Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Sci Rep ; 14(1): 8698, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622215

RESUMEN

The coordinated development of intelligence and greening is an intrinsic demand for high-quality economic and social development. Intelligentization and greening are the leading directions of sustainable development of the power industry. This paper directs of sustainable development of the power industry. This paper empirically analyzes the effect and mechanism of intelligence on the green environmental friendliness of electric power substations by using a panel fixed-effects model and instrumental variable regression, using substation engineering data from China southern power grid during 2013-2022. It is found that the level of intelligence significantly promotes the green performance of substation projects, and this conclusion still holds after a series of robustness tests. Intelligence can reduce material waste and pollutant emissions by improving the engineering environmental monitoring capability and the refinement of engineering resource control, thus improving the environmental friendliness of the project. The research in this paper helps to promote the integrated development of intelligent and green power engineering, to better achieve economic and green goals.

2.
Ophthalmic Res ; 67(1): 192-200, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38253044

RESUMEN

INTRODUCTION: So far, there has been no closure grade system synthesizing morphological and microstructural features for large idiopathic macular holes (IMHs) treated by vitrectomy and internal limiting membrane (ILM) peeling. This study aimed to propose a concise one and explore its relevance with visual acuity and the related preoperative factors. METHODS: Consecutive patients with large IMHs (minimum diameter >400 µm), undergoing vitrectomy and ILM peeling, obtaining primary closure and regularly followed-up were enrolled. Preoperative clinical charts and spectral-domain optical coherence tomography (SD-OCT) parameters were reviewed. SD-OCT images and best corrected visual acuity (BCVA) were assessed at 1, 4, and 10 months postoperatively. SD-OCT features at last visit were categorized by BCVA significance, and preoperative risk factors were analyzed. RESULTS: Sixty-eight eyes from 64 patients were enrolled. The 10-month postoperative SD-OCT images were categorized into closure grade 1, 2, and 3 with successively decreased BCVA (p < 0.001). During early follow-up, part of grades 2 and 3 could evolve into the upper grade, respectively, but grade 3 could never evolve into grade 1 and exhibited the least satisfactory long-term BCVA. Binary logistic regression showed that large minimum linear diameter (MLD) was a risk factor for grade 3 occurrence (p < 0.001), with a cutoff value of 625.5 µm from the receiver operating characteristic curve for MLD predicting grade 3 occurrence (p = 0.001). CONCLUSION: Long-term closure status of large IMHs could be categorized into three grades with BCVA significance. Large horizontal MLD is a risk factor for occurrence of grade 3 closure with unsatisfactory visual recovery.


Asunto(s)
Perforaciones de la Retina , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía , Humanos , Tomografía de Coherencia Óptica/métodos , Perforaciones de la Retina/cirugía , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/fisiopatología , Masculino , Femenino , Agudeza Visual/fisiología , Vitrectomía/métodos , Anciano , Persona de Mediana Edad , Estudios Retrospectivos , Estudios de Seguimiento , Membrana Basal/cirugía , Curva ROC , Mácula Lútea/patología , Mácula Lútea/diagnóstico por imagen
3.
BMC Ophthalmol ; 23(1): 274, 2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37316769

RESUMEN

BACKGROUND: The internal limiting membrane (ILM) insertion technique was widely used to treat large macular hole (MH) for the high closure rate. However, the prognosis of closed MH after ILM insertion compared to ILM peeling remains controversial. This study aimed to compare foveal microstructure and microperimeter in large idiopathic MH surgically closed by ILM peeling and ILM insertion. METHODS: This retrospective, non-randomized, comparative study included patients with idiopathic MH (minimum diameter ≥ 650 µm) who underwent primary pars plana vitrectomy (PPV) with ILM peeling or ILM insertion. The initial closure rate was recorded. Patients with initially closed MHs were divided into two groups according to the surgery methods. The best-corrected visual acuity (BCVA), optical coherence tomography (OCT) and microperimeter-3 (MP-3) outcomes of two groups were compared at baseline, 1 and 4 months postoperatively. RESULTS: For idiopathic MH (minimum diameter ≥ 650 µm), ILM insertion had a significantly higher initial closure rate than ILM peeling (71.19% vs. 97.62%, P = 0.001). Among 39 patients with initially closed MHs who were on regular follow-up, twenty-one were assigned to the ILM peeling group and 18 to the ILM insertion group. Postoperative BCVA improved significantly in both groups. The final BCVA (logMAR) (0.40 vs. 0.88, P < 0.001), macular hole sensitivity (19.66 dB vs. 14.14 dB, P < 0.001), peripheral sensitivity of macular hole (24.63 dB vs. 21.95 dB, P = 0.005), and fixation stability (FS) within 2 degrees (82.42% vs. 70.57%, P = 0.031) were significantly better and external limiting membrane (ELM) defect (330.14 µm vs. 788.28 µm, P < 0.001) and ellipsoid zone (EZ) defect (746.95 µm vs. 1105.11 µm, P = 0.010) were significantly smaller in the ILM peeling group than in the ILM insertion group. CONCLUSION: For initially closed MHs (minimum diameter ≥ 650 µm), both ILM peeling and ILM insertion significantly improved the microstructure and microperimeter in the fovea. However, ILM insertion was less efficient at microstructural and functional recovery after surgery.


Asunto(s)
Perforaciones de la Retina , Humanos , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/cirugía , Estudios Retrospectivos , Fóvea Central , Periodo Posoperatorio , Recuperación de la Función
4.
Retina ; 43(2): 222-229, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36695794

RESUMEN

PURPOSE: To compare the anatomical and visual outcomes of extra-large idiopathic macular holes treated with internal limiting membrane peeling and two inverted internal limiting membrane flap techniques, namely insertion and cover technique. METHODS: Patients with idiopathic macular holes (minimum linear diameter ≥ 650 µm) were divided into peeling group, insertion group, and cover group. The initial closure rate, final length of external limiting membrane and ellipsoid zone recovery, and best-corrected visual acuity were evaluated. RESULTS: A total of 124 eyes were included, and the average follow-up was 7.2 months. All the baseline characteristics were comparable among the three groups. Initial closure rate of the peeling group, the insertion group, and the cover group was 65.0% (26/40), 97.6% (41/42), and 90.5% (38/42), respectively (P < 0.001). In closed idiopathic macular holes, the peeling group and the cover group exhibited significantly longer length of external limiting membrane recovery than the insertion group (P < 0.001), and the peeling group exhibited significantly longer length of ellipsoid zone recovery than the other two groups (P = 0.021). The peeling group and the cover group exhibited significantly better best-corrected visual acuity improvement than the insertion group (P = 0.009). CONCLUSION: For extra-large idiopathic macular holes, cover technique surpasses internal limiting membrane peeling technique in closure rate and outperforms insertion technique in anatomical and functional recovery, whereas insertion technique may adversely affect the recovery of foveal microstructure and best-corrected visual acuity.


Asunto(s)
Membrana Epirretinal , Perforaciones de la Retina , Humanos , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/cirugía , Membrana Basal/cirugía , Agudeza Visual , Resultado del Tratamiento , Vitrectomía/métodos , Estudios Retrospectivos , Membrana Epirretinal/cirugía , Tomografía de Coherencia Óptica
5.
Retina ; 43(1): 42-48, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36228145

RESUMEN

PURPOSE: To compare the efficacy of air and perfluoropropane (C3F8) with pars plana vitrectomy (PPV) in highly myopic macular holes (HMMHs) and explore the factors related to surgical prognosis. METHODS: A retrospective comparison of a consecutive series of HMMHs undergone vitrectomy and internal limiting membrane peeling. According to tamponade type, they were divided into air group and C3F8 group, which were further divided into subgroups based on hole diameter or axial length (AXL). Anatomical and functional outcomes were compared between tamponades. Related factors of initial closure rate and postoperative best-corrected visual acuity (BCVA) were analyzed by logistic regression. RESULTS: The baseline characteristics in air group (n = 63) and C3F8 group (n = 37) were similar except the age of air was older ( P = 0.019). The mean follow-up period was 17.16 ± 17.97 months. After surgery, the initial closure rate of air group was 85.7% and that of C3F8 group was 83.7% ( P = 0.780). And the initial closure rate showed no difference between tamponades in the same subgroup classified by hole diameter or AXL (all P > 0.05). Postoperative BCVA improved significantly in both groups ( P < 0.001), but no difference between them ( P = 0.793). Logistic regression showed that age, minimum linear diameter, and AXL were risk factors of initial closure rate, and preoperative BCVA was the only factor associated with postoperative BCVA (all P < 0.05). CONCLUSION: With a long-term follow-up of HMMH, we found air had a similar tamponade effect anatomically and functionally compared with C3F8. Air may also be a good choice for patients with HMMH.


Asunto(s)
Miopía , Perforaciones de la Retina , Humanos , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/etiología , Perforaciones de la Retina/cirugía , Vitrectomía/efectos adversos , Estudios Retrospectivos , Endotaponamiento/efectos adversos , Agudeza Visual , Miopía/complicaciones
6.
Graefes Arch Clin Exp Ophthalmol ; 261(1): 57-65, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35867147

RESUMEN

PURPOSE: To observe the characteristics of highly myopic macular holes (HMMHs) with macular retinoschisis (MRS) by optical coherence tomography (OCT) and explore the possible relationship between HMMHs and different types of MRS. METHODS: We consecutively reviewed the clinical data and OCT images of the patients with HMMHs from June 2015 to February 2021. Then we picked eyes with MRS from these HMMHs for analysis. The minimum linear diameter (MLD), basal diameter (BD), and height (H) of HMMHs were measured. HMMHs were grouped according to the extent or layer involvement of the concomitant MRS and the characteristics were compared among groups. The impact of MRS on the MLD of macular hole was analyzed with multivariable linear regression. RESULTS: We included 127 patients with MRS from 168 HMMHs (75.5%) for analysis. According to the different classification systems, the most frequent type of MRS in HMMHs was S3 (foveal but not entire macular area MRS) (62.2%) and both inner- and outer- (I/O-MRS) involved types. In our study, HMMHs with more extensive MRS had larger MLD, larger BD, larger H, and poorer best-corrected visual acuity (BCVA). Meanwhile, HMMHs with outer layer-involved MRS (outer MRS and I/O-MRS) had larger BD than HMMH with only inner layer-involved MRS. (All P < 0.05) Multivariable linear regression further illustrated only the extent of MRS was significantly associated with the MLD of HMMH, while there was no significant correlation between the involved retinal layers and the MLD of HMMH. CONCLUSION: HMMH with MRS presented as a predominant type in HMMHs. The MRS was always with a relatively large extent and involved both inner and outer layers. MLD of HMMH was mainly affected by the extent of MRS.


Asunto(s)
Degeneración Macular , Miopía Degenerativa , Perforaciones de la Retina , Retinosquisis , Humanos , Retinosquisis/complicaciones , Retinosquisis/diagnóstico , Perforaciones de la Retina/etiología , Perforaciones de la Retina/complicaciones , Miopía Degenerativa/complicaciones , Miopía Degenerativa/diagnóstico , Agudeza Visual , Estudios Retrospectivos , Tomografía de Coherencia Óptica/métodos , Degeneración Macular/complicaciones
7.
Retina ; 42(10): 1874-1882, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-36129264

RESUMEN

PURPOSE: To observe the characteristics and prognosis of different types of intraretinal cystoid spaces in idiopathic epiretinal membranes (iERMs). METHODS: Two hundred and seven consecutive patients with symptomatic iERM who underwent vitrectomy between September 2016 and December 2019 were included. According to spectral-domain optical coherence tomography images, intraretinal cystoid spaces were classified into cystoid macular edema (CME) and microcystic macular edema (MME). Other optical coherence tomography characteristics, including ectopic inner foveal layers, central foveal thickness, and interdigitation zone integrity, were also evaluated. RESULTS: Intraretinal cystoid spaces were presented in 30.1% of the iERMs, 21.5% were CME-type, 66.2% were MME-type, and 12.3% were combined-type. Compared with CME, eyes with MME-type and combined-type showed a significantly lower best-corrected visual acuity (BCVA) preoperatively and postoperatively. Cystoid macular edema is always presented in earlier stages (92.9%) and has no significant effects on BCVA (PStage I = 0.927, PStage II = 0.985). Conversely, MME is the primary type in advanced stages associated with a longer duration of symptoms (P = 0.037) and lower preoperative BCVA (P = 0.008). After surgery, cystoid spaces were newly occurred in 33 eyes (21.6%), with no effects on BCVA (P = 0.668). In the multiple regression analysis, the presence of MME was a risk factor for preoperative BCVA (P = 0.001). However, it is not an independent predictor for the postoperative VA. CONCLUSION: Our research further proved that MME is an adverse factor for preoperative and postoperative VA in iERMs. Moreover, we underlined the importance of distinguishing between CME and MME, which may affect prognosis differently.


Asunto(s)
Membrana Epirretinal , Edema Macular , Endrín/análogos & derivados , Membrana Epirretinal/complicaciones , Membrana Epirretinal/diagnóstico , Membrana Epirretinal/cirugía , Humanos , Edema Macular/etiología , Pronóstico , Retina , Estudios Retrospectivos , Tomografía de Coherencia Óptica/métodos , Agudeza Visual , Vitrectomía/métodos
8.
Retina ; 42(8): 1472-1478, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35502976

RESUMEN

PURPOSE: To investigate the effects of ectopic inner foveal layers (EIFLs) on foveal configuration recovery and visual acuity after idiopathic epiretinal membrane removal and analyze the relationship of foveal configuration recovery between 1-month and long-term postoperatively. METHODS: This retrospective study included 216 consecutive eyes with idiopathic epiretinal membrane that underwent vitrectomy surgery. A comprehensive ophthalmic examination was performed for all patients before and 1, 4, 10, and 24 months after surgery. We observed the postoperative anatomical and functional recovery of eyes with and without EIFLs and analyzed the association between short-term and long-term anatomical recovery. RESULTS: The presence of EIFL was associated with severe preoperative visual damage ( P < 0.001) and was considered as a negative factor for postoperative foveal depression recovery ( P < 0.001). No significant difference was found in postoperative best-corrected visual acuity between the eyes with and without EIFLs ( P = 0.442). For eyes with Stage II epiretinal membranes, 17.6% developed EIFLs postoperatively, which did not affect the final best-corrected visual acuity. Overall, 24.5% of epiretinal membranes restored the foveal configurations at 1 month postoperatively, and 14.7% continued recovering during the follow-up. Foveal structure recovery in eyes with EIFLs was associated with earlier stage, fewer microcystic macular edema, complete interdigitation zone layer, and a thinner central foveal thickness (all P < 0.05) at 1 month postoperatively. CONCLUSION: The EIFL is associated with severe preoperative visual damage and is a negative factor for postoperative anatomical recovery, but it is a minor factor for postoperative visual acuity. We also found an association of foveal configuration recovery between 1 month and long-term after surgery.


Asunto(s)
Membrana Epirretinal , Membrana Epirretinal/diagnóstico , Fóvea Central , Humanos , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Trastornos de la Visión/cirugía , Vitrectomía
9.
Retina ; 42(5): 883-891, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-34954775

RESUMEN

PURPOSE: This study aimed to evaluate fixation stability and position changes after epiretinal membrane (ERM) surgery. METHODS: This is a retrospective study that included 60 consecutive eyes with idiopathic ERM. All patients received comprehensive ophthalmic examinations preoperatively and 1, 4, and 10 months postoperatively. Main outcome measures included fixation stability and position, bivariate contour ellipse area, and preferred retinal locus. RESULTS: The number of patients with stable fixation and predominantly central fixation was increased significantly after ERM surgery (61.7 vs. 73.3%, P = 0.001; 41.7 vs. 71.7%, P = 0.037). The correlation analysis showed that the preoperative factors associated with improved postoperative fixation stability were a larger bivariate contour ellipse area value (P < 0.001), poorer visual acuity (P = 0.002), advanced stage (P = 0.002), thicker central fovea thickness (P = 0.015), and a longer preferred retinal locus-fovea distance (P = 0.025). As for the improved fixation location, the associated preoperative factors were age (P = 0.003), central fovea thickness (P = 0.044), and preferred retinal locus-fovea distance (P < 0.001). CONCLUSION: Our observations point to the changes of fixation parameters in patients after ERM surgery. We found that patients with preoperative unstable, eccentric fixation and poor BCVA can significantly benefit from the surgery. This result indicates that even in patients with severe macular damage, the ERM surgery still has great benefits in recovering visual function.


Asunto(s)
Membrana Epirretinal , Membrana Epirretinal/cirugía , Fijación Ocular , Fóvea Central , Humanos , Estudios Retrospectivos , Agudeza Visual
10.
Front Cardiovasc Med ; 8: 624796, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33791345

RESUMEN

Peroxiredoxin 2 (PRDX2), an inhibitor of reactive oxygen species (ROS), is potentially involved in the progression of atherosclerosis (AS). The aim of this study was to explore the role and mechanism of PRDX2 in AS. The expression of PRDX2 was evaluated in 14 human carotid artery tissues with or without AS. The results showed that the positive reaction of PRDX2 was observed in the carotid artery vascular smooth muscle cells (CAVSMCs). To assess the mechanism by which PRDX2 may function in AS, the CAVSMCs were transfected with pEX4-PRDX2 and si-PRDX2. The catalase, hydrogen peroxide (H2O2) scavenger, was used to further confirm that PRDX2-induced inhibitory effects might be mediated through reducing ROS levels. Phenotype alteration and functional testing included transcription testing, immunostaining, and expression studies. The drug of MAPK signaling pathway inhibitors SB203580, SP600125, and PD98059 was used to evaluate the underlying mechanism. In this study, we found that the protein level of PRDX2 and the level of H2O2 were higher in the human AS carotid artery tissues than in the normal carotid artery tissues, accompanied with the activation of MAPK signaling pathway. The up-regulation of PRDX2 in the CAVSMCs significantly decreased the expression of ROS, collagen type I (COL I), collagen type III (COL III), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) and inhibited the proliferation, migration, and transformation of the CAVSMCs. The up-regulation of PRDX2 reversed the effect of the CAVSMCs treated with tumor necrosis factor-α (TNF-α). In addition, PRDX2 down-regulation promoted the protein levels of p-p38, p-JNK, and p-ERK, which was confirmed in relevant MAPK inhibitor treatment experiments. Our results suggest a protective role of PRDX2, as a scavenger of ROS, in AS progression through inhibiting the VSMC phenotype alteration and function via MAPK signaling pathway.

11.
Int J Nanomedicine ; 15: 4959-4967, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32764929

RESUMEN

BACKGROUND: Particle-based drug delivery systems (DDSs) have a demonstrated value for drug discovery and development. However, some problems remain to be solved, such as limited stimuli, visual-monitoring. AIM: To develop an intelligent multicolor DDSs with both near-infrared (NIR) controlled release and macroscopic color changes. MATERIALS AND METHODS: Microparticles comprising GO/pNIPAM/PEGDA composite hydrogel inverse opal scaffolds, with dextran and calcium alginate hydrogel were synthesized using SCCBs as the template. The morphology of microparticle was observed under scanning electron microscopy, and FITC-dextran-derived green fluorescence images were determined using a confocal laser scanning microscope. During the drug release, FITC-dextran-derived green fluorescence images were captured using fluorescent inverted microscope. The relationship between the power of NIR and the drug release rate was obtained using the change in optical density (OD) values. Finally, the amount of drug released could be estimated quantitatively used the structural color or the reflection peak position. RESULTS: A fixed concentration 8% (v/v) of PEGDA and 4mg/mL of GO was chosen as the optimal concentration based on the balance between appropriate volume shrinkage and structure color. The FITC-dextran was uniformly encapsulated in the particles by using 0.2 wt% sodium alginate. The microcarriers shrank because of the photothermal response and the intrinsic fluorescence intensity of FITC-dextran in the microparticles gradually decreased at the same time, indicating drug release. With an increasing duration of NIR irradiation, the microparticles gradually shrank, the reflection peak shifted toward blue and the structural color changed from red to orange, yellow, green, cyan, and blue successively. The drug release quantity can be predicted by the structural color of microparticles. CONCLUSION: The multicolor microparticles have great potential in drug delivery systems because of its vivid reporting color, excellent photothermal effect, and the good stimuli responsivity.


Asunto(s)
Portadores de Fármacos/química , Microesferas , Resinas Acrílicas/química , Alginatos/química , Color , Dextranos/química , Liberación de Fármacos , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Hidrogeles/química , Fenómenos Ópticos , Polietilenglicoles/química
12.
Graefes Arch Clin Exp Ophthalmol ; 258(10): 2117-2124, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32607661

RESUMEN

PURPOSE: To explore the evolution of outer foveolar lucency (OFL) after vitrectomy and the correlation between OFL and visual acuity (VA) outcome in eyes with large idiopathic macular hole (IMH). METHODS: In this retrospective study, 244 eyes of 233 subjects with large IMH (diameter > 400 µm), who underwent vitrectomy, were included. Preoperative clinical data, postoperative optical coherence tomography (OCT) images, and VA at 1-, 4-, and 10-month visits were documented. The prevalence, incidence, and width of OFL and their correlation with postoperative VA were analyzed. RESULTS: The prevalence of OFL was 10.4% (24/231) at 1 month and significantly increased to 30.4% (55/181) at 4 months (P < 0.001) and 34.2% (25/73) at 10 months (P < 0.001). The incidence was 26.1% (40/153) and 22.0% (9/41) at 4 and 10 months, respectively. OFL appeared at 1 month while disappeared at 4 or 10 months in 8 eyes (50.0%). The presence of OFL at 1 month was negatively associated with IMH diameter (Nagelkerke R2 = 0.06; P = 0.02). Eyes with OFL at 4 months had better VA at their 4-month visit than eyes without OFL (P = 0.02). Eyes with early-developed OFLs had better VA at 10 months than those with later-developed ones (P = 0.02). Width of OFL was not associated with postoperative VA at any point. CONCLUSIONS: OFL is not rare in eyes with large IMH after surgery. It can occur gradually and remain during the 10-month follow-up. The presence of OFL appears to have no negative impact on the postoperative VA and it may represent the remodeling of foveal photoreceptors.


Asunto(s)
Perforaciones de la Retina , Fóvea Central , Humanos , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/cirugía , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía
14.
J Nanobiotechnology ; 17(1): 37, 2019 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-30841927

RESUMEN

BACKGROUND: Magnetosomes (also called bacterial magnetic nanoparticles; BMPs) are biomembrane-coated nanoparticles synthesized by magnetotactic bacteria (MTB). Engineered BMPs fused to protein A (termed ∆F-BMP-FA) bind antibodies (Abs) automatically, and thus provide a series of potential advantages. However, no report so far has systematically evaluated functional applicability of genetically engineered BMPs. RESULTS: We evaluated properties of ∆F-BMP-FA, and developed/optimized culture methods for host strain Magnetospirillum gryphiswaldense ΔF-FA, ∆F-BMP-FA extraction conditions, conditions for Ab conjugation to ∆F-BMP-FA surface, and procedures for antigen detection using ∆F-BMP-FA/Ab complexes (termed BMP-A-Ab). Fed-batch culture for 36 h in a 42-L fermentor resulted in yields (dry weight) of 2.26 g/L for strain ΔF-FA and 62 mg/L for ∆F-BMP-FA. Optimal wash cycle number for ∆F-BMP-FA purification was seven, with magnetic separation following each ultrasonication step. Fusion of protein A to BMPs resulted in ordered arrangement of Abs on BMP surface. Linkage rate 962 µg Ab per mg ∆F-BMP-FA was achieved. BMP-A-Ab were tested for detection of pathogen (Vibrio parahaemolyticus; Vp) surface antigen and hapten (gentamicin sulfate). Maximal Vp capture rate for BMP-A-Ab was 90% (higher than rate for commercial immunomagnetic beads), and detection sensitivity was 5 CFU/mL. ∆F-BMP-FA also bound Abs from crude mouse ascites to form complex. Lowest gentamicin sulfate detection line for BMP-A-Ab was 0.01 ng/mL, 400-fold lower than that for double Ab sandwich ELISA, and gentamicin sulfate recovery rate for BMP-A-Ab was 93.2%. CONCLUSION: Our findings indicate that engineered BMPs such as ∆F-BMP-FA are inexpensive, eco-friendly alternatives to commercial immunomagnetic beads for detection or diagnostic immunoassays, and have high Ab-conjugation and antigen-adsorption capacity.


Asunto(s)
Nanopartículas de Magnetita/química , Magnetosomas/química , Magnetospirillum/química , Proteína Estafilocócica A/química , Animales , Anticuerpos/química , Antígenos Bacterianos/análisis , Reactores Biológicos , Ensayo de Inmunoadsorción Enzimática , Gentamicinas/análisis , Haptenos/análisis , Límite de Detección , Ratones , Ingeniería de Proteínas , Propiedades de Superficie , Vibrio parahaemolyticus/aislamiento & purificación
15.
Front Microbiol ; 5: 136, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24765089

RESUMEN

Magnetosomes are membrane-enclosed magnetite nanocrystals synthesized by magnetotactic bacteria (MTB). They display chemical purity, narrow size ranges, and species-specific crystal morphologies. Specific transmembrane proteins are sorted to the magnetosome membrane (MM). MamC is the most abundant MM protein of Magnetospirillum gryphiswaldense strain MSR-1. MamF is the second most abundant MM protein of MSR-1 and forms stable oligomers. We expressed staphylococcal protein A (SPA), an immunoglobulin-binding protein from the cell wall of Staphylococcus aureus, on MSR-1 magnetosomes by fusion with MamC or MamF. The resulting recombinant magnetosomes were capable of self-assembly with the Fc region of mammalian antibodies (Abs) and were therefore useful for functionalization of magnetosomes. Recombinant plasmids pBBR-mamC-spa and pBBR-mamF-spa were constructed by fusing spa (the gene that encodes SPA) with mamC and mamF, respectively. Recombinant magnetosomes with surface expression of SPA were generated by introduction of these fusion genes into wild-type MSR-1 or a mamF mutant strain. Studies with a Zeta Potential Analyzer showed that the recombinant magnetosomes had hydrated radii significantly smaller than those of WT magnetosomes and zeta potentials less than -30 mV, indicating that the magnetosome colloids were relatively stable. Observed conjugation efficiencies were as high as 71.24 µg Ab per mg recombinant magnetosomes, and the conjugated Abs retained most of their activity. Numbers of Vibrio parahaemolyticus (a common pathogenic bacterium in seafood) captured by recombinant magnetosome/Ab complexes were measured by real-time fluorescence-based quantitative PCR. One mg of complex was capable of capturing as many as 1.74 × 10(7) Vibrio cells. The surface expression system described here will be useful for design of functionalized magnetosomes from MSR-1 and other MTB.

16.
Genome Announc ; 2(2)2014 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-24625872

RESUMEN

We report the complete genomic sequence of Magnetospirillum gryphiswaldense MSR-1 (DSM 6361), a type strain of the genus Magnetospirillum belonging to the Alphaproteobacteria. Compared to the reported draft sequence, extensive rearrangements and differences were found, indicating high genomic flexibility and "domestication" by accelerated evolution of the strain upon repeated passaging.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...