RESUMEN
Chronic obstructive pulmonary disease (COPD) is one of the most common chronic respiratory diseases with high morbidity and mortality. It has become the fifth most burdened and the third most deadly disease in the global economy and increases year by year. The prevention and treatment of COPD are urgent. Smoking is the main and most common risk factor for COPD. Cigarette smoke (CS) contains a large number of toxic substances, can cause a series of changes in the trachea, lung tissue, pulmonary blood vessels, and promotes the occurrence and development of COPD. In recent years, the development of epigenetics and molecular biology have provided new guidance for revealing the pathogenesis, diagnosis, and treatment of diseases. The latest research indicates that pulmonary vascular endothelial cell apoptosis initiates and participates in the pathogenesis of COPD. In this review, we summarize the current research on the epigenetic mechanisms and molecular biology of CS-induced pulmonary vascular endothelial cell apoptosis in COPD, providing a new research direction for pathogenesis of COPD and a new target for the diagnosis, treatment, and prevention of COPD.
Asunto(s)
Apoptosis/fisiología , Fumar Cigarrillos/efectos adversos , Fumar Cigarrillos/epidemiología , Endotelio Vascular/fisiología , Circulación Pulmonar/fisiología , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Animales , Metilación de ADN/fisiología , Epigénesis Genética/fisiología , Humanos , Enfermedad Pulmonar Obstructiva Crónica/genética , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Contaminación por Humo de Tabaco/efectos adversosRESUMEN
BACKGROUND: Increasing evidence shows that endothelial apoptosis contributes to cigarette smoke (CS)-induced disease progression, such as chronic obstructive pulmonary disease (COPD). Our previous studies have validated Notch1 as an anti-apoptotic signaling in CS-induced endothelial apoptosis. Resveratrol (RESV) is a naturally occurring polyphenol that exhibits an anti-apoptotic activity in endothelial cells that exposed to many kinds of destructive stimulus. However, the effects of resveratrol on Notch1 signaling in CS-induced endothelial apoptosis have not yet been fully elucidated. Therefore, the aim of this study was to examine whether RESV can protect endothelial cells from CS-induced apoptosis via regulating Notch1 signaling. METHODS: Human umbilical vein endothelial cells (HUVECs) were pretreated with RESV for 2 h, followed by cotreatment with 2.5%CSE for 24 h to explore the role of RESV in CSE induced endothelial apoptosis. 3-methyladenine (3-MA) or rapamycin was used to alter autophagic levels. Lentivirus Notch1 intracellular domain (LV-N1ICD), γ-secretase inhibitor (DAPT) and Notch1 siRNA were used to change Notch1 expression. The expression of Notch1, autophagic and apoptotic markers were examined by Western blot and the apoptosis rate was detected by Flow cytometry analysis. RESULTS: Our results showed that activating autophagy reduced CSE-induced endothelial apoptosis, while blocking autophagy promoted cell apoptosis in HUVECs. RESV pretreatment attenuated the CSE-induced endothelial apoptosis and activated Notch1 signaling. RESV pretreatment also increased LC3b-II and Beclin1 production, decreased p62 and mTOR expression. 3-MA treatment inhibited autophagy and aggravated CSE induced apoptosis, while rapamycin promoted autophagy, led to a decrease in cell apoptosis. LV-N1ICD transfection upregulated autophagy and reduced apoptosis. However, this protective effect was abolished by 3-MA treatment. In cells treated with DAPT or Notch1 siRNA, autophagy was decreased, while apoptosis was increased. RESV partly rescued the DAPT or Notch1 siRNA induced apoptosis by activating Notch1 signaling. CONCLUSION: In HUVECs, RESV attenuates CSE induced endothelial apoptosis by inducing autophagy in a Notch1-dependent manner.
Asunto(s)
Apoptosis/fisiología , Autofagia/fisiología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Receptor Notch1/metabolismo , Resveratrol/farmacología , Humo/efectos adversos , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Fumar Cigarrillos/efectos adversos , Fumar Cigarrillos/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
The design of small molecules that can target the aggregation of Aß as potential therapeutic agents for Alzheimer's disease is an area of study that has attracted a lot of attention recently. The novel ligand methyl 1-butyl-2-pyridyl-benzimidazole carboxylate was prepared for the synthesis of a series of new iridium(III), ruthenium(II), and platinum(II) 2-pyridyl-benzimidazole complexes. The crystal structure of the half-sandwich iridium(III) complex was established by X-ray diffraction. An arrangement of two cationic complexes in the unit cell is observed, and it seems to be organized by weak π···π interactions that are taking place between two symmetry-related benzimidazole ring systems. All new compounds inhibited aggregation of Aß1-42 in vitro as shown by both thioflavin T fluorescence assay and transmission electron microscopy. Among them the Ir compound rescued the toxicity of Aß1-42 in primary cortical neurons effectively.
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Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/toxicidad , Bencimidazoles/química , Neuronas/efectos de los fármacos , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/toxicidad , Multimerización de Proteína/efectos de los fármacos , Animales , Técnicas de Química Sintética , Diseño de Fármacos , Femenino , Iridio/química , Ligandos , Ratones , Modelos Moleculares , Conformación Molecular , Neuronas/citología , Compuestos Organometálicos/química , Platino (Metal)/química , Embarazo , Estructura Secundaria de Proteína , Rutenio/químicaRESUMEN
Subclinical infection of vaccinated chickens with a highly pathogenic avian influenza A(H5N2) virus was identified through routine surveillance in China. Investigation suggested that the virus has evolved into multiple genotypes. To better control transmission of the virus, we recommend a strengthened program of education, biosecurity, rapid diagnostics, surveillance, and elimination of infected poultry.
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Infecciones Asintomáticas , Pollos/virología , Virus de la Influenza A/clasificación , Gripe Aviar/epidemiología , Gripe Aviar/virología , Animales , China/epidemiología , Genotipo , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Filogenia , VacunaciónRESUMEN
OBJECTIVE: Despite the controversy surrounding brain invasion (BI) as the sole indicator used to diagnose atypical meningioma, this criterion was still incorporated in the 2021 WHO classification scheme. In this study, the authors investigated the reproducibility of this prognostic effect and the impact of BI on the prognosis in otherwise benign meningioma (benign meningioma with BI). METHODS: Patients (n = 1006) with a pathological diagnosis of benign or atypical meningioma according to the latest WHO classification criteria were enrolled in this study. In patients with atypical meningioma, the cases were further categorized as benign meningioma with BI and classical atypical meningioma. Clinical, pathological, and follow-up data were collected. Kaplan-Meier curves were compared with a log-rank test, and univariate and multivariate analyses were performed. RESULTS: The study patient cohort included 282 (28.0%) individuals who were pathologically confirmed as having BI among all 1006 patients with benign or atypical meningioma. A significant difference in recurrence-free survival was observed between patients who had benign meningioma with BI and those who had classical atypical meningioma (p < 0.001), as well as between patients with benign meningiomas and those without BI (p = 0.003). Multivariate Cox analysis indicated that BI was independently associated with increased risk of relapse in the entire population (HR 1.46, 95% CI 1.01-2.12, p = 0.049) and in the atypical meningioma subcohort (HR 2.21, 95% CI 1.32-3.71, p = 0.003), as well as the benign meningioma with and without BI subcohorts (HR 1.89, 95% CI 1.01-3.56, p = 0.049). Moreover, patients with classical atypical meningiomas had a risk of relapse four times higher than those who had benign meningioma with BI (p < 0.001). CONCLUSIONS: The findings demonstrate that benign meningioma with BI typically has an intermediate prognosis and can be differentiated from benign meningioma and classical atypical meningioma, which suggests that the importance of the diagnostic effect of BI is insufficiently accounted for in grading of atypical meningioma. Increased emphasis on the presence of BI in patients with atypical meningioma may be helpful in postsurgical decision-making and facilitating improvements in individual therapy.
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Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/cirugía , Neoplasias Meníngeas/cirugía , Reproducibilidad de los Resultados , Recurrencia Local de Neoplasia , Pronóstico , Recurrencia , Encéfalo/patología , Estudios RetrospectivosRESUMEN
Up to now, flue-gas desulfurization (FGD) is one of the most effective techniques to control SO(2) emission from the combustion of fossil fuels. The conventional technology for FGD poses serious inherent drawbacks such as formation of byproducts and volatilization of solvents. In this work, polyethylene glycol (PEG)-functionalized Lewis basic ionic liquids (ILs) derived from DABCO were proved to be highly efficient absorbents for FGD due to its specific features such as high thermal stability, negligible vapor pressure, high loading capacity. Notably, PEG(150)MeDABCONTf(2) gave an extremely high SO(2) capacity (4.38 mol mol(-1) IL), even under 0.1 bar SO(2) partial pressure (1.01 mol mol(-1) IL), presumably owing to the strong SO(2)-philic characterization of the PEG chain. Furthermore, the absorbed SO(2) could be easy to release by just bubbling N(2) at room temperature, greatly reducing energy requirement for SO(2) desorption. In addition, SO(2)/CO(2) selectivity (110) of PEG(150)MeDABCONTf(2) is two times larger than the non-functionalized imidazolium IL (45). On the other hand, through activation of SO(2) with the tertiary nitrogen in the cation, Lewis basic ILs such as PEG(150)MeDABCOBr proved to be efficient catalysts for the conversion of SO(2) to some value-added chemicals such as cyclic sulfites without utilization of any organic solvent or additive. Thus, this protocol would pave the way for the development of technological innovation towards efficient and low energy demanded practical process for SO(2) absorption and subsequent transformation.
Asunto(s)
Líquidos Iónicos/química , Polietilenglicoles/química , Dióxido de Azufre/química , Estructura Molecular , Sulfitos/síntesis química , Sulfitos/químicaRESUMEN
Two new onoceranoid triterpenoids, (3 alpha,8 beta,14 alpha,21 beta)-26,27-dinoronocerane-3,8,14,21-tetrol (1) and 26-nor-8 beta-hydroxy-alpha-onocerin (2), were isolated from Lycopodium obscurum L. Their structures were elucidated on the basis of spectroscopic analyses.
Asunto(s)
Medicamentos Herbarios Chinos/aislamiento & purificación , Lycopodium/química , Triterpenos/aislamiento & purificación , Medicamentos Herbarios Chinos/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Estereoisomerismo , Triterpenos/químicaRESUMEN
The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and Co (II) EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc) extract showed the highest free-radical-scavenging activity compared with the other three (n-BuOH, water and petroleum ether) extracts. Free-radical-scavenging assay-guided chromatographic separation of the EtOAc extract, using a normal-phase and reverse-phase silica gel column chromatography yielded five compounds: a new triterpene named methyl 3beta-O-p-hydroxy-E-cinnamoyloxy-2alpha,23-dihydroxyolean-12-en-28-oate (1), whose spectral data are presented for the first time, together with four known compounds, epicatechin (2), 3-trans-feruloyl maslinic acid (3), maslinic acid (4) and sucrose (5). All of the compounds were isolated from Microcos paniculata for the first time. The compounds were identified by spectroscopic methods. Among them, compound 2 displayed significant free-radical-scavenging activity which is similar to that of standard antioxidant ascorbic acid (V(C)) and therefore may be a promising natural antioxidant.
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Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Malvaceae/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Tallos de la Planta/química , Depuradores de Radicales Libres/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , SolventesRESUMEN
Previous studies indicated that one of the action targets of carvedilol is the voltage-gated potassium (Kv) channel, which has a fundamental role in the control of electrical properties in excitable cells. It is not clear whether this compound exerts any actions specifically on delayed rectifier Kv2.1 channels. The present study is conducted on Kv2.1 currents heterologously expressed in HEK293â¯cells to characterize the block by carvedilol in detail, identifying molecular determinants and providing biophysical insights of the block. Macroscopic Kv2.1 currents obtained by whole-cell recording were substantially inhibited after addition of carvedilol with an IC50 value of 5.1⯵M. This drug also led to a largely hyperpolarizing shift (30â¯mV) of the inactivation curve, which may contribute to the blocking action due to more inactivation of Kv2.1 currents occurred in depolarization potentials. Mutations at Y380 (a putative TEA binding site) and K356 (a K+ binding site) in the outer vestibule of Kv2.1 channels significantly eliminated the inhibitory effects of carvedilol and prevented the leftward shift of inactivation. Moreover, mutations at above positions modulated the effects of carvedilol on the deactivation but not activation kinetics of Kv2.1 channels. Collected data indicate that carvedilol can exert a blocking effect on the closed-state of Kv2.1 channels, and specific residues within the S5-P and P-S6 linkers in the outer vestibule may play crucial roles in carvedilol-induced blocking for Kv2.1 channels.
Asunto(s)
Carvedilol/farmacología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio Shab/antagonistas & inhibidores , Células HEK293 , Humanos , Activación del Canal Iónico/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Canales de Potasio Shab/metabolismoRESUMEN
Vanilloid receptor 1 (VR1) is a noxious receptor and a novel target for pain therapy. Cochinchinenin B (6-hydroxy-7-methoxy-3-(4'-hydroxybenzyl) chromone; CB) is one of the small-molecular components from the flavonoids of Dragon's Blood, a well-known herbal medicine to treat various types of pain. Using whole-cell patch clamp technique, we found that capsaicin (CAP)-activated currents (ICAP) was inhibited by CB with an IC50 of 0.92 mM in acutely isolated rat dorsal root ganglion (DRG) neurons. The inhibition was reversible and not competitive. We also found that the inhibition was neither voltage- nor agonist-dependent. The bind site was on the extracellular part of the channel since intracellular application of CB did not alter the inhibition effect on ICAP. In addition, CB inhibited CAP-evoked depolarization under current-clamp condition. Our findings indicate that CB may be a candidate in developing new analgesic drugs targeting the VR1 receptor.
Asunto(s)
Chalcona/análogos & derivados , Ganglios Espinales/efectos de los fármacos , Neuronas Aferentes/efectos de los fármacos , Nociceptores/efectos de los fármacos , Dolor/tratamiento farmacológico , Canales Catiónicos TRPV/antagonistas & inhibidores , Analgésicos/farmacología , Analgésicos/uso terapéutico , Animales , Sitios de Unión/efectos de los fármacos , Sitios de Unión/fisiología , Unión Competitiva/efectos de los fármacos , Unión Competitiva/fisiología , Capsaicina/antagonistas & inhibidores , Capsaicina/farmacología , Células Cultivadas , Chalcona/farmacología , Chalcona/uso terapéutico , Relación Dosis-Respuesta a Droga , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Femenino , Ganglios Espinales/metabolismo , Masculino , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Estructura Molecular , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Neuronas Aferentes/metabolismo , Nociceptores/metabolismo , Dolor/metabolismo , Dolor/fisiopatología , Técnicas de Placa-Clamp , Ratas , Ratas Sprague-Dawley , Fármacos del Sistema Sensorial/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismoRESUMEN
The glucose solution was broken down by focusing the 1.064 microm beam of a Nd : YAG laser, and the plasma was produced. The spectral signals were detected by an experimental setup including spectrograph and ICCD. The spectral line at 247.86 nm was identified as the characteristic of glucose by contrasting the spectra of glucose solution and pure water. Comparing the spectral intensities of three kinds of glucose solution with different concentrations (3%, 6% and 9%), the experimental result showed that the bigger the concentration, the stronger the spectral intensity,and the characteristic spectral intensities with the three concentrations present the trend of logarithm increase. At the same concentration, the time evolution curve of the characteristic spectra was obtained by changing the delay time of ICCD. It is concluded that the intensity of the characteristic spectra first increases and then decreases with the delay time. With the glucose solution concentration altering, the decay time of the characteristic spectra is nearly fixed, meaning that the decay time is independent of the concentration. The decay time of the characteristic spectra is about 300 ns. Furthermore, it was found that the characteristic spectral intensities of glucose solution with different concentrations reach the maximum at the same delay time.
RESUMEN
Carvedilol is a non-selective ß-adrenoreceptor antagonist and exhibits a wide range of biological activities. The voltage-gated K+ (Kv) channel is one of the target ion channels of this compound. The rapidly activating Kv1.3 channel is expressed in several different tissues and plays an important role in the regulation of physiological functions, including cell proliferation and apoptosis. However, little is known about the possible action of carvedilol on Kv1.3 currents. Using the whole-cell configuration of the patch-clamp technique, we have revealed that exposure to carvedilol produced a concentration-dependent blocking of Kv1.3 channels heterologously expressed in HEK293 cells, with an IC50 value of 9.7⯵M. This chemical decelerated the deactivation tail current of Kv1.3 currents, resulting in a tail crossover phenomenon. In addition, carvedilol generated a markedly hyperpolarizing shift (20â¯mV) of the inactivation curve, but failed to affect the activation curve. Mutagenesis experiments of Kv1.3 channels identified G427 and H451, two related sites of TEA block, as important residues for carvedilol-mediated blocking. The present results suggest that carvedilol acts directly on Kv1.3 currents by inducing closed- and open-channel block and helps to elucidate the mechanisms of action of this compound on Kv channels.
Asunto(s)
Carvedilol/farmacología , Canal de Potasio Kv1.3/antagonistas & inhibidores , Bloqueadores de los Canales de Potasio/farmacología , Células HEK293 , Humanos , Cinética , Canal de Potasio Kv1.3/genética , Canal de Potasio Kv1.3/metabolismo , MutaciónRESUMEN
AIM: To explore the modulation of Salvia miltiorrhiza on hyperpolarization-activated current (Ih) channels in dorsal root ganglion (DRG) neurons of rats and identify the mechanism of Salvia miltiorrhiza in alleviating pain and inhibiting calcium overload. Methods The effect of Salvia miltiorrhiza injection on Ih channels in DRG neurons of rats were examined by using whole-cell patch clamp technique. Results The experimental results showed that the amplitude of Ih evoked by -150 mV was (-1.06 +/- 0.18) nA. The Ih could be fitted well into the single kinetics and the time constant of activation, pi was clearly voltage-dependent with tau = (322.14 +/- 28.81) ms at -100 mV, decreasing to tau = (62.51 +/- 9.78) ms at -150 mV. The reversal potential of Ih was (-35.03 +/- 1.12) mV measured from tail currents. But no significant differences were found between the DRG neurons in the absence and presence of Salvia miltiorrhiza injection (10%, 25%, 50%) in the current amplitude, the time constant of activation and the reversal potential. The only difference between the DRG neurons in the absence and presence of Salvia miltiorrhiza injection was the half-activation potential of Ih. In control recordings the half-activation potential was (-106.07 +/- 3.59) mV. By comparison, the half-activation potentials changed to (-111.59 +/- 3.79) mV (n=31 neurons, P < 0.05), (-119.37 +/- 4.96) mV (n=31 neurons, P < 0.05) and (-121.23 +/- 3.86) mV (n=31 neurons, P < 0.05) in the presence of 10%, 25%, 50% Salvia miltiorrhiza injection, respectively. CONCLUSION: Only the half-activation potential of Ih in the arthritic and neuropathic rat models shifted in the depolarizing direction, which increased the electrophysiological activity of Ih and made it related to peripheral hyperalgesia. The selective inhibition of Salvia miltiorrhiza on the electrophysiological activity of Ih may be one of the mechanisms underlying its analgesic effects.
Asunto(s)
Potenciales de Acción/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Neuronas/efectos de los fármacos , Salvia miltiorrhiza/química , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/aislamiento & purificación , Analgésicos no Narcóticos/farmacología , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/aislamiento & purificación , Ganglios Espinales/citología , Inyecciones , Canales Iónicos/fisiología , Neuronas/citología , Neuronas/fisiología , Técnicas de Placa-Clamp , Plantas Medicinales/química , Ratas , Ratas WistarRESUMEN
OBJECTIVE: To study the effects of Injection Stauntoniae (IS) on voltage-gated sodium currents in dorsal root ganglion neurons and analyze its pharmacological mechanism of blocking the nerve conduction and anal gesic action. METHODS: Whole-cell patch-clamp recordings were performed in acutely isolated rat dorsal root ganglion neurons and the effects of 10% , 25% and 50 % IS on voltage-gated sodium currents were observed. RESULTS: IS inhibited the peak sodium currents in dorsal root ganglion neurons in a dose-dependent way and affected the activation and inactivation process of the channels. CONCLUSION: The analgesic effect of IS was presumably caused by modulation of voltage-gated sodium channels in primary sensory neurons besides structure destruction of myelin sheath and axon membrane.
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Analgésicos/farmacología , Medicamentos Herbarios Chinos/farmacología , Helechos , Analgésicos/administración & dosificación , Animales , Medicamentos Herbarios Chinos/administración & dosificación , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Inyecciones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Ratas , Canales de Sodio/efectos de los fármacosRESUMEN
BACKGROUND: Contrast-enhanced ultrasound is a dynamic and continuous modality providing real-time view of vascularization and flow distribution patterns of different organs and tumors. In order to evaluate the diagnostic significance of intraoperative contrast-enhanced ultrasound in assessing the resection degree of brain glioma by transmission electron microscopic (TEM) examination, it is important to have specific knowledge about contrast-enhanced ultrasound. Methods : Ultrasound contrast was applied in operations of 120 cases of brain glioma, to evaluate the degree of tumor resection. Biopsy tissues were obtained the suspicious residual tumors surrounding the tumor cavity. The sensitivity and specificity of the residual tumors were determined by the intraoperative ultrasound contrast according to TEM examination results. RESULTS: There were 44 cases of low-grade gliomas and 76 cases of high-grade gliomas. Three hundred and sixty biopsy tissues were obtained. The sensitivity of intraoperative ultrasound contrast in diagnosing the residual tumor was 62.2%, while the specificity degree of it was 92.8%. The consistency coefficient of the ultrasound contrast diagnosis and TEM examination results was 0.584 (Kappa = 0.584), which was between 0.4 and 0.6, therefore it was of medium consistency. Conclusions : Intraoperative ultrasound contrast was of a high sensitivity and specificity in evaluating the excision degree of tumor. The consistency of the residual tumor rate detected, respectively, by ultrasound contrast and TEM examination was of medium consistency. The application of intraoperative ultrasound contrast can improve the resection rate of brain glioma.
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Glioma/diagnóstico , Adulto , Anciano , Medios de Contraste , Femenino , Glioma/diagnóstico por imagen , Glioma/ultraestructura , Humanos , Masculino , Microscopía Electrónica de Transmisión , Persona de Mediana Edad , Ultrasonografía , Adulto JovenRESUMEN
The kinetics of ion channels have been widely modeled as a Markov process. In these models it is assumed that the channel protein has a small number of discrete conformational states and kinetic rate constants connecting these states are constant. To study the gating kinetics of voltage-dependent K(+) channel in rat dorsal root ganglion neurons, K(+) channel current were recorded using cell-attached patch-clamp technique. The K(+) channel characteristic of kinetics were found to be statistically self-similar at different time scales as predicted by the fractal model. The fractal dimension D for the closed times and for the open times depend on the pipette potential. For the open and closed times of kinetic setpoint, it was found dependent on the applied pipette potential, which indicated that the ion channel gating kinetics had nonlinear kinetic properties. Thus, the open and closed durations, which had the voltage dependence of the gating of this ion channel, were well described by the fractal model.
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Fractales , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Activación del Canal Iónico , Modelos Biológicos , Neuronas/metabolismo , Canales de Potasio/metabolismo , Animales , Electrofisiología , Cinética , Técnicas de Placa-Clamp , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Adipose tissue-derived stromal cells (ADSCs) can be greatly expanded in vitro, and induced to differentiate into multiple mesenchymal cell types, including osteogenic, chondrogenic, myogenic, and adipogenic cells. This study was designed to investigate the possibility of ADSCs differentiating into neurons. METHODS: Adipose tissue from rats was digested with collagenase, and adherent stromal cells were cultured. A medium containing a low concentration of fetal bovine serum was adopted to induce the cells to differentiate. ADSCs were identified by immunocytochemistry, and semi-quantitative RT-PCR was applied to detect mRNA expression of neurofilament 1 (NF1), nestin, and neuron-specific enolase (NSE). RESULTS: Nestin-positive cells were found occasionally among ADSCs. ADSCs were found to express NSE mRNA and nestin mRNA, but not NF1 mRNA. ADSCs could differentiate into neuron-like cells in a medium composed of a low concentration of fetal bovine serum, and these differentiated cells displayed complicated neuron-like morphologies. CONCLUSIONS: The data support the hypothesis that adipose tissue contains stem cells capable of differentiating into neurons. These stem cells can overcome their mesenchymal commitment, and may represent an alternative autologous stem cell source for CNS cell transplantation.
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Tejido Adiposo/citología , Diferenciación Celular/fisiología , Proteínas del Tejido Nervioso , Neuronas/citología , Animales , Células Cultivadas , Inmunohistoquímica , Proteínas de Filamentos Intermediarios/análisis , Nestina , Proteínas de Neurofilamentos/análisis , Fenotipo , Fosfopiruvato Hidratasa/análisis , RatasRESUMEN
OBJECTIVE: To investigate the culture method of skin-derived precursors (SKPs) and to explore a new cell source for cell transplantation of central nervous system. METHODS: Cells from skins of juvenile and adult mice were isolated and cultured in serum-free medium. A mechanical method was chosen to passage these cells and they were identified by the immunocytochemistry assay. RESULTS: SKPs could be isolated from adult and neonatal skins. They could be maintained in vitro for long periods with stable proliferation, and expanded as undifferentiated cells in culture for more than 12 passages. About 50% of SKPs expressed nestin and majority of these cells expressed fibronectin when they were plated on polyornithine and laminin coated plates. About 5% cells showed neuronal differentiation and expressed neurofilament-M (NF-M) and NSE when SKPs were plated in serum-containing medium, and these cells could also differentiate into adipocytes and fibroblast-like cells. CONCLUSIONS: The data support the hypothesis that adult skin contains stem cells capable of differentiating into neurons, adipocytes, and fibroblast-like cells. They may represent an alternative autologous stem cell source for CNS cell transplantation.
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Diferenciación Celular , Piel/citología , Trasplante de Células Madre , Adipocitos , Animales , Diferenciación Celular/fisiología , Células Cultivadas , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , NeuronasRESUMEN
OBJECTIVE: To explore the culture conditions of human neural stem cells and to investigate the ultrastructure of neurospheres. METHODS: The cells from the embryonic human cortices were mechanically dissociated. N2 medium was adapted to culture and expand the cells. The cells were identified by immunocytochemistry and EM was applied to examine the ultrastructure of neurospheres. RESULTS: The neural stem cells from human embryonic brains were successfully cultured and formed typical neurospheres in suspension, and most of the cells expressed vimentin, which was a marker for neural progenitor cells, and the cells could differentiate into neurons, astrocytes and oligodendrocytes. In vitro myelin formation in neurospheres were observed at an early stage of culture. CONCLUSIONS: Human neural stem cells can be cultured from embryonic brains, can form the typical neurospheres in suspension in vitro and have the ability of myelinating, and may be potential source for transplantation in treating myelin disorders.
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Vaina de Mielina/ultraestructura , Neuronas/ultraestructura , Encéfalo/citología , Células Cultivadas , Medios de Cultivo , Femenino , Humanos , Inmunohistoquímica , Masculino , Microscopía Electrónica , Vaina de Mielina/patología , Neuronas/citología , Neuronas/patología , Sensibilidad y Especificidad , Trasplante de Células Madre , Células Madre/fisiología , Células Madre/ultraestructuraRESUMEN
The history and current situation of cell membrane ion-channel gating mechanism study were reviewed, with an emphasis on the application and the latest developments of kinetic model in gating mechanism study; the problems in present study and ion-channel gating mechanism kinetics model for future investigations were finally discussed.