying the Ol-4 gene, HR to KTP-01 results in induction of HR in the adjacent epidermal cells challenged with KTP-02. Our results show that LAR can be triggered only in adjacent cell layer and lasts 24 to 48 h after HR occurred in the first cell. We did not observe the reverse phenomenon, induced susceptibility to KTP-01 by KTP-02. Altogether, we report an advanced technique for investigating LAR phenomena, and provide data on spatiotemporal characteristics of LAR in tomato epidermal cells.


Assuntos
Ascomicetos/patogenicidade , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Solanum lycopersicum/imunologia , Solanum lycopersicum/microbiologia , Ascomicetos/genética , Ascomicetos/imunologia , Sequência de Bases , Morte Celular , DNA de Plantas/química , DNA de Plantas/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Dados de Sequência Molecular , Filogenia , Doenças das Plantas/microbiologia , Epiderme Vegetal/microbiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Análise de Sequência de DNA
6.
Insects ; 13(3)2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35323551

RESUMO

In the present study, we analyzed negative electricity released from insects captured by an electric field (EF)-producing apparatus. Adult houseflies (Musca domestica) were used as the model insect. The EF producer consisted of a negatively charged polyvinyl chloride membrane-insulated iron plate (N-PIP) and a non-insulated grounded iron plate (GIP) paralleled with the N-PIP. An EF was formed in the space between the plates. A housefly placed on the GIP was physically attracted to the N-PIP, and electricity released from the fly was detected as a specific transient electric current at the time of attraction and during subsequent confinement of the fly to the N-PIP. The magnitude of the insect-derived electric current became larger as the voltage applied to the N-PIP increased. We determined the total amount of electric current and confinement time within the apparatus necessary to kill all captured flies. These results demonstrate the insecticidal function and insect-capturing ability of the EF-producing apparatus.

7.
Plants (Basel) ; 11(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36559568

RESUMO

Powdery mildew fungi produce progeny conidia on conidiophores, and promote the spread of powdery mildew diseases by dispersal of the conidia from conidiophores in the natural environment. To gain insights and devise strategies for preventing the spread of powdery mildew infection, it is important to clarify the ecological mechanism of conidial dispersal from conidiophores. In this study, all of the progeny conidia released from single colonies of strawberry powdery mildew fungus (Podosphaera aphanis (Wallroth) U. Braun and S. Takamatsu var. aphanis KSP-7N) on true leaves of living strawberry plants (Fragaria × ananassa Duchesne ex Rozier cv. Sagahonoka) were consecutively collected over the lifetime of the colony with an electrostatic rotational spore collector (insulator drum) under greenhouse conditions, and counted under a high-fidelity digital microscope. The insulator drum consisted of a round plastic container, copper film, thin and transparent collector film, electrostatic voltage generator, and timer mechanism. When negative charge was supplied from the voltage generator to the copper film, the collector film created an attractive force to trap conidia. The electrostatically activated collector film successfully attracted progeny conidia released from the colony. Experiment was carried out at just one colony on one leaf for each month (in February, May, July, October, November, and December in 2021), respectively. Each collector film was exchanged for a new collector film at 24 h intervals until KSP-7N ceased to release progeny conidia from single colonies. Collection experiments were carried out to estimate the total number of conidia released from a single KSP-7N colony over a 35-45-day period after inoculation. During the fungal lifetime, KSP-7N released an average of 6.7 × 104 conidia from each of the single colonies at approximately 816 h. In addition, conidial release from KSP-7N colonies was largely affected by the light intensity and day length throughout a year; the number of conidia released from single KSP-7N colonies in night-time was clearly smaller than that in daytime, and the time of conidial release from single KSP-7N colonies was shorter by approximately 2 to 4 h in autumn and winter than in spring and summer. The ecological characteristics related to conidial releases from KSP-7N colonies will be helpful information for us to successfully suppress the spread of strawberry powdery mildews onto host plants under greenhouse conditions.

8.
Insects ; 12(11)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34821761

RESUMO

Our aim was to develop an electrostatic apparatus to lure and capture silverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) that invade tomato greenhouses. A double-charged dipolar electric field producer (DD-EFP) was constructed by filling water in two identical transparent soft polyvinyl chloride tubes arrayed in parallel with fixed separation, and then, inserting the probes of grounded negative and positive voltage generators into the water of the two tubes to generate negatively and positively charged waters, respectively. These charged waters electrified the outer surfaces of the opposite tubes via dielectric polarization. An electric field formed between the oppositely charged tubes. To lure these phototactic insects, the water was colored yellow using watercolor paste, then introduced into the transparent insulator tubes to construct the yellow-colored DD-EFP. This apparatus lured insects in a manner similar to commercially available yellow sticky traps. The yellow-colored DD-EFP was easily placed as a movable upright screen along the plants, such that invading pests were preferentially attracted to the trap before reaching the plants. Furthermore, pests settling on the plants were attracted to the apparatus, which used a plant-tapping method to drive them off the plants. Our study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses.

9.
Insects ; 12(7)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34357281

RESUMO

This study analysed the mechanism of avoidance behaviour by adult Turkestan cockroaches (Shelfordella lateralis Walker) in response to a static electric field (S-EF) formed in the space between a negatively charged polyvinyl chloride-insulated iron plate (N-PIP) and a grounded metal net (G-MN). The negative surface charge supplied to the iron plate by a voltage generator caused the G-MN to polarise positively via electrostatic induction. In the S-EF, the negative charge of the N-PIP created a repulsive force that pushed free electrons in the field toward the ground via the G-MN. When insects released in the space surrounded by the S-EF inserted their antennae into the S-EF, they pulled them back reflexively and moved backward. The analysis indicated that an electric current flowed transiently toward the ground when an insect inserted its antennae into the S-EF. The insect became positively charged via this discharge and was attracted to the opposite pole (N-PIP). In response to this attractive force, the insect pulled its antennae back quickly. The positive electrification caused by the removal of free electrons from the antenna tip triggered the avoidance behaviour.

10.
Insects ; 12(6)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199841

RESUMO

We developed an arc discharge exposer (ADE) that kills rice weevils nesting in dried rice. The ADE features multiple identical metal plates, half of these are linked to a voltage generator and the others are grounded. The plates were arrayed in parallel and an electric field formed between them. Any insect entering the field was arced from the negatively charged plate and killed. The ADE was placed on a vessel containing pest-infested rice grains; the insects were lured out of the grains by mechanically vibrating the vessel. When rice grains move, insects tend to climb upward, thus, the weevils were effectively removed. Our electrostatic apparatus is easy to construct and could be used to control pests in stored rice.

11.
Artigo em Inglês | MEDLINE | ID: mdl-34066356

RESUMO

The purpose of this study was to develop a simple electrostatic apparatus to precipitate virus particles spread via droplet transmission, which is especially significant in the context of the recent coronavirus disease 2019 (COVID-19) pandemic. The bacteriophage φ6 of Pseudomonas syringae was used as a model of the COVID-19 virus because of its similar structure and safety in experiments. The apparatus consisted of a spiked, perforated stainless plate (S-PSP) linked to a direct-current voltage generator to supply negative charge to the spike tips and a vessel with water (G-water) linked to a ground line. The S-PSP and G-water surface were paralleled at a definite interval. Negative charge supplied to the spike tips positively polarised the G-water by electrostatic induction to form an electric field between them in which ionic wind and negative ions were generated. Bacteriophage-containing water was atomised with a nebuliser and introduced into the electric field. The mist particles were ionised by the negative ions and attracted to the opposite pole (G-water). This apparatus demonstrated a prominent ability to capture phage-containing mist particles of the same sizes as respiratory droplets and aerosols regardless of the phage concentration of the mist particles. The trapped phages were successfully sterilised using ozone bubbling. Thus, the present study provides an effective system for eliminating droplet transmission of viral pathogens from public spaces.


Assuntos
COVID-19 , Aerossóis , Humanos , Pandemias , SARS-CoV-2 , Eletricidade Estática , Vírion
12.
PLoS One ; 16(5): e0251444, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33974648

RESUMO

A total of 26 Ampelomyces strains were isolated from mycelia of six different powdery mildew species that naturally infected their host plants in Japan. These were characterized based on morphological characteristics and sequences of ribosomal DNA internal transcribed spacer (rDNA-ITS) regions and actin gene (ACT) fragments. Collected strains represented six different genotypes and were accommodated in three different clades of the genus Ampelomyces. Morphology of the strains agreed with that of other Ampelomyces strains, but none of the examined characters were associated with any groups identified in the genetic analysis. Five powdery mildew species were inoculated with eight selected Ampelomyces strains to study their mycoparasitic activity. In the inoculation experiments, all Ampelomyces strains successfully infected all tested powdery mildew species, and showed no significant differences in their mycoparasitic activity as determined by the number of Ampelomyces pycnidia developed in powdery mildew colonies. The mycoparasitic interaction between the eight selected Ampelomyces strains and the tomato powdery mildew fungus (Pseudoidium neolycopersici strain KTP-03) was studied experimentally in the laboratory using digital microscopic technologies. It was documented that the spores of the mycoparasites germinated on tomato leaves and their hyphae penetrated the hyphae of Ps. neolycopersici. Ampelomyces hyphae continued their growth internally, which initiated the atrophy of the powdery mildew conidiophores 5 days post inoculation (dpi); caused atrophy 6 dpi; and complete collapse of the parasitized conidiphores 7 dpi. Ampelomyces strains produced new intracellular pycnidia in Ps. neolycopersici conidiophores ca. 8-10 dpi, when Ps. neolycopersici hyphae were successfully destroyed by the mycoparasitic strain. Mature pycnidia released spores ca. 10-14 dpi, which became the sources of subsequent infections of the intact powdery mildew hyphae. Mature pycnidia contained each ca. 200 to 1,500 spores depending on the mycohost species and Ampelomyces strain. This is the first detailed analysis of Ampelomyces strains isolated in Japan, and the first timing and quantification of mycoparasitism of Ps. neolycopersici on tomato by phylogenetically diverse Ampelomyces strains using digital microscopic technologies. The developed model system is useful for future biocontrol and ecological studies on Ampelomyces mycoparasites.


Assuntos
Ascomicetos/isolamento & purificação , Controle Biológico de Vetores , Solanum lycopersicum/microbiologia , Ascomicetos/classificação , Ascomicetos/fisiologia , Ascomicetos/ultraestrutura , Genes Fúngicos , Especificidade de Hospedeiro , Processamento de Imagem Assistida por Computador , Japão , Filogenia , Plântula/microbiologia , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Esporos Fúngicos/ultraestrutura , Fatores de Tempo , Tricomas/microbiologia
13.
Insects ; 11(12)2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33287266

RESUMO

An electrostatic apparatus was developed to control weeds and houseflies emerging from ground soil in a greenhouse simultaneously. Identical iron plates were placed in parallel at a defined interval and fixed in an iron frame. Two sets of fixed iron plates were used, one for weed control and one for fly control. For weed control, all of the iron plates were negatively charged, and negative charges accumulated on the plates were released to weed shoots through arc discharge. Houseflies were introduced into the space between the negatively charged and grounded plates, then subjected to arc discharge from the charged plates. Both plant shoots and adult houseflies are electrically conductive; thus, they were killed by discharge-exposure in the electric field between the charged iron plate and the ground soil, and between the charged and grounded plates, respectively. In practical use, these two devices were assembled as a two-level apparatus for simultaneous control of both targets. Several apparatuses were linked together, which increased the total electricity charge on the plates and produced a stronger discharge force sufficient to kill all targets. Thus, this study provides an electrostatics-based pest-control method for pesticide-independent greenhouse farming.

14.
Insects ; 11(3)2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32188072

RESUMO

The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-ascending-descending action by the insect, which was highly reproducible and precisely corresponded to the changed expansion of the electric field. Other pole-climbing insects including the cigarette beetle (Lasioderma serricorne), which was shown to adopt the same behavior.

15.
Int Cancer Conf J ; 9(2): 82-87, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32257759

RESUMO

We present the case of a synchronous bilateral low-grade upper-tract urothelial carcinoma patient who underwent left nephroureterectomy and right total ureterectomy with ileal ureteric replacement resulting in a favorable prognosis. A 66-year-old male presented with bilateral hydronephrosis. Computed tomography revealed left pelvic and right upper-middle ureteral tumors with no lymph node swelling or distant metastasis. The patient underwent a left nephroureterectomy with a bladder cuff, and histopathology revealed a low-grade urothelial carcinoma. Considering the contralateral low-grade nature as revealed in histopathology and the right retrograde ureterography being noninvasive, he underwent a right total ureterectomy with ileal ureteric replacement. Histopathology of the right ureter revealed a low-grade urothelial carcinoma. The patient successfully avoided an anephric status without renal function deterioration for 4 years with a transurethral resection for a recurrent small papillary bladder tumor on 18 months after the total ureterectomy.

16.
Artigo em Inglês | MEDLINE | ID: mdl-28098835

RESUMO

An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica, from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure.


Assuntos
Acessibilidade Arquitetônica , Cryptomeria/efeitos adversos , Pólen/efeitos adversos , Prevenção Primária/instrumentação , Rinite Alérgica Sazonal/etiologia , Rinite Alérgica Sazonal/prevenção & controle , Eletricidade Estática , Poluentes Atmosféricos/efeitos adversos , Alérgenos/efeitos adversos , Feminino , Humanos , Masculino , Pólen/imunologia
17.
Phytopathology ; 96(9): 967-74, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18944052

RESUMO

ABSTRACT In an attempt to physically protect greenhouse tomato plants from the powdery mildew fungus Oidium neolycopersici, we developed a new electrostatic spore precipitator in which a copper wire conductor is linked to an electrostatic generator and covered with a transparent acrylic cylinder (insulator). The conductor was negatively charged by the generator, and the electrostatic field created by the conductor was used to dielectrically polarize the insulator cylinder. The dielectrically polarized cylinder also produced an electrostatic force without a spark discharge. This force was directly proportional to the potential applied to the conductor and was used to attract conidia of the pathogen. The efficacy of this spore precipitator in protecting hydroponically cultured tomato plants from powdery mildew was evaluated in the greenhouse. The hydroponic culture troughs were covered with a cubic frame installed with the spore precipitator, and the disease progress on precipitator-guarded and unguarded seedlings was traced after the conidia were disseminated mechanically from inoculum on tomato plants. Seedlings in the guarded troughs remained uninfected during the entire experiment, in spite of rapid spread of the disease to all leaves of the unguarded seedlings.

18.
J Biochem ; 137(2): 235-42, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15749838

RESUMO

Family 19 chitinase from Aeromonas sp. No.10S-24 (72.6 kDa) is composed of two chitin-binding domains (ChBDs), two proline- and threonine-rich (PT-rich) linkers, and a catalytic domain. The purified enzyme was labile in a standard buffer condition and spontaneously degraded into a 46-kDa fragment upon storage at 4 degrees C. The N-terminal sequence of the 46-kDa fragment was found to correspond to the sequence of the C-terminal region of the second PT-rich linker, indicating that the 46-kDa fragment is produced by truncation of the two ChBDs and the two PT-rich linkers from the mature protein, and consists only of the catalytic domain. The hydrolytic activities toward insoluble and soluble substrates were significantly reduced by the truncation of two ChBDs. In addition, antifungal activity determined from the digestion rate of haustoria of powdery mildew was reduced by the ChBD truncation. Although the profile of the time-course of N-acetylglucosamine hexasaccharide [(GlcNAc)6] degradation catalyzed by the ChBD-truncated enzyme was similar to that of the mature enzyme protein, the specific activity of the ChBD-truncated enzyme determined from the rate of hexasaccharide degradation was lower than that of the mature enzyme. The two CBDs appear to be responsible for facilitating the hydrolytic reaction. The sugar residue affinities (binding free energy changes) at the individual subsites, (-2) (-1) (+1) (+2) (+3) (+4), were estimated by modeling the hexasaccharide hydrolysis by the mature and ChBD-truncated enzymes. The truncation of ChBDs was found to strongly affect the affinity at the (-1) site. This situation seems to result in the lower enzymatic activity of the ChBD-truncated enzyme toward the chitinous substrates.


Assuntos
Aeromonas/enzimologia , Quitina/metabolismo , Quitinases/química , Quitinases/metabolismo , Sequência de Aminoácidos , Quitina/química , Quitinases/isolamento & purificação , Hidrólise , Dados de Sequência Molecular , Polissacarídeos/química , Estrutura Terciária de Proteína , Especificidade por Substrato
19.
Phytopathology ; 95(10): 1137-43, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18943465

RESUMO

ABSTRACT Greenhouse-grown tomato seedlings were inoculated naturally with two genera of powdery mildew conidia forming appressorial germ tubes that could not be differentiated by length alone. For direct identification, single germinated conidia were removed from leaves by means of a glass pipette linked to the manipulator of a high-fidelity digital microscope. This microscope enabled in vivo observation of the fungi without leaf decoloration or fungal staining. The isolated conidia were subjected to PCR amplification of the 5.8S rDNA and its adjacent internal transcribed spacer sequences followed by nested PCR to attain sensitivity high enough to amplify target nucleotide sequences (PCR/nested PCR). Target sequences from the conidia were completely coincident with those of the pathogen Oidium neolycopersici or Erysiphe trifolii (syn. Microsphaera trifolii), which is nonpathogenic on tomato. Using RT-PCR/nested PCR or multiplex RT-PCR/nested PCR, it was possible to amplify transcripts expressed in single conidia. Conidia at pre- and postgermination stages were removed individually from tomato leaves, and two powdery mildew genes were monitored. The results indicated that the beta-tubulin homolog TUB2-ol was expressed at pre- and postgermination stages and the cutinase homolog CUT1-ol was only expressed postgermination. Combining digital microscopic micromanipulation and two-step PCR amplification is thus useful for investigation of individual propagules on the surface of plants.

20.
Insects ; 6(2): 442-54, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-26463195

RESUMO

Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse.

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