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1.
Lung ; 202(1): 41-51, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38252134

RESUMEN

BACKGROUND: The determinants linked to the short- and long-term improvement in lung function in patients with severe eosinophilic asthma (SEA) on biological treatment (BioT) remain elusive. OBJECTIVE: We sought to identify the predictors of early and late lung function improvement in patients with SEA after BioT. METHODS: 140 adult patients with SEA who received mepolizumab, dupilumab, or reslizumab were followed up for 6 months to evaluate improvement in forced expiratory volume in one second (FEV1). Logistic regression was used to determine the association between potential prognostic factors and improved lung function at 1 and 6 months of treatment. RESULTS: More than a third of patients with SEA using BioT showed early and sustained improvements in FEV1 after 1 month. A significant association was found between low baseline FEV1 and high blood eosinophil count and sustained FEV1 improvement after 1 month (0.54 [0.37-0.79] and 1.88 [1.28-2.97] odds ratios and 95% confidence interval, respectively). Meanwhile, among patients who did not experience FEV1 improvement after 1 month, 39% exhibited improvement at 6 months follow-up. A high ACT score measured at this visit was the most reliable predictor of late response after 6 months of treatment (OR and 95% CI 1.75 [1.09-2.98]). CONCLUSION: Factors predicting the efficacy of biological agents that improve lung function in SEA vary according to the stage of response.


Asunto(s)
Antiasmáticos , Asma , Productos Biológicos , Eosinofilia Pulmonar , Adulto , Humanos , Antiasmáticos/uso terapéutico , Productos Biológicos/uso terapéutico , Eosinófilos , Eosinofilia Pulmonar/tratamiento farmacológico , Pulmón
2.
Ann Allergy Asthma Immunol ; 132(4): 457-462.e2, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37977324

RESUMEN

BACKGROUND: Although various monoclonal antibodies have been used as add-on therapy for severe eosinophilic asthma (SEA), to the best of our knowledge, no direct head-to-head comparative study has evaluated their efficacy. OBJECTIVE: To compare the efficacy of reslizumab, mepolizumab, and dupilumab in patients with SEA. METHODS: This was a multicenter, prospective observational study in patients with SEA who had received 1 of these biologic agents for at least 6 months. Cox proportional hazard models were used to compare the risk of the first exacerbation event, adjusting for sputum or blood eosinophils and common asthma-related covariates. The annual exacerbation rate was analyzed using a negative binomial model, and a mixed-effect model was used to analyze changes in forced expiratory volume in 1 second and asthma control test score over time. RESULTS: A total of 141 patients with SEA were included in the analysis; 71 (50%) received dupilumab; 40 (28%) received reslizumab, and 30 (21%) received mepolizumab. During the 12-month follow-up, 27.5%, 43.3%, and 38.0% of patients in the reslizumab, mepolizumab, and dupilumab groups, respectively, experienced at least 1 exacerbation. However, after adjusting for confounding factors, the dupilumab and mepolizumab groups showed similar outcomes in time-to-first exacerbation, exacerbation rate, forced expiratory volume in 1 second, and asthma control test score to those of the reslizumab group. CONCLUSION: In patients with SEA, treatment with reslizumab, mepolizumab, and dupilumab resulted in comparable clinical outcomes within a 12-month period. TRIAL REGISTRATION: The cohort protocol was sanctioned by the Institutional Review Board of each study center (clinicaltrial.gov identifier NCT05164939).


Asunto(s)
Antiasmáticos , Asma , Productos Biológicos , Eosinofilia Pulmonar , Humanos , Estudios Prospectivos , Eosinófilos , Anticuerpos Monoclonales/uso terapéutico , Eosinofilia Pulmonar/tratamiento farmacológico , Productos Biológicos/uso terapéutico , Antiasmáticos/uso terapéutico
3.
Opt Express ; 31(21): 34677-34687, 2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37859218

RESUMEN

This paper introduces the characteristics and efficiency of post-treatment methods for enhancing the timing resolution of ceramic Ce:GAGG scintillators. The thermal annealing and surface treatments were included to analyze their impact on time-resolved photoluminescence (TRPL) and thermoluminescence (TL) characteristics. Optical properties were improved by suppressing nonradiative recombination due to the reduced surface defects, while heat-treatment removes traps as confirmed by TL measurements. TRPL decay characteristics revealed that samples treated with mechanical polishing followed by heat treatment exhibited the best scintillation performance, with a slow component of 272.3 ns. These findings will aid in developing techniques for improving the luminescence of other inorganic scintillators.

4.
Med Phys ; 50(10): 6118-6129, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37469146

RESUMEN

BACKGROUND: Positron probes can accurately localize malignant tumors by directly detecting positrons emitted from positron-emitting radiopharmaceuticals that accumulate in malignant tumors. In the conventional method for direct positron detection, multilayer scintillator detection and pulse shape discrimination techniques are used. However, some γ-rays cannot be distinguished by conventional methods. Accordingly, these γ-rays are misidentified as positrons, which may increase the error rate of positron detection. PURPOSE: To analyze the energy distribution in each scintillator of the multilayer scintillator detector to distinguish true positrons and γ-rays and to improve the positron detection algorithm by discriminating true and false positrons. METHODS: We used Autoencoder, an unsupervised deep learning architecture, to obtain the energy distribution data in each scintillator of the multilayer scintillator detector. The Autoencoder was trained to separate the combined signals generated from the multilayer scintillator detector into two signals of each scintillator. An energy window was then applied to the energy distribution obtained using the trained Autoencoder to distinguish true positrons from false positrons. Finally, the performance of the proposed method and conventional positron detection algorithm was evaluated in terms of the sensitivity and error rate for positron detection. RESULTS: The energy distribution map obtained using the trained Autoencoder was proven to be similar to that of the simulated results. Furthermore, the proposed method demonstrated a 29.79% (+0.42%p) increase in positron detection sensitivity compared to the conventional method, both having an equal error rate of 0.48%. However, when both methods were set to have the same sensitivity of 1.83%, the proposed method had an error rate that was 25.0% (-0.16%p) lower than that of the conventional method. CONCLUSIONS: We proposed and developed an Autoencoder-based positron detection algorithm that can discriminate between true and false positrons with a smaller error rate than conventional methods. We verified that the proposed method could increase the positron detection sensitivity while maintaining a low error rate compared to the conventional method. If the proposed algorithm is implemented in handheld positron detection probes or cameras, diseases such as cancers can be more accurately localized in a shorter time compared with using traditional methods.


Asunto(s)
Aprendizaje Profundo , Neoplasias , Humanos , Tomografía de Emisión de Positrones/métodos , Partículas beta , Algoritmos
5.
Artículo en Inglés | MEDLINE | ID: mdl-37268246

RESUMEN

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

6.
PLoS One ; 18(3): e0281262, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36881579

RESUMEN

We investigated the correlation between the surface finish and luminescence properties of chemically polished cerium-doped single-crystal Gd3Al2Ga3O12 scintillators (Ce:GAGG), from the crystallographic perspective. The intrinsic defects in the crystals were identified via photoluminescence spectroscopy followed by scanning electron microscopy and X-ray diffraction to analyze their surface morphologies. Finally, the samples were individually wrapped with an enhanced specular reflector (ESR), coupled with a photomultiplier tube, placed inside a dark box, connected to a digitizer, and irradiated with a 137Cs radioactive source to evaluate the relative light (signal) output and energy resolution of each sample. The as-cut (rough) Ce:GAGG single-crystal samples, that were chemically polished with phosphoric acid at 190°C in air for 60 min, demonstrated a 33.1% increase in signal amplitude (light output to photosensor) and 2.4% (absolute value) improvement in energy resolution, which were comparable to those obtained for the mechanically polished sample. For these samples, the surface roughness was found to be ~430 nm, which was approximately half of that of the mechanically polished sample. The chemical polishing method used in this study is a cost-effective and straightforward technique to improve structural imperfections and can facilitate the treatment of inorganic scintillators with complex shapes and/or on a large scale.


Asunto(s)
Cerio , Radioisótopos de Cesio , Cristalografía , Luminiscencia
7.
Materials (Basel) ; 15(4)2022 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-35207948

RESUMEN

We compared thermal stability, open-circuit voltage, short-circuit current, and fill factor values of single-crystal Cadmium telluride (CdTe) grown using the vertical Bridgman (VB) technique and doped with group V elements (phosphorus and arsenic), and group Ⅰ element (sodium), followed by an annealing process. The sodium-doped CdTe maintained a hole density of 1016 cm-3 or higher; after annealing for a long time, this decreased to 1015 cm-3 or less. The arsenic-doped CdTe maintained a hole density of approximately 1016 cm-3 even after the annealing process; however its bulk minority carrier lifetime decreased by approximately 10%. The phosphorus-doped CdTe maintained its properties after the annealing process, ultimately achieving a hole density of ~1016 cm-3 and a minority carrier lifetime of ~40 ns. The characteristics of a single-crystal solar cell were evaluated using a solar cell device that contained single-crystal CdTe with various dopants. The sodium-doped sample exhibited poor interfacial properties, and its performance decreased rapidly during annealing. The samples doped with group V elements exhibited stable characteristics even during long-term annealing. We concluded, therefore, that group V elements dopants are more suitable for CdTe single-crystal-based solar cell applications involving thermal stress conditions, such as space missions or extreme fabrication temperature environments.

8.
Opt Express ; 29(2): 751-760, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33726305

RESUMEN

Surface modification of ceramic Ce-doped Gd3Al2Ga3O12 (Ce:GAGG) was performed by exposing small samples to anhydrous phosphoric acid (H3PO4) under different conditions (temperature and duration) to investigate the effects of chemical polishing treatment. When coupled to a photomultiplier tube (PMT) and used as a radiation detector, chemical treatment for 3 min at 190 °C improved the light (signal) output by 24.8% and energy resolution by 2.5% (percentage point), respectively. This can be attributed to a reduction in surface roughness that enhanced optical properties. Thus, chemical polishing could be a low-cost alternative to mechanical polishing especially for small or complex shaped ceramic scintillators.

9.
Sensors (Basel) ; 21(4)2021 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-33557045

RESUMEN

We propose an integrated front-end data acquisition circuit for a hybrid ultrasound (US)-gamma probe. The proposed circuit consists of three main parts: (1) a preamplifier for the gamma probe, (2) a preprocessing analog circuit for the US, and (3) a digitally controlled analog switch. By exploiting the long idle time of the US system, an analog switch can be used to acquire data of both systems using a single output channel simultaneously. On the nuclear medicine (NM) gamma probe side, energy resolutions of 18.4% and 17.5% were acquired with the standalone system and with the proposed switching circuit, respectively, when irradiated with a Co-57 radiation source. Similarly, signal-to-noise ratios of 14.89 and 13.12 dB were achieved when US echo signals were acquired with the standalone system and with the proposed switching circuit, respectively. Lastly, a combined US-gamma probe was used to scan a glass target and a sealed radiation source placed in a water tank. The results confirmed that, by using a hybrid US-gamma probe system, it is possible to distinguish between the two objects and acquire structural information (ultrasound) alongside molecular information (gamma radiation source).

10.
Korean J Intern Med ; 35(6): 1507-1516, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32450676

RESUMEN

BACKGROUND/AIMS: Emotional distress is thought to cause or maintain chronic urticaria (CU). We aimed to investigate the presence of anxiety, depression, and stress in Korean adult CU patients and to explore their potential impact on treatment. METHODS: We enrolled 79 CU patients and a disease control group comprising 39 persistent asthma patients. The Hospital Anxiety and Depression Scale (HADS) was used to evaluate depression and anxiety. Stress and quality of life (QoL) were assessed by Stress Response Inventory and CU-QoL questionnaires. The sociodemographic and clinical data such as urticaria activity score (UAS-15, UAS-6) were obtained. RESULTS: The prevalence of depression and anxiety based on the HADS were 48.1% and 38.0%. Although the prevalence of anxiety didn't differ between the CU and asthma patients, depression was significantly more prevalent in the CU patients (48.1% vs. 28.2%). Stress tended to be lower in CU patients. Anxiety, depression, and stress exhibited negative correlations with QoL. Anxiety showed significant correlation with UAS-6 and pruritus-visual analog scale (VAS; r = 0.256, r = 0.272, p < 0.05, respectively); depression correlated with sleep difficulty-VAS (r = 0.261, p < 0.05). Stress was associated with UAS-15, UAS-6, pruritus-VAS, and sleep difficulty-VAS (r = 0.251, r = 0.317, r = 0.302, r = 0.258, p < 0.05, respectively). CONCLUSION: The current study first presented that Korean CU patients frequently have anxiety and depression, which affect their QoL and demonstrated that anxiety, depression, and stress had different effects on sleep difficulty, pruritus, and urticaria severity in Korean CU patients.


Asunto(s)
Ansiedad , Urticaria Crónica , Depresión , Adolescente , Adulto , Anciano , Ansiedad/diagnóstico , Ansiedad/epidemiología , Enfermedad Crónica , Urticaria Crónica/psicología , Depresión/diagnóstico , Depresión/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Calidad de Vida , República de Corea/epidemiología , Encuestas y Cuestionarios , Adulto Joven
11.
Arch Pharm Res ; 35(10): 1763-70, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23139127

RESUMEN

Six stilbenes were isolated from the methanol extract of Rheum undulatum rhizomes by bioactivity-guided fractionation. The structures of the compounds were determined by spectroscopic analysis ((1)H-, (13)C-NMR and MS), to be desoxyrhapontigenin (1), rhapontigenin (2), trans-resveratrol (3), piceatannol (4), piceatannol-3'-O-ß-D-glucopyranoside (5) and isorhapontin (6). Compounds 1-4 inhibited the direct binding between sICAM-1 and LFA-1 of the THP-1 cells in a dose-dependent manner with IC(50) values of 50.1, 25.4, 33.4 and 45.9 µM, respectively. On the other hand, the other compounds 5 and 6 with a glucose moiety in each molecule did not show any inhibitory activity in the cell adhesion assay (IC(50) values of >100.0 µM). Compounds 2, 3 and 4 also had an inhibitory effect on direct binding between sVCAM-1 and VLA-4 of THP-1 cells. This suggests that the stilbenes from Rheum undulatum rhizomes are good candidates for therapeutic strategies towards inflammation.


Asunto(s)
Antiinflamatorios/aislamiento & purificación , Molécula 1 de Adhesión Intercelular/metabolismo , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Rheum/química , Estilbenos/aislamiento & purificación , Antiinflamatorios/farmacología , Sitios de Unión , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Humanos , Ligandos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Plantas Medicinales , Rizoma/química , Espectrometría de Masa por Ionización de Electrospray , Estilbenos/química , Estilbenos/farmacología
12.
J Med Microbiol ; 61(Pt 5): 705-711, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22282461

RESUMEN

Chlamydophila pneumoniae infection has been suggested to be associated with severe asthma characterized by persistent airway limitation, which may be related to airway remodelling. We investigated whether C. pneumoniae infection affected the secretion of metalloproteinase-9 (MMP9) and tissue inhibitor metalloproteinase-1 (TIMP1), and altered the responsiveness of inflammatory cells to corticosteroids. Human peripheral blood mononuclear cells (PBMCs) were cultured in vitro in the presence or absence of C. pneumoniae. Secretion of both MMP9 and TIMP1 was strongly suppressed by dexamethasone treatment in uninfected cells. MMP9 secretion was also significantly inhibited by dexamethasone in C. pneumoniae-infected cells, but TIMP1 secretion was not; hence the MMP9 to TIMP1 ratio decreased. Interestingly, expression of human glucocorticoid receptor ß, which is believed to confer resistance to corticosteroids, was enhanced by dexamethasone treatment in C. pneumoniae-infected PBMCs. We conclude that C. pneumoniae infection may promote airway remodelling by decreasing the ratio of MMP9 to TIMP1 secreted by inflammatory cells, and by altering cellular responsiveness to corticosteroids.


Asunto(s)
Corticoesteroides/farmacología , Chlamydophila pneumoniae/patogenicidad , Inmunosupresores/farmacología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/microbiología , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Células Cultivadas , Chlamydophila pneumoniae/inmunología , Experimentación Humana , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/enzimología
13.
Life Sci ; 90(13-14): 502-8, 2012 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-22285837

RESUMEN

AIMS: Oxidative stress is involved in the pathogenesis of asthma, and peroxiredoxins (PRDX) may be critical in controlling intracellular oxidative stress. The aim of this study was to evaluate expressions of PRDX and their hyperoxidized forms in asthmatic individuals. MAIN METHODS: The levels of expression of PRDX1, PRDX2, PRDX3, and PRDX6 and their hyperoxidized forms (PRDX-SO(3)) were measured in PBMCs from asthma patients and control subjects. In addition, cells from these subjects were treated with hydrogen peroxide (H(2)O(2)) and their intracellular concentrations of reactive oxygen species (ROS) were measured. KEY FINDINGS: The ratios of hyperoxidized to total PRDX (PRDX-SO(3/)PRDX) in PBMCs were significantly higher in asthma patients than in normal subjects and were correlated with disease severity, with the highest ratio seen in patients with severe asthma. Furthermore, H(2)O(2) treatment of PBMCs, particularly lymphocytes, increased intracellular ROS concentrations with greater and more persistent increases observed in cells from asthmatic than from control subjects. SIGNIFICANCE: Hyperoxidation of PRDX may serve as a biomarker of asthma severity and may predict enhanced susceptibility to oxidative stress load in PBMCs of asthmatics.


Asunto(s)
Asma/sangre , Asma/fisiopatología , Estrés Oxidativo , Peroxirredoxinas/sangre , Isoformas de Proteínas/sangre , Adulto , Femenino , Humanos , Peróxido de Hidrógeno/metabolismo , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad , Oxidantes/metabolismo , Peroxirredoxinas/química , Isoformas de Proteínas/química , Especies Reactivas de Oxígeno/metabolismo
14.
Allergy Asthma Immunol Res ; 3(2): 111-7, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21461250

RESUMEN

PURPOSE: Airway remodeling may be responsible for irreversible airway obstruction in asthma, and a low post-bronchodilator FEV1/FVC ratio can be used as a noninvasive marker of airway remodeling. We investigated correlations between airway wall indices on computed tomography (CT) and various clinical indices, including post-bronchodilator FEV1/FVC ratio, in patients with asthma. METHODS: Volumetric CT was performed on 22 stable asthma patients who were taking inhaled corticosteroids. Airway dimensions were measured at four segmental bronchi using in-house software based on the full-width/half-maximum method. Parameters included luminal area, wall thickness (WT), wall thickness percentage (WT%), wall area percentage (WA%), bronchial-to-arterial diameter (BA) ratio on inspiration CT, airway collapsibility (AC), and air trapping index (ATI). Correlations were analyzed between CT parameters and clinical indices, including %FEV1, FEV1/FVC, FEF(25-75%), and post-bronchodilator FEV1/FVC ratio. RESULTS: Post-bronchodilator FEV1/FVC showed significant correlations with WT%, WT, BA ratio, AC, and ATI (r=-0.503, -0.576, 0.454, 0.475, and -0.610, respectively). WT showed negative correlations with FEV1/FVC and FEF(25-75%) (r=-0.431 and -0.581), and WT% was negatively correlated with %FEV1, FEV1/FVC, and FEF(25-75%) (r=-0.434, -0.431, and -0.540, respectively). WA% showed correlations with FEF(25-75%) and body mass index (r=-0.459 and 0.453). The BA ratio was positively correlated with %FEV1 (r=0.459) and FEF(25-75%) (r=0.479). AC showed strong positive correlation with FEV1/FVC (r=0.592), and ATI showed negative correlations with FEV1/FVC (r=-0.534) and FEF(25-75%) (r=-0.591). CONCLUSIONS: WT%, WT, BA ratio, and AC on inspiration and expiration CT are good indices for measuring airway remodeling defined by post-bronchodilator FEV1/FVC in stable asthma patients treated with inhaled corticosteroids.

15.
Biotechnol Lett ; 33(8): 1663-6, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21487781

RESUMEN

A new zymogram method, silver-stained fibrin zymography, for separation of protease bands and activity detection using a single substrate gel, was developed. The method takes advantage of the nanoscale sensitivity of both zymography and silver staining. After SDS-PAGE in a gel containing fibrin, the gel was incubated in enzyme reaction buffer and the zymogram was silver-stained. Bands with protease activity were stained with silver in clear areas where the protein substrate had been degraded. The molecular sizes of proteases were accurately determined. Furthermore, proteases of high molecular weight were clearly and sharply resolved.


Asunto(s)
Electroforesis en Gel de Poliacrilamida/métodos , Péptido Hidrolasas/aislamiento & purificación , Proteínas Bacterianas/química , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Precursores Enzimáticos , Fibrina/química , Fibrina/metabolismo , Peso Molecular , Péptido Hidrolasas/química , Péptido Hidrolasas/metabolismo , Tinción con Nitrato de Plata
16.
Allergy Asthma Immunol Res ; 2(1): 41-7, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20224677

RESUMEN

PURPOSE: Chlamydophila pneumoniae infection in the airways is thought to be associated with the pathogenesis of asthma, especially in non-atopic severe asthma with irreversible airway obstruction that may be related to airway remodeling. Here, we investigated whether C. pneumoniae infection enhances the secretion of critical chemical mediators for airway remodeling, such as VEGF, TGF-beta, and TIMP-1, in human bronchial epithelial cells (BECs) in a Th2-dominant microenvironment. METHODS: Human bronchial epithelial cells (BEAS-2B cells) were infected with C. pneumoniae strain TW183 and cultured in both a Th1-dominant microenvironment with INF-gamma and a Th2-dominant microenvironment with IL-4 or IL-13 added to the culture medium. The VEGF, TGF-beta, and TIMP-1 levels in the culture supernatants were measured using enzyme-linked immunosorbent assays (ELISA). The activation of NF-kappaB in each experimental condition was determined using an electrophoretic mobility shift assay. RESULTS: Chlamydophila pneumoniae-infected BECs showed enhanced secretion of VEGF, TGF-beta, and TIMP-1 compared with non-infected BECs. The levels of cytokines secreted from BECs were increased more when IL-13 was added to the culture medium. C. pneumoniae-infected BECs also showed increased NF-kappaB activation. CONCLUSIONS: These results suggest that C. pneumoniae plays a role in the pathogenesis of airway remodeling in asthma, revealing a Th2-dominant immune response. Further studies are required to clarify the precise mechanism of C. pneumoniae infection in airway remodeling.

17.
Anal Biochem ; 397(2): 259-61, 2010 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19799850

RESUMEN

A new zymography for detecting nisin-like acidic bacteriocins was developed using a tricine-sodium dodecyl sulfate (SDS) gel and an acidic gel matrix (pH 4.0). After electrophoresis, proteins in the tricine gel were electrotransferred to an optimal pH-conditioned gel matrix (OP-CGM). The OP-CGM was overlaid with indicator cells (Bacillus cereus) embedded in nutrient broth soft agar (0.8%, w/v). Antibacterial activity shown as a growth inhibition using B. cereus was detected at approximately 3.8kDa. Because nisin is unstable in buffers at pH values over 6.0, the common electrophoretic systems, SDS-polyacrylamide gel electrophoresis and tricine gel, are not suitable for detection of nisin-like acidic bacteriocins.


Asunto(s)
Bacteriocinas/análisis , Ácidos , Bacillus cereus/efectos de los fármacos , Bacteriocinas/farmacología , Electroforesis en Gel de Poliacrilamida/métodos , Concentración de Iones de Hidrógeno , Nisina/análisis
18.
Biotechnol Lett ; 32(1): 137-42, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19760116

RESUMEN

By disruption of the pullulan synthetase gene (pul) of Aureobasidium pullulans IMS822 KCTC11179BP, we constructed a mutant strain, A. pullulans NP1221, which produced a pure beta-glucan exopolysaccharide. The mutant NP1221 was white, whereas the wild-type strain produced a black dye. When we compared fermentation kinetics between wide-type and mutant strains, the mutant NP1221 did not produce pullulan. Substrate uptake rate and beta-glucan production were similar in both strains. However, the biomass yield of mutant NP1221 was 2.3-fold (9.2 g l(-1)) greater than that of wild-type.


Asunto(s)
Ascomicetos/metabolismo , Glucanos/genética , beta-Glucanos/metabolismo , Ascomicetos/genética , Fermentación/genética , Fermentación/fisiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Cinética , Modelos Genéticos , Reacción en Cadena de la Polimerasa
19.
Ann Allergy Asthma Immunol ; 103(3): 238-47, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19788022

RESUMEN

BACKGROUND: The exact pathogenic role of oxidative stress in the development of allergic airway inflammation is still largely unknown. OBJECTIVE: To investigate a possible link between increased pulmonary oxidative stress and the pivotal features of asthma during the mounting of an allergic inflammatory response. METHODS: To determine the relationship between oxidative stress and allergic inflammatory responses, we evaluated the sequential kinetics of oxidative stress in the lung, the development of airway inflammation, mucin hypersecretion, and airway hyperresponsiveness (AHR) in an ovalbumin (OVA)-sensitized and challenged mouse with and without antioxidant. Parameters were measured at 9 points for more than 28 days, starting from the first day of OVA challenge with or without antioxidant treatment. The ratio of reduced to oxidized glutathione in the lungs and levels of intracellular reactive oxygen species (ROS) in the bronchial epithelium were serially measured. Bronchoalveolar lavage fluid cells, histopathologic features, and AHR were analyzed at the same time points. RESULTS: The reduced to oxidized glutathione ratio was reduced from immediately after OVA challenge to day 1, remained at this level until day 1, and rapidly recovered to the normal level after more than 2 days. Intracellular ROS levels in the bronchial epithelium followed similar kinetics. The inflammatory cells in bronchoalveolar lavage fluid reached a maximum of 3 days and decreased progressively thereafter. Histopathologic examination revealed that substantial airway inflammation persisted through day 28. The proportion of mucin-producing epithelial cells significantly increased after day 1, reached a maximum at day 3, and remained at this level until day 5. The AHR peaked on day 1 and normalized within 5 days. The pretreatment of antioxidant significantly reduced not only the increased ROS levels but also development of other phenotypes of asthma. CONCLUSION: These results indicate that increased oxidative stress in the lung precedes other pivotal phenotypes of allergic airway disease, suggesting a critical role for increased oxidative stress in the induction of allergic airway inflammation.


Asunto(s)
Asma/fisiopatología , Pulmón/fisiología , Ovalbúmina/inmunología , Estrés Oxidativo/fisiología , Mucosa Respiratoria/fisiología , Acetilcisteína/administración & dosificación , Animales , Asma/tratamiento farmacológico , Asma/patología , Líquido del Lavado Bronquioalveolar/química , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Depuradores de Radicales Libres/administración & dosificación , Glutatión/análogos & derivados , Glutatión/análisis , Inmunización , Inflamación , Pulmón/efectos de los fármacos , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Mucinas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/patología
20.
J Clin Immunol ; 29(5): 629-36, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19479364

RESUMEN

BACKGROUND: Chlamydophila pneumoniae may contribute to the pathogenesis of asthmatic airway inflammation through chemical mediators secreted by C. pneumoniae-infected bronchial epithelial cells (BECs). Recently, CCL20 and vascular endothelial growth factor (VEGF) were reported to be released from BECs and to play a role in the pathogenesis of asthma. OBJECTIVE AND METHODS: To determine if C. pneumoniae infection of BECs induces the secretion of CCL20 and VEGF, we measured that by ELISA in human BECs infected with C. pneumoniae. Transcripts of CCL20 and VEGF were assayed by semi-quantitative RT-PCR. To investigate the underlying mechanism, the activation of MAPK and intracellular reactive oxygen species (ROS) in these C. pneumoniae-infected BECs was measured, as well as the effects of inhibitors of MAPK and ROS on CCL20 and VEGF expression. RESULTS: Compared with non-infected BECs, C. pneumoniae-infected BECs showed enhanced secretion of CCL20 and VEGF. C. pneumoniae-infected BECs also showed enhanced intracellular ROS and an increased ratio of phosphorylated to non-phosphorylated p38. Inhibition of p38 suppressed CCL20 and VEGF secretion, as did a NADPH oxidase blocker and an antioxidant, in C. pneumoniae-infected BECs. CONCLUSION: C. pneumoniae infection of BECs may play a role in the pathogenesis of asthma through the enhanced production of CCL20 and VEGF. The association between increased cytokine production and increased intracellular ROS suggests that antioxidants may benefit asthmatics in selected situations.


Asunto(s)
Asma/metabolismo , Quimiocina CCL20/metabolismo , Infecciones por Chlamydophila/metabolismo , Chlamydophila pneumoniae/inmunología , Mucosa Respiratoria/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Antioxidantes/farmacología , Asma/complicaciones , Asma/inmunología , Asma/patología , Línea Celular , Quimiocina CCL20/genética , Quimiocina CCL20/inmunología , Infecciones por Chlamydophila/complicaciones , Infecciones por Chlamydophila/inmunología , Infecciones por Chlamydophila/patología , Chlamydophila pneumoniae/patogenicidad , Activación Enzimática/efectos de los fármacos , Humanos , NADP/antagonistas & inhibidores , Compuestos Onio/farmacología , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/microbiología , Mucosa Respiratoria/patología , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/inmunología , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
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