Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Drug Des Devel Ther ; 18: 1459-1467, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38707613

RESUMEN

Background: Ondansetron reduces the median effective dose (ED50) of prophylactic phenylephrine to prevent spinal-induced hypotension (SIH) during cesarean delivery. However, the exact dose response of phenylephrine in combination with prophylactic ondansetron for preventing SIH is unknown. Therefore, this study aimed to determine the dose-response of phenylephrine to prevent SIH in cesarean delivery when 4 mg of ondansetron was used as a preventive method. Methods: A total of 80 parturients were enrolled and divided randomly into four groups (n = 20 in each group) who received either 0.2, 0.3, 0.4, or 0.5 µg/kg/min of prophylactic phenylephrine. Ten minutes before the initiation of spinal induction, 4 mg prophylactic ondansetron was administered. The effective dose of prophylactic phenylephrine was defined as the dose required to prevent hypotension after the period of intrathecal injection and up to neonatal delivery. The ED50 and ED90 of prophylactic phenylephrine and 95% confidence intervals (95% CI) were calculated using probit analysis. Results: The ED50 and ED90 for prophylactic phenylephrine to prevent SIH were 0.25 (95% CI, 0.15 to 0.30), and 0.45 (95% CI, 0.39 to 0.59) µg/kg/min, respectively. No significant differences were observed in the side effects and neonatal outcomes between the four groups. Conclusion: The administration of 4 mg of prophylactic ondansetron was associated with an ED50 of 0.25 (95% CI, 0.15~0.30) and ED90 of 0.45 (95% CI, 0.39~0.59) µg/kg/min for phenylephrine to prevent SIH.


Asunto(s)
Anestesia Raquidea , Cesárea , Relación Dosis-Respuesta a Droga , Hipotensión , Ondansetrón , Fenilefrina , Adulto , Femenino , Humanos , Embarazo , Anestesia Epidural , Anestesia Raquidea/efectos adversos , Hipotensión/prevención & control , Hipotensión/inducido químicamente , Ondansetrón/administración & dosificación , Fenilefrina/administración & dosificación
2.
Front Cell Infect Microbiol ; 11: 631921, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33718280

RESUMEN

Salmonella spp. is among the main foodborne pathogens which cause serious foodborne diseases. An isothermal real-time recombinase polymerase amplification (RPA) and lateral flow strip detection (LFS RPA) were used to detect Salmonella spp. targeting the conserved sequence of invasion protein A (invA). The Real-time RPA was performed in a portable florescence scanner at 39°C for 20 min. The LFS RPA was performed in an incubator block at 39°C for 15 min, under the same condition that the amplifications could be inspected by the naked eyes on the LFS within 5 min. The detection limit of Salmonella spp. DNA using real-time RPA was 1.1 × 101 fg, which was the same with real-time PCR but 10 times higher than that of LFS RPA assay. Moreover, the practicality of discovering Salmonella spp. was validated with artificially contaminated lamb, chicken, and broccoli samples. The analyzing time dropped from 60 min to proximately 5-12 min on the basis of the real-time and LFS RPA assays compared with the real-time PCR assay. Real-time and LFS RPA assays' results were equally reliable. There was no cross-reactivity with other pathogens in both assays. In addition, the assays had good stability. All of these helped to show that the developed RPA assays were simple, rapid, sensitive, credible, and could be a potential point-of-need (PON) test required mere resources.


Asunto(s)
Técnicas de Amplificación de Ácido Nucleico , Recombinasas , Animales , Nucleotidiltransferasas , Salmonella , Sensibilidad y Especificidad , Ovinos
3.
Exp Ther Med ; 19(3): 2384-2390, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32104307

RESUMEN

Anti-T-lymphocyte globulin (ATG) is frequently used in the induction regimen of renal transplantation, but its dose has not been standardized. In the present study, the efficacy of different ATG-Fresenius (ATG-F) doses was assessed in recipients of renal transplantation. A total of 131 adult recipients of renal transplantation who received ATG-F induction between August 2015 and July 2018 were included. The incidence of biopsy-confirmed acute rejection, graft function, as well as graft and patient survival within 12 months post-transplant, was assessed, and adverse events, including hematologic and infection-associated side effects, were compared between patients receiving a cumulative ATG-F dose of <7 or ≥7 mg/kg. The incidence of biopsy-confirmed acute rejection was similar between patients receiving cumulative doses of <7 and ≥7 mg/kg (7.5 vs. 4.7%, P=0.766). The incidence of infection within 12 months was lower in the ATG-F <7 mg/kg group compared with that in the ≥7 mg/kg group (26.9 vs. 50.0%, P=0.006), but the incidence of pneumonia did not differ between the ATG-F <7 and ≥7 mg/kg groups (10.4 vs. 20.3%, P=0.117). The incidence of urinary infection was higher in the ≥7 mg/kg group than in the <7 mg/kg group (20.4 vs. 7.46%, P=0.033), while the extent and duration of anemia and lymphopenia was similar between groups. There was no difference in graft function, delayed graft function, as well as overall and graft survival between the groups. In conclusion, a moderate reduction in the cumulative ATG-F dose was not associated with an increased risk of acute rejection, while the risk of infection was reduced. Optimization of the ATG-F dose for induction may facilitate the reduction of the risk of infection without compromising the induction efficacy in renal transplant recipients.

4.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 41(5): 622-629, 2019 Oct 30.
Artículo en Chino | MEDLINE | ID: mdl-31699192

RESUMEN

Objective To investigate the clinical value of preoperative lymphocyte-to-monocyte ratio(LMR)in evaluating the prognosis of patients with stage T1 non-muscle invasive bladder cancer(NMIBC).Methods A total of 215 patients with stage T1 NMIBC who underwent transurethral resection of bladder tumor were enrolled.Clinical data were collected.Patients were followed up and their disease-free survival(DFS)and overall survival(OS)were recorded.The receiver operating characteristic(ROC)curve of preoperative LMR in detecting patient prognosis was used to determine the optimal cut-off value for LMR.Patients were divided into low LMR group(LMR <3.86,n=77)and high LMR group(LMR ≥ 3.86,n=138).Kaplan-Meier survival curves were explored to compare cumulative DFS and OS rates in patients with different LMR levels,and COX proportional hazards regression model was used to analyze factors associated with DFS and OS.Results All these 215 patients with T1 stage NMIBC were followed up for 2-92 months,and the DFS rate was 59.07% and OS rate was 65.12%.Kaplan-Meier curves showed that the cumulative DFS rate(χ 2=4.784,P=0.029)and cumulative OS rate(χ 2=7.146, P=0.008)in the low LMR group were significantly lower than those in the high LMR group.Tumor size ≥ 3 cm(HR=1.398,95% CI:1.042-1.875,P=0.025),pathological grade G3(HR=1.266,95% CI:1.026-1.563,P=0.028),and LMR ≥ 3.86(HR=2.347,95% CI:1.080-5.101,P=0.031)were independent factors associated with DFS in patients with stage T1 NMIBC.In addition,tumor size ≥ 3 cm(HR=1.228,95% CI:1.015-1.484,P=0.034),pathological grade G3(HR=1.366,95% CI:1.017-1.834,P=0.038),and LMR<3.86(HR=2.008,95% CI:1.052-3.832,P=0.035)were independent factors associated with OS in patients with T1 stage NMIBC. Conclusion Preoperative LMR is an independent factor associated with patients' prognosis in T1 stage NIMBC.Patients with low LMR tend to have higher risk of NMIBC progression and death.


Asunto(s)
Linfocitos/citología , Monocitos/citología , Neoplasias de la Vejiga Urinaria/diagnóstico , Supervivencia sin Enfermedad , Humanos , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Neoplasias de la Vejiga Urinaria/patología
5.
BMC Microbiol ; 19(1): 186, 2019 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-31409301

RESUMEN

BACKGROUND: Vibrio parahaemolyticus (V. parahaemolyticus) is a leading cause of food poisoning and is of great importance to public health due to the frequency and seriousness of the diseases. The simple, timely and efficient detection of this pathogen is a major concern worldwide. In this study, we established a simple and rapid method based on recombinase polymerase amplification (RPA) for the determination of V. parahaemolyticus. According to the gyrB gene sequences of V. parahaemolyticus available in GenBank, specific primers and an exo probe were designed for establishing real-time recombinase polymerase amplification (real-time RPA). RESULTS: The real-time RPA reaction was performed successfully at 38 °C, and results were obtained within 20 min. The method only detected V. parahaemolyticus and did not show cross-reaction with other bacteria, exhibiting a high level of specificity. The study showed that the detection limit (LOD) of real-time RPA was 1.02 × 102 copies/reaction. For artificially contaminated samples with different bacteria concentrations, V. parahaemolyticus could be detected within 5-12 min by real-time RPA in oyster sauce, codfish and sleeve-fish at concentrations as low as 4 CFU/25 g, 1 CFU/25 g and 7 CFU/25 g, respectively, after enrichment for 6 h, but were detected in a minimum of 35 min by real-time PCR (Ct values between 27 and 32). CONCLUSION: This study describes a simple, rapid, and reliable method for the detection of V. parahaemolyticus, which could potentially be applied in the research laboratory and disease diagnosis.


Asunto(s)
Reacción en Cadena de la Polimerasa/métodos , Alimentos Marinos/microbiología , Vibrio parahaemolyticus/aislamiento & purificación , Animales , Proteínas Bacterianas/genética , Girasa de ADN/genética , Peces/microbiología , Contaminación de Alimentos/análisis , Ostreidae/microbiología , Sensibilidad y Especificidad , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/crecimiento & desarrollo
6.
J Microbiol Methods ; 157: 31-36, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30576752

RESUMEN

Campylobacter jejuni (C. jejuni), a foodborne pathogen, is a major contributor to human bacterial gastroenteritis worldwide and detrimental to public health. It is crucial for initiating appropriate outbreak control strategies to rapidly detect C. jejuni. As a novel isothermal gene amplification technique, recombinase polymerase amplification (RPA) has been developed for the molecular detection of diverse pathogens. In this study, we developed a real-time RPA assay so as to achieve the rapid and efficient detection of C. jejuni by targeting the hipO gene. The specificity and senstivity of real-time RPA was validated and the practical applicability of the method for the detection of C. jejuni in artificially contaminated milk and chicken breast samples was proved by comparing their reaction time, sensitivity, and efficacy with those of real-time PCR and culture-based methods. Based on the real-time RPA assay, analysis time was reduced to approximately 13 mins from 60 mins and the results were as reliable as those of the real-time PCR assay. Taken together, in terms of the detection of C. jejuni, the real-time RPA method was simple, rapid, sensitive, and reliable.


Asunto(s)
Amidohidrolasas/genética , Campylobacter jejuni/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Recombinasas/genética , Animales , Infecciones por Campylobacter/prevención & control , Campylobacter jejuni/genética , Pollos/microbiología , Enfermedades Transmitidas por los Alimentos/microbiología , Enfermedades Transmitidas por los Alimentos/prevención & control , Humanos , Carne/microbiología , Leche/microbiología , Técnicas de Diagnóstico Molecular/métodos , Sensibilidad y Especificidad
7.
Chirality ; 30(3): 268-274, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29232000

RESUMEN

Numbers of resolving factors were investigated to improve resolution of venlafaxine 1. An effective resolving agent, O,O'-di-p-toluoyl-(R, R)-tartaric acid 2, was screened using similar method of 'Dutch resolution' from tartaric acid derivatives. The resolution efficiency was up to 88.4%, when the ratio of rac-1 and 2 was 1:0.8 in THF with little water (10:1 v/v). Enantiomerically pure venlafaxine was prepared with 99.1% ee in 82.2% yield. The chiral resolution mechanism was first explained through X-ray crystallographic study. One diastereomeric salt with well solubility forms a columnar supramolecular structure as the acidic salt (R)-1·2, while the other diastereomeric salt with less solubility forms a multilayered sandwich supramolecular structure by enantio-differentiation self-assembly as the neutral salt 2(S)-1·2. The water molecules play a key role in the optical resolution, as indicated by the special structures of the diastereomeric salts.

8.
Mol Med Rep ; 16(6): 9652-9658, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29039541

RESUMEN

Sepsis is the most important predisposing cause inducing acute respiratory distress syndrome (ARDS); however, the mechanism of sepsis leading to the development of ARDS remains to be elucidated. Suppression of the mitogen­activated protein kinase (MAPK) signal by blocking the phosphorylation of Jun N­terminal kinase (JNK) and p38 in lung tissues could alleviate acute lung injury induced by sepsis. MAPK signaling may have a crucial role in development of the sepsis­induced acute lung injury. The specific inhibitors of JNK and p38 MAPK, SP600125 and SB203580, were administrated by intragastric injection 4 h before induction of ARDS after cecal ligation and puncture (CLP). Rats were sacrificed at 1, 6 or 24 h after CLP challenge. The histological evaluation, lung water content, and biochemical analysis were performed. The results revealed that the JNK and p38 MAPK inhibitor improved lung permeability, attenuated system inflammation, further alleviated the lung injury induced by sepsis. In conclusion, JNK and p38 MAPK signaling are essential for the development of ARDS following sepsis. Further studies are needed to illuminate the detailed mechanisms of JNK and p38 MAPK signaling in sepsis­induced ARDS.


Asunto(s)
Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/metabolismo , Sepsis/complicaciones , Lesión Pulmonar Aguda/patología , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Mediadores de Inflamación/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Masculino , Ratas , Síndrome de Dificultad Respiratoria/patología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Oncol Rep ; 38(4): 1941-1948, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28791382

RESUMEN

Besides being a key contributor to epithelial­to­mesenchymal transition (EMT) activation and stemness maintenance, zinc finger E-box binding homeobox 1 (ZEB1) is also a crucial inducer of chemoresistance and radioresistance. Unlike the clear mechanism that mediates its effect on EMT and dedifferentiation, the mechanism of how ZEB1 promotes chemo- and radio-resistance remains to be elucidated. It has been previously reported that ZEB1 promotes DNA double-strand break clearance by enhancing the deubiquitylating activity of ubiquitin-specific peptidase (USP)7 on checkpoint kinase 1, which is an important step during DNA repair. It was hypothesized that as a transcriptional suppressor, ZEB1 may be involved in an unbalanced DNA damage response (DDR) by affecting other key components. Therefore, in the present study, the target gene occupancy of ZEB1 was mapped in colorectal cancer cells using the ChIP-on-chip method, revealing positive intervals enriched along the three DDR-associated genes: USP17, chromodomain helicase DNA-binding protein 1-like and double homeobox 4. The E-boxes identified in the binding regions and the enhanced mRNA expression of the three genes following the knockdown of ZEB1 supported the identification of these three genes as downstream target genes of ZEB1. Furthermore, ZEB1 knockdown initiated a chemosensitization effect, induced G1/S arrest and increased apoptosis, which functionally validated the three ZEB1 downstream targets. In summary, the present study identified three DDR-associated genes as ZEB1 downstream targets, and demonstrated that their suppression by ZEB1 contributes to ZEB1-mediated chemoresistance.


Asunto(s)
Neoplasias Colorrectales/genética , Reparación del ADN , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/genética , Apoptosis/genética , Línea Celular Tumoral , Cisplatino/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Daño del ADN , ADN Helicasas/genética , ADN Helicasas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Endopeptidasas/genética , Endopeptidasas/metabolismo , Etopósido/farmacología , Técnicas de Silenciamiento del Gen , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismo
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 24(4): 1019-23, 2016 Aug.
Artículo en Chino | MEDLINE | ID: mdl-27531767

RESUMEN

OBJECTIVE: To investigate the effect and possible mechanism of bromo-domain inhibitors (JQ1) on proliferation inhibition and inducing apoptosis of acute T lymphocyte leukemia cell line (Jurkat) . METHODS: Jurkat cell line was treated by JQ1 at different concentrations. MTT was used to detect the cell proliferation inhibition rate. The flow cytometry with AnnexinV-FITC/PI fluorescence staining was used to detect the changes of apoptosis rate, and real-time fluorescent quantitative PCR was used to detect c-Myc/Notch1 gene expression levels. RESULTS: With the increasing of drug concentration and prolonging of time, the inhibitory rate of Jurkat cell growth was enhanced in time-dose dependent manner; Jurkat cells was treated by 0.8, 1.6, and 4 µ mol/LJQ1 for 48 h and 72 h, the cell apoptosis rate was enhanced with the increase of drug concentration and prolonging of time, and the difference was statistically different in comparison with the control group(P<0.05); PCR detection indicated that Notch1 and c-Myc mRNA expression was reduced in 48 h after JQ1 treatment, which was statistically different from the control group,(P<0.05) . CONCLUSION: JQ1 can effectively inhibit the growth of Jurkat cell line, and potentially induce apoptosis through Notch1 and c-Myc gene. Hence JQ1 may be one of new methods used to treat T-ALL.


Asunto(s)
Apoptosis , Proliferación Celular , Azepinas , Proteínas de Ciclo Celular , Citometría de Flujo , Genes myc , Humanos , Células Jurkat , Proteínas Nucleares , Factores de Transcripción , Triazoles
11.
Molecules ; 20(5): 9455-67, 2015 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-26007193

RESUMEN

This study aimed to explore the spectrum-effect relationships between high-performance liquid chromatography fingerprints and the uric acid-lowering activities of chicory. Chemical fingerprints of chicory samples from ten different sources were determined by high-performance liquid chromatography, and then investigated by similarity analysis and hierarchical clustering analysis. Pharmacodynamics experiments were conducted in animals to obtain the uric acid-lowering activity information of each chicory sample. The spectrum-effect relationships between chemical fingerprints and the uric acid-lowering activities of chicory were established by canonical correlation analysis. The structures of potential effective peaks were identified by liquid chromatography with tandem mass spectrometry. The results showed that a close correlation existed between the spectrum and effect of chicory. Aesculin, chlorogenic acid, chicoric acid, isochlorogenic acid A/B/C and 13,14-seco-stigma5(6),14(15)-diene-3α-ol might be the main effective constituents. This work provides a general model of the combination of high-performance liquid chromatography and uric acid-lowering activities to study the spectrum-effect relationships of chicory, which can be used to discover the principle components responsible for the bioactivity.


Asunto(s)
Cichorium intybus/metabolismo , Hiperuricemia/tratamiento farmacológico , Extractos Vegetales/farmacología , Ácido Úrico/sangre , Animales , Enfermedades Cardiovasculares/sangre , Cromatografía Líquida de Alta Presión , Hiperuricemia/sangre , Extractos Vegetales/química , Codorniz
12.
Chirality ; 27(3): 281-5, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25640306

RESUMEN

Efficient preparation of (R)-2-chloromandelic acid based on a recycle process of resolution is described. In the process, the desired was obtained by coordination-mediated resolution with D-O,O'-di-(p-toluoyl)-tartaric acid in the presence of Ca(2+) . Meanwhile, the undesired could be racemized in the presence of sodium hydroxide and the product was suitable for further resolution. A carbanion mechanism for the racemization of is proposed.


Asunto(s)
Ácidos Mandélicos/química , Estereoisomerismo
13.
Plant Cell Rep ; 33(8): 1333-41, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24756881

RESUMEN

KEY MESSAGE: We isolated an MYB-like gene from Korla fragrant pear using differential display RT-PCR. Expression of this gene in flowers appears to be correlated with calyx persistence. Korla fragrant pear (Pyrus brestschneideri Rehd) is an economically important pear cultivar in China. A persistent calyx results in the deformation of the fruit. We used differential display RT-PCR to obtain 42 cDNA fragments from Korla fragrant pear flowers. Alignments of nucleotide and amino acid sequences suggested that two fragments (kfp1and kfp4) were related to calyx persistence. The fragments were 78% homologous with Malus × domestica SPL transcription factor (SPL3) and 83% homologous with Malus × domestica MYB transcription factor (MYB12). The complete cDNA sequence of kfpMYB was determined to clarify the role of MYB in calyx persistence. kfpMYB contained a 116 bp 5'-UTR, a 1122 bp open reading frame encoding 374 amino acids, and a 319 bp 3'-UTR. The nucleotide and amino acid sequences of the cDNA in Korla fragrant pear were highly homologous with those of MYB transcription factors in other plant species, suggesting that the sequence is a MYB transcription factor gene. The abundance of kfpMYB mRNA varied significantly between the second and fourth flowers on the branch. Furthermore, kfpMYB expression changed significantly during anthesis and was significantly higher in Jinfeng pear (persistent calyx) and Korla fragrant pear than in Yali pear (deciduous calyx). Expression of kfpMYB was significantly reduced by naphthalene (NAA), abscisic acid (ABA), PBO, and paclobutrazol (PP333). Uniconazole, ethylene (ETH), and gibberellic acid (GA3) had no signicant effect on kfpMYB expression. In conclusion, the expression of kfpMYB appears to be correlated with calyx persistence in Korla fragrant pear.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Pyrus/genética , Factores de Transcripción/genética , Ácido Abscísico/farmacología , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Flores/genética , Frutas/genética , Frutas/crecimiento & desarrollo , Perfilación de la Expresión Génica , Datos de Secuencia Molecular , Naftalenos/farmacología , Filogenia , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estructura Secundaria de Proteína , Pyrus/crecimiento & desarrollo , ARN de Planta/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Factores de Transcripción/metabolismo , Triazoles/farmacología
14.
Biochim Biophys Acta ; 1814(12): 1703-12, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21979582

RESUMEN

Increasing evidence indicates that amyloid aggregates, including oligomers, protofibrils or fibrils, are pivotal toxins in the pathogenesis of many amyloidoses such as Alzheimer's disease (AD), Parkinson's disease, Huntington's disease, prion-related diseases, type 2 diabetes and hereditary renal amyloidosis. Various oligomers assembled from different amyloid proteins share common structures and epitopes. Here we present data indicating that two oligomer-specific single chain variable fragment (scFv) antibodies isolated from a naïve human scFv library could conformation-dependently recognize oligomers assembled from α-synuclein, amylin, insulin, Aß1-40, prion peptide 106-126 and lysozyme, and fibrils from lysozyme. Further investigation showed that both scFvs inhibited the fibrillization of α-synuclein, amylin, insulin, Aß1-40 and prion peptide 106-126, and disaggregated their preformed fibrils. However, they both promoted the aggregation of lysozyme. Nevertheless, the two scFv antibodies could attenuate the cytotoxicity of all amyloids tested. Moreover, the scFvs recognized the amyloid oligomers in all types of plaques, Lewy bodies and amylin deposits in the brain tissues of AD and PD patients and the pancreas of type 2 diabetes patients respectively, and showed that most amyloid fibril deposits were colocalized with oligomers in the tissues. Such conformation-dependent scFv antibodies may have potential application in the investigation of aggregate structures, the mechanisms of aggregation and cytotoxicity of various amyloids, and in the development of diagnostic and therapeutic reagents for many amyloidoses.


Asunto(s)
Amiloide/inmunología , Amiloide/metabolismo , Amiloidosis/metabolismo , Dominios y Motivos de Interacción de Proteínas/inmunología , Anticuerpos de Cadena Única/metabolismo , Amiloide/química , Amiloidosis/patología , Reacciones Antígeno-Anticuerpo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Humanos , Cuerpos de Lewy/metabolismo , Cuerpos de Lewy/patología , Complejos Multiproteicos/inmunología , Complejos Multiproteicos/metabolismo , Unión Proteica , Conformación Proteica , Pliegue de Proteína , Multimerización de Proteína/inmunología , Anticuerpos de Cadena Única/inmunología , Distribución Tisular , Células Tumorales Cultivadas
15.
Neurochem Int ; 57(8): 914-22, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20933033

RESUMEN

Alzheimer's disease (AD) is a complex, multifactorial neurodegenerative disease. The aggregation of beta-amyloid (Aß) into extracellular fibrillar deposition is a pathological hallmark of AD. The Aß aggregate-induced neurotoxicity, inflammatory reactions and oxidative stress are linked strongly to the etiology of AD. The currently available hitting-one-target drugs are insufficient for the treatment of AD. Therefore, finding multipotent agents able to modulate multiple targets simultaneously is attracting more attention. Previous studies indicated that vitamin E or its constituent such as α-tocopherol (α-T) was able to attenuate the effects of several pathogenetic factors in AD. However, ineffective or detrimental results were obtained from a number of clinical trials of vitamin E. Here, we showed that naturally synthesized RRR-α-tocopherol quinone (α-TQ), a main derivative of α-T, could inhibit Aß42 fibril formation dose-dependently. Further investigations indicated that α-TQ could attenuate Aß42-induced neurotoxicity toward SH-SY5Y neuroblastoma cells, disaggregate preformed fibrils and interfere with natural intracellular Aß oligomer formation. Moreover, α-TQ could decrease the formation of reactive oxygen species (ROS) and NO, and modulate the production of cytokines by decreasing TNF-α and IL-1ß and increasing IL-4 formation in microglia. Taken together, α-TQ targeting multiple pathogenetic factors deserves further investigation for prevention and treatment of AD.


Asunto(s)
Péptidos beta-Amiloides/antagonistas & inhibidores , Amiloide/antagonistas & inhibidores , Antioxidantes/farmacología , Citocinas/antagonistas & inhibidores , Mediadores de Inflamación/antagonistas & inhibidores , Óxido Nítrico/antagonistas & inhibidores , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Vitamina E/análogos & derivados , Amiloide/biosíntesis , Péptidos beta-Amiloides/metabolismo , Péptidos beta-Amiloides/toxicidad , Animales , Antioxidantes/uso terapéutico , Células CHO , Línea Celular Tumoral , Cricetinae , Cricetulus , Citocinas/fisiología , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/fisiología , Humanos , Mediadores de Inflamación/fisiología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Óxido Nítrico/fisiología , Especies Reactivas de Oxígeno/metabolismo , Vitamina E/farmacología , Vitamina E/uso terapéutico
16.
Biochem Biophys Res Commun ; 390(4): 1250-4, 2009 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-19878655

RESUMEN

Smaller, soluble oligomers of beta-amyloid (Abeta) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of Abeta oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against Abeta neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on Abeta42 aggregation and neurotoxicity in vitro. EA promoted Abeta fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited Abeta aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in Abeta42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic Abeta aggregates to render them harmless, our MTT results showed that EA could significantly reduce Abeta42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Ácido Elágico/farmacología , Fragmentos de Péptidos/antagonistas & inhibidores , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Línea Celular , Humanos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Estructura Secundaria de Proteína/efectos de los fármacos
17.
Neurotoxicology ; 30(6): 986-95, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19744518

RESUMEN

Beta-amyloid (Abeta) aggregation has been strongly associated with the neurodegenerative pathology and a cascade of harmful event rated to Alzheimer's disease (AD). Inhibition of Abeta assembly, destabilization of preformed Abeta aggregates and attenuation of the cytotoxicity of Abeta oligomers and fibrils could be valuable therapeutics of patients with AD. Recent studies suggested that moderate consumption of red wine and intake of dietary polyphenols, such as resveratrol, may benefit AD phenotypes in animal models and reduce the relative risk for AD clinical dementia. To understand the mechanism of this neuroprotection, we studied the effects of resveratrol, an active ingredient of polyphenols in wine and many plants, on the polymerization of Abeta42 monomer, the destabilization of Abeta42 fibril and the cell toxicity of Abeta42 in vitro using fluorescence spectroscopic analysis with thioflavin T (ThT), transmission electron microscope (TEM), circular dichroism (CD) and MTT assay. The results showed that resveratrol could dose-dependently inhibit Abeta42 fibril formation and cytotoxicity but could not prevent Abeta42 oligomerization. The studies by Western-blot, dot-blot and ELISA confirmed that the addition of resveratrol resulted in numerous Abeta42 oligomer formation. In conjunction with the concept that Abeta oligomers are linked to Abeta toxicity, we speculate that aside from potential antioxidant activities, resveratrol may directly bind to Abeta42, interfere in Abeta42 aggregation, change the Abeta42 oligomer conformation and attenuate Abeta42 oligomeric cytotoxicity.


Asunto(s)
Péptidos beta-Amiloides/efectos de los fármacos , Péptidos beta-Amiloides/metabolismo , Amiloide/efectos de los fármacos , Antioxidantes/farmacología , Estilbenos/farmacología , Amiloide/química , Amiloide/ultraestructura , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/toxicidad , Péptidos beta-Amiloides/ultraestructura , Animales , Benzotiazoles , Proliferación Celular/efectos de los fármacos , Dicroismo Circular/métodos , Relación Dosis-Respuesta a Droga , Humanos , Ratones , Microscopía Electrónica de Transmisión/métodos , Conformación Molecular , Estructura Molecular , Neuroblastoma/patología , Fragmentos de Péptidos/toxicidad , Estructura Cuaternaria de Proteína , Resveratrol , Espectrometría de Fluorescencia/métodos , Sales de Tetrazolio , Tiazoles/metabolismo
18.
FEBS Lett ; 583(3): 579-84, 2009 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-19162022

RESUMEN

Increasing evidence indicates that beta-amyloid (Abeta) oligomers rather than monomers or fibrils are the major toxic agents that specifically inhibit synaptic plasticity and long-term potentiation (LTP) in Alzheimer's disease (AD). Neutralization of Abeta oligomeric toxicity was found to reverse memory deficits. Here, we report four single-chain variable fragment (scFv) antibodies isolated from the naive human scFv library by phage display that specifically recognized Abeta oligomers but not monomers and fibrils. These conformation-dependent scFv antibodies inhibit both Abeta fibrillation and cytotoxicity and bind to the same type of eptitope displayed on the Abeta oligomers. Such scFv antibodies specifically targeting toxic Abeta oligomers may have potential therapeutic and diagnostic applications for AD.


Asunto(s)
Amiloide/inmunología , Amiloide/metabolismo , Anticuerpos/inmunología , Especificidad de Anticuerpos/inmunología , Multimerización de Proteína , Amiloide/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Epítopos/inmunología , Humanos , Cinética , Unión Proteica
19.
Ying Yong Sheng Tai Xue Bao ; 19(12): 2651-5, 2008 Dec.
Artículo en Chino | MEDLINE | ID: mdl-19288718

RESUMEN

By using a population of 123 F12 lines (recombinant inbred lines, RILs) derived from a cross between India variety Dular and Japanica variety Lemont, an analysis of quantitative trait loci (QTL) was conducted for the flag leaf chlorophyll content of rice. The chlorophyll content was determined by SPAD-502 in 2005 and 2006, respectively, and software QTLMapper 1.6 was applied to analyze the QTL, including the additive and epistatic effects and the QTL interactions with environment for chlorophyll content. A total of ten QTL showing additive effects on chlorophyll content (Chl) were detected, which accounted for 73.51% of the phenotypic variation. The percentage of phenotypic variation explained by single QTL was 2.08%-20.14%, and the interactions of 6 QTLs with environment (AE) were significant. Epistasis analysis indicated that there existed 13 significant additive x additive interactions on chlorophyll content, 6 pairs of which were significant in additive x additive interactions with environment (AAE).


Asunto(s)
Clorofila/análisis , Oryza/genética , Oryza/metabolismo , Hojas de la Planta/metabolismo , Sitios de Carácter Cuantitativo/genética , Ambiente , Oryza/crecimiento & desarrollo , Factores de Tiempo
20.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 10): o1913, 2008 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-21201122

RESUMEN

The title compound, C(14)H(30)N(2)O(2)S(2), is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R)-N-tert-butanesulfinyl]ethanediimine. There are two almost identical mol-ecules in the asymmetric unit, the mol-ecular conformation of which is stabilized by an intra-molecular N-H⋯N hydrogen bond.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...