Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
J Transl Med ; 20(1): 574, 2022 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-36482390

RESUMEN

BACKGROUND: This study aimed to develop a radiogenomic prognostic prediction model for colorectal cancer (CRC) by investigating the biological and clinical relevance of intratumoural heterogeneity. METHODS: This retrospective multi-cohort study was conducted in three steps. First, we identified genomic subclones using unsupervised deconvolution analysis. Second, we established radiogenomic signatures to link radiomic features with prognostic subclone compositions in an independent radiogenomic dataset containing matched imaging and gene expression data. Finally, the prognostic value of the identified radiogenomic signatures was validated using two testing datasets containing imaging and survival information collected from separate medical centres. RESULTS: This multi-institutional retrospective study included 1601 patients (714 females and 887 males; mean age, 65 years ± 14 [standard deviation]) with CRC from 5 datasets. Molecular heterogeneity was identified using unsupervised deconvolution analysis of gene expression data. The relative prevalence of the two subclones associated with cell cycle and extracellular matrix pathways identified patients with significantly different survival outcomes. A radiogenomic signature-based predictive model significantly stratified patients into high- and low-risk groups with disparate disease-free survival (HR = 1.74, P = 0.003). Radiogenomic signatures were revealed as an independent predictive factor for CRC by multivariable analysis (HR = 1.59, 95% CI:1.03-2.45, P = 0.034). Functional analysis demonstrated that the 11 radiogenomic signatures were predominantly associated with extracellular matrix and immune-related pathways. CONCLUSIONS: The identified radiogenomic signatures might be a surrogate for genomic signatures and could complement the current prognostic strategies.


Asunto(s)
Neoplasias Colorrectales , Genómica , Humanos , Anciano , Estudios Retrospectivos , Estudios de Cohortes , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/genética , Tomografía Computarizada por Rayos X
2.
Med Image Anal ; 80: 102515, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35780593

RESUMEN

Since segmentation labeling is usually time-consuming and annotating medical images requires professional expertise, it is laborious to obtain a large-scale, high-quality annotated segmentation dataset. We propose a novel weakly- and semi-supervised framework named SOUSA (Segmentation Only Uses Sparse Annotations), aiming at learning from a small set of sparse annotated data and a large amount of unlabeled data. The proposed framework contains a teacher model and a student model. The student model is weakly supervised by scribbles and a Geodesic distance map derived from scribbles. Meanwhile, a large amount of unlabeled data with various perturbations are fed to student and teacher models. The consistency of their output predictions is imposed by Mean Square Error (MSE) loss and a carefully designed Multi-angle Projection Reconstruction (MPR) loss. Extensive experiments are conducted to demonstrate the robustness and generalization ability of our proposed method. Results show that our method outperforms weakly- and semi-supervised state-of-the-art methods on multiple datasets. Furthermore, our method achieves a competitive performance with some fully supervised methods with dense annotation when the size of the dataset is limited.


Asunto(s)
Aprendizaje Profundo , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Automático Supervisado
3.
Br J Radiol ; 94(1122): 20201007, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33881930

RESUMEN

OBJECTIVES: To develop and validate a radiomic model to predict the rapid progression (defined as volume growth of pneumonia lesions > 50% within seven days) in patients with coronavirus disease 2019 (COVID-19). METHODS: Patients with laboratory-confirmed COVID-19 who underwent longitudinal chest CT between January 01 and February 18, 2020 were included. A total of 1316 radiomic features were extracted from the lung parenchyma window for each CT. The least absolute shrinkage and selection operator (LASSO), Relief, Las Vegas Wrapper (LVW), L1-norm-Support Vector Machine (L1-norm-SVM), and recursive feature elimination (RFE) were applied to select the features that associated with rapid progression. Four machine learning classifiers were used for modeling, including Support Vector Machine (SVM), Random Forest (RF), Logistic Regression (LR), and Decision Tree (DT). Accordingly, 20 radiomic models were developed on the basis of 296 CT scans and validated in 74 CT scans. Model performance was determined by the receiver operating characteristic curve. RESULTS: A total of 107 patients (median age, 49.0 years, interquartile range, 35-54) were evaluated. The patients underwent a total of 370 chest CT scans with a median interval of 4 days (interquartile range, 3-5 days). The combination methods of L1-norm SVM and SVM with 17 radiomic features yielded the highest performance in predicting the likelihood of rapid progression of pneumonia lesions on next CT scan, with an AUC of 0.857 (95% CI: 0.766-0.947), sensitivity of 87.5%, and specificity of 70.7%. CONCLUSIONS: Our radiomic model based on longitudinal chest CT data could predict the rapid progression of pneumonia lesions, which may facilitate the CT follow-up intervals and reduce the radiation. ADVANCES IN KNOWLEDGE: Radiomic features extracted from the current chest CT have potential in predicting the likelihood of rapid progression of pneumonia lesions on the next chest CT, which would improve clinical decision-making regarding timely treatment.


Asunto(s)
COVID-19/diagnóstico por imagen , Neumonía Viral/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Árboles de Decisión , Progresión de la Enfermedad , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/virología , Valor Predictivo de las Pruebas , SARS-CoV-2 , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
4.
Sci Total Environ ; 776: 145735, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33640544

RESUMEN

Odor emissions from intensive livestock farms have attracted increased attention due to their adverse impacts on the environment and human health. Nevertheless, a systematic summary regarding the characteristics, sampling detection, and control technology for odor emissions from livestock farms is currently lacking. This paper compares the development of odor standards in different countries and summarizes the odor emission characteristics of livestock farms. Ammonia, the most common odor substance, can reach as high as 4100 ppm in the compost area. Sampling methods for point and area source odor emissions are introduced in this paper, and odor analysis methods are compared. Olfactometers, odorometers, and the triangle odor bag method are usually used to measure odor concentration. Odor control technologies are divided into three categories: physical (activated carbon adsorption, masking, and dilution diffusion), chemical (plant extract spraying, wet scrubbing, combustion, non-thermal plasma, and photocatalytic oxidation), and biological (biofiltration, biotrickling, and bioscrubbing). Each technology is elucidated, and the performance in the removal of different pollutants is summarized. The application scopes, costs, operational stability, and secondary pollution of the technologies are compared. The generation of secondary pollution and long-term operation stability are issues that should be considered in future technological development. Lastly, a case analysis for engineering application is conducted.


Asunto(s)
Compostaje , Odorantes , Amoníaco , Animales , Granjas , Humanos , Ganado
5.
Chem Commun (Camb) ; 57(12): 1518-1521, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33443496

RESUMEN

We demonstrate a 3,5-di(p-oxethyl)styryl conjugated BODIPY showing deep-red upconversion luminescence with a high efficiency of 16.6%. Furthermore, water-soluble BODIPY-doped upconversion nanoparticles with efficiency up to 6.9% under low excitation power density (∼1 mW cm-2) are developed and enable high-performance bioimaging in vivo.


Asunto(s)
Colorantes Fluorescentes/química , Ganglios Linfáticos/diagnóstico por imagen , Nanopartículas/química , Porfobilinógeno/análogos & derivados , Imagen de Cuerpo Entero/métodos , Animales , Rayos Infrarrojos , Ratones , Porfobilinógeno/química
6.
J Enzyme Inhib Med Chem ; 36(1): 130-137, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33243025

RESUMEN

A series of C4-substituted tertiary nitrogen-bearing 2'-hydroxychalcones were designed and synthesised based on a previous mixed type acetylcholinesterase inhibitor. Majority of the 2'-hydroxychalcone analogues displayed a better inhibition against acetylcholinesterase (AChE) than butyrylcholinesterase (BuChE). Among them, compound 4c was identified as the most potent AChE inhibitor (IC50: 3.3 µM) and showed the highest selectivity for AChE over BuChE (ratio >30:1). Molecular docking studies suggested that compound 4c interacts with both the peripheral anionic site (PAS) and catalytic anionic site (CAS) regions of AChE. ADMET analysis confirmed the therapeutic potential of compound 4c based on its blood-brain barrier penetrating. Overall, the results suggest that this 2'-hydroxychalcone deserves further investigation into the therapeutic lead for Alzheimer's disease (AD).


Asunto(s)
Acetilcolinesterasa/metabolismo , Chalconas/farmacología , Inhibidores de la Colinesterasa/farmacología , Butirilcolinesterasa/metabolismo , Chalconas/síntesis química , Chalconas/química , Inhibidores de la Colinesterasa/síntesis química , Inhibidores de la Colinesterasa/química , Relación Dosis-Respuesta a Droga , Humanos , Simulación del Acoplamiento Molecular , Estructura Molecular , Relación Estructura-Actividad
8.
BMC Cancer ; 20(1): 94, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32013960

RESUMEN

BACKGROUND: Lymphovascular invasion (LVI) is a vital risk factor for prognosis across cancers. We aimed to develop a scoring system for stratifying LVI risk in patients with breast cancer. METHODS: A total of 301 consecutive patients (mean age, 49.8 ± 11.0 years; range, 29-86 years) with breast cancer confirmed by pathological reports were retrospectively evaluated at the authors' institution between June 2015 and October 2018. All patients underwent contrast-enhanced Magnetic Resonance Imaging (MRI) examinations before surgery. MRI findings and histopathologic characteristics of tumors were collected for analysis. Breast LVI was confirmed by postoperative pathology. We used a stepwise logistic regression to select variables and two cut-points were determined to create a three-tier risk-stratification scoring system. The patients were classified as having low, moderate and high probability of LVI. The area under the receiver operating characteristic curve (AUC) was used to evaluate the discrimination ability of the scoring system. RESULTS: Tumor margins, lobulation sign, diffusion-weighted imaging appearance, MRI-reported axillary lymph node metastasis, time to signal intensity curve pattern, and HER-2 were selected as predictors for LVI in the point-based scoring system. Patients were considered at low risk if the score was < 3.5, moderate risk if the score was 3.5 to 6.0, and high risk if the score was ≥6.0. LVI risk was segmented from 0 to 100.0% and was positively associated with an increase in risk scores. The AUC of the scoring system was 0.824 (95% confidence interval [CI]: 0.776--0.872). CONCLUSION: This study shows that a simple and reliable score-based risk-stratification system can be practically used in stratifying the risk of LVI in breast cancer.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Metástasis Linfática/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Área Bajo la Curva , Femenino , Humanos , Modelos Logísticos , Persona de Mediana Edad , Invasividad Neoplásica , Estudios Retrospectivos
9.
Huan Jing Ke Xue ; 40(10): 4585-4593, 2019 Oct 08.
Artículo en Chino | MEDLINE | ID: mdl-31854827

RESUMEN

Under transient conditions, a biotrickling filter was developed to treat gaseous H2S produced from the fine-grid reservoir of a municipal wastewater treatment plant (WWTP) with AAO excess sludge as the inoculum and polypropylene rings as the packing material. The start-up process and steady-state operation of the biotrickling filter were studied. With an empty bed retention time of 14 s, an ambient temperature of 7.8-32.5℃, and an inlet concentration of 2.02-319.19 mg·m-3, an average removal efficiency of 91.8% was achieved with a maximum H2S elimination capacity of 78.37 g·(m3·h)-1. Over a 247-day period, the pressure drop across the biotrickling filter was maintained at 96 Pa·m-1. Microbial analysis using high-throughput sequencing technology showed a variation in the microbial community during the experiment; the Shannon index dropped from 4.99 to 3.75, and the functional genera Pseudomonas and Thiobacillus were identified as good performers in the biotrickling filter system. These results indicate that the application of AAO excess sludge as an inoculum for biotrickling filters is feasible for effective H2S removal. A steady pressure drop was achieved using polypropylene rings as the packing material. The diversity of the microbial community showed a downward trend when exposed to H2S, but the elimination capacity could be increased.


Asunto(s)
Biodegradación Ambiental , Sulfuro de Hidrógeno , Microbiota , Aguas Residuales , Reactores Biológicos , Filtración , Polipropilenos
10.
J Mater Chem B ; 7(17): 2782-2789, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-32255080

RESUMEN

Serum albumins perform various biological functions in bioorganisms, and abnormal levels of serum albumin are predictors of many diseases; contrary to the various approaches developed for the detection of serum albumins in blood and urine samples, limited tools are available for tracing and exploring endogenous serum albumins in living bioorganisms. Specifically, fluorescent probes have not been used for the exploration of endogenous serum albumins in zebrafish. Herein, we presented a versatile fluorescent probe (C7H) that highly specifically interacted with the site I of serum albumins. We succeeded in developing C7H as a visualized tool for tracing endogenous serum albumins in living larval zebrafish. Furthermore, C7H could be used as a fluorescent probe for the real-time monitoring of the wound area in larval zebrafish. Our results suggest that the larval zebrafish has a strong self-repair capacity for wound areas. Thus, C7H could be an efficient probe for studying wound healing in live zebrafish. Moreover, C7H can significantly expand the further understanding of wound healing in zebrafish, which may also promote the research on wound healing in human beings.


Asunto(s)
Albúmina Sérica/metabolismo , Cicatrización de Heridas/fisiología , Animales , Pez Cebra
11.
Chem Biol Drug Des ; 93(2): 132-138, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30216681

RESUMEN

Compounds with activity at serotonin (5-hydroxytryptamine) 5-HT2 and α1 adrenergic receptors have potential for the treatment of central nervous system disorders, drug addiction or overdose. Isolaureline, dicentrine and glaucine enantiomers were synthesized, and their in vitro functional activities at human 5-HT2 and adrenergic α1 receptor subtypes were evaluated. The enantiomers of isolaureline and dicentrine acted as antagonists at 5-HT2 and α1 receptors with (R)-isolaureline showing the greatest potency (pKb  = 8.14 at the 5-HT2C receptor). Both (R)- and (S)-glaucine also antagonized α1 receptors, but they behaved very differently to the other compounds at 5-HT2 receptors: (S)-glaucine acted as a partial agonist at all three 5-HT2 receptor subtypes, whereas (R)-glaucine appeared to act as a positive allosteric modulator at the 5-HT2A receptor.


Asunto(s)
Aporfinas/química , Receptor de Serotonina 5-HT2A/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Serotonina/química , Agonistas de Receptores Adrenérgicos alfa 1/química , Agonistas de Receptores Adrenérgicos alfa 1/metabolismo , Aporfinas/metabolismo , Sitios de Unión , Células HEK293 , Humanos , Cinética , Simulación del Acoplamiento Molecular , Estructura Terciaria de Proteína , Receptor de Serotonina 5-HT2A/química , Receptor de Serotonina 5-HT2A/genética , Receptores Adrenérgicos alfa 1/química , Receptores Adrenérgicos alfa 1/genética , Serotonina/metabolismo , Agonistas del Receptor de Serotonina 5-HT2/química , Agonistas del Receptor de Serotonina 5-HT2/metabolismo , Estereoisomerismo , Relación Estructura-Actividad
12.
Mikrochim Acta ; 185(7): 338, 2018 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-29946991

RESUMEN

A sandwich-type electrochemical cytosensor is described for quantitative determination of CD44-overexpressing HeLa cells. Hyaluronic acid (HA) acts as a targeting molecule that was in-situ incorporated into the sensor based on the use of an indium tin oxide (ITO) electrode modified with multi-walled carbon nanotubes (MWCNTs). The 3D-MWCNT structure is shown to strongly improve the electronic properties and surface chemical reactivities. The HA-modified sensor exhibits a highly sensitive response to HeLa cells. A sandwiched hybridization protocol was then established using BIO [an N-butyl-4-(6'-aminohexyl)amino-1,8-naphthalimide probe modified with HA] as the tracing labels of the fluorescent probes for targeting CD44-positive tumor cells. The signal amplification was thereby maximized and measured by chronocoulometry. The binding of CD44-positive HeLa cells to the HA modified sensing layer causes a decrease in chronocoulometric response. The signal decreases linearly in the 2.1 × 102 to 2.1 × 107 HeLa cells·mL-1 concentration range with a detection limit of 70 cells·mL-1. Such a sandwich-type assay may be tailored as a sensitive candidate for detecting low levels of tumor cells. Graphical abstract Schematic of a sandwich cytosensor based on hyaluronic acid-grafted 3D-MWCNT as biosensing interface and BIO as fluorescent probe. This biosensor possessed excellent electrochemical activity, high sensitivity and selectivity, providing a dynamical tracking and detecting platform for CD44-positive tumor cells.


Asunto(s)
Técnicas Biosensibles/métodos , Colorimetría/métodos , Regulación Neoplásica de la Expresión Génica , Receptores de Hialuranos/metabolismo , Ácido Hialurónico/química , Nanotubos de Carbono/química , Imagen Óptica/métodos , Línea Celular Tumoral , Humanos , Límite de Detección
13.
Small ; 12(29): 3995-4006, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27345304

RESUMEN

Hypoxia, which has been well established as a key feature of the tumor microenvironment, significantly influences tumor behavior and treatment response. Therefore, imaging for tumor hypoxia in vivo is warranted. Although some imaging modalities for detecting tumor hypoxia have been developed, such as magnetic resonance imaging, positron emission tomography, and optical imaging, these technologies still have their own specific limitations. As computed tomography (CT) is one of the most useful imaging tools in terms of availability, efficiency, and convenience, the feasibility of using a hypoxia-sensitive nanoprobe (Au@BSA-NHA) for CT imaging of tumor hypoxia is investigated, with emphasis on identifying different levels of hypoxia in two xenografts. The nanoprobe is composed of Au nanoparticles and nitroimidazole moiety which can be electively reduced by nitroreductase under hypoxic condition. In vitro, Au@BSA-NHA attain the higher cellular uptake under hypoxic condition. Attractively, after in vivo administration, Au@BSA-NHA can not only monitor the tumor hypoxic environment with CT enhancement but also detect the hypoxic status by the degree of enhancement in two xenograft tumors with different hypoxic levels. The results demonstrate that Au@BSA-NHA may potentially be used as a sensitive CT imaging agent for detecting tumor hypoxia.


Asunto(s)
Medios de Contraste/química , Tomografía Computarizada por Rayos X/métodos , Hipoxia Tumoral/fisiología , Animales , Línea Celular Tumoral , Fibrosarcoma/diagnóstico por imagen , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Pancreáticas/diagnóstico por imagen
14.
ACS Appl Mater Interfaces ; 7(18): 10013-21, 2015 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-25898141

RESUMEN

Fluorescence polarization (FP)-based signal is a self-referencing fluorescence signal, and it is less dependent on dye concentration and environmental interferences, which makes FP measurement an attractive alternative sensing technology to fluorescence intensity-based detection. However, most of the fluorescence polarization probes were constructed by introducing fluorescein, rhodamine, and cyanine dyes, which have relatively shorter excited-state lifetimes compared with BODIPY and naphthalimide dyes. Herein, a first naphthalimide based fluorescence polarization probe (BIO) was designed and synthesized for selective and direct detection of cancer cells. The relatively longer excited-state lifetimes and high photostability of naphthalimide makes BIO more sensitive and accuracy in quantitative determination of HeLa cells in homogeneous solution without cell lysis and further separation steps. The detection limit of BIO for HeLa cells was about 85 cells mL(-1), the linear range was from 2.5 × 10(2) cells mL(-1) to 1 × 10(6) cells mL(-1) and the response time is no more than 25 min. Moreover, due to the relatively high photostability of naphthalimide, BIO was particularly suitable for live cell imaging under continuous irradiation with confocal microscopy, and the specific interaction of BIO with CD44-overexpressing cell lines was clearly visualized. Importantly, this BIO based sensing platform offers a direct and real-time tool for cancer cell diagnosis when complemented with the use of naphthalimide-based fluorescence polarization probe.


Asunto(s)
Colorantes Fluorescentes/química , Naftalimidas/química , Neoplasias/diagnóstico , Supervivencia Celular , Endocitosis , Polarización de Fluorescencia , Células HeLa , Humanos , Receptores de Hialuranos/metabolismo , Lisosomas/metabolismo , Naftalimidas/síntesis química , Fracciones Subcelulares/metabolismo
15.
Biosens Bioelectron ; 63: 513-518, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25145984

RESUMEN

Periodate is widely used in organic and bioorganic chemistry, and also related to food and environmental safety. To best of our knowledge, there is no efficient tools reported for simultaneously quantifying periodate with high accuracy and discriminating periodate from other forms of iodine. We have synthesized, characterized and applied a first ratiometric fluorescent probe (PDS-2) for simultaneous monitoring of changes of periodate based on the excited-state intramolecular proton transfer mechanism. This PDS-2 based fluorescent technique may enable for a better understanding of periodate related biological and chemical processes. Also, it is an efficient tool for public health, food safety and environmental protection.


Asunto(s)
Colorantes Fluorescentes/química , Microscopía Fluorescente/métodos , Imagen Molecular/métodos , Ácido Peryódico/análisis , Ácido Peryódico/metabolismo , Colorantes Fluorescentes/análisis , Células HeLa , Humanos , Ácido Peryódico/química , Agua/química
16.
Chem Asian J ; 9(12): 3397-402, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25294398

RESUMEN

An easily available naphthalimide-based fluorescent probe NPA for Pb(2+) detection was successfully developed. NPA exhibited an obvious fluorescence turn-on response toward Pb(2+) in aqueous solution and in living cells. Moreover, a series of model compounds were rationally designed and synthesized in order to explore the sensing mechanism and binding mode of NPA with Pb(2+) .


Asunto(s)
Fluorescencia , Colorantes Fluorescentes/química , Plomo/análisis , Naftalimidas/química , Supervivencia Celular , Células HeLa , Humanos , Estructura Molecular , Soluciones , Agua/química
17.
Org Biomol Chem ; 12(42): 8422-7, 2014 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-25220214

RESUMEN

Three fluorescent probes TP1­3 for thiols were rationally designed and synthesized to distinguish cysteine (Cys) from glutathione (GSH)/homocysteine (Hcy). TP1­3 are almost non-fluorescent and colorless 4-nitro-1,8-naphthalimide derivatives. Upon the substitution of nitro by Cys, TP1­3 were transformed into weakly fluorescent green-emitting 4-amino analogs via highly fluorescent blue-emitting thioether intermediates. The three-channel signaling capability allows discrimination between Cys and GSH/Hcy. The fluorescence intensity at 498 nm was linearly proportional to GSH concentration in the range of 0-20 µM, and the detection limit was 5 × 10(-8) mol L(-1). A good linear relationship between A446/A350 and Cys concentration was found in the range of 0-70 µM, and the detection limit was 2 × 10(-7) mol L(-1). Moreover, TP3 was used for living cell imaging as well as for detecting mercapto-containing proteins.


Asunto(s)
Cisteína/análisis , Colorantes Fluorescentes/química , Glutatión/análisis , Homocisteína/análisis , Línea Celular , Humanos , Límite de Detección , Imagen Óptica/métodos , Espectrometría de Fluorescencia/métodos
18.
J Am Chem Soc ; 136(40): 14237-44, 2014 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-25225148

RESUMEN

Protein vicinal dithiols play fundamental roles in intracellular redox homeostasis due to their involvement in protein synthesis and function through the reversible vicinal dithiol oxidation to disulfide. To provide quantitative information about the global distribution and dynamic changes of protein vicinal dithiols in living cells, we have designed and synthesized a ratiometric fluorescent probe (VTAF) for trapping of vicinal dithiol-containing proteins (VDPs) in living cells. VTAF exhibits a ratiometric fluorescence signal upon single excitation, which enables self-calibration of the fluorescence signal and quantification of endogenous vicinal dithiols of VDPs. Its potential for in situ dynamic tracing of changes of protein vicinal dithiols under different cellular redox conditions was exemplified. VTAF facilitated the direct observation of subcellular distribution of endogenous VDPs via ratiometric fluorescence imaging and colocalization assay. And the results suggested that there are abundant VDPs in mitochondria. Moreover, some redox-sensitive VDPs are also present on cell surface which can respond to redox stimulus. This ratiometric fluorescence technique presents an important extension to previous fluorescence intensity-based probes for trapping and quantifying protein vicinal dithiols in living cells, as well as its visible dynamic tracing of VDPs.


Asunto(s)
Colorantes Fluorescentes/química , Imagen Molecular , Proteínas/química , Proteínas/metabolismo , Tolueno/análogos & derivados , Animales , Bovinos , Supervivencia Celular , Humanos , Células MCF-7 , Mitocondrias/metabolismo , Fenómenos Ópticos , Oxidación-Reducción
19.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 5): m599-600, 2011 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-21754319

RESUMEN

The asymmetric unit of the title compound, [Cu(2)(C(16)H(31)O(2))(4)(C(10)H(8)N(2))(2)]·2CH(3)OH, contains one half-mol-ecule of the metal complex solvated by a methanol mol-ecule. In the complex, two of the metal atoms are doubly bridged by two monodentate bridging hexa-deca-noate ligands around a center of inversion. The square-pyramidal geometry around each Cu(II) ion is completed by a terminal hexa-deca-noate O atom and two N atoms from a 2,2'-bipyridine ligand. The alkyl chains of the carboxyl-ate ligands are arranged in a parallel manner with an all-trans conformation. In the crystal, a π-π inter-action formed by the bipyridine rings [centroid-centroid separation = 3.7723 (17) Å] and inter-molecular C-H⋯O hydrogen bonds link the complex mol-ecules into infinite chains along the b axis. An O-H⋯O interaction between the methanol solvate and one of the carboxylate O atoms is also observed.

20.
Zhonghua Yi Xue Za Zhi ; 91(35): 2468-71, 2011 Sep 20.
Artículo en Chino | MEDLINE | ID: mdl-22321841

RESUMEN

OBJECTIVE: To explore the efficacy of arthroscopic repair of medial patellofemoral ligament (MPFL) for adolescents with epiphyseal non-closure by allogenic tendon in the treatment of instable patellofemoral joint. METHODS: There were a total of 38 cases including 61 knees with patellofemoral instability from June 2008 to January 2010 at our department. They were diagnosed according to the history of illness, apprehension test and tangential position radiograph in patellofemoral joint. RESULTS: A total of 33 patients with 52 knees were followed up for an average of 12 months (range: 8 - 19). All apprehension tests were negative. No recurrent displacement was found. The pre-operative Lysholm score of 75.5 ± 4.7 increased to 91.1 ± 5.7. There was significant difference. CONCLUSION: Arthroscope-assisted allograft reconstruction of medial patellofemoral ligament tendon is both mini-invasive and reliable for the treatment of epiphyseal non-closure adolescents with traumatic patellofemoral instability.


Asunto(s)
Luxación de la Rótula , Articulación Patelofemoral , Adolescente , Humanos , Ligamentos Articulares/cirugía , Procedimientos de Cirugía Plástica , Tendones/trasplante
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...